Area Forecast Discussion
Issued by NWS Burlington, VT

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000
FXUS61 KBTV 041708
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
108 PM EDT MON MAY 4 2015

.SYNOPSIS...
AN UPPER RIDGE WILL PUSH OFFSHORE AS A WEAK COLD DROPS SOUTH FROM
QUEBEC ACROSS THE NORTH COUNTRY. AHEAD OF THE FRONT THERE WILL BE
GUSTY SOUTHWEST WINDS THAT WILL COMBINE WITH VERY DRY CONDITIONS
TO PRODUCE NEAR CRITICAL FIRE WEATHER CONDITIONS IN LOCATIONS
BELOW 2000 FEET. SCATTERED SHOWERS WILL ACCOMPANY THE FRONT ON
MONDAY NIGHT WITH COOLER AIR ARRIVING ON TUESDAY RETURNING THE
REGION TO NEAR SEASONAL TEMPERATURES AND DRY WEATHER THROUGH THE
REST OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 103 PM EDT MONDAY...VERY MINOR UPDATE TO INCREASE TEMPS
ACROSS PARTS OF THE CHAMPLAIN AND SAINT LAWRENCE VALLEYS BY
SEVERAL DEGREES. BASED ON GOOD MIXING AND VERY DRY SFC
CONDITIONS...EXPECTING HIGHS IN THE LOW/MID 80S CPV/SLV WITH M/U
70S IN THE MTN TOWNS...INCLUDING THE NEK. WINDS HAVE GUSTED TO 39
MPH AT KMSS THIS AFTN...BUT MUCH LESS OVER THE CPV AND MOST OF
VT...WITH GUSTS IN THE 15 TO 20 MPH RANGE. THESE WINDS WILL
INCREASE AS SFC HEATING CONTS OVER MOST OF THE REGION THIS
AFTN...WITH RH VALUES DROPPING INTO THE 20% RANGE...BEFORE
INCREASING AS SFC FRONT APPROACHES LATE TODAY. ALREADY SEEING SOME
WEAK RADAR RETURNS ASSOCIATED WITH FRONT ACROSS THE OTTAWA
VALLEY...BUT GIVEN DRY LOW LEVELS...NOT EXPECTING ANY PRECIP TO
REACH THE GROUND THROUGH THIS AFTN.

HAVE UPDATED FCST TO INCLUDE A USER REQUESTED RED FLAG WARNING
FOR ENTIRE CWA FROM 11 AM TO 7 PM THIS EVENING...GIVEN THE
EXTREMELY DRY FINE FUELS. THE SLOWER TIMING OF SURFACE BOUNDARY
WILL ALLOW MIN RH`S TO DROP BTWN 20 AND 30% MOST LOCATIONS THIS
AFTN...BUT WINDS WILL BE MARGINAL...ESPECIALLY ACROSS THE
PROTECTED VALLEYS OF CENTRAL/EASTERN AND SOUTHERN VT. EXPECTING
STRONGEST WINDS WITH GUSTS BTWN 25 AND 30 MPH ACROSS THE SAINT
LAWRENCE VALLEY AND NORTHERN DACKS. A FEW LOCALIZED GUSTS TO 40
MPH WILL BE POSSIBLE IN THE SAINT LAWRENCE VALLEY WHERE ALIGNED
FLOW WILL ENHANCE THE WIND SPEEDS. OTHERWISE...TEMPS WILL WARM
INTO THE MID 70S MTNS TO LOWER 80S WITH INCREASING CLOUDS FROM
APPROACHING SFC BOUNDARY THIS AFTN. ANY PRECIP WILL ARRIVE TWD
SUNSET ACROSS THE SAINT LAWRENCE VALLEY AND SPREAD INTO VT
OVERNIGHT...WITH AMOUNTS GENERALLY < 0.25" AND CONFINED TO THE
MOUNTAINS.

PREVIOUS FCST BELOW...

