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Many locals are surprised to learn that decades ago, pioneering research on thunderstorms was conducted right here in the skies over Wilmington, Ohio. In fact, the summer of 2012 marked the 65th anniversary of the Ohio phase of this groundbreaking, nationally-significant study known as the Thunderstorm Project. Today's understanding of the life-cycle and structure of thunderstorms has come a long way since the 1940s, but try to imagine a time before Doppler radars and weather satellites -- a time before computers were commonplace and when weather maps were plotted by hand from data received over teletype or radio.

Prior to and during World War II, the aviation industry, both civilian and military, expanded rapidly but remained vulnerable to adverse weather conditions. After a number of serious thunderstorm-related aircraft incidents, thunderstorms became widely recognized as aviation's most serious weather hazard, yet little was known about them. In 1945, Congress mandated and funded a large-scale, multi-agency meteorological study to investigate the causes and characteristics of thunderstorms. This study, which became known as the Thunderstorm Project, was a cooperative undertaking on the part of four federal agencies:
(Left to right) Ferguson Hall of the Weather Bureau, Lt. Col. Lewis Meng of the Air Force, and Dr. Horace Byers of the University of Chicago.
the Weather Bureau, the Army Air Force, the Navy, and the National Advisory Committee for Aeronautics (NACA, the predecessor of NASA).

The Weather Bureau was assigned responsibility for organizing the study, and by early August 1945, Dr. Horace R. Byers of the University of Chicago was appointed Director of the Thunderstorm Project. World War II finally came to an end just weeks later, a circumstance that could not have come at a better time for the Thunderstorm Project. It meant that suitable equipment, airplanes, and large numbers of trained personnel would be available for peacetime use for this major meteorological research effort.

The first phase of the Thunderstorm Project was carried out near Orlando, Florida during the summer of 1946, since thunderstorms occur more frequently in Florida than anywhere else in North America. All the equipment was then loaded onto railroad freight cars and transported to Wilmington, Ohio for the second phase of the study the following summer (May-September, 1947). Wilmington was selected primarily for its large military airbase, the Clinton County Army Air Force Base (CCAAFB, now the present-day site of Wilmington Air Park), which served as headquarters for the Ohio phase of the Thunderstorm Project. In addition, this site was chosen for its relatively flat terrain and its tendency to experience both frontal and non-frontal thunderstorms.

P-61 squadron ready for takeoff at the Clinton County Army Air Force Base during the Ohio phase of the Thunderstorm Project.
As part of the study, pilots from the CCAAFB All-Weather Flying Division of the Air Material Command made numerous and nearly simultaneous flights through thunderstorms by flying a vertical stack of five radar-equipped P-61C Black Widow airplanes at altitudes of approximately 5000, 10,000, 15,000, 20,000, and 25,000 feet. According to Roscoe Braham, Jr., senior analyst for the Thunderstorm Project, their objective was "to obtain the maximum number of traverses through each storm and to sample storms in all stages of development. No storm was to be avoided because it appeared too large or too violent" (1997).

Meanwhile, a surface network of dozens of weather observing stations (arranged in a two mile grid that spanned portions of Clinton, Brown, and Highland counties) continuously monitored and recorded the surrounding environment.
Launching a weather balloon with a corner-reflector to measure winds aloft and monitor the environment for thunderstorm development.
These surface observing stations were inspected daily by Weather Bureau observers and supplemented by a concentrated network of six radiosonde (weather balloon) stations and five radar-wind stations. Thunderstorms were detected and monitored, and airplanes were tracked and guided, using a large ground radar that was originally located near the operations area at the CCAAFB until a longer-range, high-power radar was installed near Jamestown, Ohio.

The Thunderstorm Project was significant for many reasons, as evidenced by the fact the War Department gave it priority second only to the Bikini atomic bomb tests. It was the nation's first large-scale scientific study of thunderstorms and the first multi-agency meteorological project mandated and funded by Congress. As such, it was also the first weather research study in which radar and airplanes had a central role (radar was new, highly classified, and essentially limited to the military during WWII). The Project demonstrated that radar could be used to detect the most dangerous parts of thunderstorms and guide airplanes around them. Furthermore, the density of observations used during the Thunderstorm Project had never been attempted before and set the standard for similar projects to come. All of the analysis, computation, and plotting of the massive amount of data obtained from the Thunderstorm Project was performed by hand without the aid of computers by scientists at the University of Chicago and completed by May 1949. Most importantly, the theories and findings that stemmed from the Thunderstorm Project, such as the stages in the life-cycle of a thunderstorm, became the cornerstone of today's understanding of thunderstorms and related weather phenomena.

