Tornado Watch 691

Issued

Jul 26, 2011, 7:32 PM CDT (00:32 UTC)

Expired

Jul 27, 2011, 12:36 AM CDT

In force

5 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Aberdeen radar (KABR), 110 km from the middle of the area, began a volume at 00:33 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

30%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

40%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1752Jul 26, 3:59 PM CDT
• Mesoscale Discussion 1758Jul 26, 7:24 PM CDT
• Mesoscale Discussion 1759Jul 26, 8:10 PM CDT
• Mesoscale Discussion 1761Jul 26, 9:53 PM CDT

260 
WWUS20 KWNS 270035
SEL1  
SPC WW 270035
MNZ000-NDZ000-SDZ000-270800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 691
NWS STORM PREDICTION CENTER NORMAN OK
735 PM CDT TUE JUL 26 2011

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

       WEST-CENTRAL MINNESOTA
       SOUTHEAST NORTH DAKOTA
       NORTHEAST SOUTH DAKOTA

EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 735 PM
UNTIL 300 AM CDT.

TORNADOES...HAIL TO 2 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 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES SOUTHEAST OF
WATERTOWN SOUTH DAKOTA TO 85 MILES NORTHWEST OF ALEXANDRIA
MINNESOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

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 687...WW 688...WW
689...WW 690...

DISCUSSION...TSTMS CONTINUE TO DEVELOP THIS EVENING ALONG A COUPLE
OF W-E ORIENTED WARM FRONTAL SEGMENTS WITHIN INTENSIFYING LOW-LEVEL
WAA REGIME.  00Z ABR SOUNDING IS QUITE REPRESENTATIVE OF THE AMBIENT
ENVIRONMENT...FEATURING MLCAPE OF AROUND 3500 J/KG...45 KT OF
DEEP-LAYER SHEAR...A LOW LCL HEIGHT AND EFFECTIVE SRH OF AROUND 400
M2/S2.  AS SUCH...A RISK FOR TORNADOES WILL EXIST WITH ANY STORMS
THAT CAN REMAIN MORE DISCRETE...IN ADDITION TO LARGE HAIL AND
DAMAGING WINDS.

AVIATION...TORNADOES AND 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
550. MEAN STORM MOTION VECTOR 26020.


...MEAD

Tornado Watches in Minnesota, 2011Tornado Watches in South Dakota, 2011Tornado Watches in North 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.