

166 

WWUS20 KWNS 230128

SEL4

SPC WW 230128

ILZ000-MOZ000-230900-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 334

NWS STORM PREDICTION CENTER NORMAN OK

825 PM CDT SUN MAY 22 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND SOUTHWEST ILLINOIS

       EASTERN AND SOUTHERN MISSOURI



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 825 PM UNTIL

400 AM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE

MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH OF CHAMPAIGN

ILLINOIS TO 45 MILES WEST SOUTHWEST OF WEST PLAINS MISSOURI.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 323...WW 325...WW

326...WW 327...WW 329...WW 330...WW 332...WW 333...



DISCUSSION...EARLIER SUPERCELLS ARE NOW MERGING INTO TWO MCS/S...ONE

NEAR STL...AND ANOTHER ALONG THE SW MO/NW AR BORDER.  MODERATE

INSTABILITY IS STILL PRESENT IN A CORRIDOR IN ADVANCE OF THIS

CONVECTION...W OF A MORE STABLE AIR MASS OVER SRN IL/WRN KY.  GIVEN

THE ORGANIZED CONVECTIVE STRUCTURES...INCLUDING BOWS AND

SUPERCELLS...AND SUFFICIENT LOW-LEVEL AND DEEP-LAYER SHEAR TO

MAINTAIN THESE STORM TYPES...A RISK FOR TORNADOES...DAMAGING

WINDS...AND LARGE HAIL WILL PERSIST.  THE MORE PERSISTENT TORNADO

THREAT IS EXPECTED ACROSS SRN MO INVOF OF A RETREATING OUTFLOW

BOUNDARY NEAR THE MO/AR BORDER.



AVIATION...TORNADOES AND 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

550. MEAN STORM MOTION VECTOR 28035.





...THOMPSON



317 

WWUS20 KWNS 230128

SEL4

SPC WW 230128

ILZ000-MOZ000-230900-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 334

NWS STORM PREDICTION CENTER NORMAN OK

825 PM CDT SUN MAY 22 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND SOUTHWEST ILLINOIS

       EASTERN AND SOUTHERN MISSOURI



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 825 PM UNTIL

400 AM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE

MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH OF CHAMPAIGN

ILLINOIS TO 45 MILES WEST SOUTHWEST OF WEST PLAINS MISSOURI.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 323...WW 325...WW

326...WW 327...WW 329...WW 330...WW 332...WW 333...



DISCUSSION...EARLIER SUPERCELLS ARE NOW MERGING INTO TWO MCS/S...ONE

NEAR STL...AND ANOTHER ALONG THE SW MO/NW AR BORDER.  MODERATE

INSTABILITY IS STILL PRESENT IN A CORRIDOR IN ADVANCE OF THIS

CONVECTION...W OF A MORE STABLE AIR MASS OVER SRN IL/WRN KY.  GIVEN

THE ORGANIZED CONVECTIVE STRUCTURES...INCLUDING BOWS AND

SUPERCELLS...AND SUFFICIENT LOW-LEVEL AND DEEP-LAYER SHEAR TO

MAINTAIN THESE STORM TYPES...A RISK FOR TORNADOES...DAMAGING

WINDS...AND LARGE HAIL WILL PERSIST.  THE MORE PERSISTENT TORNADO

THREAT IS EXPECTED ACROSS SRN MO INVOF OF A RETREATING OUTFLOW

BOUNDARY NEAR THE MO/AR BORDER.



AVIATION...TORNADOES AND 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

550. MEAN STORM MOTION VECTOR 28035.





...THOMPSON

