While much of eastern Nebraska was lashed with multiple severe storms on this Thursday afternoon and evening, South Central Nebraska caught only a glancing blow across a handful of far eastern counties as a southward-moving supercell cluster tracked through areas mainly east of a line from Fullerton to York. This supercell initiated in Holt County around 4 PM CDT, and gradually pushed southeast,…
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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 GID wrote it up.
While much of eastern Nebraska was lashed with multiple severe storms on this Thursday afternoon and evening, South Central Nebraska caught only a glancing blow across a handful of far eastern counties as a southward-moving supercell cluster tracked through areas mainly east of a line from Fullerton to York. This supercell initiated in Holt County around 4 PM CDT, and gradually pushed southeast, first entering eastern Nance County around 8 PM, and slipping southeast out of Polk and York Counties around 930 PM. Although this storm appeared to have tornadic potential as it moved into the area, it quickly become outflow-dominant, and resulted in only limited severe weather reports including quarter size hail between Genoa and Fullerton and 60 MPH winds near Shelby.
South Central Nebraska was likely spared a more significant coverage of severe storms by a stout capping inversion aloft, evidenced by 700 millibar temperatures of at least 14-16 degrees Celsius. Just off to the east though, slightly cooler air aloft and pronounced low-mid level warm air advection focused a much greater coverage of severe storms. Despite the limited scope of storms in the local area, the mesoscale environment was quite supportive of severe weather given a very unstable airmass featuring at least 4000 J/kg mixed-layer CAPE, seasonably strong deep-layer vertical wind shear around 50 knots, and the presence of a northwest-southeast oriented surface warm front. In the mid and upper levels, pronounced west-northwest flow was noted, along the northeast periphery of an expansive subtropical ridge centered over the southwest United States.
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 Hastings, NE wrote its last area forecast discussion before the first event at Aug 18, 2:07 PM CST, 5 hours 23 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 307 PM CDT THU AUG 18 2011 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT. CONVECTION WAS ALREADY ONGOING THIS MORNING IN SOUTHERN SOUTH DAKOTA AND STORMS HAVE NOW REACH NORTHEAST NEBRASKA EARLY THIS AFTN. MESO ANALYSIS PAGE INDICATES MIXED LAYER CAPES AROUND 3000 J/KG IN EASTERN NEBRASKA WITH EFFECTIVE SHEAR NEAR 50KTS. STORMS LOOK TO MAKE A RIGHT TURN THIS AFTN AND EVENING...AND ALTHOUGH BRUNT OF ACTIVITY LOOKS TO REMAIN TO OUR NORTH AND EAST GIVEN CURRENT TRENDS...WILL MAINTAIN SOME BUFFER POPS JUST IN CASE. IF CONVECTION DOES REACH OUR AREA...SEVERE WEATHER IS POSSIBLE GIVEN THE HIGH INSTABILITY AND SHEAR PARAMETERS. FARTHER WEST...SURFACE TROUGH OR DRY LINE HAD EDGED EAST OF THE PANHANDLE INTO WESTERN NEBRASKA...AND CANNOT COMPLETELY RULE OUT CONVECTION HERE BUT CAP IS STRONGER IN THIS AREA AND POTENTIAL LOOKS LIMITED AT BEST. THE EASTERN CONVECTION IS EXPECTED TO CONTINUE TO PROPAGATE EAST/SOUTHEAST WITH TIME TONIGHT WITH PCPN CHCS DECREASING WITH TIME. STRATUS LOOKS TO REDEVELOP ACROSS OUR NORTHERN AND EASTERN COUNTIES AND SREF INDICATES 30 TO 40 PCPN CHCS OF VSBYS BELOW A MILE NORTH OF INTERSTATE 80 AND THIS IS SUPPORTED BY MOS GUIDANCE. WILL GO WITH AREAS OF FOG IN OUR NORTH/EAST WITH PATCHY FOG IN THE SOUTHWEST...WITH VSBYS IMPROVING BY MID MORNING. HEADING INTO FRIDAY...SHORTWAVE ENERGY TRANSLATES ACROSS THE SOUTHERN CANADIAN PROVINCES/NORTHERN PLAINS REGION WITH THE SURFACE COOL FRONT SAGGING SOUTH ACROSS THE CENTRAL PLAINS...WHILE WARM FRONT ESTABLISHES ACROSS SOUTHERN KANSAS. EASTERLY UPSLOPE FLOW IS EXPECTED TO GENERATE CONVECTION ALONG THE HIGH PLAINS REGION DURING THE AFTERNOON WITH STORMS ADVANCING EASTERLY IN THE MEAN FLOW DURING THE AFTN/NIGHT. THE LLVL JET STRENGTHENS NEAR 40KTS OVER THE BAROCLINIC ZONE AND CONVECTION IS EXPECTED TO PERSIST INTO THE NOCTURNAL HOURS. STORMS SHLD REACH OUR SW CWA DURING THE EVENING AND STRONG TO SEVERE STORMS ARE POSSIBLE