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A
UGUST
1999 507CORFIDI
The Birth and Early Years of the Storm Prediction Center
S
TEPHEN
F. C
ORFIDI
NOAA/NWS/NCEP/Storm Prediction Center, Norman, Oklahoma
(Manuscript received 12 August 1998, in final form 15 January 1999)
ABSTRACT
An overview of the birth and development of the National Weather Service’s Storm Prediction Center, formerly
known as the National Severe Storms Forecast Center, is presented. While the center’s immediate history dates
to the middle of the twentieth century, the nation’s first centralized severe weather forecast effort actually
appeared much earlier with the pioneering work of Army Signal Corps officer J. P. Finley in the 1870s.
Little progress was made in the understanding or forecasting of severe convective weather after Finley until
the nascent aviation industry fostered an interest in meteorology in the 1920s. Despite the increased attention,
forecasts for tornadoes remained a rarity until Air Force forecasters E. J. Fawbush and R. C. Miller gained
notoriety by correctly forecasting the second tornado to strike Tinker Air Force Base in one week on 25 March
1948. The success of this and later Fawbush and Miller efforts led the Weather Bureau (predecessor to the
National Weather Service) to establish its own severe weather unit on a temporary basis in the Weather Bureau–
Army–Navy (WBAN) Analysis Center Washington, D.C., in March 1952.
The WBAN severe weather unit became a permanent, five-man operation under the direction of K. M. Barnett
on 21 May 1952. The group was responsible for the issuance of ‘‘bulletins’’ (watches) for tornadoes, highwinds,
and/or damaging hail; outlooks for severe convective weather were inaugurated in January 1953. An unusually
large number of strong tornadoes, forecaster inexperience, and criticism regarding the unit’sproducts culminated
in staff and policy changes after it was renamed the Severe Local Storms Warning Service (SELS) in June 1953.
SELS moved from Washington to Kansas City in September 1954 in part to be closer to ‘‘tornado alley’’ and
to take advantage of existing nationwide teletype communication facilities. The unit also gained a new leader
when D. C. House replaced Barnett as SELS chief early that year. House instituted changes that led to more
accurate watches. He also fostered the development of a separate research and development unit, an effort which
had been initiated by Barnett.
SELS continued to grow as additional forecast and support staff were added through the remainder of the
1950s and 1960s. It was renamed the National Severe Storms Forecast Center (NSSFC) upon relocation to a
new facility and the assumption of local and regional forecast duties in 1966. Meanwhile, the research group
to which SELS had given birth in the mid-1950s left Kansas City and merged with the Weather Bureau’s Weather
Radar Laboratory to form the National Severe Storms Laboratory (NSSL) in Norman, Oklahoma, in 1964. SELS,
renamed the Storm Prediction Center, joined NSSL in Norman in January 1997.
1. Introduction
The Storm Prediction Center (SPC) in Norman,
Oklahoma, provides short-term forecasts of hazardous
weather in the United States to the public and the Na-
tional Weather Service’s (NWS) field offices. The SPC,
formerly known as the National Severe StormsForecast
Center (NSSFC), is a component of the NWS’sNational
Centers for Environmental Prediction (NCEP; see Mc-
Pherson 1994). The center continuously monitors for all
types of hazardous weather and issues tornado and se-
vere thunderstorm watches on an as-needed basis. It also
issues special messages highlighting the mesoscale as-
pects of developing weather hazards and prepares reg-
Corresponding author address: Stephen F. Corfidi, NOAA/NWS/
NCEP, 1313 Halley Circle, Norman, OK 73069.
E-mail: stephen.corfidi@noaa.gov
ularly scheduled convective weather outlooks. The cen-
ter is responsible for the 48 contiguous states and the
adjacent coastal waters.
The SPC is an outgrowth of a series of efforts dating
back to the late 1800s to better understand and predict
severe convective storms. Several papers have examined
some of these endeavors in recent years. Schaefer (1986)
tracked the development of severe weather forecasting
from the purely empirical techniques of the nineteenth
century to the more physically based methods of today.
Galway (1989, 1992) discussed the evolution of severe
weather warning criteria in the United States and de-
scribed some of the early investigations that made tor-
nado forecasts a reality by 1950. Ostby (1992) and Do-
swell et al. (1993) reviewed the operational aspects of
the NSSFC in the early 1990s. Lewis (1996) examined
the life and work of Joseph G. Galway, who devoted
nearly his entire career to the forecasting of severe local
storms. Elsewhere in this issue, Bradford (1999) de-
508 V
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14WEATHER AND FORECASTING
scribes the development of severe weather warning and
preparedness activities in the United States. The present
paper focuses on the birth and early years of the SPC,
and on its relationship to other federal severe weather
programs.
While SPC’s immediate history dates to the early
1950s, its roots may be traced much further. The de-
velopment of a centralized weather forecast service in
the 1870s (Whitnah 1961; Hughes 1970) made apparent
the need for improved documentation and increased un-
derstanding of destructive local storms. Leading this
effort was Sgt. John P. Finley, of the U.S. Army Signal
Corps.
1
Between 1883 and 1887, Finley organized a
team of more than 2000 ‘‘tornado reporters’’ east of the
Rockies to document observations of tornadoes and
their associated weather conditions (Galway 1992). Us-
ing these data, a set of maps and guidelines were as-
sembled to describe characteristic tornado-producing
weather patterns based on the shape, intensity, and ori-
entation of the observed isobaric and isothermic fields.
Finley used these charts along with what limited cli-
matological data was available to issue 57 experimental
tornado ‘‘alerts’’ in 1884 and 1885. While the accuracy
of these alerts remains the subject of some controversy
(e.g., Murphy 1996), it must be conceded that his effort
marks the first scientific attempt to anticipate severe
local storm activity in the United States (Schaefer
1986).
2
A ban on the use of the word ‘‘tornado’’ in Signal
Corps forecasts kept Finley’s predictions from being
made public after 1886. The chief signal officer believed
that public fear induced by a prediction of tornadoes
‘‘would eventually be greater than that which results
from the tornado itself’’ (U.S. Army 1887).
Little progress was made in the understanding and
forecasting of severe convective weather in the 1890s
and early 1900s. Although researchers such as Letzmann
pursued the topic in Europe (see Peterson 1992), tor-
nadoes garnered little interest in this country. Forecasts
did occasionally mention the possibility of ‘‘destruc-
tive’’ local storms, such as on the morning of 27 May
1896, prior to the touchdown of a killer tornado in St.
Louis. But Weather Bureau policy continuedto prohibit
use of the word tornado in public forecasts (Galway
1973). Bureau officials held firm to the belief that the
word tornado would provoke undue fear and alarm, and
that greater knowledge of upper atmospheric conditions
was needed before sufficiently accurate forecasts could
be made for the small areas involved. Indeed, J. I. Wid-
meyer, director of the Oklahoma section of the Weather
Bureau, charged that residents in his state were ‘‘fleeing
1
The Signal Corps was responsible for the collection of weather
data and the dissemination of forecasts prior to the creation of the
U.S. Weather Bureau in 1890.
2
The interesting story of Finley and his work may be found in
Galway (1985a,b).
to caves and cellars whenever thunderstorms appeared’’
because of earlier sensationalist reports about tornadoes
(Abbe 1899). Widmeyer felt that ‘‘exposure to the
dampness of (storm) shelters resulted in more deaths
than all the tornadoes that had ever occurred.’’
