FXUS61 KBTV 110227
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
927 PM EST THU DEC 10 2009
.SYNOPSIS...
LAKE EFFECT SHOWERS AND GUSTY WESTERLY WINDS DOMINATE OUR WEATHER
TONIGHT. LAKE EFFECT SHOWERS CONTINUE TONIGHT AND TOMORROW AS COLDER
IS MOVING INTO THE NORTH COUNTRY. AN AREA OF LOW PRESSURE OVER IS
EXITING EAST OVER THE CANADIAN MARITIMES WHILE HIGH PRESSURE
BUILDS TO OUR SOUTHWEST. THE GRADIENT IN BETWEEN IS CAUSING SOME
GUSTY WINDS OVER THE NORTH COUNTRY TONIGHT AND EVEN TOMORROW. THEN
THIS WEEKEND EXPECT THE COLDEST AIRMASS THUS FAR OF THE SEASON.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 927 PM EST THURSDAY...ANOTHER QUICK UPDATE...UNFORTUNATELY TO
ISSUE QUICK WINTER WX ADVISORY FOR PORTIONS OF
CHITTENDEN/ADDISON/WASHINGTON COUNTY. I APOLOGIZE FOR ANY
CONFUSION...BUT COORD WITH VT HWY DEPT INDICATES NEAR WHITEOUT CONDS
AND 4 INCHES OF SNOW IN MONTPELIER AT 8PM. VERY IMPRESSIVE AND
LONG-FETCHED LK SNOW BAND CURRENTLY EXTENDING ALL THE WAY FROM LK
ONTARIO EAST THROUGH VT AND NEARLY TO THE MAINE COAST. LATEST 00Z
4KM WRF MODEL SHOWING THIS QUITE NICELY WITH ENHANCED CONVERGENCE
ALONG FEATURE AND ROBUST MESOSCALE LIFT. IF PROGS ARE CORRECT...AND
I'M A VICTIM OF THEM AS WELL...THINK FLOW WILL VEER SLIGHTLY MORE
WEST LATER TONIGHT...WITH BAND WEAKENING AND SHIFTING SLOWLY
SOUTHWARD AFTER MIDNIGHT. THAT SAID...GIVEN ABOVE
REPORT/CONDS...BELIEVE LOCALIZED ACCUM IN THIS NARROW BAND LIKELY TO
END UP IN THE 2-6 INCH RANGE WHEN ALL IS SAID AND DONE. FURTHER
WEST...QUICK CALLS TO SPOTTERS HAVE INDICATED THAT WHILE RADAR
RETURNS QUITE NICE OVER CHVLY IN ADDISON COUNTY...ACCUM ARE NOT
NEARLY AS GREAT...SO IN THESE LOCALES (I.E. SRN CHITTENDEN/NRN
ADDISON) STILL EXPECTING ACCUM TO BE 2 INCHES OR LESS OVERNIGHT.
REST OF FCST UNCHANGED.
PREVIOUS DISCUSSION FROM 827 PM EST THURSDAY...
UPDATE TO THIS EVENING'S FCST...MAINLY TO DROP WINTER WX ADVISORIES
FOR OUR VT ZONES...TO EXTEND WINTER WEATHER ADVISORY AND LAKE SNOW
WARNING ACROSS NRN NY...AND TO TWEAK POPS/SNOWFALL AMOUNTS BASED
OFF LATEST RADAR TRENDS/MODEL GUIDANCE. CURRENT RADAR SHOWING
INTENSE SNOW BAND OFF LK ONTARIO CONTINUES TO POUND THE FAR SOUTHERN
SECTIONS OF SAINT LAWRENCE AND FRANKLIN COUNTIES THIS EVENING...AND
AS NEW 18Z MODEL SUITE HAS SUGGESTED...THE BAND HAS SHIFTED SLIGHTLY
NORTHWARD SINCE 5 PM. BASED OFF ESTIMATES FROM THE TYX
RADAR...SNOWFALL RATES NEARING 3 INCHES PER HOUR IN CENTER OF THIS
BAND FROM STAR LAKE TO WANAKENA AND CRANBERRY LAKE. WITH WINDS
REMAINING QUITE STRONG FROM 250/260 DEG...SNOW BAND IS ACTUALLY
SPLITTING THE GAP BETWEEN THE HIGH PEAKS AND WHITEFACE MTN ACROSS
