Moderately unstable conditions developed over eastern Nebraska during the afternoon and evening of May 18th as temperatures warmed into the 80s and dew point temperatures reached the mid to upper 60s. As an upper level trough approached from the Rockies, thunderstorms developed in western Nebraska and western Kansas.
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.
Moderately unstable conditions developed over eastern Nebraska during the afternoon and evening of May 18th as temperatures warmed into the 80s and dew point temperatures reached the mid to upper 60s. As an upper level trough approached from the Rockies, thunderstorms developed in western Nebraska and western Kansas. These storms moved east across eastern Nebraska and western Iowa and produced isolated areas of wind damage.
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 18, 5:38 PM CST, 3 hours 53 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 638 PM CDT SAT MAY 18 2013 .AVIATION... 00Z TAFS FOR KOFK...KOMA AND KLNK THUNDERSTORM TIMING/COVERAGE TONIGHT AND AGAIN SUNDAY AFTERNOON PLUS LOW CLOUD DEVELOPMENT LATE TONIGHT ARE AMONG AVIATION ISSUES. TAF FORECAST REFLECTED BEST ESTIMATES OF TSTM ACTIVITY TONIGHT WITH TEMPO GROUPS AND PROB30S WERE THEN CARRIED AT SITES SUNDAY AFTERNOON. HOWEVER...CONVECTION COULD LINGER ACROSS THE AREA SUNDAY MORNING AND TRENDS WILL NEED MONITORING. WOULD SUSPECT WITH UPPER 60S SFC DWPTS FM SERN NEBR INTO KS THAT LOW CLOUD DEVELOPMENT QUITE POSSIBLE BY SUNDAY MORNING OVER MUCH OF THE REGION AND THIS WAS CARRIED IN 00Z FORECASTS. MIXING DUE TO CONVECTION COULD ALTER THE TIMING/COVERAGE...HOWEVER. CHERMOK && .PREV DISCUSSION... /ISSUED 338 PM CDT SAT MAY 18 2013/ DISCUSSION... SEVERE THUNDERSTORM CHANCES THROUGH SUNDAY EVENING ARE THE PRIMARY FORECAST CONCERNS. WESTERN UPPER WAVE WAS DRIFTING TOWARD THE ROCKIES THIS AFTERNOON. STRONG SOUTHWEST FLOW AHEAD OF THIS SYSTEM WAS OVERSPREADING HIGH PLAINS REGION...INDUCING CYCLOGENESIS IN SOUTHWEST NEBRASKA AND WESTERN KANSAS WHERE SKIES HAD CLEARED. STRONG INSTABILITY HAS DEVELOPED AHEAD OF THIS LOW WITH MOST UNSTABLE CAPES RUNNING OVER 4000 J/KG FROM SOUTHWEST NEBRASKA THROUGH CENTRAL KANSAS...JUST AHEAD OF DRY LINE. SPC HAS JUST ISSUED A TORNADO WATCH FOR THESE AREAS COVERING WESTERN NEBRASKA THROUGH MUCH OF WESTERN INTO CENTRAL KANSAS. FOR OUR AREA...BROKEN MID LEVEL CLOUD COVER HAS DAMPENED INSOLATION THIS AFTERNOON...HOLDING TEMPERATURES IN THE LOWER 80S. OVERNIGHT EXPECT CONVECTION FROM WESTERN AREAS TO ROLL EAST AND NORTHEAST ACROSS CENTRAL INTO EASTERN NEBRASKA...AND EVENTUALLY SOUTHWEST IOWA...AS LOW LEVEL JET PUSHING 40KT CONTINUES TO PUMP HIGHER THETA-E AIR INTO OUR REGION. HOWEVER...EXACT EVOLUTION OF WESTERN CONVECTION WILL HAVE TO BE WATCHED AS SEVERAL SHORT RANGE MODELS SUGGEST A SPLIT IN ACTIVITY WITH ONE AREA LIFTING INTO NORTHEAST NEBRASKA AND ANOTHER SETTING UP OVER NORTHERN KANSAS. BUT OTHERS SUGGEST A MCS WILL ROLL RIGHT INTO EASTERN NEBRASKA LATE THIS EVENING. AT ANY RATE...PRECIP CHANCES WILL BE ON THE INCREASE FROM LATE EVENING ON...WITH THE THREAT OF SEVERE WEATHER STILL THERE. MODELS SUGGEST ELEVATED CAPE VALUES WILL STILL BE TOPPING 2000 J/KG AS STORMS MOVE IN...SO HAIL IS CERTAINLY A THREAT. IF STORMS DO NOT