FXUS61 KBTV 041810
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
210 PM EDT SAT JUL 4 2009

.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL CONTINUE TO AFFECT THE NORTH COUNTRY 
THROUGH INDEPENDENCE DAY...AND FINALLY MOVE EAST OF THE AREA 
SATURDAY NIGHT. SCATTERED SHOWERS WILL TAPER OFF FROM WEST TO EAST 
DURING THE MORNING HOURS OF THE HOLIDAY...WITH SOME BREAKS OF SUN 
EXPECTED IN THE AFTERNOON AND EVENING. SUNSHINE AND DRIER WEATHER 
IS EXPECTED FOR SUNDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1145 AM EDT SATURDAY...HAVE ISSUED A ZONE UPDATE TO
INCREASE POPS FOR THE NEXT FEW HOURS. LOOKS LIKE VORT PUSHING
THROUGH THE NORTH COUNTRY HAS SPARKED SOME ISOLATED THUNDERSTORMS
AND SCATTERED SHOWERS...ESPECIALLY ACROSS SOUTH CENTRAL VERMONT.
OTHERWISE...MADE VERY LITTLE CHANGES. PREVIOUS DISCUSSION
FOLLOWS.

CURRENT SATELLITE AND RADAR TRENDS SHOWING 500HPA SHORTWAVE OVER
SOUTHERN ONTARIO AND QUEBEC WILL CONTINUE TO BE THE FOCUS FOR
SCATTERED SHOWERS AND AREAS OF DRIZZLE ACROSS THE FORECAST AREA
THROUGH THE MORNING HOURS OF INDEPENDENCE DAY. SHOWER ACTIVITY
SHOULD MAINLY BE LIGHT TO MODERATE...WITH SOME OROGRAPHIC
ENHANCEMENT LIKELY AS WINDS BEGIN TO TURN TO THE WEST- NORTHWEST.
AS THE SHORTWAVE ROUNDS THE BASE OF THE TROUGH DURING THE
AFTERNOON HOURS...SOME MID LEVEL DRY AIR WILL BE ADVECTED INTO
THE FORECAST AREA AND SHOULD DRY THE LOW LEVELS AND BEGIN TO
BREAK THE CLOUDS UP A BIT. WITH SUCH COLD AIR ALOFT (850HPA TEMPS
4-8C) TEMPS WILL BE RELATIVELY COOL FOR THE HOLIDAY RANGING FROM
THE MID TO UPPER 60S...ABOUT 10-15 DEGREES BELOW NORMAL. AS WINDS
TURN TO THE WEST- NORTHWEST PRESSURE GRADIENT WILL TIGHTEN A BIT
AS WELL WHICH SHOULD RESULT IN WIDESPREAD WIND GUSTS UP TO 20-25
MPH IN THE AFTERNOON HOURS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 302 AM EDT SATURDAY...UPPER LEVEL TROUGH AXIS PUSHES EAST
OF THE REGION OVERNIGHT...WITH A GENERAL WEST-NORTHWEST UPPER
LEVEL FLOW DEVELOPING SATURDAY NIGHT THROUGH SUNDAY. SOME
CLEARING SHOULD OCCUR SATURDAY NIGHT AS A WEAK UPPER RIDGE TRIES
TO BUILD INTO THE REGION...AND WITH TEMPS ALOFT WELL BELOW NORMAL
FOR THIS TIME OF YEAR...OVERNIGHT MINS WILL LIKELY RUN ABOUT 10
DEGREES BELOW NORMAL WITH VALLEYS IN THE LOWER 50S...AND
ELSEWHERE IN THE MID TO UPPER 40S. SUNDAY SHOULD BE RELATIVELY
DRY WITH WEAK UPPER RIDGE OVERHEAD...THOUGH WITH CONTINUED
NORTHWEST SURFACE FLOW AND AMPLE MID LEVEL MOISTURE...EXPECT
CONSIDERABLE CLOUDINESS DURING THE DAY. TEMPS WILL BE SLIGHTLY
WARMER THAN ON SATURDAY AS COLD AIR ALOFT RETREATS A LITTLE TO
THE NORTH...BUT STILL RUNNING A LITTLE BELOW NORMAL RANGING FROM
