An upper level disturbance developed isolated severe storms which produced marginal severe hail and heavy rainfall that lead to localized flash flooding.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SGF wrote it up.
An upper level disturbance developed isolated severe storms which produced marginal severe hail and heavy rainfall that lead to localized flash flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Springfield, MO wrote its last area forecast discussion before the first event at May 1, 12:02 AM CST, 17 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
102 AM CDT TUE MAY 1 2012
...MESOSCALE CONVECTIVE DISCUSSION...
.UPDATE...
/ISSUED 102 AM CDT TUE MAY 1 2012/
MESOSCALE CONVECTIVE COMPLEX CONTINUES TO EVOLVE THIS MORNING.
PRIMARY CONCERN REMAINS FLOODING...BUT STILL CONCERNED ABOUT THE
RISK FOR SEVERE ACROSS FAR SOUTHWEST PORTIONS OF THE OUTLOOK AREA.
CONCERNING THE SEVERE RISK...STORMS ACROSS NORTHERN OK HAVE
TRANSITIONED TO A DISTINCTLY LINEAR MODE. THIS ACTIVITY IS NOW
RACING TO THE EAST AND SHOULD REACH WESTERN PORTIONS OF NEWTON AND
MCDONALD COUNTIES AT OR JUST BEFORE 230 AM (BASED OFF OF CURRENT
RADAR TRENDS). SOUTHERN PORTIONS OF CHEROKEE COUNTY KS AND JASPER
COUNTY MO COULD BE AFFECTED BY THIS LINE SEGMENT AS WELL AND WILL
NEED TO WATCH CLOSELY. THIS LINE SEGMENT HAS A HISTORY OF
PRODUCING SEVERE WEATHER. IN ADDITION...SEVERAL MESOVORTS HAVE
BEEN OBSERVED ALONG THE LEADING EDGE OF THIS LINE. STRONG LOW
LEVEL JET AND SUFFICIENT INSTABILITY WILL HELP MAINTAIN THIS LINE
OF CONVECTION AS IT ENTERS THE OUTLOOK AREA. 0-3KM SHEAR VECTORS
ARE ORIENTED AT A BIT OF ANGLE TO THIS LINE...THOUGH NOT
PERPENDICULAR. AS A RESULT...WILL STILL HAVE THE POTENTIAL FOR
MESOVORT PRODUCTION ON THE LEADING EDGE OF THE LINE THOUGH THEY
MAY BE RATHER SHORT LIVED. PRIMARY CONCERN WITH THIS LINE WILL BE
WIND GUSTS IN EXCESS OF 60 MPH. HAIL REMAINS A SECONDARY CONCERN.
IF A MESOVORT CAN BECOME STRONG ENOUGH...THERE REMAINS A LIMITED
RISK FOR A BRIEF TORNADO.
CONCERNING THE FLASH FLOOD RISK...HEAVY RAIN CONTINUES IN AREAS
THAT JUST PLAIN DON/T NEED IT. RAIN WILL CONTINUE FOR THE NEXT
SEVERAL HOURS AND EXPAND EASTWARD AS THE LOW LEVEL JET CONTINUES
TO VEER AND INTERACTS WITH A WEAK LOW LEVEL BOUNDARY OVERHEAD.
TRADITIONAL STORM MOTION VECTORS WEAKEN A BIT...WHICH ONCE AGAIN
SUPPORTS TRAINING OF CELLS. ENTIRE COMPLEX SHOULD GRADUALLY SHIFT
WEST TO EAST...THEREFORE THE BIGGEST RISK FOR FLASH FLOODING WILL
BE ACROSS EXTREME SOUTHEAST KANSAS AND PORTIONS OF WESTERN AND
WEST CENTRAL MISSOURI.
GAGAN
&&
.DISCUSSION...
MAIN FOCUS IN THIS FORECAST PACKAGE WILL BE CENTERED ON CONVECTION
POTENTIAL THIS EVENING INTO TUESDAY.
CURRENTLY...AN UPPER LEVEL DISTURBANCE THAT BROUGHT THE RAINFALL
TO THE AREA LAST NIGHT HAS SHIFTED EAST OF THE AREA THIS
AFTERNOON ALONG WITH ALL ASSOCIATED RAINFALL. SKIES ARE SCATTERED
OUT FROM WEST TO EAST ACROSS THE PLAINS INTO THE MISSOURI OZARKS.
A MOIST AIRMASS REMAINS ACROSS THE REGION ESPECIALLY ACROSS OKLAHOMA
AND TEXAS WHERE DEWPOINTS ARE IN THE MIDDLE TO UPPER 70S AS OF THE
MID AFTERNOON. INSTABILITY IS INCREASING WITH THE HEATING OF THE
DAY AND WITH THE MOIST AIRMASS. MUCAPE VALUES OF OVER 1000 J/KG
ARE BEGINNING TO SPREAD INTO THE WESTERN PORTIONS OF THE FORECAST
AREA WITH MUCH HIGHER VALUES ACROSS WESTERN TEXAS AND OKLAHOMA
NUDGING INTO SOUTHERN KANSAS.
