Flash Flood and Hail in Nebraska, August 18, 2011

Name: Flash Flood and Hail in Nebraska, August 18, 2011
Start: 2011-08-18T15:05
End: 2011-08-18T21:30
Location: Nebraska

August 18, 2011 · NWS FSD · 18 events in 2 counties and zones

Large hail caused widespread crop and property damage in most of Dixon and Dakota Counties in extreme northeast Nebraska during the afternoon of August 18th. There were also reports of damaging winds, and one report of flash flooding as the evening began.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $435,000
Crop damage: None recorded
Events: 18

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.

What happened

The episode as NWS FSD wrote it up.

What forecasters said that day

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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Aug 18, 1:48 PM CST, 1 hour 17 minutes earlier.

Area forecast discussion, Aug 18, 1:48 PM CST, 1 hour 17 minutes before

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
248 PM CDT THU AUG 18 2011

.DISCUSSION...
DESPITE THE SIGNIFICANCE OF AFTERNOON SHOWERS AND STORMS MOVING EAST
SOUTHEAST OVER THE AREA...THE KEY TO TONIGHT IS IN THE STORMS WEST
OF OUR AREA YET TO DEVELOP. THESE STORMS LIKELY TO DEVELOP BY THE
END OF THE AFTERNOON IN CENTRAL/SOUTH CENTRAL SOUTH DAKOTA SHOULD
AFFECT MOST OF THE AREA THIS EVENING. SEVERE STORMS SHOULD ORGANIZE
AS A MESO SYSTEM WHICH MAY OR MAY NOT STAY SEVERE THROUGH 06Z AS IT
MOVES EAST/SOUTHEAST. IN ANY EVENT LIKELY POPS ARE IN ORDER FOR MOST
OF THE AREA FOR THIS EVENING WITH ACTIVITY WANING LATER AS UPPER
SUPPORT MOVES ON BY. WILL CONTINUE TO MENTION SEVERE TONIGHT. AS FOR
TEMPERATURES...60S LOWS SEEM IN ORDER FOR TONIGHT...NOT FAR FROM MET
GUIDANCE. DONT KNOW WHERE THE MAV GUIDANCE GETS ITS 50S ALL THE WAY
DOWN TO SUX AS I DONT SEE IT DRYING AND COOLING THAT MUCH. /WILLIAMS

SURFACE FRONT WILL PUSH THROUGH SOUTHERN CWA FRIDAY MORNING AND
STALL ALONG NEB/KSD BORDER FRIDAY NIGHT INTO SATURDAY. H85 BOUNDARY
WILL ALSO BE ACROSS ACROSS SOUTHERN NEBRASKA THROUGH THAT TIME
PERIOD AS WEAK SHORT WAVES MOVE SOUTHEAST ACROSS THE CENTRAL AND
NORTHERN PLAINS. WOULD EXPECT THE BULK OF THUNDERSTORMS WILL REMAIN
SOUTH OF CWA FRIDAY AFTERNOON...BUT CAN NOT RULE OUT A FEW ELEVATED
STORMS SLIDING EAST ACROSS THE SOUTHERN CWA FRIDAY NIGHT THROUGH
SATURDAY. SO WILL KEEP 20% POPS SOUTH OF I90 FRIDAY AND IN THE 20 TO
40% RANGE ALONG AND SOUTH OF I90 FRIDAY NIGHT AND SATURDAY AS
BOUNDARY TRIES TO LIFT A LITTLE FURTHER NORTH.

OTHERWISE EXPECT COOLER THAN NORMAL TEMPERATURES FRIDAY AND SATURDAY
AS SURFACE HIGH SETTLES OVER THE NORTHERN PLAINS WITH NORTHEASTLY
LOW LEVEL FLOW.

