240
FXUS61 KALY 160840
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
340 AM EST MON DEC 16 2024
SYNOPSIS
AN UPPER-LEVEL DISTURBANCE IS BRINGING LIGHT SNOW EARLY THIS
MORNING, BEFORE PRECIPITATION TRANSITIONS TO A WINTRY MIX AND
ULTIMATELY RAIN LATER TODAY. SOME AREAS IN THE MID-HUDSON VALLEY
AND NORTHWESTERN CONNECTICUT MAY SEE LIGHT ICE ACCUMULATIONS
AND A SLIPPERY MONDAY MORNING COMMUTE. MILDER CONDITIONS AND
WIDESPREAD RAIN ARRIVE MONDAY NIGHT INTO EARLY TUESDAY, FOLLOWED
BY ADDITIONAL CHANCES FOR RAIN AND SNOW MIDWEEK.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- LIGHT SNOW EARLY THIS MORNING WILL CHANGE TO FREEZING RAIN
AROUND DAYBREAK ACROSS PORTIONS OF THE MID-HUDSON VALLEY,
SOUTHEAST CATSKILLS, AND LITCHFIELD HILLS.
- A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR LITCHFIELD,
DUTCHESS, AND EASTERN ULSTER COUNTIES FOR ACCUMULATIONS OF ICE
AND SNOW AND SLICK TRAVEL DURING THE MONDAY MORNING COMMUTE.
- LOCALLY SLIPPERY TRAVEL CONDITIONS EXPECTED ELSEWHERE FOR THE
MORNING COMMUTE DUE TO LIGHT SNOWFALL.
DISCUSSION:
AN UPPER-LEVEL LOW CONTINUES TO TRACK EASTWARD ALONG THE TWIN
TIERS OF NY AND PA EARLY THIS MORNING. TO ITS EAST, LIGHT SNOW
HAS SPREAD ACROSS THE REGION FROM THE SOUTHWEST WITHIN AN AREA
OF ISENTROPIC ASCENT AND WARM ADVECTION. GOES WATER VAPOR IMAGERY
SHOWS ARCS OF ENHANCED MOISTURE CONTENT WITHIN LOCAL AREAS OF
CONVERGENCE, RESULTING IN AREAS OF ENHANCED PRECIPITATION RATES
AND BRIEF MODERATE SNOWS.
AS A WARM NOSE ASSOCIATED WITH THE LOW-LEVEL JET ENCROACHES
INTO THE REGION BEFORE DAYBREAK, SNOW MAY MIX WITH OR TRANSITION
TO LIGHT FREEZING RAIN ACROSS NORTHWESTERN CONNECTICUT, THE
MID-HUDSON VALLEY, AND THE SOUTHEASTERN CATSKILLS, WHERE A
WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM EST.
ELSEWHERE, EXPECT GENERALLY A COATING TO 2 INCHES OF SNOWFALL BY
SUNRISE, WITH SLIGHTLY HIGHER AMOUNTS OF 1 TO 3 INCHES ALONG
THE SOUTHERN ADIRONDACK FOOTHILLS AND 2 TO 4 INCHES IN THE
SOUTHEASTERN CATSKILLS. A FURTHER TRANSITION TO RAIN IS EXPECTED
AS PRECIPITATION TAPERS OFF THROUGH THE MORNING, WITH SCATTERED
LINGERING SHOWERS OR DRIZZLE POSSIBLE THROUGH THE AFTERNOON AND
EVENING, ESPECIALLY SOUTH OF I-90, BUT FEW AREAS OF FREEZING
DRIZZLE OR LIGHT FLURRIES CANNOT BE RULED OUT ACROSS THE
SOUTHERN ADIRONDACKS AND SOUTHERN GREENS.
TEMPERATURES WILL SLOWLY TREND UPWARD TODAY WITHIN PERSISTENT
SOUTHWESTERLY MID-LEVEL FLOW, REACHING LATE AFTERNOON HIGHS IN
THE 30S TO MID 40S ACROSS THE REGION.
SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/
KEY MESSAGES:
- WIDESPREAD LIGHT TO MODERATE RAIN DEVELOPS TONIGHT BEFORE
ENDING TUESDAY MORNING. POCKETS OF FREEZING RAIN POSSIBLE WHEN
PRECIPITATION BEGINS ACROSS PORTIONS OF THE SOUTHERN
ADIRONDACKS, UPPER HUDSON VALLEY, AND SOUTHERN VERMONT.
- MILDER CONDITIONS TUESDAY AFTERNOON BEFORE TURNING COOLER WITH
SOME LAKE-EFFECT SNOW SHOWERS ACROSS THE WESTERN ADIRONDACKS
TUESDAY NIGHT.
DISCUSSION:
RISING HEIGHTS ALOFT BEHIND THE DEPARTING UPPER LOW WILL SEE THE
BRIEF BREAK FROM WIDESPREAD PRECIPITATION BUT WITH LINGERING
SHOWERS AND DRIZZLE INTO THE EVENING WITHIN A MOIST BOUNDARY
LAYER. HOWEVER, AN APPROACHING UPPER-LEVEL TROUGH WILL SEE A
RETURN TO WIDESPREAD LIGHT PRECIPITATION THROUGH TONIGHT AS
ANOTHER REGION OF ISENTROPIC ASCENT TRACKS ACROSS THE REGION.
TEMPERATURES WILL CONTINUE TO RISE THROUGH MUCH OF THE OVERNIGHT
PERIOD FROM 30S TO MID 40S SHORTLY AFTER SUNSET TO UPPER 30S TO
UPPER 40S BY SUNRISE TUESDAY MORNING. PRECIPITATION WILL
THEREFORE LARGELY BE RAIN, HOWEVER A FEW POCKETS OF FREEZING
RAIN ARE POSSIBLE BEFORE MIDNIGHT WHERE COLD AIR LINGERS NEAR
THE SURFACE, MOST LIKELY IN SHELTERED VALLEYS WITHIN THE
SOUTHERN ADIRONDACKS AND SOUTHERN GREENS. IF THE COLD AND MOIST
SHALLOW BOUNDARY LAYER REMAINS LARGELY DECOUPLED AND FAILS TO
WARM AS EXPECTED THROUGH THE DAY TODAY, THERE IS POTENTIAL FOR
FREEZING RAIN TO BE MORE WIDESPREAD, WHICH MAY NECESSITATE
ADDITIONAL WINTER WEATHER ADVISORIES FOR SOME NORTHERN AREAS.
PRECIPITATION WILL NONETHELESS TRANSITION TO RAIN THROUGH
TONIGHT, AND THEN TAPER TOWARD SUNRISE TUESDAY, WITH SOME
LINGERING LIGHTS SHOWERS OR DRIZZLE POSSIBLE IN THE HIGHER
TERRAIN OF WESTERN NEW ENGLAND AND THE SOUTHERN ADIRONDACKS.
CONDITIONS IMPROVE THROUGH THE DAY TUESDAY WITH CLEARING SKIES,
ESPECIALLY NEARER TO THE I-84 CORRIDOR. BY THE AFTERNOON, A
MID-LEVEL COLD POOL AROUND -5 TO -10C AND WESTERLY FLOW ALONG
LAKE ONTARIO WILL SEE SOME LAKE-EFFECT RAIN AND SNOW SHOWERS
REACH INTO THE WESTERN ADIRONDACKS NORTH OF ROUTE 28 AND WEST OF
ROUTE 30. ELSEWHERE, DRY CONDITIONS ARE EXPECTED, WITH BREEZY
SOUTH WINDS IN THE MORNING TURNING OUT OF THE WEST BY TUESDAY
AFTERNOON. TEMPERATURES WILL REACH EARLY AFTERNOON HIGHS IN THE
UPPER 30S TO MID 40S IN HIGH TERRAIN AND MID 40S TO MID 50S AT
LOWER ELEVATIONS BEFORE FALLING THROUGH THE EVENING AND OVERNIGHT
TO LOWS IN THE MID 20S TO LOW 30S.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
KEY MESSAGE:
-BEHIND RAIN AND SNOW ON WEDNESDAY, MUCH COLDER AIR TO MOVE INTO
THE REGION FOR LATER THIS WEEK INTO THE WEEKEND.
