

000 

WWUS20 KWNS 281720

SEL9

SPC WW 281720

CTZ000-MAZ000-RIZ000-CWZ000-290000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 559

NWS STORM PREDICTION CENTER NORMAN OK

120 PM EDT SAT JUL 28 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CONNECTICUT

       MASSACHUSETTS

       RHODE ISLAND

       COASTAL WATERS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 120 PM UNTIL

800 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH

NORTHWEST OF BOSTON MASSACHUSETTS TO 35 MILES WEST SOUTHWEST OF

PROVIDENCE RHODE ISLAND.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 558...WW 599...



DISCUSSION...BROKEN LINES OF STRONG TSTMS EXPECTED TO INCREASE IN

INTENSITY ACROSS PARTS OF SOUTHEAST NEW ENGLAND AS GREATER

INSTABILITY IS REALIZED. THIS ACTIVITY IS SUPPORTED BY COMPACT BUT

VIGOROUS SHORT WAVE IMPULSE SPREADING ENEWD ACROSS ERN NY ATTM.

MLCAPE TO 1200 J/KG AND EFFECTIVE SHEAR APPROACHING 30KT SHOULD

ALLOW FOR A FEW STORMS TO REACH SEVERE LEVELS WITH HAIL AHD LOCALLY

HIGH/DAMAGING WINDS POSSIBLE THROUGH THE REST OF THE 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 450. MEAN STORM

MOTION VECTOR 24025.





...CARBIN