THE LACK OF CLOUD COVER HAS ALLOW FOR TEMPS TO QUICKLY BEGIN
HEATING UP THIS MORNING AFTER DAY BREAK. TEMPS OVER NORTHERN NEW
YORK IN THE SAINT LAWRENCE VALLEY ARE ALREADY IN THE LOW 60S WITH
MID 50S ELSEWHERE AND EXPECT TO CONTINUE WARMING THROUGH THE DAY
MOST LIKELY REACHING THE 80S FOR A DAYTIME MAX TEMP BEFORE THE
FRONT THIS EVENING. LIGHT WINDS ARE CURRENTLY SOUTHWEST 4-8 KTS
ACROSS THE REGION. UNDER CLEAR SKIES. EXCEPT FOR THE POTENTIALLY
DANGEROUS FIRE WEATHER CONDITIONS... TODAY THROUGH THE AFTERNOON
IS SHAPING UP TO BE A LOVELY DAY AND POTENTIALLY THE FIRST DAY IN
THE 80S IN BURLINGTON SINCE 10/15/2014. THE FORECAST IS IN PRETTY
GOOD SHAPE SO OTHER THAN A QUICK UPDATE TO FRESHEN UP THE TEMPS IN
THE FIRST 3-4 HOURS NO CHANGES NECESSARY.

PREVIOUS DISCUSSION AS OF 355 AM MONDAY...WE WILL DRY OUT TODAY
BECAUSE OF THE UPPER LEVEL RIDGE THAT HAS BEEN IN PLACE FOR THE
PREVIOUS COUPLE OF DAYS AND THE SOUTHERLY WINDS AT THE SURFACE.
THIS WILL WARM THE AREA VERY QUICKLY DURING THE DAY TODAY. LOW AND
MID LEVEL MOISTURE IS QUITE LOW ACROSS THE NORTH COUNTRY AND THUS
OVERALL CLOUD COVER WILL BE MINIMAL. EXPECT MOSTLY CLEAR SKIES
THROUGH THIS AFTERNOON BEFORE A COLD FRONT BEGINS TO MOVE SOUTH
INTO THE REGION. CLOUDS WILL OVERSPREAD FROM NORTHWEST TO
SOUTHEAST AHEAD OF THE FRONT AND THE ATMOSPHERE WILL BECOME VERY
WELL MIXED UP TO 7000 FEET ACROSS THE NORTH COUNTRY. THE WELL
MIXED ATMOSPHERE AND STEEP LOW LEVEL LAPSE RATE WILL BRING GUSTY
WINDS AHEAD OF THE FRONT GUSTING 20-30KTS ACROSS MUCH OF NORTHERN
NEW YORK AND 15-20KTS ACROSS VERMONT.

THE DRY AIR AND GOOD MIXING WILL ALLOW FOR TEMPERATURES ACROSS THE
REGION TO WARM INTO AT LEAST THE UPPER 70S FOR THE SECOND DAY IN A
ROW WITH 80F BEING A REAL POSSIBILITY IN THE SAINT LAWRENCE AND
CHAMPLAIN VALLEYS. WITH LAKE CHAMPLAIN STILL BEING QUITE COLD THE
AIR TEMP OVER THE LAKE WILL BE SIGNIFICANTLY COOLER AND SO ACROSS
THE BROAD LAKE I`VE ONLY GOT MAX TEMPS TODAY WARMING TO AROUND 70
AND THE NEAR SHORE AREAS IN THE LOW TO MID 70S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
AS OF 355 AM EDT MONDAY...
BY 23Z THIS EVENING OR 7PM, EXPECT THE FIRST SHOWERS TO START TO
MOVE INTO NORTHERN NEW YORK AS THE COLD FRONT DRAWS CLOSER TO THE
AREA. AS THE LINE OF SHOWERS DROPS TO THE SOUTH AND MEETS MODERATE
SOUTHWEST FLOW EXPECT IT TO STRUGGLE TO HOLD TOGETHER OVER THE
ADIRONDACKS AND SEE THE CHAMPLAIN VALLEY BECOME SHADOWED FROM THE
SHOWERS WITH ONLY LIGHT SHOWERS EXPECTED. IN THE HIGHER TERRAIN
HOWEVER EXPECT THE OROGRAPHIC LIFT TO COMBING WITH THE WEAK
INSTABILITY ASSOCIATED WITH A 500MB VORT AXIS AND PRODUCE A FEW
MODERATE RAIN SHOWERS ESPECIALLY OVER THE NORTHERN ADIRONDACKS AND
SOUTHERN AND CENTRAL GREENS. HOWEVER WIDESPREAD PRECIPITATION WILL
BE LIGHT EXPECTING TOTAL PRECIP AMOUNTS TO RANGE FROM 0.10" TO
0.30". SIMILAR TO THE PREVIOUS FORECAST WITH THE WEAKER
INSTABILITY I CHOSE TO LEAVE OUT MENTION OF TS IN THE FORECAST BUT
IT WOULDN`T SURPRISE ME TO HEAR A FEW RUMBLES OF THUNDER AS THE
LINE MOVES THROUGH NEW YORK.

