

198 

WWUS20 KWNS 212029

SEL9

SPC WW 212029

CTZ000-MAZ000-MEZ000-NHZ000-220100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 729

NWS STORM PREDICTION CENTER NORMAN OK

420 PM EDT FRI AUG 21 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHERN CONNECTICUT

       MASSACHUSETTS

       WESTERN MAINE

       SOUTHERN NEW HAMPSHIRE



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 420 PM UNTIL 900

PM EDT.



TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE

MILES EITHER SIDE OF A LINE FROM 15 MILES SOUTHWEST OF WESTFIELD

MASSACHUSETTS TO 20 MILES NORTH NORTHEAST OF PORTLAND MAINE.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 726...WW 727...WW 728...



DISCUSSION...SURFACE ANALYSIS INDICATED A MESOLOW WAS LOCATED NEAR

THE NY/CT BORDER...AND IS EXPECTED TO TRACK NEWD ALONG STRONG

SURFACE BOUNDARY EXTENDING NEWD FROM THE LOW INTO WRN MAINE. DEEP

LAYER SHEAR WILL SUPPORT SUPERCELLS ALONG AND AHEAD OF THE SURFACE

LOW. GIVEN THE VERY MOIST/UNSTABLE BOUNDARY LAYER...STRONG LOW LEVEL

CONVERGENCE AND ENHANCED LOW LEVEL SHEAR AHEAD OF THE LOW...

TORNADOES ARE POSSIBLE.



AVIATION...TORNADOES AND 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 24030.





...IMY

