Tornado Watch 116

Issued

Apr 9, 2011, 5:48 PM CDT (22:48 UTC)

Expired

Apr 10, 2011, 1:00 AM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

3 in

Strongest gust expected

70 kt

The Omaha radar (KOAX), 53 km from the middle of the area, began a volume at 22:51 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

70%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

50%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

80%

One or more hailstones of 2 inches or more

40%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 388Apr 9, 5:00 PM CDT
• Mesoscale Discussion 392Apr 9, 9:06 PM CDT
• Mesoscale Discussion 394Apr 9, 10:43 PM CDT

176 
WWUS20 KWNS 092251
SEL6
SPC WW 092251
IAZ000-NEZ000-SDZ000-100600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 116
NWS STORM PREDICTION CENTER NORMAN OK
550 PM CDT SAT APR 9 2011

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

       WESTERN AND NORTHERN IOWA
       EASTERN NEBRASKA
       SOUTHEAST SOUTH DAKOTA

EFFECTIVE THIS SATURDAY AFTERNOON AND SUNDAY MORNING FROM 550 PM
UNTIL 100 AM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 95 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES SOUTH SOUTHWEST OF
LINCOLN NEBRASKA TO 25 MILES NORTH NORTHEAST OF SPENCER IOWA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...CONTINUE...WW 113...WW 114...WW 115...

DISCUSSION...TSTMS EXPECTED TO INCREASE OVER WW AREA THROUGH LATE
TONIGHT...WITH STRONG SUPERCELLS LIKELY AS CONVERGENCE/ASCENT AND
WIND FIELD FURTHER STRENGTHEN WITH APPROACH OF UPR AIR IMPULSE IN
FAST SWLY MID/UPR FLOW.  LOW-LVL HELICITY/UPLIFT SHOULD MAXIMIZE
NEAR AND ENE OF SFC LOW NOW NEAR KOFK...WITH THE LOW EXPECTED TO
REMAIN LARGELY STNRY THROUGH WW PERIOD.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 24035.


...CORFIDI

Tornado Watches in Iowa, 2011Tornado Watches in Nebraska, 2011Tornado Watches in South Dakota, 2011Every tornado watch in 2011

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.