207
FXUS61 KALY 160242
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
942 PM EST SUN DEC 15 2024
SYNOPSIS
AN APPROACHING UPPER LEVEL DISTURBANCE WILL BRING SOME LIGHT
SNOW TONIGHT, BEFORE TRANSITIONING TO A WINTRY MIX AND
ULTIMATELY RAIN ON MONDAY. 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, BEFORE
ADDITIONAL RAIN AND SNOW ARRIVE LATE WEDNESDAY AND WEDNESDAY
NIGHT.
NEAR TERM /UNTIL 6 AM MONDAY MORNING/
KEY MESSAGES:
- LIGHT SNOW DEVELOPS TONIGHT, CHANGING 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:
UPDATE...AS OF 9:40 PM EST
CURRENT GOES 16 WV IMAGERY SHOWS
A CLOSED UPPER LOW LOCATED NEAR THE EASTERN END OF LAKE ERIE,
WHILE CORRESPONDING RADAR RETURNS SHOW LIGHT SNOW OVERSPREADING
AREAS AS FAR EAST AS I-87. SO FAR, PRECIPITATION HAS BEEN VERY
LIGHT, LIKELY DUE IN PART TO A DRY LOW TO MID-LEVEL AIRMASS SEEN
ON THE 00Z KALY SOUNDING. WE'VE SEEN AT MOST UP TO A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT PRECIP SO FAR FOR
AREAS WEST OF THE HUDSON VALLEY PER LATEST NYS MESONET OBS, BUT
DID RECEIVE A REPORT OF A LIGHT COATING OF SNOW IN AMSTERDAM
EARLIER THIS EVENING.
RADAR IMAGERY SHOWS MORE EXPANSIVE PRECIP SHIELD OFF TO OUR
WEST, WHERE CONVERGENCE IS MAXIMIZED AT THE NOSE OF THE 850 MB
LLJ. AS THE LLJ SHIFTS EASTWARDS, SO SHOULD THE STEADIER
PRECIP. PRECIP WILL BE MAINLY LIGHT TO OCCASIONALLY MODERATE.
TEMPERATURES REMAIN NEAR OR BELOW FREEZING WITH DEW POINTS IN
THE 10S TO MID 20S, SO WITH WET-BULB EFFECTS PRECIP SHOULD BE
MAINLY SNOW REGION-WIDE THROUGH MOST OF TONIGHT. THE MID-LEVEL
WARM NOSE APPROACHING FROM THE SOUTHWEST LATE TONIGHT AND/OR
A LACK OF ICE IN THE CLOUDS COULD ALLOW FOR A TRANSITION TO
LIGHT FREEZING RAIN/FREEZING DRIZZLE LATE TONIGHT OR TOMORROW
MORNING BEFORE PRECIP TAPERS OFF. NEWER HI-RES GUIDANCE SUGGESTS
THE POSSIBILITY FOR SOME SPOTTY LIGHT ICING IN PARTS OF THE
EASTERN CATSKILLS, AND IF THIS TREND CONTINUE THROUGH THE NEXT
FEW HOURS THEN AN SPS OR EXPANSION OF THE WINTER WEATHER
ADVISORY INTO THIS AREA MAY BE NEEDED. OVERALL, THOUGH, LITTLE
HAS CHANGED WITH OUR FORECAST THINKING, AND RELATIVELY MINOR
ADJUSTMENTS WERE MADE WITH THIS ESTF. PLEASE SEE PREVIOUS
DISCUSSION BELOW FOR ADDITIONAL DETAILS...
PREVIOUS
SLIGHTLY MILDER AIR ALOFT MAY ALLOW THE SNOW TO
MIX WITH/CHANGE TO LIGHT FREEZING RAIN PRIOR TO DAYBREAK ACROSS
PORTIONS OF THE SE CATSKILLS, MID HUDSON VALLEY AND NW CT, WHERE
A WINTER WEATHER ADVISORY IS IN EFFECT.
BY DAYBREAK, EXPECT GENERALLY A COATING TO 2 INCHES FOR MOST
AREAS NEAR AND SOUTH OF I-90, WITH PERHAPS SLIGHTLY GREATER
AMOUNTS OF 2-3 INCHES ACROSS PORTIONS OF THE MOHAWK VALLEY, AS
WELL AS ACROSS THE SE CATSKILLS, WHERE ISOLATED AMOUNTS OF 3-4"
ARE POSSIBLE.
LIGHTER AMOUNTS OF LESS THAN AN INCH ARE EXPECTED ACROSS THE
SOUTHERN ADIRONDACKS, FARTHER REMOVED FROM BETTER DYNAMICS AND
MOISTURE WITH INCOMING SYSTEM.