ESPECIALLY FOR THE FIRST PART OF THE EVENT. DAMAGING WINDS/LARGE HAIL ARE POSSIBLE AND IT LOOKS AS IF THE EVENT WILL TRANSITION TO A HEAVY RAINER IN THE PRESENCE OF HIGH PRECIPITABLE WATER VALUES NEAR OR IN EXCESS OF TWO INCHES IN OUR SOUTHERN CWA AND THIS AREA HAS BEEN OUTLINE IN THE HPC HEAVY RAINFALL OUTLOOK. .LONG TERM...SATURDAY THROUGH THURSDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS SATURDAY THROUGH SUNDAY NIGHT. AN UPPER WAVE CONTINUES TO MOVE THROUGH THE FORECAST AREA ON SATURDAY BUT IS MAINLY THROUGH THE AREA BY AFTERNOON. MODELS HAVE SOME MINOR DIFFERENCES IN WHERE THE SURFACE BOUNDARY IS BUT THEY ALL HAVE IT SOUTH OF THE FORECAST AREA. EXPECT THE BEST PRECIPITATION CHANCES TO BE NORTH OF THE BOUNDARY AND LIKELY NEAR THE KANSAS/NEBRASKA STATE LINE. AS THE UPPER WAVE MOVES OUT OF THE AREA THE PRECIPITATION CHANCES WILL PROBABLY DECREASE. TEMPERATURES WILL BE ON THE COOL SIDE WITH THE CLOUDS AND RAIN AROUND. SATURDAY NIGHT INTO SUNDAY NORTHWEST FLOW CONTINUES ACROSS THE AREA. THERE ARE SOME WEAK WAVES THAT MOVE THROUGH THE AREA BUT CHANCES FOR THUNDERSTORMS SHOULD BE SMALL. TEMPERATURES WILL WARM BACK UP AGAIN AS THE UPPER LEVEL RIDGE BUILDS TO THE WEST OF THE FORECAST AREA. THE RIDGE CONTINUES IN THE WESTERN UNITED STATES GAINING AMPLITUDE DURING THE WEEK. THERE IS A WEAK UPPER WAVE THAT TRIES TO MOVE THROUGH THE REGION ON MONDAY OR MONDAY NIGHT. MODELS KEEP PRECIPITATION MAINLY OUT OF THE FORECAST AREA SO WILL KEEP THE FORECAST DRY FOR NOW...BUT WILL HAVE TO WATCH TO SEE WHERE THIS WAVE GOES AS IT MOVES THROUGH THE AREA. WITH THE RIDGE BUILDING THE TEMPERATURES WILL LIKELY WARM UP DURING THE WEEK SO HAVE TRENDED UP A BIT. && .AVIATION...18Z TAF. CLEAR SKIES AT THE ONSET OF THE TAF PERIOD WILL GIVE WAY TO SCATTERED CU DURING THE AFTN AND EVENING. TSTMS HAVE ALREADY DEVELOPED IN SOUTHEAST SOUTH DAKOTA/NORTHEAST NEBRASKA AND CONVECTION IS EXPECTED TO MOVE EAST/SOUTHEAST WITH TIME. KGRI STILL LOOKS TO BE ON THE WESTERN PERIPHERY OF CONVECTION INTO TONIGHT AND WILL NOT INCLUDE IN TAF ATTM. MODELS CONTINUE TO INDICATE STRATUS WILL REDEVELOP TONIGHT WITH POTENTIAL IFR OR LIFR CIGS AND VSBYS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE HASTINGS NE 731 PM CDT THU AUG 18 2011 KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087- 191200- PHILLIPS-SMITH-JEWELL-ROOKS-OSBORNE-MITCHELL-VALLEY-GREELEY-NANCE- SHERMAN-HOWARD-MERRICK-POLK-DAWSON-BUFFALO-HALL-HAMILTON-YORK- GOSPER-PHELPS-KEARNEY-ADAMS-CLAY-FILLMORE-FURNAS-HARLAN-FRANKLIN- WEBSTER-NUCKOLLS-THAYER- 731 PM CDT THU AUG 18 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL NEBRASKA AND PORTIONS OF NORTH CENTRAL KANSAS. .DAY ONE...TONIGHT. SEVERE THUNDERSTORMS ARE POSSIBLE FOR LOCATIONS EAST OF A LINE FROM ORD TO HEBRON NEBRASKA. IF THUNDERSTORMS REACH THIS AREA...THE MAIN HAZARDS FROM THE STORMS WILL BE TORNADOES...LARGE HAIL THE SIZE OF GOLF BALLS...AND DAMAGING WINDS IN EXCESS OF 70 MPH. THE SEVERE WEATHER THREAT WILL DIMINISH AFTER DARK. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY. THUNDERSTORMS ARE FORECAST FROM FRIDAY AFTERNOON THROUGH SUNDAY NIGHT. SEVERE THUNDERSTORMS ARE POSSIBLE FRIDAY AND FRIDAY NIGHT PRIMARILY SOUTHWEST OF A LINE FROM LEXINGTON NEBRASKA TO BELOIT KANSAS...WITH HAIL TO THE SIZE OF QUARTERS AND THUNDERSTORM WIND GUSTS TO 60 MPH BEING THE PRIMARY SEVERE WEATHER HAZARDS. HEAVY RAINFALL AMOUNTS IN EXCESS OF ONE AND TWO INCHES MAY OCCUR FRIDAY NIGHT...MAINLY ACROSS NORTH CENTRAL KANSAS AND LOCATIONS SOUTH OF INTERSTATE 80 IN NEBRASKA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING FOR LOCATIONS EAST OF A LINE FROM ORD TO HEBRON NEBRASKA. && MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE: HTTP://WWW.WEATHER.GOV/HASTINGS (ALL LOWERCASE) HEINLEIN
The Omaha radar (KOAX), 123 km away, was scanning. The volume nearest the first event began at 01:30 UTC.
1 hail, 1 thunderstorm wind. Local standard time, as filed.
Quarter size hail was accompanied by strong winds on Highway 22 between Fullerton and Genoa.
Wind gusts were estimated at 60 MPH, knocking down tree limbs up to 5 inches in diameter.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2011Every state in 2011This day in weather historyWarnings in Nebraska, August 2011
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: 335458, 335459.