Airplane, kite, and pilot balloon observations brought
major advances to the science of meteorology in the
1920s and 1930s. Important studies such as those by
Humphreys (1926) and Varney (1926) for the first time
examined the unusual temperature profiles associated
with many tornadic storms. The development of the
radiosonde was especially significant since it made pos-
sible routine upper air observations by the late 1930s
(Galway 1973).
Meteorological research accelerated following the na-
tion’s entry into World War II in December 1941. The
war brought a heightened awareness of the threat posed
by lightning and tornadoes on munitions plants. In re-
sponse to this threat and in cooperation with the military,
the Weather Bureau established a dense network of
storm spotters in the vicinity of plants devoted to the
manufacture or storage of ammunition during the early
1940s (Altman 1954; Galway 1992; Doswell et al.
1999). This network was soon expanded to include air-
fields, training camps, and other military posts. The net-
works were used for local warning purposes and were
disbanded shortly after the war.
Concern over the vulnerability of war-related facili-
ties to severe storms and an unusually active tornado
season over the central United States prompted the War
Advisory Committee on Meteorology to specifically ad-
dress the problem of tornado development during the
latter part of 1942 (Galway 1992). A result of this effort
was publication of a significant two-part paper by Show-
alter and Fulks (1943) that discussed the surface and
upper-level synoptic environment of tornadoes. But
even though knowledge of the conditions that fostered
tornado formation was on the increase, and the ban on
the word tornado was lifted in 1938, very few forecasts
of tornadoes were issued during the 1940s. The con-
tinuing reluctance on the part of WeatherBureau district
offices to forecast tornadoes reflected the feeling that
the public for the most part was uninformed as to the
nature and purpose of tornado forecasts. There was, in
fact, evidence to back this belief as some communities
responded in near panic to rumors of impending tor-
nadoes (Altman 1954).
2. A forecasting renaissance
It was the fortuitous occurrence of two tornadoes at
the same place in less than a week that would lead to
the reestablishment of a centralized severe weather fore-
casting program in the United States by the midpoint
of the twentieth century. On the evening of 20 March
1948, a tornado struck Tinker Air Force Base,
Oklahoma, without warning, causing more than $10 mil-
lion in damage and several injuries. The funnel moved
A
UGUST
1999 509CORFIDI
diagonally across the airfield, destroying aircraft and
shattering the control tower’s windows. The following
day, the commanding general of the Oklahoma City Air
Materiel Area, Fred S. Borum, directed the base weather
officers at work that evening, Major E. J. Fawbush and
Captain R. C. Miller, to study the event and investigate
the possibility of forecasting tornadic storms.
Fawbush and Miller immediately set out to review
the work of Showalter and Fulks and others such as
Lemons (1938) and Lloyd (1942). The officers did not
have to wait very long to put their newfound knowledge
to the test. On the afternoon of 25 March, meteorological
conditions somewhat similar to those that had appeared
five days earlier
3
prompted the officers to put their rep-
utations (and jobs) on the line: they forecast that another
tornado might strike the base that night. Shortly after
1800 local time, the second tornado in less than a week
raked Tinker Air Force Base, causing $6 million in dam-
age but, thanks at least in part to preparedness efforts,
no injuries or deaths.
The accuracy of Fawbush and Miller’s forecast drew
attention throughout the meteorological community, and
the officers were soon responsible for the prediction of
tornadoes across much of the central United States (see
Miller 1972; Miller and Crisp 1999). A formal Air
Weather Service unit, the Severe Weather WarningCen-
ter (SWWC), was established at Tinker under the di-
rection of Fawbush and Miller in February 1951. The
unit was responsible for the preparation of advisories
for tornadoes, damaging winds, and extreme turbulence
at all air force sites on the U.S. mainland.
Early on, many of SWWC’s forecasts were routinely
released to the Weather Bureau and the public, espe-
cially in Oklahoma and across the South (Popkin 1967).
This ended on 5 March 1952, following an outbreak of
tornadoes in Alabama, Arkansas, and Georgia. Word
had leaked out that military bases in the region had been
warned of possible tornadoes to, as Lynch (1970) puts
it, ‘‘the exclusion of the public.’’ In response to the
ensuing controversy, air force personnel were soon pro-
hibited from releasing SWWC forecasts to the public
(Altman 1954).
Limiting access to its forecasts drew only more at-
tention to the air force’s successful tornado program.
The prohibition also increased pressure on Weather Bu-
reau officials to either relay SWWC forecasts to the
public or issue their own. In July 1950, such pressure
prompted Bureau Chief Francis W. Reichelderfer to is-
sue a memorandum advising field office employees to
avoid phrases such as ‘‘The Weather Bureau does not
make tornado forecasts’’ or ‘‘We are not permitted to
issue tornado forecasts’’ when conducting poststorm
media interviews (U.S. Weather Bureau 1950). Such
3
See Maddox and Crisp (1999 in this issue) for a comparison of
the synoptic environments of 20 and 25 March 1948.
statements, Reichelderfer said, incorrectly implied that
the bureau was unwilling or unable to make tornado
forecasts. The note also warned, however, that because
tornado forecasting was one of the bureau’s ‘‘most dif-
ficult tasks,’’ that a ‘‘good probability of verification’’
should exist when such forecasts are made.
3. The Weather Bureau responds
Another season of mounting public and congressional
(Congressional Record 1952) debate finally persuaded
Reichelderfer to establish the bureau’s own severe
weather unit in March 1952. The unit was set up in
Washington, D.C., at the WBAN Center, a jointweather
analysis and forecasting operation of the Weather Bu-
reau, army, and navy.
4
Fifteen forecasters from the
WBAN analysis section, the bureau’s central research
office, and its field stations were chosen to staff the unit
on an interim basis. Some of these individuals had par-
ticipated in a ‘‘visiting forecaster’’ program started by
Reicheldefer in 1950 that brought selected field per-
sonnel to the bureau’s Central Office to help develop
severe weather forecast techniques (Galway 1992). In
addition, during the winter of 1951/52, L. Carstensen
and Frederick Shuman
5
of the bureau’s Scientific Ser-
vices Division had been tasked with studying the large-
scale synoptic features associated with tornadoes in the
Midwest (Altman 1954). The efforts of these and other
pilot programs were now about to pay off.
The new WBAN group was prepared to issue public
forecasts on Sunday, 9 March, but another week would
pass before conditions were deemed favorable for tor-
nadic storms. On the morning of Monday, 17 March,
the 1500 UTC 500-kPa analysis revealed a small but
rather intense short-wave trough over the Four Corners
region (Fig. 1). The disturbance was expected to move
rapidly east around the periphery of an upper low over
Colorado. Forecasters reasoned that this motion would
cause the low to redevelop and strengthen over the
southern plains, creating an environment favorable for
tornadoes. At 2300 EST on Monday, 17 March, the
WBAN unit issued its first public tornado ‘‘bulletin’’
(Altman 1954; Galway 1989). This forecast, shown in
Fig. 2, mentioned the ‘‘possibility of tornadoes in east-
4
The WBAN Center was located at 24th and M Streets in northwest
Washington. It was created by the executive order of F. D. Roosevelt
in 1942 to consolidate civilian (Weather Bureau) and military (army
and navy) meteorological efforts during World War II. Centralization
proved so advantageous that the office remained in operation after
the war. To better exploit the emerging power of computers, the center
moved to Suitland, Maryland, to join the bureau’s Extended Forecast
Section and the Joint Numerical Weather Prediction Unit as the Na-
tional Weather Analysis Center (NAWAC) in 1955. These three
groups were later combined to form the National Meteorological Cen-
ter (NMC) in January 1958. More recently, NMC was reorganized
as NCEP in October 1995.
