WATCHES: Severe Thunderstorm Watch Number 152

WWUS20 KWNS 201827
SEL2
SPC WW 201827
NDZ000-SDZ000-210200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 152
NWS STORM PREDICTION CENTER NORMAN OK
125 PM CDT FRI APR 20 2007

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

SOUTHEASTERN NORTH DAKOTA
A LARGE PART OF SOUTH DAKOTA

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 125 PM UNTIL 900
PM CDT.

HAIL TO 2 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 65
STATUTE MILES EAST AND WEST OF A LINE FROM 80 MILES NORTH
NORTHEAST OF ABERDEEN SOUTH DAKOTA TO 75 MILES SOUTHWEST OF
CHAMBERLAIN SOUTH DAKOTA. FOR A COMPLETE DEPICTION OF THE WATCH
SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

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...WARM ADVECTION STORMS EXPECTED TO STRENGTHEN INVOF
FRONT STALLED SW/NE ACROSS SD. STEEP MID LEVEL LAPSE
RATES...ESPECIALLY FROM CNTRL SD NWD...AND INCREASING LOW LEVEL
MOISTURE INFLOW SHOULD SUPPORT POTENTIAL FOR LARGE HAIL AND POSSIBLY
HIGH WIND GIVEN 40+ KT CLOUD LAYER SHEAR DESPITE SLIGHTLY ELEVATED
NATURE OF STORMS.

AVIATION...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 450. MEAN STORM
MOTION VECTOR 21030.

..CORFIDI

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.