weather.gov     
National Weather Service

Area Forecast Discussion
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to SR-SRH.Webmaster@noaa.gov with any concerns.


Current Version
Previous Version:    01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  
   31  32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47  48  49  50  51  52  53  54  55  56  57  58  59  60  
[Printable]
801
FXUS61 KBTV 291427
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
927 AM EST THU JAN 29 2015

.SYNOPSIS...
A WEAK CLIPPER LIKE SYSTEM WILL PRODUCE A WIDESPREAD LIGHT SNOW
THIS EVENING INTO FRIDAY...FOLLOWED BY UPSLOPE SNOW SHOWERS AND
BITTERLY COLD TEMPERATURES FRIDAY NIGHT. HIGH PRESSURE WILL BUILD
IN FOR THE WEEKEND WITH TEMPERATURES MUCH BELOW NORMAL.
TEMPERATURES OF 10 TO 15 DEGREES BELOW NORMAL WILL PERSIST INTO
THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 4 PM THIS AFTERNOON/...
AS OF 919 AM EST THURSDAY...THE DAY IS STARTING OFF WITH PLENTY OF
SUNSHINE THANKS TO 1030 MB HIGH OVER THE REGION THIS MORNING. AS
THE HIGH SLIDES EAST AND SHORTWAVE AND ASSOCIATED CLIPPER SYSTEM
APPROACH FROM THE GREAT LAKES...CLOUDS WILL BE ON THE INCREASE
THIS AFTERNOON WITH THE CHANCE OF SNOW WESTER PORTION OF FORECAST
AREA LATE IN THE DAY. TEMPS STILL QUITE COLD WITH READINGS STILL
WELL BELOW ZERO IN MANY LOCATIONS...BUT THEY WILL BE MODERATING
RATHER QUICKLY AS SOUTHERLY FLOW DEVELOPS. STILL LOOKING AT HIGHS
IN THE MID TO UPPER 20S. ONLY CHANGES TO GOING FORECAST WITH
LATEST UPDATE WERE SOME ADJUSTMENTS TO HOURLY TEMPS THIS MORNING
TO ACCOUNT FOR LATEST OBS AND TRENDS.

PREVIOUS DISCUSSION...
COLD MORNING THANKS TO RIDGING ALOFT WITH TEMPERATURES GENERALLY
BELOW ZERO WITH COLDEST TEMPS IN THE NORTHEAST KINGDOM AND
ADIRONDACKS REPORTING NEGATIVE TEENS. THE RIDGE WILL ERODE TODAY,
WHILE AT THE SURFACE A CLIPPER SYSTEM APPROACHING FROM THE GREAT
LAKES REGION WILL INCREASE CLOUDS ACROSS THE NORTH COUNTRY.
SOUTHERLY WINDS WILL PICK UP AT 5-15 KTS WITH GUSTS DEVELOPING
AHEAD OF THE CLIPPER. THIS FLOW WILL RESULT IN WARM AIR ADVECTION
WITH 925MB INCREASING TO AROUND -4C. AFTERNOON TEMPERATURES WILL
REACH THE M20S TO AROUND 30.

THE CLIPPER WILL INCREASE CHANCE FOR SNOW TO SPREAD EASTWARD THIS
AFTERNOON...REACHING THE SOUTHWESTERN ST LAWRENCE VALLEY FIRST.

&&

.SHORT TERM /4 PM THIS AFTERNOON THROUGH SATURDAY/...
AS OF 629 AM EST THURSDAY...SNOW WILL SPREAD INTO THE ST LAWRENCE
VALLEY...AFFECTING THE AFTERNOON/EVENING COMMUTE. A STRONG SOUTH-
SOUTHWESTERLY LOW LEVEL JET WILL BRING GUSTY WINDS, RESULTING IN
BLOWING SNOW AND REDUCED VISIBILITIES. THIS JET WILL ALSO CAUSE
SHADOWING AFFECTS IN THE CHAMPLAIN VALLEY AND NORTHEASTERN SLOPES.
AS PWATS REACH AROUND HALF AN INCH TONIGHT, THIS WILL COINCIDE
WITH THETA-E RIDGE, SO EXPECT HEAVIEST SNOWFALL TO OCCUR MAINLY
BETWEEN 06Z-15Z FRIDAY.

