SPC Severe Thunderstorm Watch 236

WW 236 SEVERE TSTM IA IL KS MO 040555Z – 041000Z


URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 236
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT FRI MAY 4 2012

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

       SOUTHEASTERN IOWA
       A SMALL PART OF WESTERN ILLINOIS
       FAR NORTHEAST KANSAS
       NORTHERN MISSOURI

EFFECTIVE THIS FRIDAY MORNING FROM 1255 AM UNTIL 500 AM 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 125
STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES EAST
NORTHEAST OF LAMONI IOWA TO 30 MILES SOUTHEAST OF CHILLICOTHE
MISSOURI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

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...THIS SEVERE THUNDERSTORM WATCH REPLACES
TORNADO WATCH NUMBER 234. WATCH NUMBER 234 WILL NOT BE IN EFFECT
AFTER 1255 AM CDT. CONTINUE...WW 235...

DISCUSSION...TSTMS EXPECTED TO PERSIST ALONG SRN FRINGE OF DIFFUSE
W-E FRONTAL ZONE OVER SRN IA/NRN MO...SUPPORTED BY 25-30 KT LLJ THAT
WILL FURTHER VEER FROM SWLY TO WSWLY.  OTHER THAN LOW LVL
WAA...FORCING FOR ASCENT WILL REMAIN WEAK.  BUT DEGREE OF BUOYANCY
/PER 00Z TOP RAOB/ AND RELATIVELY RICH MOISTURE INFLOW SUGGEST
CONTINUED RISK FOR SVR HAIL AND STRONG...PRECIP-ENHANCED DOWNDRAFTS
AS THE STORMS GRADUALLY EVOLVE INTO A LARGER SCALE...POSSIBLY
FORWARD-PROPAGATING MCS.

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 500. MEAN STORM
MOTION VECTOR 27025.


...CORFIDI

via SPC Forecast Products http://www.spc.noaa.gov/products/watch/ww0236.html