Tornado Watch 673

Issued

Jul 22, 2011, 4:35 PM MDT (22:35 UTC)

Expired

Jul 23, 2011, 1:00 AM MDT

In force

8 hr

Issued by

the Storm Prediction Center

Largest hail expected

3 in

Strongest gust expected

70 kt

The Bismarck radar (KBIS), 164 km from the middle of the area, began a volume at 22:34 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

70%

One or more EF2 to EF5 tornadoes

30%

Ten or more severe wind reports

95%

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

50%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 1694Jul 22, 4:17 PM MDT
• Mesoscale Discussion 1696Jul 22, 4:46 PM MDT
• Mesoscale Discussion 1701Jul 22, 7:56 PM MDT
• Mesoscale Discussion 1702 Severe potential...watch possibleJul 22, 9:11 PM MDT
• Mesoscale Discussion 1703Jul 23, 12:25 AM MDT

536 
WWUS20 KWNS 222241
SEL3
SPC WW 222241
NDZ000-SDZ000-230700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 673
NWS STORM PREDICTION CENTER NORMAN OK
535 PM CDT FRI JUL 22 2011

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

       WESTERN AND SOUTHERN NORTH DAKOTA
       NORTHERN SOUTH DAKOTA

EFFECTIVE THIS FRIDAY AFTERNOON AND SATURDAY MORNING FROM 535 PM
UNTIL 200 AM CDT.

TORNADOES...HAIL TO 3 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 90 STATUTE
MILES EAST AND WEST OF A LINE FROM 70 MILES NORTHWEST OF MINOT
NORTH DAKOTA TO 55 MILES SOUTH OF LEMMON SOUTH 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.

OTHER WATCH INFORMATION...CONTINUE...WW 670...WW 671...WW 672...

DISCUSSION...TSTMS ARE BEGINNING TO FORM ALONG WNW/ESE ORIENTED WARM
FRONT IN  S CNTRL ND.  MODERATE TO STRONGLY VEERING LOW LVL WIND
PROFILES IN THIS REGION...STEEP LOW LVL LAPSE RATES...AND PRESENCE
OF AMPLE MOISTURE SUGGEST POTENTIAL FOR SUPERCELLS WITH
TORNADOES...IN ADDITION TO VERY LARGE HAIL/LOCALLY DMGG WIND.  WITH
TIME...BROKEN BAND OF STORMS WITH EMBEDDED SUPERCELLS NOW IN ERN MT
EXPECTED TO MOVE INTO WRN ND AS ASSOCIATED UPR LVL JET STREAK
CONTINUES NEWD.  THIS ACTIVITY MAY EVOLVE INTO A LARGER SCALE BOW
MCS...POSSIBLY YIELDING A MORE WIDESPREAD DMGG WIND THREAT...IN
ADDITION TO A CONTINUING RISK FOR ISOLD TORNADOES/SVR HAIL INTO LATE
TNGT/EARLY SAT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
600. MEAN STORM MOTION VECTOR 24020.


...CORFIDI

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