THE CENTER OF THE CLIPPER TRAVERSES NEAR THE INTERNATIONAL BORDER
EARLY FRIDAY MORNING THEN REDEVELOPS OFF THE SOUTHERN NEW ENGLAND
COAST IN THE AFTERNOON AS THE ASSOCIATED MID LEVEL TROUGH BEGINS
TO NEGATIVELY TILT. THIS TILTING WILL RESULT IN THE SURFACE LOW
SLOWING ITS PROGRESSION AND KEEPING CENTRAL AND EASTERN VERMONT IN
SNOW/SNOW SHOWERS INTO FRIDAY AFTERNOON/EVENING. BEHIND THE
SURFACE LOW, SOUTHERLY WINDS OVER THE NORTH COUNTRY WILL SHIFT
NORTHEAST. THIS COMBINED WITH LINGERING MOISTURE WILL PRODUCE
UPSLOPE SNOW SHOWERS WITH FROUDE NUMBERS SHOWING BLOCKED FLOW.
WHEN ALL IS SAID AND DONE, EXPECT 3-6 INCHES OF SNOWFALL FOR THE
ST LAWRENCE VALLEY, STRETCHING ACROSS THE NORTHERN TIER OF OUR
ZONES INTO THE CENTRAL CHAMPLAIN VALLEY, NORTHWESTERN, NORTH
CENTRAL AND NORTHEASTERN VERMONT. DUE TO SHADOWING, ESSEX COUNTY
NY AND THE SOUTHERN CHAMPLAIN VALLEY AND SOUTH CENTRAL VT LOOK TO
RECEIVE 2-4 INCHES. LOCALLY HIGHER AMOUNTS ARE POSSIBLE,
ESPECIALLY IN THE IN THE WESTERN ST LAWRENCE VALLEY, AS MODELS
DEPICT BEST MOISTURE AND DEFORMATION TO OCCUR IN THIS AREA.

THE NW FLOW WILL USHER IN COLDER AIR WITH NON DIURNAL TREND
EXPECTED FRIDAY. DRIER AIR WILL ALSO BE FILTERING IN, ALLOWING
SKIES TO CLEAR. AS THE SURFACE LOW BECOMES A COASTAL LOW, THE
SURFACE PRESSURE GRADIENT WILL INCREASE LATE FRIDAY INTO FRIDAY
NIGHT WITH HIGH PRESSURE BUILDING TO OUR WEST. THESE FEATURES WILL
RESULT IN VERY COLD TEMPERATURES FRIDAY NIGHT INTO SATURDAY. 925MB
TEMPS WILL FALL INTO THE NEGATIVE UPPER TEENS TO AROUND -20C
FRIDAY NIGHT, WHICH WILL BE REFLECTED AT THE SURFACE IN TERMS OF
SATURDAY MORNING LOWS RANGING FROM -2F TO -17F. THIS COLD AIR WILL
COINCIDE WITH NORTHWEST WINDS OF 10-20 MPH, PRODUCING WIND CHILL
VALUES OF -20 TO -35. IF MODELS CONTINUE THIS TREND, WIND CHILL
HEADLINES MAY NEED TO BE ISSUED.

SATURDAY WILL NOT WARM UP MUCH WITH NEW SNOW HELPING TO REFLECT
INSOLATION. MAX TEMPERATURES WILL RANGE FROM NEAR ZERO TO 12F.
INCREASING SUNSHINE WILL HELP, BUT WINDS WILL BE SLOW TO SUBSIDE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 341 AM EST THURSDAY...MODELS SHOWING AN ARCTIC COLD FRONT
TO MOVE THROUGH THE REGION SATURDAY NIGHT...SO HAVE GONE WITH
SLIGHT CHANCE POPS FOR SNOW SHOWERS...ALTHOUGH MOISTURE APPEARS TO
BE LIMITED WITH THIS FEATURE. A RIDGE OF HIGH PRESSURE WILL SLIDE
EAST FROM THE GREAT LAKES ON SUNDAY AND WILL REMAIN THROUGH SUNDAY
NIGHT.

