

399 

WWUS20 KWNS 211807

SEL4

SPC WW 211807

CTZ000-MAZ000-NHZ000-RIZ000-220100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 204

NWS STORM PREDICTION CENTER NORMAN OK

205 PM EDT TUE MAY 21 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN CONNECTICUT

  WESTERN AND CENTRAL MASSACHUSETTS

  SOUTHERN NEW HAMPSHIRE

  NORTHERN RHODE ISLAND



* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 205 PM UNTIL

  900 PM EDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 40

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES WEST OF

WESTFIELD MASSACHUSETTS TO 30 MILES NORTH NORTHEAST OF PROVIDENCE

RHODE ISLAND.  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 201...WW 202...WW 203...



DISCUSSION...AT LEAST SCATTERED VIGOROUS THUNDERSTORM DEVELOPMENT IS

EXPECTED ACROSS PARTS OF SOUTHERN NEW ENGLAND THIS

AFTERNOON...WITHIN THE WARM SECTOR OF A WEAK FRONTAL WAVE.  FAIRLY

STEEP MID-LEVEL LAPSE RATES ARE CONTRIBUTING TO SIZABLE CAPE...IN

THE PRESENCE OF MODESTLY STRONG DEEP LAYER SHEAR BENEATH 30-40 KT

WESTNORTHWESTERLY 500 MB FLOW.  SUPERCELL STRUCTURES APPEAR

POSSIBLE...CONTRIBUTING TO THE RISK FOR SEVERE HAIL AND POTENTIALLY

DAMAGING WIND GUSTS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 29025.





...KERR

