

789 

WWUS20 KWNS 271845

SEL8

SPC WW 271845

MEZ000-280100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 628

NWS STORM PREDICTION CENTER NORMAN OK

245 PM EDT MON JUL 27 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN AND NORTHERN MAINE



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 245 PM UNTIL 900

PM EDT.



HAIL TO 1.5 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 55

STATUTE MILES EITHER SIDE OF A LINE FROM 10 MILES EAST NORTHEAST

OF CARIBOU MAINE TO 30 MILES WEST NORTHWEST OF AUGUSTA MAINE.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 627...



DISCUSSION...STRONGER FORCING ASSOCIATED WITH UPPER LOW IN QUEBEC

WILL SPREAD EWD ACROSS PORTIONS OF WRN AND NRN MAINE THROUGH THE

AFTERNOON HOURS. A WARMING AND DESTABILIZING BOUNDARY LAYER ALONG

WITH STRONG SPEED SHEAR SHOULD BE SUFFICIENT FOR A FEW SUPERCELLS

PRODUCING SEVERE HAIL AND DAMAGING WINDS.



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 450. MEAN STORM

MOTION VECTOR 22025.





...IMY