BEHIND THE FRONT MONDAY NIGHT TEMPS WILL FALL INTO THE MID 50S IN
THE CHAMPLAIN VALLEY AND UPPER 40S ELSEWHERE. WE WILL THEN MOVE
INTO A PATTERN OF NEAR SEASONABLE TEMPS AND DRY WEATHER AS THE
FLOW ALOFT BECOMES NORTHWEST AND SLIGHT UPPER LEVEL RIDGING BEGINS
TO OCCUR.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 355 AM EDT MONDAY...
DRY AND SPRING-LIKE WEATHER EXPECTED THROUGH FRIDAY.

ECMWF AND GFS MODELS ARE IN GENERALLY GOOD AGREEMENT THROUGH THE
PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH.

ECMWF AND GFS MODELS SHOW A RIDGE OF HIGH PRESSURE WILL BE OVER THE
REGION WEDNESDAY NIGHT THROUGH FRIDAY.

A WEAK COLD FRONT WILL MOVE SOUTH FROM CANADA ON SATURDAY...SO HAVE
GONE WITH CHANCE POPS FOR SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS. MODELS SHOWING FRONTAL SYSTEM WILL BE OVER OR JUST
SOUTH OF THE REGION ON SUNDAY...SO WILL CONTINUE WITH CHANCE POPS
FOR RAIN SHOWERS ON SUNDAY.

&&

.AVIATION /17Z MONDAY THROUGH SATURDAY/...
THROUGH 12Z TUESDAY...MAINLY VFR CONDITIONS THROUGH THE PERIOD. A
RIDGE OF HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY. THIS
WILL ALLOW FOR SOUTHERLY SURFACE WINDS TO DEVELOP ACROSS VERMONT
AND NORTHERN NEW YORK TODAY. SURFACE PRESSURE GRADIENT TO TIGHTEN
ACROSS THE REGION TODAY...WITH SOUTH TO SOUTHWEST SURFACE WIND
GUSTS OF 20 KNOTS OR GREATER TO DEVELOP BETWEEN 13Z-15Z MONDAY AND
CONTINUE THROUGH 00Z TUESDAY. A COLD FRONT WILL MOVE SLOWLY EAST
FROM THE WESTERN GREAT LAKES TODAY AND WILL MOVE INTO THE SAINT
LAWRENCE VALLEY IN NORTHERN NEW YORK AFTER 00Z TUESDAY. EXPECTING
LIGHT RAIN SHOWERS TO DEVELOP ACROSS NORTHERN NEW YORK BETWEEN
02Z-06Z TUESDAY...AND THEN ACROSS VERMONT BETWEEN 04Z-12Z...WITH
SOME LOCAL AREAS OF MVFR POSSIBLE.

OUTLOOK 12Z TUESDAY THROUGH FRIDAY...

12Z TUESDAY-00Z SATURDAY...VFR CONDITIONS WITH WEAK SURFACE HIGH
PRESSURE PREVAILING FOR MUCH OF THE PERIOD.