ANOTHER UPPER LEVEL SHORTWAVE TROUGH IS PUSHING EAST INTO THE PLAINS
AND IS EXPECTED TO INITIATE THUNDERSTORMS ALONG A DRY LINE FROM
WESTERN TEXAS THROUGH OKLAHOMA INTO KANSAS LATE THIS AFTERNOON
INTO EARLY THIS EVENING. THESE STORMS WILL THEN TRACK TO THE EAST AND
SHOULD DEVELOP INTO A COMPLEX OF THUNDERSTORMS LATE THIS EVENING.
INSTABILITY WILL BE GREAT ENOUGH TO SUPPORT A FORWARD PROPAGATING
COMPLEX OF STORMS ACROSS EASTERN OKLAHOMA/KANSAS LATER THIS
EVENING. THIS SHOULD RESULT IN THESE STORMS RACING OFF TO THE EAST
SOUTHEAST. IF THIS COMPLEX CAN DEVELOP FAR ENOUGH TO THE NORTH IT
MAY BE ABLE TO CLIP OR MOVE INTO EXTREME SOUTHEASTERN KANSAS AND
FAR WESTERN MISSOURI...WITH A DAMAGING WIND RISK AND MARGINALLY
SEVERE HAIL RISK POSSIBLE. THE COMPLEX SHOULD THEN DIVE OFF TO
THE SOUTH AS IT MOVES FARTHER INTO THE OZARKS AS INSTABILITY WILL
BE SLIGHTLY WEAKER.
ADDITIONAL SCATTERED TO ISOLATED THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE ENTIRE AREA OVERNIGHT AS THE UPPER LEVEL SHORTWAVE...A
STRONG LOW LEVEL JET...AND STALLED SURFACE BOUNDARY REMAINS OVER
AREA OVERNIGHT. THESE STORMS WILL BE ELEVATED IN NATURE AND A FEW
OF THE STRONGER ONES COULD PRODUCE SOME SMALL HAIL. AT THIS TIME
DO NOT EXPECT THE TRAINING SETUP THAT OCCURRED LAST NIGHT...AS THE
FORCING ALONG THE FRONT IS MUCH WEAKER TONIGHT. HOWEVER...WITH THE
AMOUNT OF RAINFALL THAT OCCURRED LAST NIGHT...THOSE AREAS WILL BE
MORE SUSCEPTIBLE TO ADDITIONAL FLOODING IF STORMS TRACK OVER THEM.
STORMS MAY LINGER INTO TUESDAY MORNING BUT SHOULD QUICKLY PUSH
EAST DURING THE MORNING HOURS. WILL HAVE TO WATCH WHERE THE
SURFACE BOUNDARY SETS UP AND HOW MUCH INSTABILITY CAN DEVELOP
TUESDAY AFTERNOON FOR REDEVELOPMENT OF STORMS. IF ENOUGH
INSTABILITY CAN DEVELOP THERE COULD BE A MARGINALLY SEVERE HAIL
RISK TUESDAY AFTERNOON/EVENING.
THE AREA WILL THEN BE UNDER RIDGE WEDNESDAY INTO THE WEEKEND. A
FEW DISTURBANCES MAY TRY TO DIVE SOUTH INTO CENTRAL MISSOURI LATE
THIS WEEK INTO THIS WEEKEND...BUT THE BULK OF THE ACTIVITY IS
EXPECTED TO REMAIN NORTH AT THIS TIME. HIGHS IN THE 80S AND LOWS
IN THE 50S AND 60S ARE EXPECTED THROUGHOUT THE FORECAST PERIOD.
WISE
&&
.AVIATION...
FOR THE 01/06Z KSGF/KJLN/KBBG TAFS...COMPLEX OF THUNDERSTORMS
CONTINUES TO SLOWLY SHIFT EAST INTO THE AREA. THIS ACTIVITY WILL
REMAIN THE PRIMARY CONCERN IN THE SHORT TERM. HAVE REFINED TIMING
BASED ON LATEST RADAR TRENDS AND WILL CONTINUE TO TWEAK AS
NECESSARY. GUSTY WINDS...IFR VIS AND MVFR CIG ARE EXPECTED WITH
THESE THUNDERSTORMS. SHRA/TSRA WILL PERSIST THROUGH MUCH OF THE
OVERNIGHT HOURS. IN ADDITION...LOW LEVEL WIND FIELDS MARGINALLY
SUPPORT A MENTION OF DIRECTIONAL AND SPREED SHEAR AFTER 01/06Z.
SHRA/TSRA SHOULD EXIT BY THE MID MORNING HOURS WITH VFR EXPECTED
FROM THEN ONWARD. AS CLEARING OCCURS BY LATE MORNING/EARLY
AFTERNOON...SOUTHERLY WINDS WILL BECOME QUITE GUSTY WITH GUSTS TO
NEAR 30 KT POSSIBLE AT TIMES AT JLN/SGF.
GAGAN
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR MOZ055>058-
066>070-077>081-088>090-093-094-101-102.
KS...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR KSZ073-097-101.
