Tornado Watch 233

Issued

May 5, 2007, 10:55 AM CDT (15:55 UTC)

Expired

May 5, 2007, 4:40 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

The Sioux Falls radar (KFSD), 138 km from the middle of the area, began a volume at 15:55 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

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

70%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 697May 5, 6:59 AM CDT
• Mesoscale Discussion 700May 5, 10:35 AM CDT
• Mesoscale Discussion 704May 5, 1:01 PM CDT
• Mesoscale Discussion 709May 5, 4:09 PM CDT

000
WWUS20 KWNS 051556
SEL3  
SPC WW 051556
IAZ000-MNZ000-NEZ000-SDZ000-060000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 233
NWS STORM PREDICTION CENTER NORMAN OK
1055 AM CDT SAT MAY 5 2007

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

       NORTHWEST IOWA
       SOUTHWEST CORNER OF MINNESOTA
       PARTS OF NORTHEAST NEBRASKA
       PARTS OF SOUTHEAST AND SOUTH CENTRAL SOUTH DAKOTA

EFFECTIVE THIS SATURDAY MORNING AND EVENING FROM 1055 AM UNTIL
700 PM CDT.

TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 45 MILES NORTH NORTHWEST OF
AINSWORTH NEBRASKA TO 55 MILES NORTH OF DENISON IOWA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU3).

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 232...

DISCUSSION...THUNDERSTORMS DEVELOPING ON WARM FRONT LIFTING NWD
THROUGH THE WATCH THIS AFTERNOON.  VERY STRONG DEEP LAYER SHEAR
COUPLED WITH INCREASING INSTABILITY SUPPORTS STORMS BECOMING MORE
SURFACE BASED THIS AFTERNOON.  SUPERCELLS WILL CONTINUE TO DEVELOP
AND WITH SHEAR AND CAPE AVAILABLE LARGE HAIL WILL BE COMMON WITH
INCREASING THREAT OF TORNADOES DURING THE AFTERNOON.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 23035.


...HALES

Tornado Watches in South Dakota, 2007Tornado Watches in Nebraska, 2007Tornado Watches in Iowa, 2007Every tornado watch in 2007

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.