Wind Chill Advisory 3, NWS Burlington, VT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
310 AM EST FRI JAN 16 2015

.SYNOPSIS...
WEAK HIGH PRESSURE IN PLACE OVER THE NORTH COUNTRY THROUGH
MIDNIGHT. AN ARCTIC COLD FRONT WILL MOVE ACROSS THE NORTH COUNTRY
BRINGING SNOW SHOWERS AND BRIEF SNOW SQUALLS OVERNIGHT INTO MID-
MORNING FRIDAY. BEHIND THE FRONT...FALLING TEMPERATURES AND LOW
WIND CHILLS ARE EXPECTED THROUGH FRIDAY. MODERATING TEMPERATURES
ARE THEN EXPECTED FOR SATURDAY. A LOW PRESSURE AREA MOVING UP THE
EASTERN SEABOARD HAS THE POTENTIAL TO BRING WIDESPREAD
PRECIPITATION TO THE AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 127 AM EST FRIDAY...FORECAST IS ON TRACK OVERNIGHT. ADDED A
A SLIGHT INCREASE IN POPS OVER NORTHERN NEW YORK AS RADAR ECHOS
ARE BEGINNING TO SHOW SOME PRECIP FALLING AHEAD OF THE FRONT.
OTHER THAN THAT JUST MATCHED OBS AND BLENDED IN SHORT TERM
GUIDANCE OVER THE NEXT 6 HOURS.

PREVIOUS DISCUSSION...HAVE LOWERED OVERNIGHT MIN TEMPERATURES
ACROSS PORTIONS OF EASTERN AND SOUTH CENTRAL VERMONT AS SURFACE
OBSERVATIONS SHOWING TEMPERATURES ALREADY RUNNING SEVERAL DEGREES
COLDER THAN PREVIOUS FORECAST. OTHERWISE...NO OTHER CHANGES TO THE
FORECAST.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY/...
AS OF 328 PM EST THURSDAY...

FOR FRIDAY: ARCTIC FRONT WILL BIFURCATE THE NORTH COUNTRY BY
MORNING, AND WILL CONTINUE TO PUSH THROUGH VERMONT INTO THE MID-
MORNING HOURS. EXPECT LINGERING SNOW SHOWERS/BRIEF SQUALLS TO PUSH
ACROSS VERMONT. THEREAFTER, STRONG COLD AIR ADVECTION TAKES PLACES
WITH EQUALLY STRONG COLUMNAR DRYING TAKING PLACE IN THE WAKE OF
THE FRONT. 925 MB TEMPERATURES FALL TO -18 TO -20C BY FRIDAY
EVENING. A NON-DIURNAL TREND IN TEMPS WITH TEENS/LOW 20S HIGHS
TAKING PLACE EARLY IN THE DAY, FALLING TO THE SINGLE DIGITS BY 00Z
SATURDAY. NORTHWEST WINDS WILL ALSO BE FAIRLY STRONG (15 TO 25 MPH
WITH GUSTS UP TO 30 MPH) PRODUCING WIND CHILLS IN THE SINGLE
DIGITS TO TEENS BELOW ZERO BY EVENING.

FOR FRIDAY NIGHT: RIDGE OF HIGH PRESSURE BUILDS INTO THE NORTH
COUNTRY FRIDAY NIGHT. IMPLIED STRONG RADIATIONAL COOLING WILL ALLOW
AMBIENT AIR TEMPERATURES TO FALL BELOW ZERO ACROSS THE ENTIRE AREA
(SINGLE DIGITS BELOW ZERO IN THE CHAMPLAIN VALLEY TO 15 TO 20 BELOW
ZERO ELSEWHERE). NORTHWEST GRADIENT FLOW WILL CONTINUE BUT WILL
TREND LIGHTER AS THE OVERNIGHT PROGRESSES, PRODUCING WIND CHILLS IN
THE 15 TO NEAR 30 BELOW ZERO RANGE OVERNIGHT. OVERALL, I OPTED TO
HOLD OFF ON WIND CHILL WATCH AS I WASN'T CONFIDENT IN WARNING-
CRITERIA WIND CHILLS BASED ON LOWERING WINDS, BUT IT GETS CLOSE
ACROSS PARTS OF THE NORTHEAST KINGDOM. I'LL MENTION WIND CHILL
CONCERNS IN THE HWO FOR NOW, BUT COULD SEE ADVISORY-TYPE WIND CHILL
VALUES ACROSS PARTS OF THE NORTH COUNTRY.