&&HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE SPRINGFIELD MO 115 AM CDT TUE MAY 1 2012 KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-020615- BOURBON-CRAWFORD-CHEROKEE-BENTON-MORGAN-MILLER-MARIES-VERNON- ST. CLAIR-HICKORY-CAMDEN-PULASKI-PHELPS-BARTON-CEDAR-POLK-DALLAS- LACLEDE-TEXAS-DENT-JASPER-DADE-GREENE-WEBSTER-WRIGHT-NEWTON- LAWRENCE-CHRISTIAN-DOUGLAS-HOWELL-SHANNON-MCDONALD-BARRY-STONE- TANEY-OZARK-OREGON- 115 AM CDT TUE MAY 1 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE MISSOURI OZARKS AND EXTREME SOUTHEAST KANSAS. .DAY ONE...TONIGHT. WEATHER HAZARDS EXPECTED... LIMITED TORNADO RISK. LIMITED HAIL RISK. ELEVATED THUNDERSTORM WIND DAMAGE RISK. SIGNIFICANT FLOODING RISK. SIGNIFICANT LIGHTNING RISK. DISCUSSION... A LARGE COMPLEX OF THUNDERSTORMS CONTINUES TO MOVE INTO THE OUTLOOK AREA FROM THE WEST. THE RISK OF SEVERE WEATHER IS ELEVATED FOR AREAS SOUTH OF THE HIGHWAY 60 CORRIDOR AND WEST OF THE HIGHWAY 65 CORRIDOR. A LINE SEGMENT MOVING ACROSS NORTHEASTERN OKLAHOMA WILL MOVE INTO FAR SOUTHWEST MISSOURI AFTER 2 AM. DAMAGING WIND GUSTS IN EXCESS OF 60 MPH AND HAIL TO THE SIZE OF QUARTERS WILL BE POSSIBLE. A BRIEF SPIN UP TORNADO CANNOT BE RULED OUT WITH THIS LINE. THIS LINE OF STORMS SHOULD WEAKEN AS IT APPROACHES THE HIGHWAY 65 CORRIDOR DUE TO DECREASING LEVELS OF INSTABILITY. ELSEWHERE...A LARGE AREA OF MODERATE TO OCCASIONALLY HEAVY RAINFALL WILL EXPAND FROM EXTREME SOUTHEASTERN KANSAS INTO CENTRAL MISSOURI. A FEW STRONG TO MARGINALLY SEVERE STORMS CANNOT BE RULED OUT...WITH HAIL TO THE SIZE OF QUARTERS POSSIBLE WITH THE STRONGEST CELLS. THE MAIN ISSUE WILL BE HEAVY RAINFALL AND THE RISK FOR FLASH FLOODING. THE RISK REMAINS SIGNIFICANT FROM EXTREME SOUTHEAST KANSAS INTO WEST CENTRAL MISSOURI WHERE THE GROUND REMAINS SATURATED FROM PREVIOUS HEAVY RAINFALL. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. SCATTERED TO ISOLATED THUNDERSTORMS WILL CONTINUE INTO TUESDAY WITH MARGINALLY SEVERE STORMS AND LOCALLY HEAVY RAINFALL POSSIBLE. WIND GUSTS OVER 30 MPH WILL BE POSSIBLE ACROSS EXTREME SOUTHEASTERN KANSAS AND PORTIONS OF SOUTHWESTERN MISSOURI ALONG AND WEST OF THE HIGHWAY 65 CORRIDOR ON BOTH TUESDAY AND WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED IN THE NEXT THREE HOURS FOR AREAS ALONG AND SOUTH OF HIGHWAY 60 AND WEST OF HIGHWAY 65. && THIS PRODUCT IS NOW AVAILABLE IN GRAPHICAL FORMAT...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND CLIMATE INFORMATION...AT HTTP://WWW.CRH.NOAA.GOV/SGF(ALL LOWERCASE) GAGAN
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1226 AM CDT TUE MAY 01 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1220 AM HAIL MELROSE 37.03N 94.96W
05/01/2012 E1.00 INCH CHEROKEE KS EMERGENCY MNGR
&&
BOXELLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1235 AM CDT TUE MAY 01 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1233 AM FLASH FLOOD LAMAR 37.49N 94.28W
05/01/2012 BARTON MO LAW ENFORCEMENT
WIDESPREAD FLOODING OF SECONDARY ROADS BEING REPORTED IN
BARTON COUNTY. MANY ROADS ARE BEING CLOSED.
&&
BOXELLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1236 AM CDT TUE MAY 01 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1233 AM HAIL 3 W COLUMBUS 37.17N 94.90W
05/01/2012 E1.00 INCH CHEROKEE KS EMERGENCY MNGR
&&
BOXELLThe Springfield radar (KSGF), 128 km away, was scanning. The volume nearest the first event began at 06:21 UTC.
2 hail, 1 flash flood, 1 thunderstorm wind. Local standard time, as filed.
Several streets were closed due to flooding in Columbus.
A roof was blown off a mobile home.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Kansas in 2012Every state in 2012This day in weather historyWarnings in Kansas, May 2012
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 369715, 369716, 369717, 369718.