5
Shuman was later director of the NMC (1963–81).
510 V
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14WEATHER AND FORECASTING
F
IG
. 1. Conventional surface, 850-, and 500-kPa analyses valid at 1500 UTC 17 Mar 1952 (left) and 0300 UTC 18 Mar 1952 (right).
Surface pressure in mb, heights in mb heights in dam (bold), and temperatures in 8C (italics).
ern Texas and extreme southeastern Oklahoma tonight,
spreading into southern Arkansas and Louisiana before
daybreak’’ on 18 March.
Although the low did indeed deepen over Oklahoma
(Fig. 1) and two tornadoes occurred in north Texas,
none were reported in the area outlooked (Fig. 2). In
retrospect, it appears that the persistence of an anti-
cyclone of continental origin over the forecast region
A
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1999 511CORFIDI
F
IG
. 2. Areal extent of WBAN tornado bulletin issued at 2300 EST (0400 UTC) 17 Mar 1952.
Triangles denote tornadoes reported during the valid time period of the watch.
prior to 17 March inhibited boundary layer moisture
return and destabilization despite the presence of con-
siderable kinematic support for severe convective
storms.
The active weather pattern that prompted the first
WBAN tornado forecast on 17 March continued
through the remainder of the week. On Friday, 21
March, a deep trough that had brought a late winter
storm to the Great Basin on 19 and 20 March was
poised to move east across the central United States.
Given the intensity of this system and the presence of
a strong baroclinic zone over the southern plains to
focus development, significant surface cyclogenesis
was expected to occur over Oklahoma and Arkansas
(Fig. 3). Midtropospheric winds were already in excess
of 40 m s
21
over the southern plains on the morning
of 21 March and were expected to increase as a 50 m
s
21
speed maxima over southern New Mexico contin-
ued eastward during the day. Near the surface, ample
boundary layer moisture was present to support deep
convection over the lower Mississippi Valley. The
158C isodrosotherm extended from southeast
Oklahoma to west Tennessee. Thus, it appeared that
there would be at least some threat for tornadoes as
the Oklahoma low deepened and moved northeastward
later in the day.
Forecasters issued WBAN Tornado Bulletin Number
Two at 1300 EST on Friday, 21 March. The bulletin
alerted the public to the possibility of tornadoes in ‘‘the
northern half of eastern Texas, southern Arkansas, ex-
treme southeastern Oklahoma and northern Louisiana
late this afternoon and extending into this evening.’’An
update at 2230 EST expanded the forecast to include
parts of Kentucky, west Tennessee, and southern Indiana
through daybreak (Fig. 4).
At 1530 EST, a tornado touched down in Diercks,
Arkansas, the first in a series of more than two dozen
tornadoes that continued through the next morning
across parts of Arkansas, Kentucky, Mississippi, Mis-
souri, and Tennessee. The storms claimed 204 lives and
injured more than 1000 (Carr 1952; Galway 1981). Most
of the activity occurred along the warm front associated
with the southern plains low. Total damage was esti-
mated at more than $15 million. As Fig. 4 shows, al-
though forecasters failed to anticipate the significance
of the event in northeast Arkansas, the storms elsewhere
in that state and those in Tennessee and Kentucky were
well forecast. The high death toll appears to at least
some extent reflect the comparatively poor communi-
cation and disaster preparedness plans that were in place
at the time.
The earliest tornado bulletins such as those for the
21 March event were transmitted directly from WBAN
to the district forecast offices via the Service A
6
teletype
network. Dissemination would continue as the district
centers alerted local Weather Bureau and media offices
by phone. The district centers also included thebulletins
in their appropriate state forecasts. In addition, the
WBAN unit prepared a separate release for the Wash-
6
The Service A teletype communication network was operated by
the Civil Aeronautics Administration (CAA) for aviation weather
messages.
512 V
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14WEATHER AND FORECASTING
F
IG
. 3. As for Fig. 1 but for 1500 UTC 21 Mar 1952 (left) and 0300 UTC 22 Mar 1952 (right).
ington offices of the major press associations each time
a tornado forecast was made (Altman 1954). This meth-
od of dissemination was, however, short lived. Begin-
ning later that spring and continuing through the mid-
1950s, tornado forecasts were released to the public by
the bureau’s district and local forecast offices, nearly
always after consultation with the WBAN severe weath-
er staff (see section 8).
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1999 513CORFIDI
F
IG
. 4. Areal extent of WBAN tornado bulletins issued at (a) 1300 (1800 UTC) EST 21 Mar
1952 and (b) 2230 EST (0330 UTC) 21 Mar 1952. Triangles and lines denote reported tornadoes
and tornado paths, respectively, during the valid time period of each watch.
4. A permanent severe weather unit
The WBAN severe weather group became a permanent
operation on 21 May when it was formally recognized
as the Severe Weather Unit (SWU) by Weather Bureau
Circular Letter 20-52. Although the unit continued to use
the center’s facilities, it was still not considered a part of
the joint Weather Bureau, army, and navy op-
eration (U.S. Weather Bureau 1952). Forecast responsi-
bility that had been limited to tornadoes expanded at this
time to include damaging hail, high winds (greater than
or equal to 50 mph), and extreme turbulence.
Five permanent forecasters were selected to provide
around-the-clock coverage of the SWU in the summer
of 1952 (Table 1). Members of the temporary staff that
had been at work since March continued to cover shifts
514 V
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14WEATHER AND FORECASTING
T
ABLE
1. The first permanent SWU forecasters, their enter-on-duty
dates (1952), and previous Weather Bureau assignments (WB 5
Weather Bureau; WBAS 5Weather Bureau airport station).
Forecasters Entered
on duty Previous
assignments
Brunstein, Alan I.
Carr, James A.
Galway, Joseph G.
Martin, Robert H.
Stowell, David J.
1 Oct
1 Sep
25 Jul
15 Aug
2 Oct
WBAN Center
WBAN Center
WBAS, Jacksonville, FL
WB Central Office
WBAS, Fairbanks, AK
T
ABLE
2. Known temporary SWU forecasters (Jun–Sep 1952), and
their permanent Weather Bureau assignments.
Forecasters Assignment
Bristor, Charles L. Central Office, Scientific Services
Division
Croom, Herman L.
Harris, Dale R. Unknown
Central Office, Scientific Services
Division
Hughes, Grover D.
James, Ralph P.
Opplinger, Fred K.
Smith, Clarence S.
Younkin, Russell J.
WBAN Center
WBAN Center
WBAS, Baltimore, MD
WBAN Center
WBAS, Knoxville, TN
F
IG
. 5. The first SWU Severe Weather Bulletin, issued 21 May 1952 (transcribed from original aviation contraction format).
as necessary until the transition to permanent staffing was
completed in September (Table 2).
7
The new forecasters
were comparatively young and shared similar back-
grounds. Most had been with the Weather Bureau less
than 10 years and had attended meteorology school with
the military during World War II. According to Galway
(1992), relatively inexperienced forecasters were inten-
tionally chosen as it was thought that they would be less
likely to harbor preconceived notions about severe storm
prediction. Three of the original five permanent SWU
forecasters left the group within two years of their se-
lection. Only Joseph Galway, the first forecaster to join
the unit, remained with the SWU after 1955 (Lewis
1996).
