FXUS61 KBTV 270816
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
316 AM EST FRI NOV 27 2009
.SYNOPSIS...
HIGH PRESSURE WILL MOVE AWAY FROM THE REGION TONIGHT...WHILE LOW
PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST. THIS LOW WILL
STRENGTHEN AS IT MOVES NORTH TOWARDS THE GULF OF MAINE ON FRIDAY.
THE LOW WILL CONTINUE TO AFFECT THE NORTH COUNTRY FRIDAY NIGHT INTO
SATURDAY. HIGH PRESSURE WILL RETURN ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1014 PM EST THURSDAY...BREAKS IN THE CLOUDS HAVE LED TO
SOME PATCHY DENSE FOG OVER THE AREA AND HAVE UPDATED THE FORECAST
TO INCLUDE THIS. STARTING TO SEE STEADIER PRECIPITATION DEVELOPING
OVER THE MID-ATLANTIC REGION AS SHORTWAVE TROUGH SWINGS THROUGH
THE BASE OF THE UPPER LEVEL TROUGH AND ENHANCES DYNAMIC SUPPORT.
WOULD EXPECT PRECIPITATION SHIELD TO MOVE INTO PORTIONS OF
NORTHERN NEW YORK BEFORE MIDNIGHT...THEN RAIN SPREADING FROM SOUTH
TO NORTH OVER THE REMAINDER OF THE AREA WELL AFTER MIDNIGHT. HAVE
TWEAKED TIMING AND PRECIPITATION CHANCES A BIT TO ACCOUNT FOR THE
WIDESPREAD RAIN THAT WILL DEVELOP TOWARD THE MORNING HOURS.
REMAINDER OF FORECAST IN REAL GOOD SHAPE AND NO OTHER CHANGES
NEEDED AT THIS TIME.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
AS OF 315 PM EST THURSDAY...LOW WILL DEEPEN RAPIDLY FRIDAY AS IT
MOVES NORTH INTO THE GULF OF MAINE DURING THE AFTERNOON. MODELS
IN FAIRLY GOOD AGREEMENT REGARDING OVERALL SYNOPTIC SITUATION...BUT
THEY DO DIFFER ON THE SPEED OF INTENSIFICATION OF THE LOW...AND
THE RESULTING DISTRIBUTION OF QPF. STRONG UPPER LEVEL
FORCING...JET DYNAMICS AND LIFT COMBINED WITH ADVECTION OF DEEP
MSTR INTO THE RGN WILL RESULT IN DEVELOPMENT OF WIDESPREAD PCPN
FRIDAY WHICH WILL CONTINUE INTO FRIDAY NIGHT. MODEL SOUNDINGS
CONTINUE TO INDICATE THAT ATMOSPHERE STILL RATHER MILD AT ONSET
TIME OF PCPN...SO EXPECT IT TO BE MAINLY RAIN IN LOWER ELEVATIONS
DURING THE DAY ON FRIDAY...BUT AS UPPER LOW SLIDES EAST INTO THE
REGION...EXPECT THE RAIN TO MIX WITH OR CHANGE TO SNOW OVER HIR
ELEVATIONS...MAINLY ABOVE 2000 FT. THE SNOW LEVEL WILL CONTINUE TO
LOWER FRIDAY NIGHT AS PCPN CONTINUES...BUT BOUNDARY LAYER TEMPS
STILL LOOK TOO MILD TO SUPPORT SNOW IN THE VALLEYS. WITH STRONG
UVM LATER FRIDAY PM/EVENING HOWEVER...THERE IS POTENTIAL FOR SOME
SNOW TO MIX IN EVEN AT THE LOWEST ELEVATIONS WHEN PCPN IS
HEAVIEST. GFS QPF LOOKS OVERDONE...SO HAVE OPTED FOR A BLEND OF
GFS/NAM/HPC QPF. DURING FRIDAY NIGHT...PCPN WILL GRADUALLY BECOME
MORE DRIVEN BY OROGRAPHICS AS FLOW AT ALL LEVELS TURNS NW. EXPECT
HEAVIEST PCPN LATER FRI NITE INTO SAT MORNING TO BE OVER HIR TRRN
OF NRN VT. NO HEADLINES ATTM...BUT CERTAINLY COULD LEAD INTO AT
LEAST AN ADVISORY EVENT FOR THE NRN TIER OF VT ZONES AND WRN
SLOPES...AND PERHAPS THE ADRNDKS...ALTHO QPF AMTS OVER NRN NY NOT
EXPECTED TO BE AS HIGH AS OVER VT. SNOW/RAIN EXPECTED TO GRADUALLY
DIMINISH IN COVERAGE SATURDAY...BEING MORE CONFINED TO HIR TRRN.