WARMER TEMPERATURES ALONG WITH HIGHER DEWPOINTS WILL RETURN ON
SUNDAY AS LOW LEVEL FLOW BECOMES MORE SOUTHERLY. THIS WARMER AND
MORE HUMID TREND WILL CONTINUE INTO THE MIDDLE OF NEXT WEEK WITH
HIGHS IN THE 80S TO LOWER 90S MONDAY THROUGH THURSDAY. WILL ADD A
CHANCE OF THUNDERSTORMS MONDAY AND MONDAY NIGHT AS MODELS ARE NOW A
LITTLE MORE CONSISTENT WITH WITH A WAVE DURING THIS TIME PERIOD.
THINK TIMING WOULD FAVOR MORE OF AN AFTERNOON AND OVERNIGHT EVENT.

LOOKS LIKE THE WARMER THAN NORMAL TEMPERATURES WILL PERSIST EVEN
INTO NEXT WEEKEND AFTER THIS COOL DOWN TOMORROW AND SATURDAY.

&&

.AVIATION...
VFR CONDITIONS OUTSIDE OF INCREASING THUNDERSTORMS WILL OF COURSE BE
ECLIPSED BY LOCALLY LOWER CEILINGS AND VISIBILITIES IN STORMS
THROUGH 06Z. THIS IS LIKELY TO INCLUDE BRIEF IFR VISIBILITIES IN
SOME STORMS. FROM 06Z TO 12Z STORMS WILL DECREASE FROM THE
NORTHWEST. THESE IS SOME CHANCE THAT LINGERING LOW LEVEL MOISTURE
WILL MANIFEST ITSELF IN A 1-3K FOOT CLOUD DECK OUTSIDE AND/OR AFTER
STORMS FROM 06Z TO 12Z AND A COUPLE HOURS BEYOND. FOR NOW WILL
MENTION BUT MINIMALLY...THAT IS SOME 3-5SM IN LIGHT FOG WITH MVFR
CEILINGS LIMITED TO SUX FORECAST INTO 12-14Z PERIOD. IF LOWER
CONDITIONS DEVELOP GENERAL VFR SHOULD RETURN AFTER 15Z AND CONTINUE.
/WILLIAMS

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

&&

Hazardous weather outlook, Aug 18, 1:43 PM CST, 1 hour 22 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SIOUX FALLS SD
243 PM CDT THU AUG 18 2011

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-191200-
AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA-
CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE-
DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON-
IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN-
LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN-
OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN-
SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON-
243 PM CDT THU AUG 18 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA...
SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
SCATTERED SHOWERS AND THUNDERSTORMS SOUTHWEST OF A HURON TO SIOUX
FALLS TO SPENCER IOWA LINE THE REST OF THIS AFTERNOON WILL
INCLUDE ISOLATED SEVERE STORMS NEAR THE MISSOURI RIVER...WITH
HAIL TO GOLF BALL SIZE AND ISOLATED DAMAGING WINDS. NEAR THE END
OF THIS AFTERNOON AND INTO THIS EVENING...THUNDERSTORMS WILL
INCREASE WITH SEVERE STORMS POSSIBLE OVER THE AREA. THESE STORMS
MAY PRODUCE LARGE HAIL TO BASEBALL SIZE...WITH ISOLATED TORNADOES
AND DAMAGING WIND GUSTS. THE MAIN SEVERE WEATHER THREAT WILL
TRANSITION FROM HAIL TO DAMAGING WIND GUSTS AS THE STORMS BECOME
ORGANIZED AND MOVE EAST. THE THREAT OF SEVERE WEATHER WILL
DECREASE AFTER MIDNIGHT AS THUNDERSTORMS MOVE OUT OF THE AREA.

FLOODING...
MINOR TO MODERATE FLOODING ON THE JAMES RIVER WILL CONTINUE OVER
THE NEXT FEW WEEKS...BUT RIVER LEVELS SEE A SLOW BUT STEADY DROP.
BARRING HEAVY RAINS...THE JAMES RIVER IS EXPECTED BELOW FLOOD
STAGE TOWARD THE END OF AUGUST INTO EARLY SEPTEMBER.

