December 2, 2014 Forecast Discussion

000
FXUS61 KALY 012127
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
427 PM EST MON DEC 1 2014

.SYNOPSIS…
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY. WITH ONLY
LIMITED MOISTURE AVAILABLE…ONLY A FEW PASSING SHOWERS ARE
EXPECTED. IT WILL BE MILD AHEAD OF THE FRONT…FOLLOWED BY COLDER
TEMPERATURES FOR TONIGHT AND TUESDAY AS HIGH PRESSURE BRIEFLY BUILDS
IN ACROSS THE REGION. A FAST MOVING STORM SYSTEM WILL BRING A LIGHT
WINTRY MIX TO THE REGION TUESDAY NIGHT AND EARLY WEDNESDAY…BEFORE
CHANGING TO RAIN SHOWERS ON WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/…
AS OF 425 PM EST…COLD FRONT HAS MOVED THROUGH THE FORECAST AREA
WITH A NORTHWEST WIND USHERING IN COLDER AIR ACROSS THE REGION.
TEMPERATURES CONTINUE TO GRADUALLY FALL ACROSS THE REGION WITH
MOST LOCATIONS NOW IN THE 30S AND 40S WITH 20S AND 30S EXPECTED BY
THIS EVENING. MAINLY CLOUDY SKIES HAVE PERSISTED THROUGH MUCH OF
THE AFTERNOON…ALTHOUGH A FEW BREAKS OF SUNSHINE WILL BE POSSIBLE
BEFORE SUNSET.

A STRAY SNOW SHOWER WILL BE POSSIBLE ACROSS WESTWARD-FACING SLOPES
OF THE SOUTHERN ADIRONDACKS…WHERE A RELATIVELY-MOIST NORTHWEST
UPSLOPE FLOW MAY SQUEEZE OUT A DUSTING TO A FEW TENTHS OF AN INCH OF
SNOW. A BRISK NORTHWEST WIND AT 10-15 MPH WITH GUSTS IN THE 20-25
MPH WILL MAKE IT FEEL EVEN COLDER ACROSS THE REGION…WITH WIND
CHILLS DIPPING INTO THE SINGLE DIGITS AND TEENS THIS EVENING INTO
TONIGHT.

CLOUDS SHOULD GRADUALLY DECREASE IN COVERAGE TONIGHT AS AN AREA OF
HIGH PRESSURE APPROACHES AND BUILDS INTO THE REGION…WITH MOST
AREAS PARTLY CLOUDY TO MOSTLY CLEAR BY DAYBREAK TUESDAY MORNING. LOW
TEMPERATURES ARE EXPECTED TO BE CHILLY TONIGHT…WITH SINGLE DIGITS
ACROSS FAR NORTHWEST AREAS…AND MID TEENS TO MID 20S ACROSS THE
REST OF THE REGION.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/…
LIGHT WINTRY MIX OF SNOW…SLEET AND FREEZING RAIN TO IMPACT REGION
TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.

TUESDAY…MUCH OF THE DAY TUESDAY WILL FEATURE TRANQUIL WEATHER AS
THE AFOREMENTIONED AREA OF HIGH PRESSURE SLIDES NORTH OF THE
FORECAST AREA. SKIES WILL START OUT PARTLY CLOUDY AND GRADUALLY
BECOME OVERCAST FROM SOUTH TO NORTH IN THE LATE MORNING INTO THE
AFTERNOON HOURS AHEAD OF A DEVELOPING WAVE OF LOW PRESSURE. HIGH
TEMPERATURES TUESDAY WILL STRUGGLE TO REACH FREEZING IN VALLEY
LOCATIONS…GENERALLY MID 20S TO LOW 30S ACROSS THE REGION.

AN AREA OF ISENTROPIC LIFT AHEAD OF THE DEVELOPING WAVE OF LOW
PRESSURE WILL BEGIN TO OVERSPREAD THE REGION LATE IN THE AFTERNOON
WITH SNOW SHOWERS DEVELOPING ACROSS SOUTHERN AREAS AFTER 4 PM AND
SPREADING NORTHWARD INTO THE EVENING. ANY SNOW SHOWERS THROUGH THE
EVENING COMMUTE ARE EXPECTED TO BE LIGHT IN NATURE…WITH GENERALLY
LESS THAN AN INCH OF ACCUMULATION.