FOR SATURDAY INTO SATURDAY NIGHT: HIGH PRESSURE CRESTS OVER THE
REGION, WITH MODERATING 925 MB TEMPERATURES UNDER SOUTHWESTERLY WARM
ADVECTION. BY 00Z SUNDAY, 925 MB TEMPERATURES WARM UP FROM -26C TO
NEAR -12C, WARMING FURTHER TO -3 TO -6C BY 12Z SUNDAY. SOUTHWEST
CYCLONIC FLOW WILL ONCE AGAIN BE ON THE INCREASE INTO SATURDAY
NIGHT. GUIDANCE SUGGESTS SNOW SHOWERS ACROSS ST. LAWRENCE VALLEY
INTO THE ADIRONDACKS, BUT THE AIR MASS IS QUITE DRY (PER 925-700 MB
DRY AIR LAYER EVIDENT IN FCST SOUNDINGS). IT WILL GRADUALLY SATURATE
BUT I'VE ONLY SHOWN SLIGHT CHANCE FOR SNOW SHOWERS UNTIL SATURDAY
NIGHT. DAYTIME HIGH TEMPERATURES REBOUND FROM EARLY MORNING BELOW
ZERO READINGS INTO THE SINGLE DIGITS TO THE TEENS. WARMER TEMPS INTO
SATURDAY NIGHT THOUGH, AS SOUTHWEST FLOW AND WARM ADVECTION ALLOWS
TEMPS TO CLIMB TO THE UPPER TEENS-20S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 305 AM EST FRIDAY...GENERALLY FAVORED THE 00Z ECMWF
SOLUTION WITH THIS FORECAST...WHICH HAS DISPLAYED BETTER RUN-TO-
RUN CONSISTENCY IN COMPARISON TO THE GFS. THE MOST SIGNIFICANT
WEATHER DURING THE PERIOD IS EXPECTED TO OCCUR SUNDAY NIGHT INTO
MONDAY. THE 00Z ECMWF CONTINUES WITH A SCENARIO DEPICTING SURFACE
CYCLOGENESIS OFF THE DELMARVA PENINSULA AT 00Z MONDAY...WITH
SURFACE LOW TRACKING NORTHWARD ACROSS CENTRAL MA AND INTO WESTERN
MAINE BY 12Z MONDAY. IT/S IMPORTANT TO NOTE THAT THE 18Z AND 00Z
GFS HAVE BEEN SIGNIFICANTLY FURTHER EAST WITH THIS
CYCLOGENESIS...TO THE POINT WHERE THE SYSTEM WOULD NOT HAVE A
DIRECT IMPACT ON OUR WEATHER. THE 00Z ECMWF SCENARIO BRINGS THE
PROSPECT OF ACCUMULATING SNOW...POSSIBLY MIXED WITH SLEET
CENTRAL/ERN VT...SUNDAY NIGHT INTO MONDAY MORNING...WITH SOME
CONTINUED OROGRAPHIC SNOWFALL CONTINUING MONDAY AFTN/NIGHT IN
MOIST NW FLOW AS LOW BECOMES VERTICALLY STACKED TO OUR NORTH AND
EAST. SHOWED A BIT STRONGER W-E GRADIENT IN POPS WITH THIS
CYCLE...RANGING FROM 35-75% (LOWEST IN ST. LAWRENCE COUNTY AND
HIGHEST OVER THE CT RIVER VALLEY). TRAVEL IMPACTS DUE TO
SNOWCOVERED ROADS ARE POSSIBLE...AND LIKELY TO BE GREATEST ACROSS
CENTRAL AND EASTERN VERMONT BASED ON CURRENT TRENDS. WE/LL
CONTINUE TO MONITOR THIS SYSTEM. LOWS SUNDAY NIGHT WILL GENERALLY
BE IN THE MID 20S WITH HIGHS ON MONDAY RANGING FROM THE MID 20S
ACROSS NRN NY TO THE UPR 20S TO LOWER 30S ACROSS MUCH OF VERMONT.