ESSEX COUNTY, NY AND SHOOTING INTO THE SRN CHVLY IN NRN ADDISON/FAR
SRN CHITTENDEN COUNTIES AND POINTS EASTWARD INTO THE CENTRAL GREEN
MOUNTAINS. WHILE ACTIVITY IS LESS INTENSE HERE...ADDL LIGHT ACCUM A
DEFINITE POSSIBILITY OVERNIGHT...ESP ACROSS THE HIGHER TERRAIN WHERE
LOCALIZED 4 INCH AMOUNTS POSSIBLE. ACROSS NRN NEW YORK...ADDL 1-3
INCH AMOUNTS LIKELY IN WRN ESSEX/WRN CLINTON COUNTIES AND EVEN
HEAFTIER AMOUNTS IN LK SNOW WARNING AREAS WHERE STORM TOTALS MAY
NEAR 18" IN A FEW SPOTS ALONG THE ST LAWRENCE/LEWIS COUNTY LINE BY
MORNING. ANOTHER SNOW BAND...ACTUALLY WITH A SOURCE OFF DISTANT LK
HURON IS CURRENTLY ALIGNED WEST-EAST ALONG THE INTL BORDER AND WILL
CONTINE TO AFFECT MAINLY OUR VT BORDER COUNTIES THROUGHT THE
OVERNIGHT HOURS. AGAIN ACCUM SHOULD REMAIN LIGHT AND GENERALLY 2
INCHES OR LESS WITH LOCALIZED AMOUNTS TO PERHAPS 4/5 INCHES IN MOST
FAVORED UPSLOPE AREAS SUCH AS JAY PEAK AND THE HOLLAND/MORGAN
CENTER AREA. BASED OFF THESE TRENDS/CONDS...HAVE TWEAKED POPS EVER
SO SLIGHTLY THOUGH CHANGES ESSENTIALLY AT THE NOISE LEVEL.
IN REGARDS TO THE WINDS...HAVE MAINTAINED CURRENT WIND ADVISORY
HEADLINES AS IS...BUT LATER SHIFTS WILL LIKELY ALLOW THIS TO
EXPIRE. WHILE WINDS HAVE OCCASIONALLY GUSTED TO NEAR 40-45 MPH IN A
FEW SPOTS...MOST GUSTS MORE IN THE 25 TO 35 MPH RANGE AND A QUICK
LOOK AT MODEL SOUNDING PROFILES SHOWING SOLNS A BIT TOO ROBUST ON
DEGREE OF BNDRY LYR MIXING THIS EVENING. STILL QUITE A BLUSTERY
EVENING HOWEVER...WHICH COMBINED WITH FALLING SNOW MAY LEAD TO LOCAL
REDUCTIONS IN VSBY...ESP IN HEAVIER LK SNOW BANDS ACROSS NRN NY
WHERE WHITEOUT CONDS AND TREACHEROUS TRAVEL CONDS LIKELY. HAVE A
NICE EVENING.
PRIOR DISCUSSION BELOW...
AS OF 334 PM EST THURSDAY...THE LAKE EFFECT SNOW BANDS CONTINUE
ACROSS PORTIONS OF THE NORTH COUNTRY. STRONG WESTERLY WINDS ARE
ALLOWING THE PRIMARY BAND...OF LK ONTARIO...IS SHIFTING SOUTH.
SHOWERS SHOULD DIMINISH OVER THE ADIRONDACKS THIS EVENING. IN VT
THE PRIMARY LAKE EFFECT BAND IS IMPACTING THE CENTRAL GREENS...AND
AS THE BAND MOVES SOUTH IT WILL IMPACT THE CENTRAL AND SOUTHERN
GREENS TONIGHT. IN ADDITION...A TROUGH WITH A BAND OF SHOWERS WITH
TIES TO LK SUPERIOR WILL SETTLE SOUTH OVER THE FORECAST
AREA...GIVING THE NORTHERN GREENS AND NORTHER DACKS ADDITIONAL
SNOWS THROUGH THE EVENING HOURS. HENCE WE HAVE MAINTAINED THE
WINTER WEATHER ADVISORY AND LAKE EFFECT WARNING UNTIL SHOWERS HAVE
TRULY DIMINISHED. ADDITIONAL SNOW OF 1-6 INCHES ARE
POSSIBLE...MAINLY IN THE GREENS. HIGHEST AMOUNTS TONIGHT WILL BE
IN THE WESTERN SLOPES OF THE SOUTHERN AND CENTRAL GREENS AS THIS
IS THE AREA THAT WILL CONTINUE TO BE IMPACTED BY THE PRIMARY BAND
OFF OF LK ONTARIO.