TUESDAY NIGHT INTO WEDNESDAY MORNING…THE AFOREMENTIONED WAVE OF
LOW PRESSURE WILL BE TAKING SHAPE ACROSS A FRONTAL BOUNDARY LOCATED
OFF THE MID-ATLANTIC COAST AND LIFT NORTHWARD PROPELLED ALONG A
STRENGTHENING SOUTHEAST-ORIENTED LOW-LEVEL JET. SOME ATLANTIC
MOISTURE WILL BE ENTRAINED WITH THIS SYSTEM AS ISENTROPIC LIFT
STRENGTHENS ON THE 295K AND 300K SURFACES. WILL HAVE TO WATCH FOR A
BURST OF PRECIPITATION ACROSS PORTIONS OF THE REGION AFTER SUNSET
ASSOCIATED WITH A PERIOD OF ENHANCED ISENTROPIC LIFT COINCIDING WITH
THE CORE OF THE LOW-LEVEL JET SEGMENT. LATEST MODEL GUIDANCE
SUGGESTS THAT THE BULK OF THE QPF…GENERALLY BETWEEN A QUARTER TO
HALF AN INCH OF LIQUID EQUIVALENT…WILL FALL BETWEEN 03Z-09Z BEFORE
GRADUALLY DECREASING IN COVERAGE TOWARDS DAYBREAK.

PRECIPITATION LOOKS TO START OUT AS SNOW ACROSS THE REGION…BEFORE
TRANSITIONING TO A MIX OF SNOW…SLEET AND FREEZING RAIN AS WARMER
TEMPERATURES MOVE IN ALOFT AFTER 10PM. THE DEGREE TO WHICH HOW
FAST…AND HOW WARM…THE WARM NOSE BUILDS ACROSS THE REGION WILL
ULTIMATELY DETERMINE WHETHER AREAS SEE A TRANSITION FROM SNOW TO
SLEET OR SNOW TO FREEZING RAIN OR SIMPLY SNOW TO RAIN.

SNOWFALL AMOUNTS ARE EXPECTED TO GENERALLY BE 1-2 INCHES FROM THE
IMMEDIATE CAPITAL DISTRICT…PORTIONS OF THE MOHAWK
VALLEY…MID-HUDSON VALLEY…BERKSHIRES AND NORTHWEST CONNECTICUT.
SLIGHTLY HIGHER AMOUNTS OF 2-4 INCHES WILL BE POSSIBLE ACROSS THE
SOUTHERN ADIRONDACKS…CATSKILLS…LAKE GEORGE/SARATOGA REGION AND
SOUTHERN VERMONT. LOCALLY HIGHER SNOWFALL TOTALS MAY BE POSSIBLE
ACROSS FAVORED SOUTHEASTERLY FLOW UPSLOPE AREAS ACROSS THE CATSKILLS
AND SOUTHERN ADIRONDACKS…WHERE AS MUCH AS 6 INCHES OF SNOW COULD
POSSIBLY FALL.

COMPLICATING SNOWFALL ACCUMULATIONS HOWEVER IS ANY SLEET THAT ENDS
UP MIXED IN WITH THE SNOW…WHICH COULD LOWER SNOWFALL TOTALS WHERE
THIS OCCURS. A COATING UP TO A TENTH OF AN INCH OF ICE WILL ALSO BE
POSSIBLE AS FREEZING RAIN MIXES IN OVERNIGHT ACROSS THE REGION. THIS
COMBINATION OF SNOW…SLEET AND FREEZING RAIN COULD LEAD TO
HAZARDOUS TRAVEL CONDITIONS FOR TUESDAY NIGHT AND FOR THE MORNING
COMMUTE WEDNESDAY.

THERE ARE ALSO HINTS IN THE MODEL GUIDANCE THAT LOW-LEVEL WARMING
MAY BE FASTER THAN CURRENTLY FORECAST…WHICH MAY ALLOW FOR A
QUICKER TRANSITION TO RAIN ACROSS MUCH OF THE REGION…AS WELL AS
LOWERING ANY WINTRY MIX ACCUMULATION TOTALS. WITH SO MUCH
UNCERTAINTY GIVEN THIS COMPLEX WEATHER SETUP…HAVE HELD OFF ON
ISSUING ANY WINTER WEATHER ADVISORIES AND WILL CONTINUE TO MENTION
IN HAZARDOUS WEATHER OUTLOOK.