THE UPPER 60S TO MID 70S. DRY CONDITIONS WILL PERSIST THROUGH
SUNDAY NIGHT BEFORE A WEAK SURFACE LOW LOOKS TO AFFECT THE AREA
ON MONDAY. MODELS AGREE ON SOME WEAK TO MODERATE INSTABILITY
AHEAD OF THE ASSOCIATED FRONTAL BOUNDARY WITH SURFACE BASED CAPES
OF 500-1000 J/KG AND SLIGHTLY NEGATIVE LI/S AND SW/S. WITH SUCH A
COLD COOL POOL ALOFT (850HPA TEMPS STILL ONLY IN SINGLE DIGITS)
PRIMARY THREAT FROM ANY CONVECTIVE ACTIVITY WOULD BE HAIL...BUT
LIKELY NO LARGER THAN PEA SIZE.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 408 AM EDT SATURDAY...WE REMAIN UNDER THE INFLUENCE OF AN
UPPER LEVEL TROUGH THROUGH TUESDAY EVENING...SO CANNOT RULE OUT
POTENTIAL FOR SHOWERS...ESPECIALLY DIURNALLY DRIVEN THROUGH THEN.
BELOW NORMAL TEMPERATURES ALSO ACCOMPANY THIS PATTERN. A RIDGE
MOVES OVER THE NORTH COUNTRY WEDNESDAY THROUGH THURSDAY EVENING
BRINGING DRYER CONDITIONS AND A WARMING TREND. BY THURSDAY
SOUTHWEST SFC FLOW WILL BRING TEMPERATURES BACK TO NORMAL
READINGS...WITH ABOVE NORMAL TEMPERATURES AS WE HEAD INTO NEXT
WEEKEND. ENOUGH MID TO LOW LEVEL MOISTURE WILL BE PRESENT TO
MAINTAIN PRESENCE OF FAIR WEATHER CU DEVELOPMENT ESPECIALLY IN
TERRAIN...THOUGH PROBABILITY OF SHOWERS IS LOW THROUGH THURSDAY.
THERE IS SOME DISCREPANCY REGARDING POTENTIAL FOR PRECIPITATION ON
FRIDAY. GFS SOLUTION PROVIDES FOR A MORE ZONAL UPPER LEVEL FLOW
AND THUS IS MORE ROBUST ON TIMING AND SOUTHERLY PLACEMENT OF WARM
FRONT...ASSOCIATED WITH SFC LOW CENTER OVER NORTHWEST
ONTARIO...INTO THE NORTH COUNTRY. IN CONTRAST THE ECMWF MAINTAINS
A RIDGE OVER THE NORTH COUNTRY THROUGH FRIDAY...KEEPING US IN THE
WARM/DRY SECTOR. HAVE SPLIT THE DIFFERENCE FOR NOW... WITH A
SLIGHT CHANCE OF SHOWERS FRIDAY...INCREASING FRIDAY EVENING AND
NIGHT.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
THE REGION THIS AFTERNOON WILL DIMINISH AROUND 00Z SUNDAY WITH THE LOSS
OF DAYTIME SURFACE HEATING. EXPECT LOCAL AREAS OF MVFR/IFR IN ANY SHOWERS
AND THUNDERSTORMS. OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
THE HIGHER TERRAIN OF THE ADIRONDACKS AND GREEN MOUNTAINS WILL BE OBSCURED
IN CLOUDS AT TIMES THROUGH 00Z SUNDAY.

OUTLOOK 18Z SUNDAY THROUGH THURSDAY...
18Z SUNDAY THROUGH 12Z MONDAY...MAINLY VFR.
MONDAY...MAINLY VFR. A CHANCE OF AN AFTERNOON SHOWER OR
THUNDERSTORM...WITH LOCALLY MVFR/IFR CONDITIONS POSSIBLE.
TUESDAY...MAINLY VFR...SLIGHT CHANCE OF A RAIN SHOWER.
WEDNESDAY AND THURSDAY...MAINLY VFR.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.

&&

$$
SYNOPSIS...LAHIFF
NEAR TERM...NEILES/LAHIFF
SHORT TERM...LAHIFF
LONG TERM...AMF
AVIATION...WGH