Area Forecast Discussion
Issued by NWS Burlington, VT

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000
FXUS61 KBTV 281425
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
925 AM EST WED JAN 28 2015

.SYNOPSIS...
LINGERING FLURRIES WILL END THIS MORNING WITH PARTLY TO MOSTLY SUNNY
SKIES EXPECTED BY AFTERNOON AS HIGH PRESSURE SLOWLY BUILDS EAST INTO
THE REGION. CLEAR AND COLD WEATHER IS EXPECTED TONIGHT WITH THE HIGH
OVERHEAD. BY LATER THURSDAY INTO THURSDAY NIGHT...WIDESPREAD LIGHT
SNOWS AND MILDER TEMPERATURES RETURN TO THE REGION AS LOW PRESSURE
TRACKS EAST FROM THE GREAT LAKES. BEHIND THIS SYSTEM MUCH COLDER AIR
RETURNS FOR THE UPCOMING WEEKEND WITH THE POTENTIAL FOR MORE SNOWS
BY EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 919 AM EST WEDNESDAY...MINOR UPDATE TO CLEAN UP SOME
LEFTOVER OVER POPS ACRS THE CHAMPLAIN VALLEY AND ADJUST THE SKY
GRIDS FOR LATEST TRENDS ON VIS. CRNT RADAR SHOWS PRECIP HAS ENDED
ACROSS THE CHAMPLAIN VALLEY THIS MORNING...WITH CLEARING SKIES
DEVELOPING FROM WEST TO EAST ACRS OUR CWA. THIS WL CONT THRU THE
AFTN HOURS AS SFC HIGH PRES BUILDS INTO OUR FA. TEMPS WL SLOWLY
WARM INTO THE MID/UPPER TEENS MOST LOCATIONS WITH NORTH WINDS AT 5
TO 15 MPH. SOME HIGHER GUSTS POSSIBLE IN AREAS OF ENHANCED
CHANNELING ACROSS THE CHAMPLAIN AND SAINT LAWRENCE VALLEYS.

PRIOR DISCUSSION FROM 320 AM EST WEDNESDAY...
THE STORM SYSTEM WHICH BROUGHT LIGHT ACCUMULATING SNOWS AND GUSTY
WINDS TO THE REGION YESTERDAY CONTINUES TO PULL SLOWLY AWAY INTO
THE MARITIMES EARLY THIS MORNING. THIS TREND WILL CONTINUE TODAY
WITH THE LOW GRADUALLY LOSING INFLUENCE ON AREA WEATHER
CONDITIONS...BEING GRADUALLY REPLACED BY HIGH PRESSURE BUILDING
EAST FROM THE GREAT LAKES. THUS WINDS SLOWLY ABATE AND ANY
LINGERING FLURRIES/LIGHT SHSN WILL COME TO AN END BY AFTERNOON.
CLOUDY SKIES THIS MORNING WILL TREND PARTLY TO MOSTLY SUNNY BY
DAYS END AS HIGHS TOP OUT GENERALLY IN THE TEENS PER BLENDED MODEL
OUTPUT.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 320 AM EST WEDNESDAY...NARROW RIDGE AXIS THEN BUILDS ATOP
THE REGION TONIGHT WITH MAINLY CLEAR SKIES AND LIGHT WINDS. WITH A
FRESH SNOW COVER AND LIGHT WINDS IDEAL RADIATIONAL EFFECTS ARE
EXPECTED AND I TRENDED ON THE LOWER SIDE OF TEMPERATURE GUIDANCE
OFFERING MINIMUMS GENERALLY IN THE -5 TO -15F RANGE. CUSTOMARY
VARIABILITY WILL EXIST HOWEVER AND I IMAGINE OUR TYPICAL COLDER
LOCALES ACROSS THE ADIRONDACKS INTO NC/NE VT MAY APPROACH -20F BY
MORNING. MILDEST IN THE CHAMPLAIN VALLEY...AROUND ZERO GIVE OR
TAKE A FEW DEGREES.

