

339 

WWUS20 KWNS 231756

SEL5

SPC WW 231756

INZ000-KYZ000-MDZ000-OHZ000-PAZ000-WVZ000-LEZ000-240200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 435

NWS STORM PREDICTION CENTER NORMAN OK

155 PM EDT TUE JUL 23 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTHERN INDIANA

  CENTRAL AND NORTHERN KENTUCKY

  WESTERN MARYLAND

  SOUTHERN AND EASTERN OHIO

  WESTERN PENNSYLVANIA

  NORTHWESTERN WEST VIRGINIA

  LAKE ERIE



* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 155 PM UNTIL

  1000 PM EDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH LIKELY

  SEVERAL LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75

STATUTE MILES EITHER SIDE OF A LINE FROM 35 MILES EAST OF

PITTSBURGH PENNSYLVANIA TO 60 MILES WEST OF LOUISVILLE KENTUCKY.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



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...THUNDERSTORM ACTIVITY IS CURRENTLY INCREASING ALONG A

PRE-FRONTAL SURFACE BOUNDARY ADVANCING SOUTHEASTWARD THROUGH THE

OHIO VALLEY.  AIDED BY SOME STRENGTHENING OF DEEP LAYER WESTERLY

FLOW FIELDS AND ADDITIONAL BOUNDARY LAYER HEATING...CONSOLIDATING

CONVECTIVELY-GENERATED SURFACE COLD POOLS COULD YIELD UPSCALE

CONVECTIVE GROWTH AND A MORE GENERAL RISK FOR POTENTIALLY DAMAGING

WIND GUSTS BY LATE AFTERNOON.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 28030.





...KERR