A special ‘‘Instructions and Information’’ notice dated
20 May 1952 standardized the issuance of severeweather
bulletins (U.S. Weather Bureau 1952). The notice stated
that bulletins were to be released on an as-needed basis
7
Until 12 June 1952, SWU bulletins carried no record of the issuing
forecaster. Beginning on that date, the forecaster’s initials and those
of the WBAN supervising analyst were included at the bottom of the
message. At the present time, the names of only 8 of the original 15
temporary forecasters are known.
‘‘to provide in a single message a description and short
period forecast of severe weather conditions over the
whole country in a concise, unified form.’’ These fore-
casts thus differed from conventional forecasts that cov-
ered all the types of weather that might affect a specific
locality. The period covered by each message was to be
approximately 6 h. Updates were to be prepared as nec-
essary, whether or not a previous forecast had expired,
and each issuance was to be complete within itself. While
their purpose was to highlight the potential for severe
convective weather much as a watch does today, in terms
of their geographical scope and format, bulletins were in
fact more like present-day convective outlooks (Fig. 5).
Use of standard aviation contractions minimized teletype
transmission time.
To minimize false alarms and provide the necessary
lead time to ensure adequate public response, bulletin
areas were to be kept as small as possible. No restrictions,
however, were placed on the geometric shape of the fore-
cast areas. Forecasts were typically not parallelograms,
but rather irregularly shaped regions that included parts
of one or more states. Some were even circles (see, e.g.,
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1999 515CORFIDI
Lewis 1996, p. 265). The areas were determined by the
severe weather forecaster in collaboration with the
WBAN supervising analyst and the District Forecast
Center(s) involved. Assistance was also occasionally pro-
vided by Carstensen, Shuman, and WBAN supervisor
Joseph R. Fulks. The products were consecutively num-
bered on a monthly basis until February 1954, when
annual numbering began.
The SWU gained approval for a separate supervisory
position during the summer of 1952, and Kenneth M.
Barnett was selected as unit supervisor the following
December. Barnett brought a varied operational back-
ground to the SWU. He had served as a navy aerologist
during World War II, an aviation forecaster in Kansas
City from 1946 to 1948, and, most recently, as an advisor
to the Irish Meteorological Service (Galway 1992, 1994).
Prior to Barnett’s arrival, SWU administrative duties had
been handled by WBAN chief Fulks. Even after Barnett’s
selection, however, overall responsibility for SWU prod-
ucts remained with Fulks.
During his time with the SWU, Barnett emphasized
the thermodynamic parameters involved in the prepara-
tion of tornado forecasts (Barnett 1953). His work fo-
cused on identifying regions where steep 850–700-mb
lapse rates were present above areas of high boundary
layer moisture content. Barnett’s objective technique,
plotted daily on the ‘‘potential instability’’ chart (later
known as the ‘‘raob’’ chart; Galway 1992), was the fore-
runner of the two-part ‘‘thermodynamic analysis’’ pro-
duced today at SPC.
Barnett also endeavored to develop an official defi-
nition of a severe thunderstorm. As strange as it might
seem, the Weather Bureau had embarked on a program
for forecasting severe storms without bothering to define
just what was meant by ‘‘severe.’’Even the 50 mph wind
threshold mentioned earlier was a loose figure, as early
bulletins reveal frequent use of ‘‘gusts 40 to 50 kts’’ (46–
58 mph). In fall 1953, in consultation with field and
central office staff, Barnett issued ‘‘SELS Criteria for
Severe Thunderstorms’’ (U.S. Weather Bureau 1953c),
which finally quantified the hail size (greater than or equal
to 1 in.) and wind speeds (average speed of at least 50
mph, and/or gusts to 75 mph or more) officially recog-
nized as severe (Galway 1989).
Albert K. Showalter succeeded Fulks as WBAN su-
pervisor in January 1953. Showalter was no stranger to
the field of severe weather forecasting: nine years earlier,
he had coauthored the two-paper report with Fulks al-
ready mentioned (Showalter and Fulks 1943) that dis-
cussed the synoptic conditions associated with tornado
development. This report helped lay the foundation for
Fawbush and Miller’s work in the late 1940s. Showalter
was also known for the index of thermodynamic insta-
bility that bears his name (Showalter 1953). His work
was subsequently used in the development of Galway’s
‘‘lifted index’’ in the mid-1950s (Galway 1956). Both
indices remain valuable diagnostic tools today.
5. The birth of SELS
The Severe Weather Unit evolved rapidly in 1953—a
year that produced an unusually large number of signif-
icant tornadoes. In January, the unit initiated an exper-
imental program to issue daily outlooks of the severe
weather potential for the upcoming day. These trial ‘‘Se-
vere Weather Discussions’’ were issued around 0500 CST
and were intended as guidance for selected Weather Bu-
reau district offices for the noon to midnight (CST) time
period. Both existing convective weather and the pros-
pects for additional development were discussed. The
product became operational in February and was renamed
the ‘‘Convective Outlook’’ when regular transmission on
Service A began in April 1955.
The SWU was renamed the Severe Local Storm Warn-
ing Service (SELS) on 17 June 1953, shortly after death-
dealing tornadoes struck the major population centers of
Waco, Texas; Flint, Michigan; and Worcester, Massachu-
setts. Devastating storms from Nebraska to New England
on 7–9 June alone claimed more than 200 lives, and the
Waco storm was the worst ever in Texas (Lynch 1970).
These events severely tested the endurance of the unit’s
young and relatively inexperienced staff. Although the
tornadoes on 7 and 8 June were well forecast, those that
occurred in New England on 9 June caught forecasters
by surprise. One forecaster requested, and was granted,
a transfer following the Worcester storm (Lewis 1996).
The Worcester event, taunts from those whocontinued
to believe that severe storms were unpredictable, and
complaints that the unit’s forecast areas were too large
all made SELS the focus of mounting criticism during
the summer of 1953 (Galway 1989). In addition, district
forecasters were sometimes less than enthusiastic about
accepting forecast products from a centralized forecast
center.
Criticism regarding watch size was largely unwar-
ranted as the size of tornado forecast areas was in fact
already on the decrease in 1953. Average forecast area
size decreased from nearly 38 000 mi
2
in 1952 to 27 000
mi
2
during the first half of 1953 (Galway 1989).
8
SELS
supervisor Barnett, however, did not think that this was
enough. Bowing to pressure from the Air Transport As-
sociation, a June 1953 memo was issued limiting the
suggested size of an ‘‘ideal’’ forecast area to just 10 000
mi
2
(U.S. Weather Bureau 1953b). That such a size cri-
teria would be nearly impossible to attain is illustrated
by the fact that none of the watches issued during the
remainder of the year covered less than 10 000 mi
2
, and
only three were for less than 20 000 (Galway 1989).
By midsummer, it was clear that themounting pressure
was taking its toll on Barnett and that he did not want
to spend another season with SELS. The search to find
8
By comparison, the average area covered by SPC tornado and
severe thunderstorm watches today is about 25 000 mi
2
(about half
the state of Iowa).
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IG
. 6. SELS chief D. C. House in 1961.
a new supervisor began in the late fall of 1953, after
Barnett accepted an assignment with the Army Signal
Corps. Barnett did not, however, leave SELS until the
following spring.
Kansas City Assistant Regional Director Donald C.
