Live video stream from my laptop/NECN Weather Center to commence mid-afternoon. Basic radar (works on most mobile devices) on my weather page, interactive radar on our NECN Weather Page.
There are two concerns I see - one is the fast wind aloft that will be available for "bow echoes" to produce damaging wind, and the other is the backing low-level flow in the vicinity of the warm front that will enhance low-level rotation in Central New England during the afternoon and evening, which can produce supercell thunderstorms. 11 AM surface analysis already shows weak but backed surface flow across New England with surface warm front located near MA/NH border.
This statement from the Storm Prediction Center, issued at 10:45 AM, explaining why a Severe Thunderstorm Watch is likely for New England today, and the risk will likely be upgraded from "Slight" to "Moderate" - not a common level of risk for New England from these meteorologists in Norman, Oklahoma.
MESOSCALE DISCUSSION 1395
NWS STORM PREDICTION CENTER NORMAN OK
0943 AM CDT WED JUL 21 2010
AREAS AFFECTED...VT..NY..NRN PA..NH..WRN ME..MA..NWRN CT
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 211443Z - 211645Z
CORRECTED FOR AREAS AFFECTED...STATE LISTING
THUNDERSTORMS OVER WRN NY AND SRN ONTARIO ARE EXPECTED TO SPREAD EWD
AND INCREASE IN COVERAGE/INTENSITY DURING THE NEXT 1-2 HRS. WW/S
WILL LIKELY BE NEEDED. IN ADDITION...PARTS OF NEW ENGLAND INTO NY/PA
WILL BE UPGRADED TO A MODERATE RISK WITH 45% WIND PROBABILITY IN THE
1630Z DAY 1 OUTLOOK.
12Z UPPER AIR DATA SHOW VERY STRONG UPPER LEVEL JET STREAK /120 KT
AT 250 MB/ ASSOCIATED WITH A SHORT WAVE TROUGH THAT IS CROSSING THE
WRN GREAT LAKES. THESE FEATURES WILL PROGRESS EWD ACROSS LAKES
TODAY...WITH THE LEFT EXIT JET REGION MOVING ACROSS PARTS OF NY AND
NEW ENGLAND WITH PRONOUNCED LARGE SCALE ASCENT SPREADING ACROSS THE
AREA. SURFACE LOW OVER EXTREME WRN QUE IS FORECAST TO BECOME BETTER
ORGANIZED AS IT MOVES ACROSS EXTREME SRN QUE...WITH A SURFACE COLD
FRONT SURGING EWD INTO THE NERN STATES.
LOW LEVEL MOISTURE IS INCREASING NEWD INTO NY AND PA ATTM...AND AIR
MASS DESTABILIZATION WILL CONTINUE INTO PARTS OF NEW ENGLAND IN
ADVANCE OF THE COLD FRONT AS A WARM FRONT FROM ERN LAKE ONT INTO SRN
NEW ENGLAND LIFTS NWD. MLCAPE OF 1000-1500 J/KG COUPLED WITH DEEP
LAYER SHEAR OF 40-50 KT IN THE LOWEST 6 KM WILL ENHANCE STORM
ORGANIZATION AND INTENSITY...WITH MULTIPLE BOWING LINE SEGMENTS AND
ISOLATED SUPERCELLS EXPECTED TO DEVELOP. CONVECTIVE TRENDS WILL
MONITORED CLOSELY AND WW/S WILL LIKELY BE NEEDED BY 16Z.