WITH THE GRADIENT REMAINING TIGHT ACROSS THE AREA...WESTERLY WINDS
CONTINUE...WITH SOUTHWESTERLY WINDS IN ST. LAWRENCE VALLEY. GUSTS
TO 40-50 MPH CAN BE EXPECTED IN THE ST. LAWRENCE VALLEY...THE
ELEVATIONS OF THE ADIRONDACKS...THE EAST FACING SLOPES OF THE
ADIRONDACKS...AND THE WEST FACING SLOPES OF THE GREENS. ELSEWHERE
WESTERLY WINDS OF 20-35 MPH CAN BE EXPECTED TONIGHT. WE WILL SEE A
BIT OF A LULL TONIGHT AT THE SURFACE AS WE WILL NOT MIX TO
STRONGEST WINDS DOWN...BUT TOMORROW MORNING WINDS WILL BEGIN TO
INCREASE AGAIN.
WITH COLDER AIR MOVING IN TEMPERATURES TONIGHT WILL GENERALLY COOL
TO THE 20S AND TEENS. WIND AND INCREASED CLOUD COVER WILL INHIBIT
TEMPS FROM BOTTOMING AS THEY OTHERWISE WOULD WITH 850 TEMPS OF -16
OVER THE REGION.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 500 AM EST THURSDAY...SCATTERED LAKE EFFECT SHOWERS CONTINUE
WILL CONTINUE TOMORROW ALONG WEST FACING SLOPES...MAINLY IN THE
CENTRAL
ADIRONDACKS AND SOUTHERN AND CENTRAL GREENS. WITH FLOW BECOMING
MORE WEST TO NORTHWESTERLY WE WILL NOT SEE AS FAVORABLE A LAKE
FETCH AS WE SAW TODAY. BUT...WITH SLIGHT INSTABILITY WE WILL BE
ABLE TO MIX WINDS DOWN TO THE SURFACE AGAIN. WESTERLY WINDS WILL
ONCE AGAIN BE GUSTY FRIDAY...AND EVEN SATURDAY...WITH GUSTS TO
ABOUT 35 MPH IN THE HIGHER ELEVATIONS OF THE DACKS AND ALSO EAST
FACING SLOPES.
FRIDAY NIGHT WE WILL SEE THE COLDEST AIRMASS OF THE REGION OVER
HEAD WITH 850 TEMPS OF -16 TO -18. WITH CLOUD COVER AND WIND NOT
AS MUCH AN IMPACT AS TONIGHT... WE WILL SEE TEMPS DROP INTO THE
SINGLE DIGITS AND TEENS WIDESPREAD THROUGH OUT THE AREA. EVEN A
FEW SUB ZERO TEMPS COULD OCCUR IN COLD POCKETS OF THE NORTHEAST
KINGDOM AND THE DACKS. ON SATURDAY THE RIDGE OF HIGH PRESSURE
MOVES OVER THE REGION. THIS WILL ALLOW FOR SOME BREAKS IN THE
CLOUDS. WHILE OUR AIRMASS WARMS A TAD... THESE CLEARER CONDITIONS
WILL ONCE AGAIN ALLOW FOR COLD TEMPS SAT NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 235 PM EST THURSDAY...CLDS/PRECIP/WX...CD AIR IN PLACE FOR
ENTIRE EXTENDED WILL ALLOW FOR ALL PRECIP TO BE AS SNOW. SFC LOW
WILL PASS E OVER DELMARVA REGION SUN INTO MONDAY...WITH HIGH
PRESSURE OVER SOUTHERN CANADA. THIS WILL KEEP BEST CHANCES FOR -SW
IN SOUTHERN SECTIONS OF THE REGION...W/ FLURRIES/--SW TO THE
NORTH. GD PORTION OF MONDAY WILL SEE HIGH PRESSURE BUILD DOWN OVER
THE AREA AND SLIDE EAST OFF THE COAST MON NGT WITH APPROACH OF
NEXT SYSTEM. SFC LOW TRACK FOR TUESDAY SWINGS SFC LOW JUST TO OUR
N...BUT ASSOCIATED FRNT ACROSS THE REGION..FOR A ROUND OF LGT -SW.
W/ LOW TO OUR N AND RIDGE BLOCKING OFFSHORE...NOT EXPECTING MUCH
QPF FROM THIS SYSTEM. STRONG RIDGE SETTING UP BEHIND THIS FRNT
WILL SET UP TO OUR WEST FOR WED/THURS. STRONG NORTHERLY FETCH WILL
ENSUE OVER THE ENTIRE CWA AS SFC LOW FROM EXITING SYSTEM STALLS
OVER THE CANADIAN MARITIMES. THIS WILL HIGHLIGHT BEST CHANCES FOR
ANY -SW OVER NORTHERN CWA...W/ HIR ELEVATIONS SEEING BEST CHANCES
FOR ANY ACCUM DUE TO PERSISTENT UPSLOPE EFFECTS.
