Severe Thunderstorm Watch 521

Issued

Jul 15, 2007, 5:49 PM CDT (22:49 UTC)

Expired

Jul 15, 2007, 11:28 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The Fargo/Grand Forks radar (KMVX), 111 km from the middle of the area, began a volume at 22:49 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

20%

One or more EF2 to EF5 tornadoes

10%

Ten or more severe wind reports

70%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

60%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 1484Jul 15, 3:54 PM CDT
• Mesoscale Discussion 1489Jul 15, 7:42 PM CDT
• Mesoscale Discussion 1491Jul 15, 10:20 PM CDT

000
WWUS20 KWNS 152252
SEL1  
SPC WW 152252
MNZ000-NDZ000-160600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 521
NWS STORM PREDICTION CENTER NORMAN OK
550 PM CDT SUN JUL 15 2007

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

       WESTERN MINNESOTA
       EASTERN AND CENTRAL NORTH DAKOTA

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

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80
STATUTE MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH
NORTHWEST OF DEVILS LAKE NORTH DAKOTA TO 70 MILES SOUTH OF FARGO
NORTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 518...WW 520...

DISCUSSION...TSTMS EXPECTED TO DEVELOP/INTENSIFY INVOF STALLED NW/SE
FRONT OVER ERN ND THIS EVENING...DOWNSTREAM FROM APPARENT MID LVL
VORT EMBEDDED IN NW FLOW OVER SRN MANITOBA.  STRONGLY VEERING DEEP
WIND PROFILES WILL SUPPORT SUPERCELLULAR STRUCTURE WITH ANY
SUSTAINED STORMS...AND POSSIBLY AN ISOLATED TORNADO OR TWO.  BUT
RELATIVELY MODEST BOUNDARY LAYER MOISTURE AND MODERATE TO LARGE T/TD
SPREADS ALOFT SUGGEST MAIN SVR THREATS SHOULD BE WIND/HAIL.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 33035.


...CORFIDI

Severe Thunderstorm Watches in North Dakota, 2007Severe Thunderstorm Watches in Minnesota, 2007Every severe thunderstorm 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.