-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 280530
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
1230 AM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEASTERN UNITED STATES WILL BRING
CONTINUED FAIR WEATHER AND MOSTLY CLEAR SKIES THROUGH MUCH OF THE
WEEKEND. AN APPROACHING WAVE OF LOW PRESSURE FROM THE OHIO VALLEY
WILL BRING LIGHT SNOW BEGINNING SUNDAY EVENING AND LASTING INTO
MONDAY MORNING...WITH SNOW ACCUMULATIONS OF 2 TO 4 INCHES
GENERALLY EXPECTED. ANOTHER STRONGER AREA OF LOW PRESSURE IS
EXPECTED TO PASS TO OUR WEST TUESDAY NIGHT INTO WEDNESDAY BRINGING
MIXED WINTRY PRECIPITATION AND PERIODS OF GUSTY WINDS. FOLLOWING
THE BRIEF WARMUP WEDNESDAY...COLDER WEATHER IS EXPECTED TO RETURN
FOR THURSDAY AND CONTINUE INTO FRIDAY.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 1229 AM EST SATURDAY...NO SIGNIFICANT CHANGES FOR 1230
UPDATE...PREVIOUS DISCUSSION FOLLOWS.

A FEW ADDITIONAL TWEAKS TO SKY COVER ACROSS THE WESTERN
ADIRONDACKS AS OF 900 PM TO ACCOUNT FOR DOWNSTREAM TRANSPORT OF
LAKE INDUCED CLOUD COVER. GENERALLY LIGHT BOUNDARY LAYER FLOW
SHOULD KEEP ANY FLURRY/SHSN ACTIVITY CONFINED TO AREAS CLOSER TO
THE LAKE. INCREASE IN CLOUD COVER PREDICATED A SLIGHT UPWARD
ADJUSTMENT IN MIN TEMPS IN THIS AREA. ALSO RAISED MINS A TAD IN
THE SLV WHERE PERSISTENT LIGHT SOUTHWESTERLY FLOW TONIGHT SHOULD
KEEP READINGS FROM COMPLETELY RADIATING OUT. REST OF FORECAST
REMAINS IN GOOD SHAPE. HAVE A GREAT NIGHT.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 336 PM EST FRIDAY...STRONG SFC HIGH PRESSURE REMAINS
ANCHORED OVER THE NERN CONUS THROUGH SUNDAY MORNING...PROVIDING
CONTINUED DRY AND MOSTLY CLEAR CONDITIONS THRU MOST OF THE
WEEKEND. WITH THE INCREASING SUN ANGLE AS WE CLOSE OUT
FEBRUARY...BUMPED HIGHS SEVERAL DEGREES ABOVE MOS CONSENSUS FOR
SATURDAY AND SUNDAY...WITH READINGS REACHING THE LOW/MID 20S FOR
SATURDAY IN VALLEY LOCATIONS...AND MID/UPR 20S ON SUNDAY. WILL SEE
AN INCREASE IN MID-UPPER LEVEL CLOUDS DURING THE AFTN HOURS SUNDAY
AS FRONTAL WAVE TRACKS EWD ACROSS THE OH VALLEY AND MID-LEVEL WAA
REGIME COMMENCES ACROSS NY/NEW ENGLAND. PRESSURE GRADIENT ALSO
INCREASES AS SFC ANTICYCLONE SHIFTS EWD INTO THE GULF OF MAINE.
THUS...WILL SEE SOUTH-SSW WINDS 10-15 MPH (WITH SOME GUSTS 20-25
MPH SUNDAY AFTN IN THE CHAMPLAIN VALLEY).