BECOME ELEVATED WITH TIME AS EXPECTED...THEN WINDS COULD ALSO BE A PROBLEM...ESPECIALLY DURING THE LATE EVENING. MOST LIKELY AREAS FOR SEVERE WOULD BE NEAR THE KANSAS BORDER WHERE A PLURALITY OF SHORT RANGE ENSEMBLE MEMBERS PAINT A SWATH OF STRONG STORMS...OR OVER NORTHEAST NEBRASKA WHERE SEVERAL MODELS POINT TO MCS TRACK. ACTIVITY SHOULD CONTINUE WELL PAST MIDNIGHT BEFORE MOVING EAST OF OUR AREA SUNDAY MORNING. LOOKS LIKE WE COULD HAVE A SUBSTANTIAL LULL IN ACTIVITY DURING THE MORNING BEFORE ROUND TWO BEGINS SUNDAY AFTERNOON. UPPER TROUGH WILL PUSH FARTHER INTO THE PLAINS...PUSHING SURFACE TROUGH/LOW INTO EASTERN NEBRASKA AND EASTERN KANSAS. SUBSTANTIAL INSTABILITY WILL EXIST AHEAD OF THIS BOUNDARY DURING THE AFTERNOON...BUT SHEAR PROFILES WILL BE DECREASING WITH TIME AS WE HEAD LATER IN THE AFTERNOON OWING TO SLACKENING GRADIENT CLOSER TO SURFACE/UPPER TROUGHS. VERY STEEP LOW AND MID LEVEL LAPSE RATES ON THE ORDER OF 8 C/KM WILL EXIST OVER MUCH OF OUR AREA...AND FORECAST SOUNDINGS SHOW INHIBITION GOING AWAY BY MID TO LATE AFTERNOON. MIXED LAYER CAPE VALUES OVER 2500 J/KG ARE PROGGED OVER MUCH OF OUR AREA...WITH 0-6KM SHEAR AROUND 40KT. SO SUPERCELLS LOOK LIKELY WITH LARGE HAIL AND DAMAGING WINDS CERTAINLY...BUT TORNADO POTENTIAL IS STILL IN QUESTION. LOW LEVEL SHEAR IS MOST PRONOUNCED IN OUR FAR SOUTHEAST CWA...BUT ANY WARM FRONTAL BOUNDARY THAT ROTATES NORTH AROUND SURFACE LOW WILL BE A CANDIDATE TO FOCUS TORNADO THREAT AS WELL. SEVERE THREAT WILL LAST THROUGH THE EVENING BEFORE SURFACE BOUNDARY SHIFTS EAST AND FOCUSES STORMS MORE IN IOWA AND MISSOURI. HOWEVER UPPER LOW CUTTING OFF JUST NORTH OF NEBRASKA AND LINGERING MID LEVEL INSTABILITY WILL BRING CONTINUED THUNDER CHANCE INTO MONDAY. THAT LOW WILL REMAIN IN OUR AREA THROUGH AT LEAST MID WEEK...BRINGING OFF AND ON SHOWERS AND ISOLATED THUNDERSTORMS ALONG WITH COOLER TEMPERATURES. IT LOOKS LIKE A WARMING TREND IS IN STORE FOR LATE IN THE WEEK AS UPPER LOW FINALLY MOVES EAST AND HEIGHTS BEGIN TO RISE. DERGAN && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 553 PM CDT SAT MAY 18 2013 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-191300- 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- 553 PM CDT SAT MAY 18 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF EASTERN NEBRASKA AND WESTERN IOWA. .DAY ONE...TONIGHT AND SUNDAY SCATTERED THUNDERSTORMS ARE EXPECTED TONIGHT...AND SEVERE STORMS ARE POSSIBLE. LARGE HAIL AND DAMAGING WINDS ALONG WITH LOCALLY HEAVY RAIN WILL BE THE PRIMARY HAZARDS. A LARGE UPPER LEVEL SYSTEM HAS COMBINED WITH STRONG SHEAR AND INSTABILITY TO CREATE SCATTERED THUNDERSTORMS...A FEW SEVERE...FROM WESTERN NEBRASKA INTO NORTHWEST KANSAS SATURDAY AFTERNOON. THIS ACTIVITY WILL SPREAD NORTHEAST TONIGHT AS THE UPPER SYSTEM MOVES SLOWLY EAST AND A LOW LEVEL JET STRENGTHENS OVER THE REGION. ALTHOUGH WIND SHEAR IS FORECAST TO BE LESS OVER EASTERN NEBRASKA AND SOUTHWEST IOWA THAN LOCATIONS TO THE WEST...AND SURFACE BASED INSTABILITY SHOULD WEAKEN...CONDITIONS REMAIN FAVORABLE ENOUGH SO THAT STORMS THAT MOVE OR DEVELOP INTO THE REGION COULD BE SEVERE. AFTER A POSSIBLE LULL IN THE ACTIVITY SUNDAY MORNING...ADDITIONAL THUNDERSTORMS SHOULD DEVELOP SUNDAY AFTERNOON AS THE UPPER SYSTEM CONTINUES MOVING EAST. THE