Isolated severe thunderstorms developed in northeast Nebraska during the mid afternoon of May 4th as outflow from thunderstorms over South Dakota pushed into an area that was moderately to extremely unstable. The outflow pushed south and weakened through mid evening as scattered thunderstorms continued to develop and produce large hail.
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 OAX wrote it up.
Isolated severe thunderstorms developed in northeast Nebraska during the mid afternoon of May 4th as outflow from thunderstorms over South Dakota pushed into an area that was moderately to extremely unstable. The outflow pushed south and weakened through mid evening as scattered thunderstorms continued to develop and produce large hail. Later in the evening the storms reformed north of the old outflow aided by a slightly increasing low-level jet.
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 Omaha, NE wrote its last area forecast discussion before the first event at May 4, 12:19 PM CST, 32 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 119 PM CDT FRI MAY 4 2012 .UPDATE... UPDATE TO INCLUDE PRECIP CHANCES IN NORTH AND LOWER HIGH TEMPS. OTHERWISE UPDATES FOR CLOUD COVER AND HIGHER DEWPOINTS. && .DISCUSSION... WEAK STATIONARY BOUNDARY NOTED NEAR THE SOUTH DAKOTA BORDER WITH SOUTH FLOW AND DEWPOINTS IN THE 60S TO LOWER 70S ACROSS THE FORECAST AREA. CLUSTER OF STORMS IN SOUTH DAKOTA GENERALLY LIFTING TO THE EAST NORTHEAST...HOWEVER SOME BUILDING SOUTHWARD INTO NORTH CENTRAL NEBRASKA. EXPECT THIS TREND TO CONTINUE DURING THE AFTERNOON. STILL A RISK FOR STORMS TO BECOME STRONG TO SEVERE WITH HEATING AND INSTABILITY INCREASING DURING THE AFTERNOON. BEST DEEP LAYER SHEAR IN THE NORTH. THERE IS NOT A REAL STRONG MID OR UPPER LEVEL FORCING MECHANISM FOR OUR LOCAL AREA HOWEVER INSTABILITY IS MODERATE TO HIGH AND THERE MAY BE SOME OUTFLOW BOUNDARIES TO FOCUS ON. THE STORMS SHOULD DRIFT OR DEVELOP SOUTHEAST INTO PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA WITH BETTER THETA-E ADVECTION INSTABILITY AND ATMOSPHERE IS NOT CAPPED. LOCALLY HEAVY RAIN WILL BE POSSIBLE WITH THESE STORMS. && .AVIATION...18Z TAFS FOR KOFK...KLNK AND KOMA. STILL SOME PATCHY MVFR CIGS AND VSBYS EARLY THIS AFTERNOON THEN EXPECT SCT-BKN VFR CONDITIONS LATE THIS AFTERNOON. WILL CONTINUE TO MONITOR TSRA DEVELOPMENT WITH CLUSTER OF STORMS THIS AFTERNOON IN SOUTH DAKOTA THAT WILL CLIP NORTHEAST NEBRASKA. DID INCLUDE MENTION TSRA POTENTIAL AT KOFK AFT 00Z. MORE UNCERTAINY OVERNIGHT FOR KOMA AND KLNK...HOWEVER DID INCLUDE PRECIP MENTION AT KOMA. DUE TO VERY MOIST AIRMASS AND DECREASING WINDS...HAVE DETERIORATING CIGS AND VSBYS WITH FOG AND STRATUS AFTER 06Z TO MVFR...THEN IFR/LIFR WITH IMPROVING CONDITIONS AFTER 15Z. .PREV DISCUSSION... /ISSUED 425 AM CDT FRI MAY 4 2012/ DISCUSSION... FAIRLY ACTIVE WEATHER IS EXPECTED THROUGH THE WEEKEND...WITH MOST THUNDERSTORM CHANCES OCCURRING DURING EVENING AND OVERNIGHT HOURS. A FEW STORMS POPPED UP THURSDAY EVENING BUT REALLY COULD NOT MAINTAIN THEMSELVES WITH LIGHT FLOW ALOFT. STORMS CONTINUE TO FIRE IN NORTHERN MISSOURI...AND OCCASIONALLY IN FAR SOUTHEAST NEBRASKA...BUT THESE SHOULD NOT AFFECT OUR CWA AFTER SUNRISE. THIS SHOULD LEAVE OUR AREA UNDER FAIRLY BENIGN CONDITIONS THROUGH MUCH OF THE DAY. MID FLOW PATTERN WILL BE DOMINATED BY UPPER TROUGH DROPPING INTO THE WESTERN STATES THIS