Photos and Video from the Thunderstorm Project

Inspecting SCR-720 radar housed inside the nose of a P-61C Black Widow

Setting up an anemometer at a surface observing station

Taking instrument readings from one of the many surface observing stations

Tracking a radiosonde (weather balloon) with the SCR-658 radar antenna

Installing a time-lapse camera platform for recording cloud development

Thunderstorm Project participants at the Clinton County Army Air Force Base

Pilots and radar observers from the CCAAFB being briefed before flight

An example of severe hail damage to the nose cone of one of the P-61s

A P-61C Black Widow used in the Ohio phase of the Thunderstorm Project

A P-61C Black Widow used in the Ohio phase of the Thunderstorm Project

Map showing operations area of the Thunderstorm Project's Ohio phase

P-61C squadron in flight, making traverses through thunderstorms

A network of surface observing stations monitored atmospheric conditions

Thunderstorm Project personnel operating a mobile SCR-584 radar unit

THEN AND NOW: Diagrams depicting the three stages in the life cycle of a thunderstorm. The black and white
diagrams (Byers and Braham 1949) were developed by superimposing three-dimensional aircraft data obtained from the Thunderstorm Project on a map of corresponding surface weather data. By examining numerous storms, it was found that a thunderstorm's life cycle could be divided into three stages. Comparing the black and white diagrams from 1949 to color diagrams of today, one can see that despite decades of technological advancement, the basic model of a thunderstorm's life cycle has not needed much modification since it was developed during the Thunderstorm Project.

The following photographs and publications were graciously shared with us by Kathy Drigotas, whose grandmother, Mrs. Helen Gallup Henry of Wilmington, worked in the public information office at the Clinton County Air Force Base. Mrs. Henry was responsible for the publication and preservation of these materials, and we extend a special thank you to Kathy for allowing us to share them.

CCAFB All Weather Flying Center publication (1949)

CCAFB All Weather Flying Center publication (1949)

One of five mobile SCR-584 radar units for tracking winds aloft

Husband and wife work the SCR-584

One of six SCR-658 radiosonde stations

Lightning damage to the body of a P-61C Black Widow

AN/TPS-10 radar provided vertical cross sections of storms

AN/TPS-10 indicator unit with camera

Installing V-beam radar near Jamestown

Jamestown radar console with camera

CCAFB All Weather Flying Center publication (1949)

Aerial view of CCAFB from August 1948

Long-range, high-power radar near Jamestown

Plot of radar/weather stations for the Project

This vintage Department of Defense video from the National Archives and Records
Administration thoroughly chronicles the 1947 Ohio phase of the Thunderstorm Project.
Thunderstorm Project Aircraft

Only a handful of Northrop P-61 Black Widows, the type of plane used in the Thunderstorm Project, still exist. A P-61B is displayed outside the Beijing University of Aeronautics and Astronautics in China. Another P-61B was recovered from an Indonesian jungle mountaintop in 1991 and is slowly being restored to flying condition at the Mid-Atlantic Air Museum in Reading, Pennsylvania. On display at the National Air and Space Museum's Steven F. Udvar-Hazy Center near Washington Dulles International Airport is a P-61C that participated in both the Florida and Ohio phases of the Thunderstorm Project. That plane's complete history is available here.

The fourth and only other P-61 Black Widow known to be in existence is on display not far from Wilmington at the National Museum of the U.S. Air Force near Dayton, Ohio. Although painted and marked as a P-61B that served in the Pacific in 1945, this Black Widow is actually a P-61C with an original serial number of 43-8353. The Research Division of the museum confirmed that this P-61C was indeed used in the Ohio phase of the Thunderstorm Project while it was housed at the Clinton County Air Force Base from February 1947 through December 1948. More information on this plane is available from the museum here.