House was selected as Barnett’s replacement in March
1954 (Fig. 6). In the regional office House had had fre-
quent contact with Scientific Service Division personnel
and was familiar with the various tornado research efforts
under way at the time in the central states (Galway1989).
He had also done some applied work with the Showalter
index (House 1952) and investigated the significance of
the 700-mb ‘‘no advection’’ line (U.S. Weather Bureau
1954). House’s mission, as stated by Bureau Chief Rei-
chelderfer, was two part: to improve severe weatherfore-
cast techniques and to reduce the size of forecast areas
(Galway 1989). House accomplished his second task dur-
ing his first year: The average size of SELS tornado
‘‘bulletins’’ decreased from more than 20 000 mi
2
in late
1953 to less than 15 000 mi
2
in 1954 (Galway 1989).
9
House’s enthusiasm for severe weather forecastingwas
immediately apparent. He manned the forecast desk sev-
eral days a week during severe weather season (Fig. 7)
and strived to enhance the scientific basis of the unit by
furthering staff research efforts begun under Barnett. Un-
der House’s direction, SELS meteorologists made nu-
merous lasting contributions to severe weather forecast-
9
The reduction in watch size was, unfortunately, accompanied by
a comparative decrease in forecast accuracy. As a result, average
watch size soon returned to about 27 000 mi
2
(Schaefer 1998, personal
communication).
ing in the mid- to late 1950s.
10
House also encouraged
forecasters to apply the vorticity advection concepts de-
scribed by Riehl et al. (1952). The goal was to place
more emphasis on the role high-altitude conditions play
in the development of severe convective storms. As Gal-
way (1989) states, House’s leadership was to a large ex-
tent responsible for establishing SELS ‘‘as a viable and
respected forecast unit of the Weather Bureau.’’ House
remained with SELS until August 1965, when he as-
sumed a post with the newly formed Environmental Sci-
ence Services Administration (ESSA) in Washington.
6. The move to Kansas City
In anticipation of a convective season perhaps as active
as the previous one, SELS staffing increased to include
a sixth forecaster and an additional researcher in April
1954. The researcher, Ferdinand C. Bates, joined Robert
G. Beebe and assistant Georgina Neubrand, both of
whom had come to SELS in 1953 (see section 10). In-
cluding House and the 6-member charting staff, SELS
staffing now totaled 16.
Perhaps the most noteworthy highlight of 1954 was
the unit’s relocation from Washington to Kansas City.
While the selection of House, with his Kansas City base,
as SELS supervisor may not have been totally incidental
to the late summer move, officially the relocation was
10
These papers include those by F. C. Bates (1955), R. G. Beebe
(1995), Beebe and Bates (1955), J. A. Carr (1955), D. S. Foster
(1958), Foster and Bates (1956), J. G. Galway (1956), J. T. Lee (1955),
and B. W. Magor (1958); others may be found in Galway (1992).
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F
IG
. 7. View of the SELS plotting board, showing D. C. House (center) with forecasters H.
Swenson (left) and J. Galway (right), Apr 1956.
F
IG
. 8. Federal building at 911 Walnut Street, Kansas City, MO, c.
1958.
made to satisfy two main goals. The first was to silence
plains and Midwestern critics who believed that theoffice
should be located in an area more prone to severe weather.
The second objective was to provide increased contact
and more rapid communication with those district offices
typically affected by severe weather (Chicago, Kansas
City, and New Orleans). Since Kansas City was already
an aviation message switching center, it wasstrategically
located for nationwide dissemination of teletype weather
messages. The move was also the first step in a planned
consolidation of the nation’s severe weather forecasting
efforts. This plan would see the SWWC join SELS in
Kansas City in 1956 (see section 7).
The Kansas City relocation was made in two phases.
House and three forecasters arrived in August. They
joined a fourth forecaster who was already in Kansas
City and had just been assigned to SELS. On 1 September
1954, Kansas City became responsible for that portion
of the country west of 908longitude, while Washington
continued to handle activity to the east. Two weeks later,
Kansas City assumed responsibility for the entire nation,
and the WBAN group ceased operation (Galway 1989).
Of the four remaining forecasters in Washington, twoleft
for Kansas City that week, while the other two accepted
assignments elsewhere in the analysis center.
The first tornado bulletin transmitted from KansasCity
was issued by D. C. House at 1410 CST on 8 September
1954. The forecast covered parts of northern Nebraska
and southeast South Dakota and was valid from 1700 to
2300 CST. It did not verify (Galway 1973).
SELS shared its first home in Kansas City with the
district forecast office at Municipal Airport (now known
as the ‘‘Downtown Airport’’). After about a year at the
airport, SELS joined the district office in moving to the
seventh floor of the nearby federal office building at 911
Walnut Street in November 1955 (Fig. 8). Three years
later, the office moved to more spacious quarters on the
518 V
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14WEATHER AND FORECASTING
F
IG
. 9. J. R. Lloyd, meteorologist-in-charge of the Kansas City
forecast office, 1948–52.
ninth floor. SELS remained at that location until June
1966, when it relocated to the 17th floor of the new
federal building at 601 East 12th Street.
Although SELS remained in Kansas City for more than
40 years and became closely identified with the town, it
was not, in fact, that city’s first severe weather connec-
tion. In January 1952, at the request of Meteorologist-
In-Charge (MIC) Joseph R. Lloyd (Fig. 9), the Kansas
City district office had been granted permission to es-
tablish a small research group to apply and further de-
velop the severe weather forecasting techniques pio-
neered by Lloyd (1942), Showalter and Fulks (1943),
and the SWWC. The group was authorized to request
special radiosonde ascents at Weather Bureau sites as
deemed necessary. It was Lloyd’s intention to use the
research work to help establish a tornado and severe
weather forecasting program at Kansas City in 1953 or
1954.
Lloyd was a strong-willed individual and knew that
his research proposal would not endear him to Weather
Bureau management. He was instead motivated by pres-
sure from outside sources to have Kansas City relay
SWWC tornado forecasts to the public and/or issue sim-
ilar advisories of its own (Galway 1992). Instigation in
this regard was especially strong in Oklahoma as the
SWWC routinely notified public safety and Red Cross
officials in that state whenever a tornado forecast was
issued.
11
As a result, many SWWC forecasts were finding
their way to the public. It should be remembered that at
this time ultimate forecast responsibility for tornadoes
within a given district still resided with the district office
(Foster 1953). Lloyd reasoned that if the district centers
were to reliably forecast tornadoes, it would be wise to
establish some degree of forecast expertise at the district
level.
Lloyd had invited Fawbush and Miller to present their
tornado prediction technique to the Kansas City forecast
staff in February 1950, just weeks after the two had made
a presentation at the annual meeting of the American
Meteorological Society in St. Louis. Shortly thereafter
he set up a liaison with the Tinker staff, to ensure that
all SWWC forecasts were sent to his office via teletype
(McDermott 1951; U.S. Air Force 1951). By 1952, Lloyd
himself was regularly issuing reworded air force forecasts
to the press (Lynch 1970).
After the formation of the WBAN SWU in May 1952,
Lloyd’s group was restricted to forecasting tornadoes
only within the Kansas City district office’s forecastarea,
and only after consultation with the SWWC and SWU.
Kansas City remained, however, a liaison point between
the SWU and SWWC, and all SWU coordination calls
with SWWC were to be made through Kansas City (U.S.
Weather Bureau 1953a).
