Severe Thunderstorm Warning 47, NWS Burlington, VT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
200 PM EDT FRI AUG 2 2002

SMALL LINE OF THUNDERSTORMS HAS MOVED OUT OF SOUTH CENTRAL VERMONT
THIS AFTERNOON WITH ISOLATED TO SCATTERED CONVECTION NOTED ELSEWHERE
ACROSS THE FORECAST AREA.  SPOTTER IN TYSON VERMONT REPORTED .32
INCHES OF RAIN WITH A THUNDERSTORM...BUT NO WIND.  INSTABILITY HAS
MAXIMIZED ACROSS NORTHERN NEW YORK WHERE SOME SUNSHINE WAS ABLE TO
DEVELOP...BUT THE GREATEST INSTABILITY APPEARS TO BE SOUTH OF THE
FORECAST AREA WHERE A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED.
FEEL THAT SEVERE THREAT OVER OUR FORECAST AREA IS STILL LIMITED WITH
MAIN DYNAMICS WELL NORTH OF THE AREA AND BEST INSTABILITY SOUTH OF
THE AREA.  INSTABILITY WILL BE SUFFICIENT TO PRODUCE MORE CONVECTION
OVER THE FORECAST AREA AND WILL USE A REST OF THIS AFTERNOON TIME
PERIOD TO REFERENCE SCATTERED CONVECTION...MAINLY FROM THE CHAMPLAIN
VALLEY AND POINTS EAST.  WILL CONTINUE TO MENTION THE POSSIBILITY OF
STRONG GUSTY WINDS AND HEAVY DOWNPOURS AS STORMS WILL BE MORE PULSE
IN NATURE.

LATEST SURFACE ANALYSIS SHOWS COLD FRONT STILL BACK OVER THE EASTERN
GREAT LAKES/SOUTHEAST ONTARIO/WESTERN QUEBEC AS OF 18Z.  WITH UPPER
TROUGH LIFTING WELL NORTH OF THE FORECAST AREA...SOUTHERN PORTIONS
OF THE FRONT IS GETTING HUNG UP IN THE PARALLEL FLOW ALOFT.  AS A
RESULT...DO NOT EXPECT THE FRONT TO HAVE A STRONG PUSH INTO THE
FORECAST AREA TONIGHT.  SKIES WILL CLEAR OUT AND WITH LACK OF LOW
LEVEL DRYING...EXPECT PLENTY OF FOG TO DEVELOP LATER TONIGHT AND
WILL CONTINUE IN THE FORECAST.  LOWS WILL REMAIN IN THE 60S WITH THE
HIGHER DEW POINTS.

ON SATURDAY...STEEPENING LAPSE RATES WILL HELP ENHANCE THE POTENTIAL
FOR SOME SHALLOW CUMULUS TO DEVELOP...BUT PLENTY OF SUNSHINE SHOULD
STILL EXIST ONCE THE MORNING FOG BURNS OFF.  MIXED LAYER SHOWS
LITTLE IN THE WAY OF ANY WIND FROM MAINLY THE NORTHWEST.  LOW LEVEL
THICKNESS TRENDS SUGGEST HIGH TEMPERATURES SHOULD BE A FEW DEGREES
WARMER TODAY THAN YESTERDAY...SIMPLY FOR THE FACT THAT THERE WILL BE
MORE SUNSHINE THAN TODAY.

HIGH TEMPERATURES ON SUNDAY WILL BE A DEGREE OR TWO WARMER AS LOW
LEVEL THICKNESS VALUES INCREASE A BIT.  IN ADDITION...SOUTHERLY FLOW
WILL ALSO BEGIN TO DEVELOP IN ADVANCE OF APPROACHING UPPER LEVEL
TROUGH.  THIS TROUGH WILL NOT IMPACT THE FORECAST AREA UNTIL LATE
SUNDAY NIGHT AND MONDAY.  A COLD FRONT ASSOCIATED WITH THIS FEATURE
WILL MOVE THROUGH DURING THIS TIME AND WILL THEREFORE ADD A CHANCE
OF SHOWERS TO THE FORECAST.  THIS WORKS WELL WITH THE DAY SHIFT/S
CONCERN FOR MAYBE A NEED TO MENTION A CHANCE OF PRECIPITATION DURING
THIS TIME PERIOD.

THE MOST NOTICEABLE CHANGE TO THE LATTER PERIODS WILL BE THE
DEVELOPMENT OF A SHARP UPPER TROUGH OVER EASTERN CANADA BEGINNING ON
TUESDAY AND PERSISTING FOR A FEW DAYS.  STRONG COLD FRONT AND COLD
AIR ADVECTION BEHIND THE FRONT ON TUESDAY SUGGESTS HIGH TEMPERATURES
WILL ONLY BE IN THE 70S ON TUESDAY AND WEDNESDAY WITH A SLOW WARMING
TREND THEREAFTER.  WILL ALSO THE TUESDAY THROUGH FRIDAY PERIOD DRY
AS ANY PRECIPITATION WOULD BE CLOSELY TIED TO THE CENTER OF THE
UPPER TROUGH AND ITS COLD POOL.

WORK ZONES UNDER ALBWRKCWF BY 300 PM.

EVENSON

.BTV...NONE.