Tornado Watch 236

Issued

May 5, 2007, 4:33 PM CDT (21:33 UTC)

Expired

May 5, 2007, 10:58 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Particularly dangerous situation

Yes

Largest hail expected

2.5 in

Strongest gust expected

70 kt

The Aberdeen radar (KABR), 145 km from the middle of the area, began a volume at 21:32 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

80%

One or more EF2 to EF5 tornadoes

50%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

60%

Ten or more severe hail reports

80%

One or more hailstones of 2 inches or more

50%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 704May 5, 1:01 PM CDT
• Mesoscale Discussion 706May 5, 1:45 PM CDT
• Mesoscale Discussion 709May 5, 4:09 PM CDT
• Mesoscale Discussion 712May 5, 7:26 PM CDT

000
WWUS20 KWNS 052133
SEL6  
SPC WW 052133
IAZ000-MNZ000-NEZ000-SDZ000-060400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 236
NWS STORM PREDICTION CENTER NORMAN OK
435 PM CDT SAT MAY 5 2007

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

       SMALL PART OF NORTHWEST IOWA
       SMALL PART OF SOUTHWEST MINNESOTA
       PARTS OF NORTHERN NEBRASKA
       MUCH OF CENTRAL AND EASTERN SOUTH DAKOTA

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 435 PM UNTIL
1100 PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 2.5 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 130 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 5 MILES SOUTH OF PHILIP
SOUTH DAKOTA TO 50 MILES EAST NORTHEAST OF SIOUX FALLS SOUTH
DAKOTA.  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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 233. WATCH NUMBER 233 WILL NOT BE IN EFFECT AFTER
435 PM CDT. CONTINUE...WW 232...WW 234...WW 235...

DISCUSSION...WARM FRONT CONTINUES NWD THRU SD WITH A VERY STRONG AND
INCREASINGLY UNSTABLE AIRMASS SHIFTING NWD AS WELL.  TORNADIC
SUPERCELLS EXPECTED TO DEVELOP NWD ACROSS THE WATCH WITH POTENTIAL
FOR STRONG TORNADOES GIVEN THE SHEAR/INSTABILITY IN PLACE.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 21035.


...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.