HIGH PRESSURE GENERALLY IN CONTROL TUESDAY THROUGH THURSDAY WITH NO
SIGNIFICANT PRECIPITATION EXPECTED. TEMPERATURES WILL BE COLDEST
TUESDAY WITH HIGHS GENERALLY IN THE TEENS. SHOULD SEE SOME
MODERATION CLOSER TO SEASONABLE LEVELS WITH HIGHS IN THE LOW-MID 20S
WEDNESDAY AND THURSDAY. LOW TEMPERATURES GENERALLY IN THE SINGLE
DIGITS ABOVE ZERO TUESDAY NIGHT...AND UPPER SINGLE DIGITS TO LOW-MID
TEENS FOR WEDNESDAY NIGHT.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THROUGH 12Z SATURDAY...ARCTIC FRONT APPROACHING FROM SERN ONTARIO
WILL BRING A LINE OF SNOW SHOWERS AND SNOW SQUALLS ACROSS THE
NORTH COUNTRY BETWEEN 11-15Z. SHOULD IMPACT ALL TAF SITES EXCEPT
RUT WITH 20-30 MINUTE PERIOD OF 1/4-1/2SM SNOW AND BRIEF GUSTY
WINDS TO 25 KTS FROM THE W-NW. IT APPEARS SQUALLS WILL MOVE
THROUGH BTV 14-15Z. SEE TAFS FOR SPECIFIC TIMING AS FRONT MOVES
FROM NW-SE ACROSS THE AREA. OTHERWISE...GETTING SOME LIGHTER SNOW
SHOWER ACTIVITY IN ADVANCE OF THE FRONT WHICH WILL BRING MVFR AND
BRIEF IFR VSBY TO MSS/SLK EARLY THIS MORNING. PRIMARILY VFR AT THE
OTHER TAF SITES WITH WINDS AHEAD OF THE FRONT GENERALLY S-SW 5-10
KTS. AFTER 15Z TODAY...GENERALLY W-NW WINDS 10-15 KTS WITH GUSTS
20-25 KTS. GENERALLY IMPROVING BACK TO VFR BUT WILL SEE SOME MVFR
CEILINGS LINGER AT SLK/MPV AND AROUND THE HIGHER TERRAIN.
DIMINISHING NW WINDS AND CLEARING SKIES FORECAST AFTER 00Z
SATURDAY.

OUTLOOK 12Z SATURDAY THROUGH TUESDAY...

12Z SATURDAY - 18Z SUNDAY...GENERALLY VFR WITH HIGH PRESSURE IN
CONTROL.

18Z SUNDAY - 00Z TUESDAY...UPPER TROUGH MOVING EASTWARD THROUGH
THE GREAT LAKES REGION BRINGS MVFR SNOW SHOWER ACTIVITY TO THE
NORTH COUNTRY LATE SUNDAY AFTERNOON. SECONDARY LOW DEVELOPING OFF
THE MID-ATLANTIC COAST HAS THE POTENTIAL TO BRING ADDITIONAL
SNOWFALL TO THE REGION SUNDAY NIGHT THROUGH MONDAY DEPENDING ON
EXACT TRACK OF THE SYSTEM.

00Z TUESDAY - 00Z WEDNESDAY...BECOMING VFR WITH SURFACE HIGH
PRESSURE BUILDING IN FROM THE GREAT LAKES REGION.

&&

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

&&

SYNOPSIS...LOCONTO
NEAR TERM...DEAL
SHORT TERM...LOCONTO
LONG TERM...BANACOS
AVIATION...BANACOS