INCREASING 850-700MB WAA AND ISENTROPIC ASCENT ALLOWS WIDESPREAD
LIGHT SNOW TO DEVELOP ACROSS THE NORTH COUNTRY FROM SW-NE DURING
SUNDAY EVENING. SHOULD SEE PERIODS OF LIGHT SNOW CONTINUING
THROUGH THE OVERNIGHT HOURS WITH 2-3" OF ACCUMULATION BY DAYBREAK
MONDAY IN MOST SPOTS. OVERCAST SKIES AND CONTINUED LIGHT S-SW
WINDS WILL KEEP TEMPS FROM FALLING MUCH SUNDAY NIGHT WITH
OVERNIGHT LOWS MAINLY IN THE MID-UPR TEENS.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 336 PM EST FRIDAY... MONDAY... A WEAK UPPER LEVEL TROUGH
WILL BE PASSING THROUGH THE AREA BRINGING CHANCE TO LIKELY POPS
ACROSS THE NORTH COUNTRY AS A SURFACE LOW PRESSURE SYSTEM SLIDES
TOWARDS THE EAST NORTHEAST. THIS WILL RESULT IN TEMPS SLIGHTLY
BELOW NORMAL RANGING FROM THE MID TO UPPER 20S ACROSS THE AREA FOR
MAX TEMPS AND THE OVERNIGHT LOWS IN THE SINGLE DIGITS ABOVE ZERO
IN THE VALLEYS WITH SINGLE DIGITS BELOW ZERO IN THE NORTHEAST
KINGDOM AND IN THE ADIRONDACK MOUNTAINS. MODERATELY STRONG
WESTERLY WINDS WILL BE LIKELY ON THE SOUTHERN EXTENT OF THE UPPER
LEVEL TROUGH AS THERE WILL BE A DECENT PRESSURE GRADIENT FORCE
BETWEEN THE 1008MB LOW OVER THE GULF OF MAINE AND THE 1034MB HIGH
CENTERED OVER IOWA. THIS SHOULD PRODUCE WESTERLY WINDS BETWEEN
10-15KTS GUSTING TO 25KTS ACROSS THE VALLEYS WITH MUCH HIGHER
VALUES AT THE SUMMITS GUSTING TO NEARLY 45KTS AT THE TOP OF
WHITEFACE MOUNTAIN AND MT MANSFIELD. THE WESTERLY WINDS WILL LEAD
TO SOME ADDITIONAL UPSLOPE SNOWFALL ON THE WESTERN SLOPES OF BOTH
THE GREENS AND THE ADIRONDACKS SO THAT WOULD BE WHERE I`D EXPECT
THE MOST SIGNIFICANT SNOWFALL ACCUMULATIONS. EVEN SO, I`M ONLY
LOOKING AT ADDITIONAL SNOWFALL OF 0.5 TO 1.5" INCHES ON MONDAY AND
THEN THE PRECIP SHOULD END SHARPLY AS THE LOW CONTINUES OFFSHORE
AND HIGH PRESSURE SETS IN.

TUESDAY... THE HIGH PRESSURE WILL BUILD INTO THE AREA LEAVING
SLIGHTLY COOLER TEMPERATURES THAN MONDAY BUT STILL WELL ABOVE WHAT
WE`VE BEEN SEEING MOST OF FEBRUARY. EVEN BEHIND THE MILD FRONT
THAT PASSES THROUGH ON MONDAY, THE RISING SUN ANGLE WILL ALLOW FOR
TEMPS TO BE IN THE LOW TO MID 20S ACROSS THE AREA. THE PRESSURE
GRADIENT THAT CAUSED MONDAY`S WINDS WILL HAVE SUBSIDED LEAVING
LIGHT AND VARIABLE WINDS ACROSS THE AREA SHIFTING FROM MAINLY
WESTERLY WINDS TO SOUTHERLY WINDS. OVERNIGHT LOWS TUESDAY NIGHT
INTO WEDNESDAY MORNING WILL ONLY DROP BY A FEW DEGREES AS THE
SOUTHERLY WARMER RETURN FLOW WILL SET IN OVERNIGHT BEHIND THE
DEPARTING HIGH.

WEDNESDAY...THERE ARE TWO SLIGHTLY DIFFERING SOLUTIONS FOR THE
FORECAST ON WEDNESDAY. THE BROAD SENSE OF THE FORECAST IS THAT A
DEVELOPING UPPER LEVEL RIDGE NORTH OF THE GREAT LAKES WILL SPAWN A
SURFACE LOW PRESSURE SYSTEM OVER THE GREAT LAKES. THAT SURFACE
SYSTEM WILL FEED OFF BOTH A NORTHERLY STREAM OF ENERGY AND A
SOUTHERLY STREAM OF MOISTURE FROM THE DEPARTING HIGH PRESSURE
SYSTEM. THE NET RESULT IS A WIDESPREAD PRECIPITATION EVENT
WEDNESDAY MORNING INTO THE EARLY AFTERNOON. FOR THE FIRST TIME IN
A LONG TIME THE CURRENT IDEA IS THAT RAIN WILL BE LIKELY AT SOME
POINT ON WEDNESDAY MORNING. AS THE LOW LEVEL WARM ADVECTION PUSHES
INTO THE AREA TEMPS WILL WARM INTO THE UPPER 30S TO LOW 40S ACROSS
THE NORTH COUNTRY ON WEDNESDAY. AS SUCH THERE WILL BE A WINTRY MIX
OF SNOW TRANSITIONING TO RAIN ON WEDNESDAY BY MORNING AND THEN
BACK TO SNOW IN THE LATE AFTERNOON/EVENING. USING THE GFS AS THE
THERMAL PROFILE GAVE ME QUITE THE MIX OF PTYPES. FOR THE TIME
BEING I OPTED TO REMOVE FREEZING RAIN FROM THE FORECAST TRANSITION
AND TRANSITION STRAIGHT FROM SNOW TO SLEET AND THEN TO RAIN. THERE
WILL LIKELY BE A SMALL WINDOW OF FREEZING RAIN BUT AT 5 AND 6 DAYS
OUT I JUST DON`T HAVE THAT KIND OF CONFIDENCE IN THE TIMING OF
THAT WINDOW. I DID HOWEVER WANT TO ESTABLISH THE WINTRY MIX AND
THUS NOT JUST POINT TO RAIN OR SNOW. 1000-500MB THICKNESS LEVELS
WILL BE APPROACH 5500 METERS WELL ABOVE THE "MAGIC" 5400 METER
LINE FOR RAIN/SNOW. RIGHT NOW I WENT WITH A CONSENSUS OF BOTH THE
GFS AND ECMWF ON TIMING/LOCATION/INTENSITY BUT I FAVORED THE
TRACK OF THE ECMWF A BIT MORE BECAUSE THE GFS POINTS TO A LOW
TRACKING UP THE SAINT LAWRENCE VALLEY AND THEN BOMBING OUT OVER
THE CANADIAN MARITIMES. CLIMATOLOGICALLY SPEAKING THATS QUITE RARE
AND TYPICALLY DOESN`T HAPPEN. THE BOMBING LOWS TYPICALLY RUN UP
THE COASTAL SO CONSIDER ME SKEPTICAL OF THAT SOLUTION FOR THE TIME
BEING. AS THE LOW PUSHED THROUGH THE REGION THERE WILL BE
MODERATELY STRONG WINDS ESPECIALLY ALOFT GUSTY TO 40-50KTS ABOVE
2000 FT.