DISCUSSION:
A FRONTAL SYSTEM WILL BE IMPACTING THE REGION FOR WEDNESDAY
INTO WEDNESDAY NIGHT. ALTHOUGH THE DAY WILL START OFF DRY,
PRECIP WILL BE MOVING IN DURING THE AFTERNOON AND CONTINUING
INTO THE EVENING AND MOST OF THE OVERNIGHT HOURS. A WAVE OF LOW
PRESSURE WILL BE MOVING ALONG THE FRONT, ALTHOUGH MODELS STILL
SHOW SOME DIFFERENCES REGARDING THE TRACK OF THE LOW AS IT MOVES
ALONG THE BOUNDARY AS IT CROSSES THROUGH THE AREA.
BASED ON THE LATEST ENSEMBLES AND BLENDED GUIDANCE, MOST OF THE
LOWER TERRAIN AREAS WILL BE SEEING MAINLY RAIN WITH THIS SYSTEM.
HOWEVER, NORTHERN AND HIGH TERRAIN AREAS LOOK TO SEE SNOW,
EITHER ALL SNOW OR RAIN CHANGING TO SNOW, DEPENDING ON THE EXACT
TRACK. THE LATEST NBM GUIDANCE SUGGEST THERE IS ABOUT A 30%
CHANCE FOR AT LEAST 4" IN THE ADIRONDACKS AND GREENS, SO WINTER
WEATHER ADVISORIES COULD BE NEEDED IN THESE AREAS. LOWER TERRAIN
AREAS LOOK TO HAVE LOWER PROBABILITIES, AS PRECIP WILL BE
ENDING BEFORE SURFACE TEMPS COOL ENOUGH, EVEN THOUGH TEMPS ALOFT
LOOK TO BE COOLING BELOW FREEZING QUICKER. HOWEVER, SUBTLE
CHANGES IN THE TRACK COULD MAKE A DIFFERENCE, SO THE FORECAST IS
STILL FAIRLY LOW CONFIDENCE AT THIS TIME AND SOME SNOW IN
VALLEY AREAS STILL DOES LOOK TO BE AN OPTION FOR SOME ENSEMBLE
MEMBERS.
BEHIND THIS SYSTEM, COLDER AIR WILL BE MOVING INTO THE REGION
FOR THE LATE WEEK AND INTO THE WEEKEND. SOME LAKE EFFECT WILL
BE ONGOING FOR WESTERN AND NORTHERN AREAS ON THURSDAY, AS THE
UPPER LEVEL SHORTWAVE TROUGH PASSES OVER THE AREA. DAYTIME STILL
WILL REACH THE MIDDLE TO UPPER 30S IN MANY AREAS WITH BREEZY
NORTHWEST WINDS.
FOR FRIDAY INTO THE WEEKEND, TEMPS WILL BE COLDER EACH DAY.
HIGHS WILL LIKELY ONLY BE IN THE 20S FOR HIGHS ON SATURDAY AND
TEMPS MAY GET STUCK IN THE TEENS FOR SUNDAY. BOTH THE LATEST
ECMWF AND GFS SUGGEST 850 HPA MAY BE AS LOW AS -20 C OVER THE
WEEKEND. AS A RESULT, OVERNIGHT LOWS WILL BE VERY COLD, WITH
SINGLE DIGITS OVER THE WEEKEND AND SOME HIGHER TERRAIN AREAS MAY
EVEN FALL BELOW ZERO. WHILE MOST GUIDANCE KEEPS SIGNIFICANT
PRECIP OUT OF THE REGION, THERE IS THE POTENTIAL FOR SNOW
SHOWERS AND FLURRIES THANKS TO A PASSING CLIPPER SYSTEM. SOME
LAKE EFFECT CAN'T BE RULED OUT AS WELL THANKS TO THE VERY COLD
TEMPS IN PLACE ALOFT.
