Severe Thunderstorm Watch 293

Issued

May 23, 2012, 4:07 PM CDT (21:07 UTC)

Expired

May 23, 2012, 11:00 PM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Omaha radar (KOAX), 87 km from the middle of the area, began a volume at 21:09 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

10%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

50%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 879May 23, 2:56 PM CDT
• Mesoscale Discussion 883May 23, 6:49 PM CDT
• Mesoscale Discussion 885May 23, 8:56 PM CDT
• Mesoscale Discussion 886May 23, 10:29 PM CDT

345 
WWUS20 KWNS 232109
SEL3
SPC WW 232109
IAZ000-NEZ000-SDZ000-240400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 293
NWS STORM PREDICTION CENTER NORMAN OK
405 PM CDT WED MAY 23 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

       WESTERN IOWA
       EASTERN NEBRASKA
       EXTREME SOUTHEAST SOUTH DAKOTA

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 405 PM UNTIL
1100 PM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTHWEST OF
SPENCER IOWA TO 35 MILES WEST SOUTHWEST OF BEATRICE NEBRASKA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 292...

DISCUSSION...STORMS ARE EXPECTED TO DEVELOP NEAR A SLOW MOVING COLD
FRONT EXTENDING FROM EXTREME SERN SD SSWWD INTO SOUTH CENTRAL NEB
WITHIN THE NEXT 1-2 HRS.  STRONG HEATING HAS OCCURRED AHEAD OF THE
FRONT...AND WHEN COMBINED WITH LARGE SCALE ASCENT APPROACHING FROM
THE WEST...HAVE WEAKENED THE CAP ASSOCIATED WITH A PRE-EXISTING EML.
STRONG WINDS ALOFT ARE PROVIDING SUFFICIENT DEEP LAYER SHEAR TO
SUPPORT SEVERE STORMS INCLUDING POSSIBLE SUPERCELLS.  ACTIVITY IS
EXPECTED TO DEVELOP INTO CONVECTIVE LINE BY THIS EVENING WITH
CONTINUING THREAT FOR LARGE HAIL AND DAMAGING WINDS AS IT SAGS
EWD/SEWD.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 22035.


...WEISS

Severe Thunderstorm Watches in Nebraska, 2012Severe Thunderstorm Watches in Iowa, 2012Severe Thunderstorm Watches in South Dakota, 2012Every severe thunderstorm watch in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.