FLOODING WILL CONTINUE ALONG THE MISSOURI RIVER BETWEEN
CHAMBERLAIN AND SIOUX CITY UNTIL FURTHER NOTICE...WITH RIVER
LEVELS EXPECTED TO DROP VERY SLOWLY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE INCREASINGLY LIKELY OVER THE AREA
THROUGH THIS EVENING.

&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.

WILLIAMS

In the hours before

Local storm report, Aug 18, 1:33 PM CST, 1 hour 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
233 PM CDT THU AUG 18 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0212 PM     HAIL             5 WSW SCOTLAND          43.12N 97.81W
08/18/2011  E0.88 INCH       BON HOMME          SD   TRAINED SPOTTER

&&

MDB

Local storm report, Aug 18, 2:21 PM CST, 44 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
321 PM CDT THU AUG 18 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0315 PM     TSTM WND GST     YANKTON                 42.89N 97.39W
08/18/2011  M76 MPH          YANKTON            SD   AWOS

&&

CJANSEN

Local storm report, Aug 18, 2:27 PM CST, 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
327 PM CDT THU AUG 18 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0315 PM     HAIL             YANKTON                 42.89N 97.39W
08/18/2011  M1.00 INCH       YANKTON            SD   EMERGENCY MNGR

&&

CJANSEN

Local storm report, Aug 18, 2:37 PM CST, 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
337 PM CDT THU AUG 18 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0320 PM     HAIL             YANKTON                 42.89N 97.39W
08/18/2011  M1.75 INCH       YANKTON            SD   BROADCAST MEDIA

            HAIL BROKE OUT WINDOWS AT WNAX RADIO.

&&

CJANSEN

Local storm report, Aug 18, 2:51 PM CST, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
351 PM CDT THU AUG 18 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0343 PM     HAIL             6 WSW MECKLING          42.81N 97.18W
08/18/2011  E1.00 INCH       YANKTON            SD   TRAINED SPOTTER

            LOTS OF HAIL COVERING THE GROUND

&&

BT

Local storm report, Aug 18, 2:54 PM CST, 11 minutes before

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE SIOUX FALLS SD
354 PM CDT THU AUG 18 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1140 AM     TSTM WND DMG     1 SE MARTY              42.98N 98.42W
08/18/2011                   CHARLES MIX        SD   STORM CHASER

            STRONG THUNDERSTORM WINDS DOWNED LARGE TREE BRANCHES NEAR
            MARTY.

1230 PM     HAIL             8 W SPRINGFIELD         42.85N 98.05W
08/18/2011  E1.00 INCH       BON HOMME          SD   TRAINED SPOTTER

            ALSO GUSTY THUNDERSTORM WINDS FROM 40 TO 45 MILES AN
            HOUR.

0212 PM     HAIL             5 WSW SCOTLAND          43.12N 97.81W
08/18/2011  E0.88 INCH       BON HOMME          SD   TRAINED SPOTTER

0220 PM     HAIL             SCOTLAND                43.15N 97.72W
08/18/2011  M1.00 INCH       BON HOMME          SD   TRAINED SPOTTER

0223 PM     HAIL             DANBURY                 42.24N 95.72W
08/18/2011  E1.75 INCH       WOODBURY           IA   LAW ENFORCEMENT

0230 PM     HAIL             4 N LESTERVILLE         43.10N 97.59W
08/18/2011  M1.75 INCH       YANKTON            SD   EMERGENCY MNGR

0315 PM     TSTM WND GST     YANKTON                 42.89N 97.39W
08/18/2011  M76.00 MPH       YANKTON            SD   AWOS

0315 PM     HAIL             YANKTON                 42.89N 97.39W
08/18/2011  M1.00 INCH       YANKTON            SD   EMERGENCY MNGR

0320 PM     HAIL             YANKTON                 42.89N 97.39W
08/18/2011  M1.75 INCH       YANKTON            SD   BROADCAST MEDIA

            HAIL BROKE OUT WINDOWS AT WNAX RADIO.