AVIATION /06Z MONDAY THROUGH FRIDAY/
AN AREA OF FAIRLY STEADY LIGHT SNOW IS CURRENTLY MOVING ACROSS
THE REGION. FLYING CONDITIONS HAVE ALREADY LOWERED TO IFR
THANKS TO REDUCED VISIBILITY IN SNOWFALL AT KALB/KPOU, AND
PRECIP IS JUST BEGINNING AT KGFL/KPSF. OVER THE NEXT FEW HOURS,
FLYING CONDITIONS WILL GENERALLY BE IFR, WITH SNOW LOWERING
VISIBILITY TO 3/4SM TO 2 SM FOR MOST OF THE TIME, ALTHOUGH EXACT
INTENSITY WILL VARY AS BATCHES MOVE ACROSS THE AREA. CEILINGS
ARE CURRENTLY ABOVE 3000 FT IN MOST AREAS, BUT THIS WILL BE
STEADILY LOWERING THROUGH THE OVERNIGHT AND WILL WIND UP CLOSE
TO 1000 FT TOWARDS SUNRISE. WINDS WILL BE LIGHT OR CALM THROUGH
THE REST OF THE OVERNIGHT HOURS.
STEADY PRECIP WILL BE ENDING AROUND DAYBREAK, ALTHOUGH IT MAY
SWITCH TO A LIGHT FREEZING RAIN OR DRIZZLE FOR A BRIEF TIME
BEFORE ENDING. IF TEMPS RISE ENOUGH AT KPOU, IT MAY SWITCH TO
PLAIN RAIN THERE TOO. A FEW LINGERING SPOTS OF DRIZZLE MAY
LINGER INTO THE MORNING HOURS, BUT MOST OF THE STEADY PRECIP
WILL BE DONE. HOWEVER, FLYING CONDITIONS WILL REMAIN IFR, AS
LINGERING LOW STRATUS AND SOME MIST WILL KEEP CEILINGS IN THE
700-1000 FT RANGE AND VISIBILITY IN THE 3-5SM RANGE AS WELL. A
LITTLE IMPROVEMENT IS POSSIBLE DURING THE AFTERNOON, SO A RETURN
TO MVFR IS POSSIBLE, ALTHOUGH THIS IS UNCERTAIN, AND CEILINGS
WILL STAY OVERCAST FOR ALL SITES AND MAINLY NO HIGHER THAN
1000-1200 FT AT BEST. WINDS WILL BE LIGHT AND VARIABLE THROUGH
THE DAY, ALTHOUGH SOUTH TO SOUTHEAST WINDS WILL START TO DEVELOP
AT KALB TOWARDS EVENING.
A FRONTAL BOUNDARY WILL BRING ANOTHER ROUND OF PRECIP TO THE
REGION FOR MONDAY NIGHT, BUT TEMPS ALOFT AND AT THE SURFACE
WILL BE WARM ENOUGH FOR PLAIN RAIN AT ALL SITES. THIS SHOULD
BEGIN AFTER 02Z-04Z FOR ALL SITES. FLYING CONDITIONS WILL REMAIN
IFR DUE TO THE LINGERING LOW STRATUS CLOUDS, MIST AND RAIN.
WINDS WILL BE LIGHT FOR MOST AREAS, ALTHOUGH KALB WILL START TO
BECOME GUSTY, WITH SUSTAINED WINDS AROUND 10-15 KTS AND SOME
HIGHER GUSTS. FOR SITES WITH THE LIGHT SURFACE WINDS, LLWS WILL
BE AN ISSUE, AS 2 KFT WINDS WILL BE 40-45 KTS FROM A SOUTH-
SOUTHEASTERLY DIRECTION.
OUTLOOK...
TUESDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...RA.
THURSDAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
ALY WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
CTZ001-013.
NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
NYZ064>066.
MA...NONE.
VT...NONE.
SYNOPSIS...KL/PICARD
NEAR TERM...PICARD
SHORT TERM...PICARD
LONG TERM...FRUGIS
AVIATION...FRUGIS
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