Tornado Watch 653

Issued

Aug 26, 2007, 5:10 PM CDT (22:10 UTC)

Expired

Aug 27, 2007, 1:00 AM CDT

In force

8 hr

Issued by

the Storm Prediction Center

Largest hail expected

3 in

Strongest gust expected

60 kt

The Fargo/Grand Forks radar (KMVX), 58 km from the middle of the area, began a volume at 22:10 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

60%

One or more hailstones of 2 inches or more

60%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 1897Aug 26, 3:48 PM CDT
• Mesoscale Discussion 1898Aug 26, 8:04 PM CDT
• Mesoscale Discussion 1899Aug 26, 10:25 PM CDT
• Mesoscale Discussion 1900Aug 26, 11:07 PM CDT

000
WWUS20 KWNS 262208
SEL3  
SPC WW 262208
MNZ000-NDZ000-270400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 653
NWS STORM PREDICTION CENTER NORMAN OK
505 PM CDT SUN AUG 26 2007

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

       NORTHWEST MINNESOTA
       EASTERN NORTH DAKOTA

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 505 PM UNTIL
1100 PM CDT.

TORNADOES...HAIL TO 3 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 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES NORTHEAST OF HALLOCK
MINNESOTA TO 70 MILES SOUTH SOUTHWEST OF JAMESTOWN NORTH DAKOTA. 
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.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS GROWING CUMULUS ALONG
THE SURFACE BOUNDARY FROM BIS TO DVL...AND MODIFIED SOUNDINGS
SUGGEST THAT THE CAP IS BECOMING SUFFICIENTLY WEAK TO ALLOW
THUNDERSTORM DEVELOPMENT.  STRONG INSTABILITY /MLCAPE IN EXCESS OF
3000 J/KG/ IS PRESENT E OF THE BOUNDARY IN ND...WHILE DEEP LAYER
VERTICAL SHEAR IS FAVORABLE FOR SUPERCELLS.  THE INITIAL STORM
DEVELOPMENT SHOULD BE DISCRETE SUPERCELLS WITH THE THREAT FOR VERY
LARGE HAIL AND DAMAGING WINDS.  A COUPLE OF TORNADOES WILL BE
POSSIBLE THIS EVENING GIVEN THE MODEST LOW-LEVEL SHEAR AND BOUNDARY
LAYER DEWPOINTS NEAR 70 F.  BY EARLY TONIGHT...STORMS MAY GROW INTO
LINE SEGMENTS/MIXED MODES ALONG THE FRONT AS A SHORTWAVE TROUGH
MOVES EWD ALONG THE ND/CANADIAN BORDER...WITH A CONTINUED THREAT FOR
DAMAGING WINDS AND HAIL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 28020.


...THOMPSON

Tornado Watches in North Dakota, 2007Tornado Watches in Minnesota, 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.