&&

.FIRE WEATHER...
BREEZY SOUTH TO SOUTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS TO 30
MPH WILL OCCUR BETWEEN 11 AM AND 4 PM MONDAY....WITH MINIMUM
RELATIVE HUMIDITY VALUES BETWEEN 26% AND 36%. A FEW HIGHER GUSTS
TO NEAR 40 MPH WILL BE POSSIBLE IN THE SAINT LAWRENCE VALLEY AND
PARTS OF THE NORTHERN ADIRONDACKS. THE STRONGEST WINDS WILL BE
LOCATED ACROSS THE SAINT LAWRENCE VALLEY...NORTHERN
ADIRONDACKS...AND PARTS OF THE CHAMPLAIN VALLEY INTO NORTHERN
VT...WHILE THE LOWEST RH VALUES WILL BE ACROSS SOUTHERN VT.

THESE CONDITIONS COMBINED WITH 60 TO 90 DAY DEPARTURE FROM NORMAL
PRECIPITATION DEFICITS OF 2 TO 4 INCHES HAVE RESULTED IN FINE FUELS
BECOMING VERY DRY BELOW 2000 FEET...ACCORDING TO THE VERMONT
DEPARTMENT OF FOREST...PARKS AND REC AND NEW YORK STATE DEPARTMENT
OF ENVIRONMENTAL CONSERVATION. GIVEN THE NEAR CRITICAL FIRE WEATHER
CONDITIONS...WE WILL HIGHLIGHT POTENTIAL THREAT WITH A SPECIAL
WEATHER STATEMENT AT THIS TIME.

AS A SURFACE COLD FRONT APPROACHES THE SAINT LAWRENCE VALLEY AND
NORTHERN ADIRONDACKS AFTER 4 PM MONDAY... RELATIVE HUMIDITY VALUES
WILL INCREASE AS CLOUDS AND ASSOCIATED MID LEVEL MOISTURE OVERSPREAD
THE REGION...WITH SCATTERED RAIN SHOWERS DEVELOPING BY EVENING.
THESE SHOWERS WILL SPREAD EAST INTO THE CHAMPLAIN VALLEY AND MOST OF
VERMONT OVERNIGHT...BUT PRECIPITATION WILL BE LIGHT AND MAINLY
CONFINED TO THE MTNS.

&&

.MARINE...
AS OF 1144 AM EDT MONDAY...A LAKE WIND ADVISORY IS NOW IN EFFECT
FOR LAKE CHAMPLAIN. WINDS ACROSS THE BROAD LAKE ARE JUST 15-25
KNOT THRESHOLD. THOUGH LAKE TEMPERATURES LIMIT MIXING DEPTH, A
STRENGTHENING SOUTHWEST PRESSURE GRADIENT WILL INCREASE WINDS TO
LAKE WIND ADVISORY CRITERIA. WINDS SHOULD BEGIN TO ABATE TO 10 TO
20 KNOTS LATER THIS EVENING AS A COLD FRONT MOVES THROUGH, WITH A
WIND SHIFT TO NORTHWEST. WAVES OF 1 TO 2 FEET ARE EXPECTED, WITH
THE HIGHEST WAVES PREFERENTIALLY ALONG SOUTH- FACING EXPOSURES.

BOATERS SHOULD ALSO KEEP IN MIND THAT WATER TEMPERATURES REMAIN
COLD - IN THE 40S. SWIMMING EARLY IN THE SEASON IS DISCOURAGED AS
IMMERSION FOR PROLONGED PERIODS OF TIME COULD PRODUCE HYPOTHERMIA
GIVEN THESE WATER TEMPERATURES.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR VTZ001>012-
     016>019.
NY...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NYZ026>031-
     034-035-087.

&&

$$
SYNOPSIS...DEAL
NEAR TERM...TABER
SHORT TERM...DEAL
LONG TERM...WGH
AVIATION...WGH
FIRE WEATHER...TABER/DEAL
MARINE...LOCONTO



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