HIGHEST INSTABILITY AND WIND SHEAR SUNDAY AFTERNOON AND EVENING IS EXPECTED TO EXTEND FROM SOUTHEAST NEBRASKA AND SOUTHWEST IOWA TO POINTS SOUTH. ALTHOUGH THE GREATEST CONCENTRATION OF SEVERE WEATHER SUNDAY COULD BE ACROSS THAT AREA...SEVERE STORMS ARE POSSIBLE OVER ALL OF EASTERN NEBRASKA AND WESTERN IOWA DUE TO THE STRENGTH OF THE UPPER SYSTEM AND AT LEAST MODEST INSTABILITY EXPECTED OVER MUCH OF THE AREA. VERY LARGE HAIL AND DAMAGING WINDS ARE AMONG THE HAZARDS ON SUNDAY. WITH A POSSIBLE DRY-LINE OR WARM FRONT IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA...ISOLATED TORNADOES ARE POSSIBLE AS WELL. .DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH SATURDAY THE SEVERE WEATHER THREAT OVER THE AREA SHOULD SHIFT TO FAR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA SUNDAY EVENING BEFORE MOVING OUT OF THE REGION SUNDAY NIGHT. WITH THE UPPER LEVEL SYSTEM CLOSING OFF AND STALLING OVER THE PLAINS...ISOLATED THUNDERSTORMS REMAIN POSSIBLE THEN MONDAY AND TUESDAY...MAINLY WITH AFTERNOON HEATING. ISOLATED STORMS COULD BE SEVERE MONDAY AFTERNOON IF ENOUGH LOW LEVEL MOISTURE AND INSTABILITY CAN LAG BENEATH THE COOLING UPPER LEVEL SYSTEM. .SPOTTER INFORMATION STATEMENT... ALTHOUGH STORM SPOTTER ACTIVITY MAY BE REQUIRED LATE THIS EVENING...SPOTTERS WILL MORE LIKELY BE NEEDED SUNDAY AFTERNOON AND EVENING. CHERMOK
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
931 PM CDT SAT MAY 18 2013
NEZ050-051-065-066-190300-
BUTLER NE-SEWARD NE-SAUNDERS NE-LANCASTER NE-
931 PM CDT SAT MAY 18 2013
...SIGNIFICANT WEATHER ADVISORY FOR BUTLER...SEWARD...WESTERN
SAUNDERS AND NORTHERN LANCASTER COUNTIES UNTIL 1000 PM CDT...
AT 926 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
LINE OF STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM CLARKS TO
GRESHAM TO EXETER...OR ALONG A LINE EXTENDING FROM 24 MILES SOUTHWEST
OF COLUMBUS TO 12 MILES NORTHEAST OF YORK TO 43 MILES NORTHWEST OF
BEATRICE...AND MOVING NORTHEAST AT 45 MPH.
WIND GUSTS UP TO 45 TO 50 MPH WILL BE POSSIBLE WITH THESE STORMS.
LOCATIONS IMPACTED INCLUDE...
LINCOLN...SEWARD...DAVID CITY...MILFORD...UTICA...VALPARAISO...BEAVER
CROSSING...BELLWOOD...RISING CITY...BRAINARD...PRAGUE...WESTON...
ULYSSES...STAPLEHURST...DWIGHT...GARLAND...PLEASANT DALE...BEE...
MALCOLM AND GOEHNER.
LAT...LON 4136 9736 4138 9728 4139 9710 4141 9706
4141 9700 4144 9696 4145 9691 4144 9681
4145 9675 4143 9673 4143 9668 4080 9667
4070 9726 4070 9737
TIME...MOT...LOC 0226Z 232DEG 41KT 4122 9774 4099 9740 4063 9743
MAYESSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
1005 PM CDT SAT MAY 18 2013
NEZ043-044-050-051-065-066-190330-
BUTLER NE-DODGE NE-COLFAX NE-SEWARD NE-SAUNDERS NE-LANCASTER NE-
1005 PM CDT SAT MAY 18 2013
...SIGNIFICANT WEATHER ADVISORY FOR BUTLER...WESTERN DODGE...SOUTHERN
COLFAX...SEWARD...SAUNDERS AND CENTRAL LANCASTER COUNTIES UNTIL 1030
PM CDT...
AT 1002 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A LINE OF STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES
EAST OF COLUMBUS TO BRAINARD TO DORCHESTER...OR ALONG A LINE
EXTENDING FROM 40 MILES SOUTH OF NORFOLK TO 54 MILES WEST OF OMAHA TO
25 MILES SOUTHEAST OF YORK...AND MOVING EAST AT 35 MPH.
WIND GUSTS UP TO 45 MPH WILL BE POSSIBLE WITH THESE STORMS.