Lloyd died in August 1952. His research program was
reduced to a one-man operation run by D. S. Foster for
its second and final season in 1953. The results of Foster’s
work (Foster 1953) clearly show the value of having an
individual dedicated to a specific forecast task. For ex-
ample, the percentage of days when severe weather oc-
curred but no severe weather forecast was issued rose
from 23% to 82% on Foster’s days off (i.e., when the
task was left to the regular district staff). Similarly, the
percentage of tornadoes that occurred in forecast areas
increased from 13% to 39% when Foster manned the
separate severe weather desk.
In the fall of 1953, acting MIC Henry L. Jacobson
petitioned the Weather Bureau central office to maintain
an independent severe weather operation in Kansas City
to complement the SWU in Washington. Not too sur-
prisingly, Bureau Chief Reichelderfer, a champion of fis-
cal responsibility, rejected Jacobson’s idea, citing dupli-
cation of effort. Nevertheless, although Lloyd’s operation
lasted barely two seasons, his pioneering efforts were
instrumental in hastening Washington’s decision to begin
issuing routine severe weather forecasts in 1952. His
work also, of course, helped pave the way for SELS’
move to Kansas City in September 1954.
11
Oklahoma was at the time part of the Kansas City district office’s
area of responsibility, which also included Kansas, Missouri, and
Nebraska.
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7. The operation grows
SELS of the mid-1950s was a small operation com-
pared with the Storm Prediction Center of today. Typi-
cally, each shift was covered by a single forecaster and
an accompanying chartist (data plotter). SELS did not
work in isolation, however, as the unit shared space with
the district office. The forecast desk was manned on a
24-hour basis only from March through June. Through
the remainder of the year, the forecaster scheduled to
cover the midnight shift (0000–0830 LT) worked a day
‘‘research’’ shift (0700–1530 LT) unless severe weather
was expected during the overnight hours. The midnight
person was, however, on call if unexpected severeactivity
did develop.
The receipt of data from Weather Bureau and military
weather surveillance radars on a timely basis via the
Service A teletype network was a problem that had
plagued SELS since its earliest days. Creation of the
dedicated Radar Report and Warning Coordination (RA-
WARC) teletype circuit in September 1955 solved this
problem. With RAWARC, radar observations could now
be received directly from each radar site, rather than on
a time-available basis as was the case with Service A
(Galway 1992). In addition, because the circuit’s switch-
ing and control operation was collocated with SELS and
the Kansas City district office, RAWARC could also be
used for the rapid dissemination of SELS forecast prod-
ucts. A staff of 11 ‘‘COMMS’’ (communication) tech-
nicians provided continuous monitoring and control of
the circuit. COMMS remained an integral part of SELS
until automated switching and relay equipment arrived
in 1985.
A separate Radar Analysis and Development Unit
(RADU) was created in January 1956 to better utilize
the data provided by the RAWARC circuit. RADU col-
lected and analyzed civilian and military radar obser-
vations from around the country and transmitted hourly
national summaries of the data on RAWARC. Duplicate
reports of the same echo were eliminated, and echoes
were assigned a relative strength depending upon the
characteristics of the particular radar used to observe
them. RADU’s summaries proved very valuable to SELS.
Forecasters could now not only examine the data in a
more timely fashion but were also relieved from having
to plot reports by hand. RADU was also responsible for
the quality control of network radar observations and for
the development of techniques to enhance the use of radar
data in forecasting and warning (Ostby et al. 1989). The
unit began facsimile transmission of a graphical national
radar summary in 1960.
RADU’s responsibilities changed considerably as net-
work equipment and operational procedures evolved over
the years. RADU’s original staffing of 11 was reduced
to 5 when it was reorganized as the ‘‘SIGRAD’’ Unit in
April 1978.
12
SIGRAD provided plotting and analysis
12
Digitized radar summary charts permanently replaced hourly
manual facsimile analyses at this time.
support to SELS and convective SIGMET forecasters.
13
The development of automated digitized radar plotting
software at NSSFC allowed for the decommissioning of
SIGRAD in October 1987.
Another group that joined SELS in the Kansas City
forecast complex in January 1956 was the Air Force’s
SWWC. Relocation of the 40-man operation from Tinker
Air Base was part of a larger Eisenhower administration
effort to eliminate duplication of weather-related activi-
ties in the federal government. Negotiations for a joint
severe weather center had actually been under way since
before SELS left Washington in 1954. The Weather Bu-
reau originally wanted the joint relocation to be in Chi-
cago, while the Air Force favored Kansas City.
SWWC’s advisories alerted military commanders and
personnel to the possibility of severe weather at specific
sites. The format and intent of SWWC forecast products
thus differed considerably from those of SELS. SWWC
influence fostered major content and format changes in
SELS products in 1957 and 1961 (see section 8) and
hastened the bureau-wide adoption of revised severe
weather criteria during the same period (see Galway
1989, 590–592).
Pressure continued to eliminate duplication in the fed-
eral government’s weather-related programs in the late
1950s. This eventually led to a proposal not overwhelm-
ingly supported by air force personnel that SELS assume
responsibility for all convective weather forecasts, both
civilian and military. SELS assumed this role in February
1961, and the SWWC was disbanded. For the following
three years (through March 1964), SELS was the sole
source of severe convective weather forecasts in the Unit-
ed States.
The air force’s severe weather forecast requirements
expanded to include coverage of nonconvective wind
storms, blowing dust, dense fog, heavy rainfall, and win-
ter storms in addition to severe local storms in 1964. As
a result, the SWWC was resurrected as the Military
Weather Warning Center (MWWC) in March of that year.
Collocated with SELS, the unit remained in Kansas City
until January 1970, when it moved to Offutt Air Force
Base as part of a reorganization of the Air Force’s Global
Weather Central.
8. Maturation: The late 1950s through the
mid-1960s
As previously noted, fear of public unrest was the
primary reason cited by the Weather Bureau for its re-
luctance to issue tornado forecasts during the first half
of this century. As late as 1952, Ivan R. Tannehill, chief
of the bureau’s forecast division, defended the bureau’s
‘‘no tell’’ policy by stating that because such storms affect
13
The Convective SIGMET Unit was established in April 1978 to
provide hourly significant meteorological information advisories to
in-flight aircraft regarding hazardous convective weather.
520 V
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14WEATHER AND FORECASTING
such a small area, more people were likely to lose their
lives as a result of forecast-generated hysteria than from
tornadoes themselves (Lynch 1970). As word of suc-
cessful forecasts began to spread, however, the bureau’s
justification changed. Emphasis shifted to the risk of pub-
lic indifference (the ‘‘cry wolf syndrome’’) if tornadoes
failed to occur in a forecast area (Whitnah 1961). Chief
Reicheldefer summarized the bureau’s lack of confidence
in tornado forecasting with a comment made on 18 March
1952, the day after the issuance of SWU’s first tornado
bulletin. Reichelderfer said that ‘‘in the long run,we think
that this type of forecast will not be very acceptable to
the public’’ (Lynch 1970).
Of course, Reichelderfer was wrong. By the latter half
of the 1950s, success of the air force and Weather Bureau
severe weather programs had just about eliminated public
doubt regarding the value of tornado forecasts. Alarm
over such forecasts was also lessened by intensive edu-
cational efforts promoting tornado awareness and safety.
Tornado forecasts were in fact often cited as a means of
saving lives (U.S. Weather Bureau 1955). The only crit-
icism of note was voiced in Oklahoma, where a writer
in Tulsa noted that the state’s reputation might suffer as
a result of the numerous severe weather advisories being
issued for the region (Altman 1954).