HIGH PRESSURE THEN EXITS EAST DURING THURSDAY AND IS QUICKLY
REPLACED BY QUICK MOVING NORTHERN STREAM ENERGY ADVANCING FROM THE
OHIO VALLEY/GREAT LAKES STATES. MODELS HAVE TRENDED SLIGHTLY FURTHER
NORTH WITH THIS SYSTEM...TAKING A MEAN SLV TRACK ALONG THE INTL
BORDER BY THURSDAY NIGHT INTO FRIDAY. AMPLE WARM THERMAL/MOISTURE
ADVECTION ON THE NOSE OF ROBUST LOW TO MID LEVEL JET ENERGY SHOULD
ALLOW WIDESPREAD LIGHT SNOWS TO DEVELOP ACROSS OUR REGION TOWARD
EVENING AND CONTINUE THURSDAY NIGHT INTO THE FIRST PART OF FRIDAY
BEFORE TAPERING BACK.

HARD TO PINPOINT EXACT SNOW TOTALS...BUT CURRENT FORECAST TRACK
WOULD FAVOR THE HIGHEST AMOUNTS ACROSS THE NORTH/NRN MTS WHERE A
PLOWABLE SNOWFALL OF SEVERAL INCHES WILL BE POSSIBLE. THESE TYPES
OF CLIPPER-LOW TRACKS GENERALLY FAVOR THE FAR NRN SLV INTO THE
MONTREAL AREA FOR THE HEAVIEST TOTALS HOWEVER. IN THIS AREA STRONG
FRONTOGENETICAL FORCING WILL OCCUR AS MEAN NORTHEASTERLY PBL FLOW
IS INTERSECTED BY STRONG SOUTHWESTERLY FLOW TO THE IMMEDIATE
SOUTH. TIME WILL TELL...BUT EARLY MODEL OUTPUT USING MEAN 15:1
SNOW RATIOS (16-17:1 MTS) WOULD SUGGEST AS MUCH SHOWING A GENERAL
3-6 INCH SNOWFALL ACROSS OUR AREA WITH HIGHER TOTALS (FROM 6 TO 8
INCHES OR SO) IN A SW-NE STRIPE ALONG THE ST LAWRENCE RIVER FROM
MASSENA THROUGH MONTREAL TOWARD SHERBROOKE. SOME SHADOWING ALSO
POSSIBLE IN THE CHAMPLAIN VALLEY IF LOW TRACK VERIFIES.
INDEED...CURRENT MODEL OUTPUT SHOWING A ROBUST LOW LEVEL SOUTHERLY
JET OF 45 KTS IN THE VALLEY DURING THIS TIME FRAME...BRIDGED ALOFT
BY A 50 KT SOUTHWESTERLY 850 MB JET...CLASSIC SHADOWING
SIGNATURES. AGAIN...TIME WILL TELL. AT THIS POINT I`VE LEANED
TOWARD CHAMPLAIN VALLEY TOTALS IN THE 2-4 INCH RANGE WITH HIGHEST
TOTALS TOWARD THE INTL BORDER.

IN REGARD TO TEMPERATURES A NON-DIURNAL TREND WILL BE OFFERED
WITH HIGH THURSDAY IN THE MID TO UPPER 20S...AND HOLDING NEAR
STEADY THURSDAY NIGHT UNDER BROAD SOUTHERLY FLOW. AS SYSTEM PASSES
DURING FRIDAY...ASSOCIATED ARCTIC FRONTAL BOUNDARY WILL SWING INTO
THE REGION. THUS HIGHS SHOULD OCCUR IN THE MORNING FOR MOST
SPOTS...WITH READINGS FALLING STEADILY IN THE AFTERNOON AS STRONG
POST-FRONTAL COLD ADVECTION BEGINS ON GUSTY NORTHWEST FLOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 302 AM EST WEDNESDAY...DEPARTING CLIPPER LOW WILL CONTINUE
TO PRODUCE SOME SNOW SHOWERS ACROSS THE NORTH COUNTRY FRIDAY
NIGHT, ESPECIALLY IN THE HIGHER TERRAIN, AS WINDS SHIFT OUT OF THE
NORTHWEST RESULTING IN UPSLOPE SNOW. EXPECT THESE SNOW SHOWERS TO
END SATURDAY AS THE SURFACE LOW AND ASSOCIATED NEGATIVELY TILTED
TROUGH PUSH FURTHER EAST INTO THE CANADIAN MARITIMES. THIS DRY
WEATHER WILL PERSIST INTO SUNDAY/SUNDAY NIGHT.