Shown with its original serial number, this P-61C at the National Museum of the U.S. Air Force participated in the 1947 Ohio phase of the Thunderstorm Project.
Photo courtesy National Museum of the U.S. Air Force

On display as a P-61B in the WWII gallery of the National Museum of the U.S. Air Force, this plane is actually a P-61C used in the Thunderstorm Project.
Photo courtesy National Museum of the U.S. Air Force

Commemorating the Thunderstorm Project

To commemorate this nationally-significant thunderstorm research study, two meteorologists from NWS Wilmington, Ohio collaborated with the Clinton County Historical Society to establish an Ohio historical marker in Wilmington near the former site of the Clinton County Army Air Force Base, which served as headquarters for the Thunderstorm Project in 1947. A dedication ceremony for the marker was held on Sunday, May 5, 2013 at the Lytle Creek Greenway on Davids Drive. Around 50 individuals attended the ceremony to commemorate the lasting contributions made by those brave pilots and dedicated meteorologists 66 years earlier.

Among those participating in the ceremony was Ken Haydu, Meteorologist-in-Charge of NWS Wilmington, who spoke about the history and importance of the National Weather Service. Mike Kurz and Scott Hickman, meteorologists from NWS Wilmington, spoke about the history and lasting significance of the Thunderstorm Project. Special guest speakers included Wilmington Mayor Randy Riley and Lieutenant Colonel Robert S. Wacker, a professor of atmospheric science at Wright-Patterson AFB. Lt. Col. Wacker spoke about the history of the All Weather Flying Center at the Clinton County AFB and the significant contributions it made to aviation weather safety. The culmination of the event was the unveiling of the Thunderstorm Project historical marker, carried out by meteorologists Mike Kurz and Scott Hickman.


NWS meteorologists await the marker unveiling

Getting set up for the dedication ceremony

Welcoming guests to the dedication ceremony

Learning about the Thunderstorm Project

Wilmington Mayor Randy Riley

NWS Wilmington
MIC Ken Haydu

NWS Wilmington
Met. Mike Kurz

NWS Wilmington
Met. Scott Hickman

Lt. Col. Robert Wacker of WPAFB

Getting ready for the marker unveiling

Scott Hickman & Mike Kurz unveil the marker

Scott Hickman & Mike Kurz unveil the marker

Marker committee and dedication speakers

Front side of the marker

Back side of the marker

Lytle Creek Greenway

A view of where it all began

The Thunderstorm Project historical marker is located at the Wilmington College Lytle Creek Greenway on Davids Drive in Wilmington.

If you have any questions about the Thunderstorm Project, or if you remember the Thunderstorm Project in Ohio and would like to share a story or photos with NWS Wilmington, Ohio, please send an email to Michael Kurz.


Braham, R. R., Jr., 1997: Thunderstorms and the Thunderstorm Project. Natl. Wea. Dig., 21(3), 24-31.

Byers, H.R. and R. R. Braham, Jr., 1949: The Thunderstorm. U.S. Govt. Printing Office, Washington DC, 287 pp.

Donaldson, R. J., Jr., 1990: Foundations of severe storm detection by radar. Radar in Meteorology. D. Atlas, Ed.,
       Amer. Meteor. Soc., Boston, 115-121.

Doswell, C. A. III, 2007: Historical overview of severe convective storms research. Electronic J. Severe Storms Meteor.,
       2(1), 1-25.

------, 2001: Severe Convective Storms - An Overview. Meteorological Monographs, 28(50), 1-26.

Fujita, T. T., 1986: Mesoscale classifications: Their history and their application to forecasting. Mesoscale Meteorology
        and Forecasting
. P. S. Ray, Ed., Amer. Meteor. Soc., Boston, 18-35.

Fujita, T. T. and J. McCarthy, 1990: The application of weather radar to aviation meteorology. Radar in Meteorology.
       D. Atlas, Ed., Amer. Meteor. Soc., Boston, 657-681.

Kessler, E., 1990: Radar meteorology at the National Severe Storms Laboratory. 1964-1986. Radar In Meteorology.
       D. Atlas, Ed., Amer. Meteor. Soc., Boston, 44-53.

Wilmington News Journal, "Thunderstorm Project Ends Here Thursday," September 26, 1947.