During this period, a typical SELS tornado forecast
would read as follows: ‘‘possibility of an isolated tornado
along and thirty miles either side of a line from Amarillo,
Texas, to 20 miles north of Gage, Oklahoma, from 5:15
to 9:00
PM
....’’Such a forecast would have first been
discussed via telephone with the district offices(s) in-
volved. If it was agreed that a public forecast oftornadoes
was indeed prudent, the district forecaster would notify
the local Weather Bureau offices in that area, in addition
to the media. If the proposed forecast affected only one
district office, that office had final say as to whether or
not tornadoes would be mentioned in the public forecast.
If, on the other hand, a proposed tornado forecast in-
volved more than one district office, SELS made the final
decision. It was not until 1958 that SELS assumed total
authority for public tornado and severe thunderstorm
forecasts (Galway 1989). The forecast text was prepared
by SELS and transmitted on the Service A and RAWARC
teletype circuits.
As is the case today, local offices were responsiblefor
issuing messages that canceled all or portions of severe
weather forecasts in their areas of responsibility. Nor-
mally these messages were sent only after consultation
with SELS. This was, however, not always the case. D.
C. House liked to relate an anecdote that occurred before
coordination become commonplace. An office had taken
the liberty of issuing an ‘‘all clear’’ message without
calling SELS. Just as the message was being broadcast
on a local radio station, storm winds toppled the station’s
transmitting tower, knocking it off the air in the middle
of the all clear announcement (Knox 1958).
Prior to 1957, SELS bulletins and outlooks were writ-
ten in a technical format using standard aviation weather
contractions. District offices were responsible for re-
writing the forecasts for public dissemination. With the
establishment of RAWARC, however, SELS could issue
its own plain language products directly to the public.
Thus, beginning in February 1957, SELS forecasts were
issued in two parts: one for aviation (using the same
format as in past years), and another in plain language
form for unedited use by the public. Additional format
changes were implemented in 1961, when SELS assumed
responsibility for military severe weather forecast prod-
ucts (see Galway 1989).
A new product, the daily Severe Local Storms Syn-
opsis, was initiated in February 1958. This was essen-
tially a preliminary convective outlook, describing the
threat for severe and general thunderstorm development
the upcoming day. It was issued at 0240 CST during the
severe weather season (1 February–31 August) and was
updated by the regular convective outlook issued about
three hours later (Galway 1973).
From the beginning, the SELS ‘‘operational philoso-
phy’’ emphasized the analysisof real-time meteorological
data. This philosophy did not change even after the arrival
of centralized numerical model forecasts in the late
1950s. The surface pressure field was routinely analyzed
each hour in 1-mb increments (Fig. 10). Since the ob-
servations were plotted by hand, the entire country was
generally not analyzed. Instead, forecasters indicated on
a blank map those regions where observations were to
be plotted by the chartist (Knox 1958). To maintain a
broader perspective, SELS also received copies of the
North American surface analyses completed every six
hours by the district office staff.
Upper air sounding data were also routinely plotted,
and prognostic soundings were constructed to assess the
impact of diurnal and/or advective temperature changes.
Reflecting House’s interest in the role of upper-level fea-
tures in modulating convective development, streamlines
of high-level flow were drawn by plotting the maximum
winds observed at each radiosonde site on the so-called
jet chart (Lee and Galway 1958).
The installation of an IBM 1620 computer in April
1963 was a major milestone that greatly enhanced SELS’
diagnostic capabilities. Forecasters could now obtain
real-time objective analyses of parameters such as upper-
level divergence and vorticity advection. A second-gen-
eration mainframe system using a CDC 3100 enabled
data plotting routines to be automated in the latter part
of 1965.
Allen D. Pearson, head of the Weather Bureau’s Emer-
gency Warning Branch in Washington, became the third
SELS supervisor upon the departure of House for ESSA
in the summer of 1965. Pearson came to SELS intent on
increasing public awareness of the hazards posed by se-
vere thunderstorms and tornadoes. He was especially
anxious to implement the preparedness programs rec-
ommended by the review committee on the Palm Sunday
1965 tornado outbreak. Pearson oversaw relocation of
the Kansas City forecast complex, renamed as the Na-
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F
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. 10. SELS analysis area with (left to right) A. M. James Jr., D. C. House, and C. F.
Chappell, Apr 1961 (courtesy Curtis Publishing Co.).
tional Severe Storms Forecast Center, to the new federal
building on East 12th Street in June 1966.
14
Earlier that
same year, the word ‘‘forecast’’ was replaced by ‘‘watch’’
in SELS’ public tornado and severe thunderstorm prod-
ucts. This was done to more closely parallel the ‘‘watch/
warning’’ terminology that had been in use for hurricane
products since the mid-1950s (Galway 1989).
9. Research and development
In October 1952, the Weather Bureau instituteda two-
week course on severe local storms that was conducted
by the Scientific Services Division at the WBAN center
in Washington. All 5 permanent SWU forecasters at-
tended the course, in addition to 10 forecasters from the
field. The course emphasized the need for operational-
based research, and by early 1953 each SWU forecaster
had an assigned area of study that was to be conducted
during periods of quiet weather (Galway 1992).
Building on this foundation, SELS supervisor Barnett
planted the seed for what would in large part become the
National Severe Storms Laboratory when he requested a
research forecaster and assistant to support staff research
14
In addition to SELS and its supporting staff, the NSSFC included
the Kansas City Weather Bureau office (formerly known as the district
office) and the local radar warning group (the ‘‘public service unit’’).
The severe storm ‘‘core’’ of the NSSFC was renamed the Storm
Prediction Center in October 1995.
projects in the summer of 1953.
15
As already noted,
House continued in this direction, bringing a second re-
search forecaster on board in the spring of 1954. Field
station workshop visits by SELS forecasters (begun in
1956), as well as presentations at American Meteorolog-
ical Society meetings (Galway 1994) furthered these ef-
forts and brought increased exposure to the fledgling unit.
Research staffing also continued to grow through the mid-
to late 1950s, including such names as Charles F. Chap-
pell (Fig. 10), Howard H. Hanks Jr., and Dansy T. Wil-
liams in addition to Beebe and Bates.
SELS-related research intensified with the formation
of the Tornado Research Airplane Project (TRAP) in
1956. The goal of this program was to use aircraft to
probe the temperature and humidity structure of air mas-
ses in tornado forecast areas. Extra research assistants
were hired to process the data collected by TRAP flights.
SELS forecasters provided weather briefings to the TRAP
pilots. In return, forecasters received pilot reports on the
location of significant weather features such as cold fronts
and dry lines, as well as information regarding the degree
of convective development (Galway 1992). Although
TRAP collected several years’ worth of valuable data,
aircraft mechanical difficulties and personnel problems
plagued the program from the start. As a result, TRAP
15
It should be noted that the roots of NSSL also trace back to the
mesoscale networks set up by the Weather Bureau’s director of me-
teorological research, Harry Wexler, in the early 1950s. These net-
works were originally established to test the ‘‘pressurejump’’ theory
of Morris Tepper (Tepper 1950), but later expanded in scope and
supported the pioneering mesoanalysis work of Fujita et al. (1956).