WILL HAVE TO WATCH FOR ANY BANDING THAT DEVELOPS AROUND NORTHERN
PERIPHERY OF REMNANT UPPER LEVEL LOW AS IT TRACKS EAST-SOUTHEAST
TO OUR SOUTH. THE COMBINATION OF SLIGHTLY STEEPER MID LEVEL
LAPSE RATES, AND INFLUX OF LOW LEVEL MOISTURE FROM THE ATLANTIC
COULD ALLOW SOME POCKETS OF HIGHER SNOWFALL AMOUNTS FOR AREAS
SOUTH OF I-90 AND ACCOUNTS FOR SOME UNCERTAINTY IN SNOWFALL
AMOUNTS.
SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/
KEY MESSAGES:
- LIGHT SNOW/WINTRY MIX TAPERS OFF MONDAY MORNING WITH LOCALLY
SLIPPERY TRAVEL CONDITIONS PERSISTING.
- WIDESPREAD LIGHT TO MODERATE RAIN DEVELOPS MONDAY NIGHT BEFORE
ENDING TUESDAY MORNING. POCKETS OF FREEZING RAIN POSSIBLE WHEN
PRECIPITATION BEGINS ACROSS PORTIONS OF THE SOUTHERN
ADIRONDACKS/UPPER HUDSON VALLEY AND SOUTHERN VT.
- MILDER CONDITIONS TUESDAY AFTERNOON BEFORE TURNING COOLER WITH
SOME LAKE EFFECT SNOW SHOWERS ACROSS THE SW ADIRONDACKS
TUESDAY NIGHT.
DISCUSSION: LINGERING LIGHT SNOW FOR AREAS NEAR THE I-90
CORRIDOR, AND A MIX OF PATCHY LIGHT SNOW, FREEZING RAIN AND RAIN
CLOSER TO I-84 TAPERS OFF BY MID MORNING. HOWEVER, WITH
ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE, CAN NOT RULE OUT
SOME FLURRIES OR PATCHY FREEZING DRIZZLE/PLAIN DRIZZLE INTO THE
AFTERNOON HOURS, ESPECIALLY ACROSS PORTIONS OF THE SOUTHERN
ADIRONDACKS AND SOUTHERN VT. COVERAGE SHOULD REMAIN PATCHY, SO
NO ADVISORIES INDICATED, BUT SOMETHING TO WATCH AND CAN BE
ADDRESSED WITH SPECIAL WEATHER STATEMENTS AS NEEDED. HAVE SIDED
CLOSER TO NBM 10TH PERCENTILE/NAMNEST/HRRR 2-METER TEMPS FOR
HIGH TEMPS, AS IT MAY BE TOUGH TO DISLODGE THE COLDER AIR FOR
AREAS NORTH OF I-90. EXPECTING LATE DAY HIGHS MAINLY IN THE
LOWER/MID 30S ACROSS THE SOUTHERN ADIRONDACKS, SOUTHERN VT/UPPER
HUDSON VALLEY, AND MID 30S TO LOWER 40S ELSEWHERE.
NEXT SYSTEM TRACKS ACROSS THE REGION MONDAY NIGHT, WITH STRONGER
FORCING THAN PREVIOUS SYSTEM. LINGERING LOW LEVEL COLD AIR COULD
LEAD TO POCKETS OF FREEZING RAIN MONDAY EVENING ACROSS PORTIONS
OF THE SOUTHERN ADIRONDACKS, UPPER HUDSON VALLEY AND SOUTHERN VT
BEFORE CHANGING TO PLAIN RAIN AFTER MIDNIGHT, WITH LIGHT TO
MODERATE RAIN EXPECTED ELSEWHERE TAPERING OFF AROUND DAYBREAK
TUESDAY. LOCALLY HAZARDOUS TRAVEL CONDITIONS ARE POSSIBLE WHERE
THE FREEZING RAIN OCCURS. WILL HAVE TO WATCH IN CASE COVERAGE OF
FREEZING RAIN IS GREATER THAN CURRENTLY INDICATED, WHICH MAY
NECESSITATE ISSUANCES OF ADDITIONAL WINTER WEATHER ADVISORIES
FOR SOME NORTHERN AREAS.
IMPROVING CONDITIONS TUESDAY WITH SOME BREAKS OF SUN DEVELOPING
FOR AREAS NEAR AND SOUTH OF I-90, WHILE REMAINING MOSTLY CLOUDY
TO THE NORTH WITH SOME SPOTTY RAIN/SNOW SHOWERS DEVELOPING LATE
ACROSS THE SW ADIRONDACKS. IT WILL BECOME BREEZY, WITH WEST
WINDS POSSIBLY GUSTING TO 25-35 MPH TUESDAY AFTERNOON,
ESPECIALLY WITHIN THE MOHAWK VALLEY, CAPITAL REGION AND
BERKSHIRES. MAX TEMPS SHOULD REACH THE MID 40S TO LOWER 50S,
THEN DROP INTO THE MID 20S TO LOWER 30S TUESDAY NIGHT. SOME LAKE
EFFECT SNOW SHOWERS MAY EXTEND INTO THE SW ADIRONDACKS TUESDAY
NIGHT, WITH SOME ACCUMULATIONS POSSIBLE MAINLY NORTH OF ROUTE
28.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
SEVERAL CHANCES FOR PRECIP DURING THE LONG TERM PERIOD, WITH
TEMPERATURES TRENDING COLDER FOR THE END OF THE WEEK/NEXT WEEKEND...