THURSDAY... THE SURFACE LOW THAT BROUGHT THE SNOWFALL WILL BE
PUSHING WELL OUT OF THE AREA TOWARDS THE NORTHEAST GIVING WAY TO
ANOTHER BROAD RIDGE OF HIGH PRESSURE. EARLY IN THE MORNING
THURSDAY A BURST OF ENERGY FROM THE UPPER LEVEL TROUGH AND THE
NORTHERLY WRAP AROUND WINDS ALOFT WILL PRODUCE A DECENT SHOT AT
OROGRAPHIC SNOW SHOWERS IN THE ADIRONDACKS AND THE GREENS SO I
WENT CHANCE POPS THROUGH THE DAY ON THURSDAY WITH SLIGHT CHANGE
BEGINNING EVERYWHERE ELSE BY THURSDAY MID MORNING. THE ADVANCING
HIGH PRESSURE SYSTEM WILL BRING MAX TEMPS AROUND 30 IN THE
CHAMPLAIN VALLEY WITH LOW TO MID 20S ELSEWHERE ACROSS THE FORECAST
REGION. OVERNIGHT LOWS ON THURSDAY WILL BE IN THE SINGLE DIGITS
AGAIN AS THE HIGH PRESSURE SETS IN AND WE WILL DEVELOP DECENT
RADIATIONAL COOLING CONDITIONS WITH LIGHT WINDS AND UNDER PARTLY
CLOUDY SKIES.

FRIDAY... ONCE AGAIN TEMPS WILL ONLY WARM TO THE UPPER TEENS TO
LOW 20S UNDER THE STRONG HIGH PRESSURE SYSTEM AND ONLY MARGINAL
CHANCES OF SOME OROGRAPHIC SNOW SHOWERS IN THE HIGHER TERRAIN OF
THE GREENS AND THE ADIRONDACKS.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...VFR EXPECTED THROUGH THE PERIOD WITH
GENERALLY CLEAR SKIES AND LIGHT WINDS AS HIGH PRESSURE MAINTAINS
CONTROL. EXCEPTION IS SLK WHICH WILL SEE SOME LOW CLOUDS THROUGH
SATURDAY MORNING WITH OCNL MVFR CONDITIONS. WINDS LIGHT WESTERLY
EXCEPT SOUTHWEST AND A BIT GUSTY AT TIMES AT MSS/SLK DURING
SATURDAY.

OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...

06Z SUNDAY-18Z SUNDAY...MAINLY VFR WITH HIGH PRESSURE.

18Z SUNDAY-00Z TUESDAY...DEVELOPING WARM FRONT AND ASSOCIATED
WEAK AREA OF LOW PRESSURE WILL INCREASE THE CLOUDS WITH SNOW
LIKELY BY 00Z MONDAY. EXPECT MVFR WITH PERIODS OF IFR.

00Z TUESDAY-18Z TUESDAY...VFR CONDITIONS UNDER HIGH PRESSURE.

18Z TUESDAY ONWARD...INCREASING CHANCE FOR MVFR/IFR IN MIXED
PRECIPITATION AS WARM FRONT APPROACHES FROM THE SOUTHWEST.

&&

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

&&

$$
SYNOPSIS...BANACOS
NEAR TERM...JMG/NEILES
SHORT TERM...BANACOS
LONG TERM...DEAL
AVIATION...RJS