ECMWF AND GFS MODELS DEVELOP A LOW OFF THE MID ATLANTIC COAST
EARLY MONDAY AND TAKE IT SOUTH OF THE BENCHMARK (40N 70W) BY 18Z
MONDAY...WITH THE ECMWF FURTHER SOUTH THAN THE GFS MODEL. THE
CANADIAN GLOBAL MODEL IS SLOWER THEN THE GFS AND ECMWF AND TAKES
A LOW JUST NORTH OF THE BENCHMARK (40N 70W) AFTER 00Z TUESDAY. THE
CANADIAN GLOBAL LOOKS TO BE THE OUTLIER AND WAS NOT USED. HAVE
LEANED TOWARD THE COMPROMISE GFS SOLUTION FOR MONDAY. THE GFS
HINTS THAT THE NORTHERN EDGE OF ANY SNOW ON MONDAY WOULD
JUST BARELY MAKE IT INTO SOUTH CENTRAL VERMONT ON MONDAY...SO
HAVE JUST GONE WITH SLIGHT CHANCE POPS FOR SNOW SHOWERS IN RUTLAND
AND WINDSOR COUNTIES ON MONDAY...WITH THE REMAINDER OF THE REGION
REMAINING DRY. IF ECMWF MODEL IS RIGHT...THAN THE ENTIRE FORECAST
AREA WOULD REMAIN DRY MONDAY AND MONDAY NIGHT.

ANOTHER COLD FRONT WILL APPROACH THE REGION TUESDAY NIGHT AND
WEDNESDAY...SO HAVE GONE WITH SLIGHT TO LOW CHANCE POPS FOR SNOW
SHOWERS TUESDAY NIGHT AND WEDNESDAY.

TEMPERATURES WILL BE WELL BELOW NORMAL FOR EARLY FEBRUARY.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...A RIDGE OF HIGH PRESSURE WILL MOVE EAST OF
THE REGION AND OFF THE NEW ENGLAND COAST BY 18Z TODAY. VFR
CONDITIONS EXPECTED ACROSS VERMONT AND NORTHERN NEW YORK THROUGH
00Z FRIDAY. BETWEEN 00Z-06Z FRIDAY EXPECTING CONDITIONS TO LOWER
TO MVFR/IFR IN DEVELOPING LIGHT SNOW ACROSS VERMONT AND NORTHERN
NEW YORK AS A CLIPPER SYSTEM APPROACHES FROM THE EASTERN GREAT
LAKES. EXPECTING AREAS OF MAINLY SOUTHERLY SURFACE WIND GUSTS AT
OR ABOVE 20 KNOTS TO DEVELOP BETWEEN 21Z-24Z THURSDAY AND CONTINUE
THROUGH AT LEAST 06Z FRIDAY.

OUTLOOK 12Z FRIDAY THROUGH MONDAY...

12Z FRIDAY-12Z SATURDAY...A CLIPPER SYSTEM WILL MOVE INTO THE
REGION...CIGS LIKELY REMAIN MVFR WITH PERIODS OF IFR-LIFR VSBY IN
SNOW, MAINLY FROM 12Z FRIDAY THROUGH 06Z SATURDAY. GUSTY
NORTHERLY WINDS LIKELY AFTER 21Z FRIDAY.

12Z SATURDAY-00Z SUNDAY...MVFR TRENDS TO VFR AS HIGH PRESSURE
BUILDS BACK INTO THE REGION. WINDS TREND LIGHT.

00Z SUNDAY-00Z MONDAY...GENERALLY VFR WITH MVFR SNOW POSSIBLE AS
ANOTHER CLIPPER (WEAKER) PASSES THROUGH.

00Z MONDAY-00Z TUESDAY...VFR UNDER HIGH PRESSURE.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 AM EST
     SATURDAY FOR VTZ001>008-010-016>018.
NY...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
     FRIDAY FOR NYZ026>031-087.

&&

$$
SYNOPSIS...KGM
NEAR TERM...RJS/KGM
SHORT TERM...KGM
LONG TERM...WGH
AVIATION...WGH/LAHIFF




U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE