Severe Thunderstorm Watch 583

Issued

Aug 8, 2002, 1:10 PM MDT (19:10 UTC)

Expired

Aug 8, 2002, 8:00 PM MDT

In force

7 hr

Issued by

the Storm Prediction Center

000 
WWUS20 KWNS 081914
SEL3  
SPC WW 081910
MTZ000-SDZ000-WYZ000-090200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 583
STORM PREDICTION CENTER NORMAN OK
110 PM MDT THU AUG 8 2002

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

   SOUTHEAST MONTANA                            
   WESTERN AND CENTRAL SOUTH DAKOTA                       
   NORTHEAST WYOMING                            

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 110 PM UNTIL 800
PM MDT.

HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 170 STATUTE MILES
EAST AND WEST OF A LINE FROM 80 MILES SOUTH SOUTHWEST OF PHILIP
SOUTH DAKOTA TO 45 MILES NORTHWEST OF MOBRIDGE SOUTH DAKOTA.

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.

DISCUSSION...THUNDERSTORMS EXPECTED TO INTENSIFY/DEVELOP FROM W TO
E ACROSS WW AREA DURING NEXT SEVERAL HOURS AS SURFACE HEATING
CONTINUES BENEATH MID LEVEL COLD ADVECTION ASSOCIATED WITH
APPROACHING UPPER TROUGH.  THERE WILL BE AN INCREASING POTENTIAL
FOR SUPERCELLS AS DEEP SHEAR STRENGTHENS WITH CONTINUED EWD
PROGRESS OF 40+ KT SPEED MAX NOW CROSSING NRN WY.  STEEP LOW TO MID
LEVEL LAPSE RATES AND EXISTING MOISTURE AVAILABILITY SUGGEST GOOD
THREAT FOR HAIL/HIGH WINDS...ESPECIALLY IN NW SD...DESPITE WEAK LOW
LEVEL CONVERGENCE.  OTHER STORMS WITH A THREAT FOR HIGH WINDS MAY
DEVELOP ALONG ERN FRINGE OF OLD CONFLUENCE ZONE EXTENDING NE/SW IN
ERN PART OF WATCH.  

AVIATION...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 500.  MEAN STORM
MOTION VECTOR 24035.

...CORFIDI

425,1053 455,1043 455,0973 425,0985

Severe Thunderstorm Watches in South Dakota, 2002Severe Thunderstorm Watches in Wyoming, 2002Severe Thunderstorm Watches in Montana, 2002Every severe thunderstorm watch in 2002

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.