PCPN DIMINISHES FURTHER SATURDAY NITE AND GRADIENT SLACKENS AS LOW
PULLS FURTHER AWAY THRU ERN CANADA...AND WEAK RIDGING DEVELOPS BY
SUNDAY MORNING. AS FOR THE TOTAL QPF WITH THIS EVENT...EXPECT
WDSPRD 1-2 INCH AMTS IN VT...LESS ACRS NRN NY. THIS WILL RESULT
IN MODERATE TO SIGNIFICANT RISES ON MANY RIVERS. OTHER CONCERN
WITH THIS EVENT IS THE POTENTIAL FOR STRONG GUSTY WINDS AS LOW
DEEPENS OVER ERN NEW ENGLAND. WIND GUSTS 40 MPH OR EVEN HIR PSBL
FRIDAY NITE INTO SATURDAY. AS FOR TEMPS... LITTLE DIURNAL CHANGE
EXPECTED FRI THRU SAT. EXPECT HIGHS FRIDAY MAINLY BTWN
40-45...LOWS FRI NITE IN L-M 30S..AND HIGHS SATURDAY 35-40.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 315 AM EST FRIDAY...A LOW PRESSURE AREA FROM THE GREAT
LAKES WILL MOVE NORTHEAST UP THE SAINT LAWRENCE VALLEY LATE SUNDAY
AND MONDAY. THIS LOW WILL BRING A COLD FRONT THROUGH THE REGION ON
MONDAY. WILL BRING IN SOME SNOW TO THE REGION SUNDAY NIGHT...AND
THEN SOME RAIN AND SNOW SHOWERS ON MONDAY. A WARM FRONT
APPROACHING THE REGION WILL BRING A CHANCE OF SNOW SHOWERS TO THE
REGION ON TUESDAY. THE FORECAST AREA WILL BE BETWEEN A COLD FRONT
OVER CANADA AND A DEVELOPING LOW PRESSURE AREA OVER THE CAROLINAS
ON WEDNESDAY...SO WILL GO WITH MAINLY CLOUDY SKIES FOR WEDNESDAY.
A LOW PRESSURE AREA MOVING NORTHEAST UP THE ATLANTIC COAST
WEDNESDAY NIGHT WILL BE SOUTH OF CAPE COD EARLY THURSDAY. HAVE
GONE WITH SLIGHT CHANCE POPS FOR SOUTH CENTRAL VERMONT FOR LATE
WEDNESDAY NIGHT AND THURSDAY... WITH THE REMAINDER OF THE FORECAST
AREA REMAINING MOSTLY DRY.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...A LOW PRESSURE AREA OFF THE MID ATLANTIC
COAST EARLY THIS MORNING WILL DEEPEN AND MOVE NORTHWARD TODAY...
REACHING THE GULF OF MAINE BY 00Z SATURDAY. CEILINGS WILL LOWER TO
MVFR/IFR TODAY...WITH RAIN MOVING INTO THE REGION BETWEEN 14Z- 16Z
FRIDAY. THE HIGHER TERRAIN OF THE ADIRONDACKS AND THE GREEN
MOUNTAINS WILL BECOME OBSCURED IN CLOUDS AND REMAIN SO THROUGH 06Z
SATURDAY. COLDER AIR ALOFT WILL WORK INTO THE REGION LATER THIS
AFTERNOON...WITH RAIN CHANGING TO SNOW OVER THE HIGHER ELEVATIONS
OF THE ADIRONDACKS AND GREEN MOUNTAINS. MODELS DIFFER AS TO WHAT
TIME THIS WILL OCCUR...AS ONE MODEL SUGGESTS A CHANGE TO SNOW BY
EARLY AFTERNOON AT SLK AND MPV...WHILE ANOTHER MODEL SUGGESTS THIS
WILL OCCUR LATE THIS AFTERNOON AND EARLY THIS EVENING. HAVE
SOMEWHAT LOW CONFIDENCE IN THE TAFS FOR MPV AND SLK AS TO WHAT
TIME THIS CHANGE TO SNOW WILL OCCUR...BUT COULD POTENTIALLY OCCUR
EARLIER THAN WHAT IS INDICATED IN THE CURRENT TAF FORECASTS FOR
MPV AND SLK. EXPECTING MAINLY ALL RAIN IN THE CHAMPLAIN AND SAINT
LAWRENCE VALLEYS. EXPECTING SURFACE WIND GUSTS AT OR ABOVE 20
KNOTS TO DEVELOP THIS EVENING ACROSS THE REGION.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...IFR/MVFR IN SNOW SHOWERS ON SATURDAY
...MAINLY OVER THE HIGHER TERRAIN. GUSTY NORTHWEST WINDS.
SUNDAY...MAINLY VFR ON SUNDAY...AS A WEAK RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
SUNDAY NIGHT...EXPECTING MVFR/IFRCONDITIONS IN LIGHT SNOW TO
DEVELOP ACROSS THE REGION.
MONDAY...MVFR/IFR IN RAIN AND SNOW SHOWERS...AS A COLD FRONT
MOVES INTO THE REGION.
TUESDAY...MVFR/IFR IN LIGHT SNOW POSSIBLE AS A WARM FRONT
APPROACHES THE REGION.
&&
.CLIMATE...
AS OF 1235 PM EST MONDAY...ALTHOUGH MOST OF THE NORTH COUNTRY SAW
A LIGHT COATING OF SNOW BACK IN MID OCTOBER...THE IMMEDIATE
CHAMPLAIN VALLEY HAS NOT YET HAD ITS FIRST MEASURABLE SNOW EVENT
OF THE SEASON. FOR BURLINGTON...ON AVERAGE THE FIRST MEASURABLE
SNOW HAPPENS NOVEMBER 6TH. SO WHERE DOES THIS LATE 1ST MEASURABLE
SNOW COMPARE TO THE RECORD BOOKS? HERE ARE THE 10 LATEST FIRST
SNOWS FOR BURLINGTON GOING BACK TO 1906...ALONG WITH THE SEASONAL
TOTAL SNOW THAT FOLLOWED.
SEASON TOTAL
RANK DATE SNOWFALL (INCHES)
1. 12/7/1937 45.1
2. 12/5/1915 54.4
3. 12/1/1948 40.7
4. 11/30/1918 69.6
5. 11/30/1953 83.6
6. 11/30/1960 51.6
7. 11/28/1913 56.5
8. 11/27/1941 57.7
9. 11/26/1982 80.5
10. 11/25/1957 94.9
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...EVENSON
SHORT TERM...RJS
LONG TERM...WGH
AVIATION...WGH/NEILES
CLIMATE...
