

891 

WWUS20 KWNS 252036

SEL6

SPC WW 252036

ILZ000-INZ000-260400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 476

NWS STORM PREDICTION CENTER NORMAN OK

335 PM CDT MON AUG 25 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN ILLINOIS

  NORTHERN AND CENTRAL INDIANA



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 335 PM UNTIL

  1100 PM CDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50

STATUTE MILES EITHER SIDE OF A LINE FROM 35 MILES WEST NORTHWEST

OF MARSEILLES ILLINOIS TO 35 MILES NORTHEAST OF INDIANAPOLIS

INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



&&



DISCUSSION...ONGOING TSTM COMPLEXES OVER NRN IL INTO NWRN IND ARE

EXPECTED TO FURTHER INTENSIFY WHILE MOVING SEWD AND INTERACTING WITH

A STRONGLY UNSTABLE AIR MASS WITH MLCAPE OF 3500-4500 J/KG. VERTICAL

SHEAR WILL REMAIN MARGINALLY SUPPORTIVE OF STORM ORGANIZATION WITH

THE PRIMARY HAZARD BEING DAMAGING DOWNBURST WINDS.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION

VECTOR 30030.





...MEAD



947 

WWUS20 KWNS 252036

SEL6

SPC WW 252036

ILZ000-INZ000-260400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 476

NWS STORM PREDICTION CENTER NORMAN OK

335 PM CDT MON AUG 25 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN ILLINOIS

  NORTHERN AND CENTRAL INDIANA



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 335 PM UNTIL

  1100 PM CDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50

STATUTE MILES EITHER SIDE OF A LINE FROM 35 MILES WEST NORTHWEST

OF MARSEILLES ILLINOIS TO 35 MILES NORTHEAST OF INDIANAPOLIS

INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



&&



DISCUSSION...ONGOING TSTM COMPLEXES OVER NRN IL INTO NWRN IND ARE

EXPECTED TO FURTHER INTENSIFY WHILE MOVING SEWD AND INTERACTING WITH

A STRONGLY UNSTABLE AIR MASS WITH MLCAPE OF 3500-4500 J/KG. VERTICAL

SHEAR WILL REMAIN MARGINALLY SUPPORTIVE OF STORM ORGANIZATION WITH

THE PRIMARY HAZARD BEING DAMAGING DOWNBURST WINDS.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION

VECTOR 30030.





...MEAD