0343 PM     HAIL             6 WSW MECKLING          42.81N 97.18W
08/18/2011  E1.00 INCH       YANKTON            SD   TRAINED SPOTTER

            LOTS OF HAIL COVERING THE GROUND

&&

CJANSEN

The radar

The Sioux Falls radar (KFSD), 108 km away, was scanning. The volume nearest the first event began at 21:04 UTC.

Open the radar archive at this moment

Event by event

13 hail, 4 thunderstorm wind, 1 flash flood. Local standard time, as filed.

Hail, Dixon

When: August 18, 3:05 PM CST to 3:25 PM CST
Where: Dixon County, 9 mi NNW of Martinsburg to 8 mi NW of Martinsburg
Measured: 4.25 in hail
Property damage: $100,000
Reported by: NWS Storm Survey
Coordinates: 42.620, -96.898

Large hail caused widespread crop damage, destroying some corn crops completely. The hail also damaged roofs and siding on buildings, and severely dented vehicles and broke windows. A stock trailer was destroyed by the large hail in combination with damaging winds. The hail, also in combination with damaging winds, caused severe tree damage.

Thunderstorm Wind, Dixon

When: August 18, 3:05 PM CST to 3:25 PM CST
Where: Dixon County, 9 mi NNW of Martinsburg to 8 mi NW of Martinsburg
Measured: 66 kt (76 mph) measured gust
Property damage: $50,000
Reported by: NWS Storm Survey
Coordinates: 42.620, -96.898

Thunderstorm winds, in combination with very large hail, caused damage to roofs and siding of homes, destroyed a stock trailer, and caused widespread crop and tree damage.

Hail, Dixon

When: August 18, 3:05 PM CST to 3:25 PM CST
Where: Dixon County, 8 mi N of Martinsburg to 6 mi N of Martinsburg
Measured: 2.5 in hail
Reported by: NWS Storm Survey
Coordinates: 42.616, -96.830

Large hail caused widespread damage to corn and soybean crops, and also caused widespread tree damage. The hail was accompanied by estimated 70 mph wind gusts and heavy rainfall of around 4 inches.

Thunderstorm Wind, Dixon

When: August 18, 3:05 PM CST to 3:25 PM CST
Where: Dixon County, 8 mi N of Martinsburg to 6 mi N of Martinsburg
Measured: 61 kt (70 mph) estimated gust
Reported by: NWS Storm Survey
Coordinates: 42.616, -96.830

Thunderstorm winds, combined with large hail, caused severe damage to corn and soybean crops.

Hail, Dixon

When: August 18, 3:08 PM CST
Where: Dixon County, 2.31 mi SSE of Maskell
Measured: 2.75 in hail
Property damage: $100,000
Reported by: Law Enforcement
Coordinates: 42.650, -96.950

Large hail punched a hole in the roof of a home, caused other damage to homes, businesses, and vehicles, and severely damaged crops. The amount of crop damage was not known.

Hail, Dixon

When: August 18, 3:10 PM CST to 3:20 PM CST
Where: Dixon County, 3 mi NE of Martinsburg to 2 mi NE of Martinsburg
Measured: 1 in hail
Reported by: NWS Storm Survey
Coordinates: 42.531, -96.788

Quarter size hail, accompanied by estimated 70 mph winds, caused damage to corn and soybean crops and to trees.

Thunderstorm Wind, Dixon

When: August 18, 3:10 PM CST to 3:20 PM CST
Where: Dixon County, 3 mi NE of Martinsburg to 2 mi NE of Martinsburg
Measured: 61 kt (70 mph) estimated gust
Reported by: NWS Storm Survey
Coordinates: 42.531, -96.788

Thunderstorm winds, in combination with large hail, caused damage to corn and soybean crops, and to trees.