522 V
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14WEATHER AND FORECASTING
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. 11. Cockpit view of a B26 NSSP weather research flight, Apr 1961. (courtesy Curtis
Publishing Co.)
management was transferred to the Kansas City district
meteorological office headed by Clayton F. Van Thullenar
in December 1957 (Goddard 1962). This administrative
move marked the beginning of what would be a nearly
two-decade absence of formal research and development
in SELS. It should be noted, however, that while TRAP
management was removed from SELS, some TRAP per-
sonnel continued to work as SELS forecasters on an oc-
casional basis for several years after the managerial
change (C. A. Doswell III 1998, personal communica-
tion).
TRAP assumed a new name, the National Severe Local
Storms Research Project, when joint collaboration with
the air force, the Federal Aviation Administration, and
the National Aeronautics and Space Administration be-
gan in 1960. The name was shortened to National Severe
Storms Project (NSSP) the following year, with Van
Thullenar assuming the title of project director and Ches-
ter W. Newton named as chief scientist. NSSP’s official
mission was to investigate the formation and behavior of
squall lines and to obtain knowledge that might be used
to mitigate their damaging effects. Data collection was
enhanced by access to more than a dozen aircraft (Fig.
11) and by the establishment of two surface observation
networks over parts of Kansas, Oklahoma, and Texas in
1961. The results of NSSP’s investigations are detailed
in a series of 22 technical reports published in the early
to mid-1960s.
Airborne thunderstorm investigations had been con-
ducted over Oklahoma since the late 1940s in part be-
cause of the state’s high incidence of severe convection.
Equally important, however, was the relative accessibility
of Tinker Air Force Base and Will Rogers Field compared
with the busy downtown airport in Kansas City. As a
result, Oklahoma became the focus of TRAP–NSSP field
operations to an increasing degree during the late 1950s
and early 1960s. Citing these advantages and the prox-
imity of the new Department of Meteorology at the near-
by University of Oklahoma, the Weather Bureau estab-
lished its Weather Radar Laboratory (WRL) on the
grounds of the former North Base Naval Air Station in
Norman in 1963.
To eliminate duplication and foster more focused field
research, NSSP and WRL were consolidated as the Na-
tional Severe Storms Laboratory (NSSL) in Norman in
March 1964. The lab was placed under the direction of
Edwin Kessler, formerly of The Travelers Research Cen-
ter in Connecticut. Van Thullenar, who remained in Kan-
sas City to close NSSP’s offices, retired shortly after the
Norman merger. Newton, meanwhile, left to become a
senior scientist at the National Center for Atmospheric
Research. Galway (1992) provides a more detailed dis-
cussion of SELS research efforts in the 1950s and 1960s.
After a nearly two-decade hiatus, a formal research
and development program returned to SELS with the
establishment of the Techniques Development Unit
(TDU) under the direction of Joseph T. Schaefer in March
1976. This unit was created to develop computer-based
techniques aimed at improving severe weather forecasts
and to conduct applied severe weather research. The TDU
was instrumental in procuring and evaluating the Man–
Computer Interactive Data Access System (McIDAS),
which later evolved into the Centralized Storm Infor-
mation System (CSIS). CSIS revolutionized real-time
meteorological data analysis at SELS in the early to mid-
1980s (Anthony et al. 1982; Ostby 1984).
The severe weather function of NSSFC (i.e., the SELS
unit in Kansas City) was renamed the Storm Prediction
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1999 523CORFIDI
Center on 1 October 1995 as part of an NWS modern-
ization plan that saw its parent organization, the National
Meteorological Center, reorganized as the National Cen-
ters for Environmental Prediction. In an effort to hasten
the application of theoretical advances by encouraging
interaction between research and operational personnel,
SPC joined NSSL at the lab’s Norman facility uponcom-
pletion of a move from Kansas City in January 1997.
10. Postscript
The preceding pages have presented an overview of
the development of SELS, the immediate predecessor of
today’s Storm Prediction Center. The narrative has nec-
essarily focused on policy changes and administrative
events that are documented in Weather Bureau literature.
The real history of any organization, however, is that of
its people: the myriad interpersonal exchanges and in-
dividual decisions that are made on a day-to-day basis.
Details of this nature are, of course, not readily preserved.
Whatever respect the SPC commands today is due in
large measure to SELS’ ability to attract dedicated and
motivated individuals during its formative years. These
people were committed to obtaining a better understand-
ing of severe storm behavior—and to applying that
knowledge to better serve the public.
Acknowledgments. The author would like to thank
Chuck Doswell, Joseph Schaefer, Steven Weiss, and an
anonymous reviewer for their helpful comments and sug-
gestions. Edwin Kessler provided insight on NSSP’s
move to Norman, and Carolyn Kloth and Richard Wil-
liams helped gather photographs and internal manu-
scripts. Sincere thanks are extended to Marlene Bradford,
who recently completed a doctoral dissertation at Texas
A&M University on the history of severe weather fore-
casting, for her encouragement and assistance in locating
unpublished material. Finally, the author would like to
dedicate this paper to Joseph G. Galway as a tribute to
his pioneering work in documenting the evolution of se-
vere weather forecasting in the United States.
APPENDIX
List of Acronyms with Selected Locations/Dates of
Operation/Notes
CAA Civil Aeronautics Administration
CDC Control Data Corporation
COMMS SELS Communications Unit (1956–85;
monitored RAWARC)
CSIS Centralized Storm Information System
ESSA Environmental Science Services Adminis-
tration (1965–70)
IBM International Business Machines Corpora-
tion
McIDAS Man–Computer Interactive Data Access
System
MIC Meteorologist-in-charge
MWWC Military Weather Warning Center (Kansas
City, Missouri, 1964–70)
NAWAC National Weather Analysis Center (Wash-
ington, D.C., 1955–57)
NCEP National Centers for Environmental Predic-
tion (1995–present)
NMC National Meteorological Center (1958–95)
NOAA National Oceanic and Atmospheric Admin-
istration (1970–present, formerly ESSA)
NSSFC National Severe Storms Forecast Center
(Kansas City, Missouri, 1966–95; USWB
and NWS)
NSSL National Severe Storms Laboratory (Nor-
man, Oklahoma, 1964–present)
NSSP National Severe Storms Project (Kansas
City, Missouri, and Norman, Oklahoma,
1961–64)
NWS National Weather Service (1970–present,
formerly USWB)
RADU SELS Radar Analysis and Development
Unit
RAWARC Radar Report and Warning Coordination
(teletype circuit)
SELS Severe Local Storms Warning Service
(Washington, D.C., and Kansas City, Mis-
souri, 1953–95)
SIGRAD SELS Convective SIGMET/Radar Unit
(SELS, 1978–87)
SIGMET Significant Meteorological Information Ad-
visories
SPC Storm Prediction Center (Kansas City, Mis-
souri, and Norman, Oklahoma, 1995–pres-
ent; NWS)
SWU Severe Weather Unit (Washington, D.C.,
1952–53; USWB)
SWWC Severe Weather Warning Center (Tinker Air
Force Base, Oklahoma, and Kansas City,
Missouri, 1951–61; USAF)
TDU SELS Techniques Development Unit (1976–
present)
TRAP Tornado Research Airplane Project (Kansas
City, Missouri, 1955–59; USWB)
USAF United States Air Force
USWB United States Weather Bureau (1870–1970)
WBAN Weather Bureau–Army–Navy Analysis Cen-
ter (Washington, D.C., 1942–55)
WRL Weather Radar Laboratory (Norman,
Oklahoma, 1963–64)
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