WEDNESDAY INTO WEDNESDAY NIGHT…THE BEST DYNAMICS/ISENTROPIC LIFT
WILL LIFT NORTHEAST OF THE REGION WITH ONLY SCATTERED SHOWERS
EXPECTED MAINLY ACROSS THE HIGHER TERRAIN. ANOTHER MILD DAY IS
EXPECTED WEDNESDAY AS TEMPERATURES RISE BACK IN THE 40S FOR MOST
LOCATIONS. WEDNESDAY NIGHT WILL FEATURE LOWS RANGING FROM THE MID
20S TO NEAR 30.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/…
THE PERIOD STARTS OFF DRY. BUT A WEAK…MOISTURE-STARVED SYSTEM
BRINGS BARELY CHC POPS TO PARTS OF OUR AREA DURING THE WEEKEND. A
CLIPPER-TYPE SYSTEM MAY BRING A SOMEWHAT BETTER CHANCE FOR SOME
LIGHT PRECIPITATION…MAINLY IN THE FORM OF SNOW…AS EARLY AS LATE
MONDAY.

HIGH TEMPERATURES ON MONDAY WILL RANGE FROM THE MID AND UPPER 20S IN
THE WESTERN ADIRONDACKS…TO AROUND 40 DEGREES IN THE MID-HUDSON
VALLEY…WITH TEMPERATURES MODERATING SLIGHTLY EACH DAY THROUGH
MONDAY. MONDAY/S HIGHS WILL RANGE FROM AROUND FREEZING IN THE
WESTERN ADIRONDACKS…TO THE MID 40S IN THE MID-HUDSON VALLEY.

LOW TEMPERATURES WILL FOLLOW SUIT…WITH READINGS THURSDAY NIGHT
RANGING FROM THE MID AND UPPER TEENS IN THE WESTERN ADIRONDACKS…TO
THE UPPER 20S IN THE MID HUDSON VALLEY. SUNDAY NIGHT/S LOWS WILL
RANGE FROM THE MID AND UPPER 20S IN THE MOUNTAINS…TO THE MID AND
UPPER 30S IN THE MID-HUDSON VALLEY.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/…
A COLD FRONT HAS CROSSED THE FA WITH TEMPS DROPPING DURING THE
REMAINDER OF THE AFTERNOON. THERE IS VERY LIMITED MOISTURE
ASSOCIATED WITH THIS SYSTEM AND ALL SHOWERS HAVE DISSIPATED. VFR
CONDITIONS ARE EXPECTED THROUGH THE PERIOD ENDING 18Z TUESDAY
WITH CEILINGS ABOVE 3000 FEET BECOMING SCATTERED LATER THIS
AFTERNOON AND EVENING. THERE SHOULD ONLY BE SCATTERED CLOUDS
TRENDING TO CLEAR TONIGHT WITH INCREASING HIGH CLOUDS ON TUESDAY
MORNING. THE EXCEPTION TO THIS WILL BE KPSF WHERE MVFR CONDS WL
PERSIST UNTIL ARND 21Z.

WINDS WILL SHIFT TO THE NORTHWEST AND INCREASING TO AROUND 8-12
KTS WITH HIGHER GUSTS THROUGH THE AFTERNOON… CONTINUING INTO THIS
EVENING. WINDS WILL DIMINISH TO 5 KT OR LESS AND BECOME NORTH
LATER TONIGHT AND THEN NORTH TO NORTHEAST TUESDAY MORNING.

OUTLOOK…

TUESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA…SN…FZRA…SLEET.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA…RA.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.

&&

.HYDROLOGY…
NO SIGNIFICANT HYDROLOGIC PROBLEMS ARE EXPECTED THE NEXT 5 DAYS
ENDING SATURDAY.

THE NEX CHANCE FOR PRECIPITATION WILL BE TUESDAY NIGHT AND
WEDNESDAY AS A FAST MOVING STORM SYSTEM MOVES ACROSS THE REGION.
AMOUNTS OF A QUARTER TO A HALF OF AN INCH ARE POSSIBLE…BUT THE
PRECIPITATION WILL COME IN THE FORM OF LIGHT SNOW CHANGING TO A
WINTRY MIX AND THEN RAIN.

MILD TEMPS ON WEDNESDAY WILL RESULT IN SOME SNOW MELT…BUT
TEMPERATURES ARE EXPECTED TO COOL OFF QUICKLY WEDNESDAY NIGHT WELL
BELOW FREEZING.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES…INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS…PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.

&&

.ALY WATCHES/WARNINGS/ADVISORIES…
CT…NONE.
NY…NONE.
MA…NONE.
VT…NONE.

&&

$$
SYNOPSIS…IRL
NEAR TERM…IRL
SHORT TERM…IRL
LONG TERM…ELH
AVIATION…11/NAS
HYDROLOGY…IRL/KL

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