Hail, Dixon

When: August 18, 3:25 PM CST
Where: Dixon County, Newcastle
Measured: 0.75 in hail
Reported by: Trained Spotter
Coordinates: 42.650, -96.870

Hail, Dixon

When: August 18, 3:28 PM CST
Where: Dixon County, 4.29 mi NW of Hurleys Arpt
Measured: 1.75 in hail
Property damage: $25,000
Reported by: Trained Spotter
Coordinates: 42.570, -96.870

Large hail caused damage to roofs and siding of homes, and caused tree damage. The hail also damaged crops in the area.

Hail, Dixon

When: August 18, 3:28 PM CST
Where: Dixon County, Newcastle
Measured: 1.5 in hail
Reported by: Trained Spotter
Coordinates: 42.650, -96.870

Large hail caused an an unknown amount of crop and vehicle damage.

Hail, Dixon

When: August 18, 3:35 PM CST to 3:40 PM CST
Where: Dixon County, 2.13 mi SSW of Ponca to 5 mi SW of Ponca
Measured: 1.75 in hail
Reported by: Fire Department/Rescue
Coordinates: 42.540, -96.710

Large hail caused widespread damage to corn and soybean crops. The amount of crop damage was not known.

Hail, Dixon

When: August 18, 3:40 PM CST to 3:45 PM CST
Where: Dixon County, 4 mi W of Waterbury to 0.86 mi SW of Waterbury
Measured: 2.5 in hail
Property damage: $50,000
Reported by: Storm Chaser
Coordinates: 42.470, -96.808

Large hail, driven by strong winds, broke numerous windows, dented vehicles, and caused widespread crop damage.

Hail, Dakota

When: August 18, 3:45 PM CST to 4:05 PM CST
Where: Dakota County, 4 mi SW of Willis to Hubbard
Measured: 2.5 in hail
Reported by: Newspaper
Coordinates: 42.439, -96.675

Large hail caused widespread damage to corn and soybean crops. The hail accumulated up to 6 inches and drifted higher, requiring snow plows to remove the hail from roads. The hail also broke windows and dented vehicles. The amount of crop and property damage was not known.

Hail, Dakota

When: August 18, 4:05 PM CST to 4:20 PM CST
Where: Dakota County, Hubbard to 0.51 mi W of Homer
Measured: 3 in hail
Property damage: $100,000
Reported by: Trained Spotter
Coordinates: 42.380, -96.580

Large hail caused widespread damage to crops, vehicles, and windows.

Hail, Dixon

When: August 18, 4:30 PM CST to 4:33 PM CST
Where: Dixon County, 0.69 mi N of Martinsburg to 2.55 mi W of Waterbury
Measured: 2.75 in hail
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 42.510, -96.830

Large hail broke windows and dented vehicles. Hail accumulation and resulting fog caused a semi truck to tip over, causing minor injuries to the driver. The hail also caused an unknown amount of crop damage.

Thunderstorm Wind, Dixon

When: August 18, 4:30 PM CST
Where: Dixon County, 2.64 mi ESE of Hurleys Arpt
Measured: 56 kt (64 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 42.510, -96.770

Thunderstorm winds caused tree damage, including one tree blown onto a barn.

Hail, Dixon

When: August 18, 4:52 PM CST
Where: Dixon County, 3.06 mi E of Hurleys Arpt
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 42.520, -96.760

Flash Flood, Dixon

When: August 18, 6:20 PM CST to 9:30 PM CST
Where: Dixon County, 9.61 mi ESE of Waterbury to 8.7 mi ESE of Waterbury
Cause: Heavy Rain
Reported by: Law Enforcement
Coordinates: 42.410, -96.560

Heavy rainfall from thunderstorms caused Pidgeon Creek to overflow, flooding some farmland.

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Nebraska in 2011 Every state in 2011 This day in weather history Warnings in Nebraska, August 2011

Sources

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: 340932, 340936, 340938, 340940, 340926, 340941, 340943, 340927, 340929, 340944, 340945, 340959, 340971, 340973, 341075, 341077, 341078, 341079.