

936 

WWUS20 KWNS 081811

SEL4

SPC WW 081811

ILZ000-INZ000-MOZ000-082300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 34

NWS STORM PREDICTION CENTER NORMAN OK

105 PM CDT WED APR 8 2015



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  CENTRAL AND SOUTHERN ILLINOIS

  CENTRAL AND SOUTHERN INDIANA

  EASTERN MISSOURI



* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 105 PM

  UNTIL 600 PM CDT.



* PRIMARY THREATS INCLUDE...

  SCATTERED LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL EVENTS

    TO 2.5 INCHES IN DIAMETER POSSIBLE

  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A TORNADO OR TWO POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 160

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES WEST

NORTHWEST OF DANVILLE ILLINOIS TO 25 MILES SOUTH SOUTHWEST OF

MOUNT VERNON ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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...CONTINUE...WW 32...WW 33...



DISCUSSION...WAA/MOISTURE TRANSPORT EXPECTED TO CONTINUE BETWEEN SFC

STNRY/WARM FRONT EXTENDING ROUGHLY W-E ALONG SRN PART OF WW...AND

850 MB BOUNDARY ALONG APPROXIMATELY THE SAME ORIENTATION NEAR THE

NRN PART OF WW. COMBINATION OF SFC HEATING WITH EXISTING EML IN THIS

ENVIRONMENT COULD SUPPORT SCTD CLUSTERS OF STORMS WITH A RISK FOR

LARGE HAIL/LOCALLY DMGG WIND GIVEN 35-40 WLY DEEP SHEAR.

A NON-ZERO THREAT ALSO WILL EXIST FOR A TORNADO OR TWO...MOST LIKELY

IN SRN AND WRN PART OF WW. THIS THREAT LARGELY WILL BE DEPENDENT

UPON THE PRESENCE OF SUSTAINED SUPERCELL UPDRAFTS MOVING PARALLEL TO

SFC FRONT/OUTFLOW BOUNDARY SEGMENTS. IF IT BECOME MORE APPARENT THAT

THIS SCENARIO WILL INDEED EVOLVE...PARTS OF THE WW COULD REQUIRE

UPGRADE TO TORNADO LATER THIS AFTN.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 25035.





...CORFIDI



863 

WWUS20 KWNS 081811

SEL4

SPC WW 081811

ILZ000-INZ000-MOZ000-082300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 34

NWS STORM PREDICTION CENTER NORMAN OK

105 PM CDT WED APR 8 2015



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  CENTRAL AND SOUTHERN ILLINOIS

  CENTRAL AND SOUTHERN INDIANA

  EASTERN MISSOURI



* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 105 PM

  UNTIL 600 PM CDT.



* PRIMARY THREATS INCLUDE...

  SCATTERED LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL EVENTS

    TO 2.5 INCHES IN DIAMETER POSSIBLE

  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A TORNADO OR TWO POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 160

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES WEST

NORTHWEST OF DANVILLE ILLINOIS TO 25 MILES SOUTH SOUTHWEST OF

MOUNT VERNON ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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...CONTINUE...WW 32...WW 33...



DISCUSSION...WAA/MOISTURE TRANSPORT EXPECTED TO CONTINUE BETWEEN SFC

STNRY/WARM FRONT EXTENDING ROUGHLY W-E ALONG SRN PART OF WW...AND

850 MB BOUNDARY ALONG APPROXIMATELY THE SAME ORIENTATION NEAR THE

NRN PART OF WW. COMBINATION OF SFC HEATING WITH EXISTING EML IN THIS

ENVIRONMENT COULD SUPPORT SCTD CLUSTERS OF STORMS WITH A RISK FOR

LARGE HAIL/LOCALLY DMGG WIND GIVEN 35-40 WLY DEEP SHEAR.

A NON-ZERO THREAT ALSO WILL EXIST FOR A TORNADO OR TWO...MOST LIKELY

IN SRN AND WRN PART OF WW. THIS THREAT LARGELY WILL BE DEPENDENT

UPON THE PRESENCE OF SUSTAINED SUPERCELL UPDRAFTS MOVING PARALLEL TO

SFC FRONT/OUTFLOW BOUNDARY SEGMENTS. IF IT BECOME MORE APPARENT THAT

THIS SCENARIO WILL INDEED EVOLVE...PARTS OF THE WW COULD REQUIRE

UPGRADE TO TORNADO LATER THIS AFTN.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 25035.





...CORFIDI