00Z GFS AND ECMWF SHOWING DISAGREEMENT WITH THE NEXT SYSTEMS
TRACK AND STRENGTH. SOUTHERN STREAM LOW WILL DEVELOP IN THE
MISSISSIPPI VALLEY, MOVING NORTHEAST INTO THE OHIO VALLEY BY
SUNDAY NIGHT. GFS LAGGING BEHIND ECMWF TRACK AS ECMWF KEEPS UPPER
LEVEL TROUGH MORE POSITIVELY TILTED THROUGH AT LEAST MONDAY. GFS
BEGINS NEGATIVE TILTING EARLIER, HENCE THE SLOWER TRACK. BY MONDAY
EVENING, AS BOTH MODELS BRING THE SURFACE LOW OVER/NEAR THE
COASTAL WATERS, RAPID STRENGTHENING IS DEPICTED. THROUGHOUT THE
DEVELOPMENT OF THIS LOW, BOTH MODELS AGREE THAT MOISTURE FEED FROM
THE GULF OF MEXICO WILL PERSIST WITH 250MB JET EXCEEDING 125KTS
STRETCHES ACROSS THE SOUTHEAST UNITED STATES UP TO THE MID
ATLANTIC AND NORTHEAST. SO WHILE DETAILS OF THIS SYSTEM ARE STILL
UNCERTAIN, WILL HAVE TO KEEP AN EYE ON IT.

AS FOR TEMPERATURES, WE WILL HAVE A VERY COLD START TO THE PERIOD
AS 925MB TEMPERATURES FALL TO -20C TO -15C. FRIDAY AND SATURDAY
NIGHT MINS WILL RANGE FROM ZERO TO AS LOW AS -18F. SATURDAY WILL
REMAIN IN THE SINGLE DIGITS DURING THE DAY. GFS SHOWS SIGNIFICANT
WARMING AHEAD OF NEXT WEEKS STORM, WHILE THE FASTER MOVING ECMWF
BRINGS IN REINFORCING COLD AIR BY LATE MONDAY. THEREFORE, EXPECT
WARMEST DAY TO BE SUNDAY WITH MAXES IN THE TEENS. DEPENDING ON
TRACK AND PROGRESSION OF STORM, MONDAY LOOKS TO BE SIMILAR TO
SUNDAY BEFORE MUCH COLDER THAN NORMAL TEMPERATURES RETURN FOR
MONDAY NIGHT AND TUESDAY.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...VFR WITH A BAND OF SNOW SHOWERS CREATING
MVFR CONDITIONS IN THE CHAMPLAIN VALLEY...MAINLY AFFECTING KBTV
BRIEFLY. THESE SNOW SHOWERS WILL DIMINISH AROUND 14Z/15Z AND VFR
CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD FOR ALL SITES. LOW
LEVEL INVERSION WILL KEEP LOW LEVEL MOISTURE IN PLACE FOR THE
FIRST HALF OF THE DAY WITH SCT 030-060. DRIER AIR WILL FILTER IN
ON NORTH/NORTHWEST FLOW, LEADING TO MOSTLY CLEAR SKIES BY THE
AFTERNOON AND LASTING INTO THE OVERNIGHT.

NORTH TO NORTHWEST WINDS WILL PERSIST TODAY FOR ALL BUT KSLK/KMSS
WHICH WILL SEE SOUTHWEST TO WEST WINDS. SOME GUSTINESS EXPECTED AT
KBTV AND KRUT AT 15-25KTS. KPBG/KSLK AND KMPV MAY ALSO SEE A FEW
GUSTS.

OUTLOOK 12Z THURSDAY THROUGH SUNDAY...

12Z THURSDAY THROUGH 00Z FRIDAY...VFR CONDITIONS UNDER HIGH
PRESSURE.

00Z FRIDAY THROUGH 12Z SATURDAY...MVFR/IFR IN PERIODS OF SNOW.

12Z SATURDAY ONWARD...VFR.

&&

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

&&

$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM


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