WEEKEND. SIGNIFICANT DISTURBANCE WILL EJECT FROM THE BROADER TROUGH THROUGH THE NORTHERN ROCKIES INTO NORTH DAKOTA BY SUNDAY...PUSHING A COLD FRONT SOUTHEAST THROUGH THE CENTRAL PLAINS. A COUPLE OF MORE MINOR DISTURBANCES ARE EXPECTED TO EJECT THROUGH THE CENTRAL ROCKIES INTO THE NORTHERN PLAINS IN FAST SOUTHWEST FLOW AHEAD OF THE AFOREMENTIONED FEATURES. EACH DISTURBANCE WILL TRIGGER CONVECTIVE COMPLEXES WHICH WILL AFFECT AT LEAST OUR NORTHERN CWA UNTIL THE COLD FRONT SWEEPS THROUGH SATURDAY NIGHT AND SUNDAY. THE FIRST WAVE WAS MOVING INTO SOUTH DAKOTA THIS MORNING. LOWER PRESSURES THERE WILL BRING MOIST SOUTHERLY FLOW TO EASTERN NEBRASKA DURING THE DAY. MODELS INDICATE WARM FRONT WILL SET UP NEAR THE NEBRASKA AND SOUTH DAKOTA BORDER AS SURFACE WAVE TRACKS EAST. EXPECT A COMPLEX OF STORMS TO FORM NORTH OF THIS LOW AND TRACK EAST INTO NORTHEAST NEBRASKA EARLY THIS EVENING WHERE SBCAPE VALUES WILL APPROACH 3000 J/KG. SEVERE THREAT SHOULD BE LIMITED TO LARGE HAIL GIVEN LOW SHEAR...AND LIGHT WIND REGIME SUGGESTS A FEW DOWNBURSTS COULD OCCUR. SOME MODELS SUGGEST A TURN TO THE SOUTHEAST THROUGH EASTERN NEBRASKA AND WESTERN IOWA OVERNIGHT... BUT LACK OF 850 FLOW SUGGESTS THESE CHANCES ARE SMALL. THE SECOND WAVE WILL EJECT INTO SOUTH DAKOTA SATURDAY AFTERNOON AHEAD OF COLD FRONT DROPPING SOUTHEAST. AGAIN EXPECT STORMS TO FIRE NEAR THIS WAVE...WITH DEVELOPMENT CONTINUING ALONG COLD FRONT OVERNIGHT. MOST OF OUR AREA WILL LIKELY REMAINED CAPPED THROUGH THE DAY SATURDAY...SO HAVE GONE DRY THEN. INCREASING LOW LEVEL JET WILL AID TO MAINTAIN CONVECTION SATURDAY NIGHT INTO SUNDAY MORNING. STORMS SHOULD BE INCREASINGLY ELEVATED OVERNIGHT...WITH MUCAPES CLOSE TO 4000 J/KG KEEPING A LARGE HAIL THREAT GOING ALL NIGHT. LINGERING SHOWERS OR STORMS ARE A GOOD BET IN OUR SOUTHEAST SUNDAY MORNING...BUT COOLER AND DRIER AIR SPILLING IN BEHIND FRONT SHOULD LIMIT EXTENT. HIGHS TODAY AND SATURDAY WILL AVERAGE THE MID AND UPPER 80S WITH DEW POINTS WELL INTO THE 60S. 70S SHOULD BE COMMON ON SUNDAY BEHIND COLD FRONT...WITH 60S AND LOWER 70S COMMON MONDAY THROUGH WEDNESDAY AS COOL AIR IS REINFORCED WITH ANOTHER COLD FRONT MONDAY NIGHT. RETURN FLOW LOOKS TO SET UP THURSDAY...PUSHING HIGHS BACK INTO THE 70S TO NEAR 80. OTHERWISE A BASICALLY DRY PERIOD MONDAY THROUGH THURSDAY. DERGAN && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && ZAPOTOCNY
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1206 PM CDT FRI MAY 4 2012 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-050715- MONONA-HARRISON-SHELBY-POTTAWATTAMIE-MILLS-MONTGOMERY-FREMONT- PAGE-KNOX-CEDAR-THURSTON-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON- STANTON-CUMING-BURT-PLATTE-COLFAX-DODGE-WASHINGTON-BUTLER- SAUNDERS-DOUGLAS-SARPY-SEWARD-LANCASTER-CASS-OTOE-SALINE- JEFFERSON-GAGE-JOHNSON-NEMAHA-PAWNEE-RICHARDSON- 1206 PM CDT FRI MAY 4 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA...NORTHEAST NEBRASKA AND SOUTHEAST NEBRASKA. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A SLIGHT RISK FOR STRONG TO SEVERE STORMS ACROSS ALL OF THE OUTLOOK AREA BEGINNING LATE THIS AFTERNOON IN NORTHEAST NEBRASKA...THEN THROUGH THE EVENING ACROSS THE REST OF EASTERN NEBRASKA AND SOUTHWEST IOWA. LARGE HAIL AND LOCALLY HEAVY RAIN WILL BE THE PRIMARY CONCERNS WITH DAMAGAING WINDS A SECONDARY CONCERN. AN ISOLATED TORNADO CANNOT BE RULED OUT FOR NORTHEAST NEBRASKA CLOSE TO THE SOUTH DAKOTA BORDER OR INTO WEST CENTRAL IOWA. DEEP MOISTURE IS IN PLACE AND AFTERNOON HEATING WILL PRODUCE A VERY UNSTABLE ATMOSPHERE ACROSS THE OUTLOOK AREA. A STATIONARY FRONT IS DRAPED ALONG THE SOUTH DAKOTA BORDER. IN ADDITION THERE ARE ONGOING THUNDERSTORMS IN SOUTH DAKOTA ASSOCIATED WITH A MID LEVEL WEATHER DISTURBANCE. THIS MID LEVEL WAVE WILL CONTINUE EAST AND ALONG WITH THE FRONTAL SYSTEM AND WITH THE HEATING WILL PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON. ENHANCED SHEAR NEAR THE FRONT IN NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA MEANS THAT STORMS THAT DEVELOP WILL HAVE A SMALL CHANCE TO PRODUCE A TORNADO. THIS ACTIVITY IS EXPECTED TO DRIFT OR DEVELOP SOUTHEAST ACROSS THE REST OF EASTERN NEBRASKA AND SOUTHWEST IOWA DURING THE EVENING...WITH LARGE HAIL AND LOCALLY HEAVY RAIN POSSIBLE. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SEVERE THUNDERSTORMS ARE AGAIN POSSIBLE SATURDAY EVENING AND SATURDAY NIGHT. A VERY UNSTABLE ATMOSPHERE WILL BE IN PLACE SATURDAY AFTERNOON BUT WARM MID LEVEL TEMPERATURES SHOULD CAP ANY DEVELOPMENT UNTIL A COLD FRONT APPROACHES FROM THE NORTHWEST. THAT FRONT SHOULD BE MOVING INTO NORTHEAST NEBRASKA DURING THE EVENING...THEN SWEEP THROUGH THE REST OF EASTERN NEBRASKA AND SOUTHWEST IOWA OVERNIGHT. LARGE HAIL AND LOCALLY HEAVY RAIN WILL BE POSSIBLE WITH ANY THUNDERSTORMS...EVEN THROUGH THE OVERNIGHT HOURS...AS INSTABILITY AND MOISTURE WILL REMAIN HIGH. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING IN NORTHEAST NEBRASKA...AND THIS EVENING ACROSS THE REST OF THE AREA. ZAPOTOCNY
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 834 AM CDT FRI MAY 4 2012 NEZ051-053-065>068-078-089-041515- SAUNDERS-SARPY-SEWARD-LANCASTER-CASS-OTOE-SALINE-GAGE- INCLUDING THE CITIES OF...WAHOO...ASHLAND...YUTAN...BELLEVUE... PAPILLION...LA VISTA...SEWARD...MILFORD...LINCOLN...PLATTSMOUTH... NEBRASKA CITY...CRETE...WILBER...BEATRICE 834 AM CDT FRI MAY 4 2012 ...LOCALLY DENSE FOG AROUND LINCOLN AND SEWARD... LOCALLY DENSE FOG WITH VISIBILITIES LESS A QUARTER OF A MILE CAN BE EXPECTED FOR PARTS OF EAST CENTRAL NEBRASKA FOR THE NEXT HOUR. USE CAUTION IF TRAVELING ACROSS PARTS OF LANCASTER...SEWARD... GAGE...AND SALINE COUNTIES. SLOW DOWN AND BE PREPARED FOR SUDDEN CHANGES IN VISIBILITIES. ZAPOTOCNY
The Sioux Falls radar (KFSD), 153 km away, was scanning. The volume nearest the first event began at 18:53 UTC.
10 hail. Local standard time, as filed.
Hail up to golf ball-size fell for around 20 to 30 minutes northwest of Verdigre.
Hail around quarter-size fell for about a half hour northeast of Verdigre from a slow moving thunderstorm.
Hail up to half dollar-size fell for about 30 minutes just north of Rogers from a slow moving thunderstorm.
A slow moving thunderstorm dropped hail up to half dollar-size a few miles north of Fremont for at least 10 minutes.
Hail up to ping pong ball-size fell for at least several minutes on the north side of Fremont.
Hail up to quarter-size covered the ground north of Wayne.
Hail up to quarter-size fell for about 15 minutes, although most of the hail was 1/2 or smaller.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2012Every state in 2012This day in weather historyWarnings in Nebraska, 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: 368986, 368988, 368991, 368990, 368992, 368993, 368994, 368996, 368997, 369039.