TEMPS...FOR THE FIRST PORTION OF THE EXTENDED...TEMPS TO REMAIN
NEAR NORMAL AS SEASONAL VALUES GO. NO STRONG CAA EXPECTED WITH CLD
COVER FROM SYSTEM SUN NGT/MON...AND SETUP OF RIDGE AND SOUTHERLY
WINDS FOR TUESDAY AHEAD OF FRNT. 850 TEMPS WILL RANGE FROM -4C TO
-10C...DURING THIS TIME...W/ POTENTIAL FOR SURGE OF WARM AIR FOR
WESTERN ZONES AHEAD OF TUESDAY FROPA WHERE 850 TEMPS NEAR 0C. TUES
NG THRU THURSDAY WITH SETUP OF NORTHERLY FETCH OVER CWA...STRONG
CAA WILL PUSH INTO THE AREA W/ 850 TEMPS RANGING FROM -14C TO
-20C...ESPECIALLY FOR WED/THURS. DAYTIME/NIGHTTIME TEMPS COULD
RANGE AS MUCH AS 10 DEGREES BLW NORMAL DUE TO PROLONGED CAA ON
NORTH WINDS.
WINDS...WK SSW FLOW AHEAD OF SYSTEM ON SUNDAY AND DOES EVENTUALLY
BECM LGT/VAR W/ LOW PASSING E OVER DELMARVA AND OUT TO SEA. LGT/VAR
WINDS FOR MUCH OF MONDAY AS RIDGE REMAINS OVER THE NE CORRIDOR...BUT
LATE IN DAY SOUTHERLY WINDS INCR FROM THE WEST AHEAD OF FRNTL
BOUNDARY. SSW WINDS REMAIN INTO TUESDAY WITH SLOW FRNTL MVMNT. NW
WINDS ENSUE TUES NGT THRU THURSDAY. SFC LOW ASSOCIATED W/ FRNT
STALLS OVER THE CANADIAN MARITIMES. TIGHT GRADINET DEVELOPS AS SF
CHIGH BUILDS IN FROM THE WEST. THIS WILL FUNNEL STRONG NORTHERLY
WINDS(POTENTIAL OF 30-40MPH+...ESPECIALLY OVER HIR TRRN...IN BUFKIT)
OVER CWA...ENHANCING PRECIP FOR NORTHERN ZONES.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
THROUGH 00Z SATURDAY...PERSISTENT WESTERLY FLOW OVER THE REGION
FOR THE NEXT 24HRS. CONDITIONS ACROSS THE REGION WILL VARY DURING
THIS TIME FROM VFR DOWN TO MVFR OR EVEN IFR...MAINLY FROM LAKE
EFFECT SNOW SHOWERS. PREVAILING CONDITIONS WILL BE VFR AT
KBTV/KPLB/KRUT/KMSS...LOWERING BRIEFLY TO MVFR IN ANY SNOW SHWRS.
PREVAILING CONDITIONS WILL BE MVFR AT KMPV/KSLK...LOWERING BRIEFLY
TO IFR IN HEAVIER SNOW SHWRS. WINDS SPEEDS WILL RANGE FROM
15-25KTS W/ GUSTS TO 35KTS.
00Z SATURDAY THROUGH TUESDAY...
00Z SAT-12Z SAT...WNW WINDS 15-25 KTS ALONG WITH SCT SNOW SHWRS
PRODUCING LOCALIZED MVFR CONDITIONS...ESPECIALLY AT KSLK/KMPV.
12Z SAT-12Z SUN...MAINLY VFR UNDER HIGH PRESSURE.
12Z SUN-12Z MON...AREAS OF MVFR IN LIGHT SNOW.
12Z MON-06Z TUE...MAINLY VFR.
06Z TUE-00Z WED...AREAS OF MVFR IN SNOW SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WIND ADVISORY UNTIL 5 AM EST FRIDAY FOR VTZ006>008-010-012-019.
WINTER WEATHER ADVISORY UNTIL 5 AM EST FRIDAY FOR VTZ008-017-
018.
NY...WIND ADVISORY UNTIL 5 AM EST FRIDAY FOR NYZ026>031-034-035-087.
WINTER WEATHER ADVISORY UNTIL 5 AM EST FRIDAY FOR NYZ031-034.
LAKE EFFECT SNOW WARNING UNTIL 5 AM EST FRIDAY FOR NYZ029-030.
&&
$$
SYNOPSIS...AMF
NEAR TERM...JMG/AMF
SHORT TERM...AMF
LONG TERM...JN
AVIATION...JN