LOCATIONS IMPACTED INCLUDE...
LINCOLN...SEWARD...SCHUYLER...WAHOO...DAVID CITY...WAVERLY...
MILFORD...NORTH BEND...CEDAR BLUFFS...MEAD...VALPARAISO...BEAVER
CROSSING...BELLWOOD...RISING CITY...BRAINARD...PRAGUE...WESTON...
ULYSSES...STAPLEHURST AND DWIGHT.
LAT...LON 4138 9726 4144 9725 4167 9673 4131 9646
4077 9648 4071 9734 4110 9726 4139 9737
TIME...MOT...LOC 0302Z 249DEG 33KT 4146 9724 4117 9706 4072 9716
MAYESSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
1008 PM CDT SAT MAY 18 2013
NEZ011-016>018-030>033-042>044-190345-
BOONE NE-STANTON NE-DODGE NE-ANTELOPE NE-COLFAX NE-PIERCE NE-
MADISON NE-WAYNE NE-PLATTE NE-CUMING NE-KNOX NE-
1008 PM CDT SAT MAY 18 2013
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BOONE...STANTON...
NORTHWESTERN DODGE...ANTELOPE...COLFAX...PIERCE...MADISON...WESTERN
WAYNE...PLATTE...WESTERN CUMING AND SOUTHERN KNOX COUNTIES UNTIL 1045
PM CDT...
AT 1006 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A LINE OF STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES
SOUTH OF CLEARWATER TO 7 MILES NORTHEAST OF LINDSAY TO 6 MILES
NORTHEAST OF COLUMBUS...OR ALONG A LINE EXTENDING FROM 34 MILES
SOUTHEAST OF ONEILL TO 19 MILES SOUTHWEST OF NORFOLK TO 46 MILES
NORTH OF YORK...AND MOVING NORTHEAST AT 65 MPH.
WIND GUSTS UP TO 45 MPH WILL BE POSSIBLE WITH THESE STORMS.
LOCATIONS IMPACTED INCLUDE...
NORFOLK...COLUMBUS...MADISON...PIERCE...NELIGH...STANTON...
PLAINVIEW...CREIGHTON...BATTLE CREEK...NEWMAN GROVE...OSMOND...
ELGIN...DODGE...CLARKSON...HOWELLS...WINSIDE...LEIGH...CLEARWATER...
PILGER AND PETERSBURG.
LAT...LON 4251 9799 4240 9739 4235 9737 4235 9729
4228 9715 4168 9672 4138 9727 4140 9737
4138 9741 4175 9784 4193 9830 4210 9830
TIME...MOT...LOC 0306Z 215DEG 56KT 4208 9820 4180 9762 4151 9728
MAYESSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
1011 PM CDT SAT MAY 18 2013
NEZ011-016-190400-
ANTELOPE NE-KNOX NE-
1011 PM CDT SAT MAY 18 2013
...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN ANTELOPE AND
SOUTHWESTERN KNOX COUNTIES UNTIL 1100 PM CDT...
AT 1006 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A STRONG THUNDERSTORM NEAR CLEARWATER...OR 29 MILES SOUTHEAST OF
ONEILL...MOVING NORTHEAST AT 40 MPH.
HAIL UP TO THE SIZE OF DIMES AND WIND GUSTS UP TO 45 MPH WILL BE
POSSIBLE WITH THIS STORM.
LOCATIONS IMPACTED INCLUDE...
CREIGHTON...VERDIGRE...ORCHARD...CLEARWATER...BRUNSWICK...CENTER...
ROYAL...WINNETOON AND BAZILE MILLS.
LAT...LON 4255 9831 4260 9829 4263 9788 4247 9779
4204 9820 4210 9830
TIME...MOT...LOC 0306Z 215DEG 37KT 4216 9824
MAYESThe Omaha radar (KOAX), 84 km away, was scanning. The volume nearest the first event began at 03:29 UTC.
4 thunderstorm wind, 2 hail. Local standard time, as filed.
Thunderstorm wind gusts caused spotty tree damage in Columbus including a large hackberry tree which was downed in the town square which damaged a statue and ceremonial cannon. Some power outages were also noted in town.
Thunderstorm wind gusts estimated at around 60 mph took the roof off of a shed along Highway 77 south of Beatrice.
Thunderstorm wind gusts estimated at 60 to 70 mph downed several trees and caused other tree damage in Swanton. Some of the felled trees caused vehicle and house damage.
Thunderstorm wind gusts estimated at close to 60 mph caused some tree damage in the Rulo area. A swing set also sustained significant damage.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2013Every state in 2013This day in weather historyWarnings in Nebraska, May 2013
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: 440833, 440831, 440832, 440834, 440835, 440836.