LONG TERM PERIOD BEGINS AT 12Z WEDNESDAY WITH AN UPPER TROUGH
DIGGING DOWN OVER THE UPPER MIDWEST, AS A SEPARATE UPPER SHORTWAVE
AND ASSOCIATED SFC COLD FRONT TRACKS NEAR/THROUGH THE OHIO VALLEY.
AS THE TWO UPPER SHORTWAVES BEGIN TO PHASE WEDNESDAY AFTERNOON/NIGHT
TO THE WEST OF OUR REGION, A WAVE OF LOW PRESSURE WILL DEVELOP ALONG
THE COLD FRONT, LIKELY TRACKING SOMEWHERE NEAR THE I-95 CORRIDOR
WEDNESDAY NIGHT AND MOVING INTO THE GULF OF MAINE BY 12Z THURSDAY.
THIS WILL RESULT IN WIDESPREAD LIGHT TO MODERATE PRECIPITATION
ACROSS OUR FORECAST AREA WEDNESDAY AFTERNOON AND NIGHT. THERE IS
STILL QUITE A BIT OF UNCERTAINTY IN HOW THE TWO UPER SHORTWAVES WILL
INTERACT AND WITH THE TRACK OF THE RESULTING SFC LOW, BUT AT THIS
TIME THE MOST LIKELY SCENARIO IS FOR MORE RAIN FOR VALLEY AREAS
SOUTH OF I-90, WITH SNOW MORE LIKELY FOR THE HIGHER TERRAIN AREAS
NORTH OF I-90. AT THIS TIME NBM PROBABILITIES FOR ADVISORY-LEVEL
(>4") OF SNOW ARE MAINLY CONFINED TO THE SOUTHERN ADIRONDACKS AND
SOUTHERN GREENS. HOWEVER, WITH MARGINAL THERMAL PROFILES, SMALL
CHANGES IN THE EXPECTED TRACK OF THE SFC LOW COULD RESULT IN CHANGES
TO PRECIP TYPES. IF THE SURFACE LOW TRACKS FURTHER SOUTH AND EAST
THEN WE COULD SEE A LITTLE MORE SNOW IN THE VALLEYS, SO WILL
CONTINUE TO MONITOR THIS TIME PERIOD CLOSELY.
ASIDE FROM LINGERING LAKE EFFECT SNOW SHOWERS FOR THE WESTERN
ADIRONDACKS AND POSSIBLY WESTERN MOHAWK VALLEY, PRECIP MAINLY COMES
TO AN END BY 12Z THURSDAY WITH MUCH COOLER AIR ADVECTING INTO THE
REGION WITH W/NW FLOW. WITH RISING HEIGHTS ALOFT AND A NARROW RIDGE
OF HIGH PRESSURE OVERHEAD, DRY CONDITIONS PERSIST THROUGH THURSDAY
NIGHT. HIGHS THURSDAY WILL BE MAINLY IN THE 20S(TERRAIN) TO UPPER
30S (VALLEYS) WITH OVERNIGHT LOWS IN THE 10S AND 20S THURSDAY NIGHT.
FRIDAY THROUGH SUNDAY...ANOTHER UPPER SHORTWAVE TROUGH TRACKS
THROUGH THE REGION FRIDAY INTO SATURDAY, AND THE ASSOCIATED SURFACE
LOW MAY RESULT IN SOME LIGHT PRECIPITATION (MAINLY SNOW) ACROSS OUR
AREA. SOME GUIDANCE IS HINTING AT SURFACE CYCLOGENESIS TAKING PLACE
OFF THE EAST COAST AS THE UPPER TROUGH MOVES OUT OVER THE ATLANTIC.
WHILE UNCERTAINTY IS HIGH THIS FAR OUT AND FORECAST CHANGES SHOULD BE
EXPECTED, THE CURRENT CONSENSUS IS FOR ANY RESULTING LOW TO REMAIN
EAST OF OUR AREA. HOWEVER, WITH THE UPPER TROUGH AMPLIFYING OVER THE
EASTERN US, A MUCH COLDER AIRMASS SHOULD BE ADVECTED INTO OUR
REGION. HIGHS SATURDAY AND ESPECIALLY SUNDAY MAY REMAIN IN THE 20S
EVEN FOR VALLEY AREAS. OVERNIGHT LOWS COULD DROP INTO THE SINGLE
DIGITS FOR SOME VALLEY AREAS, WITH BELOW-ZERO READINGS NOT OUT OF
THE QUESTION OVER THE HIGHER ELEVATIONS.
AVIATION /03Z MONDAY THROUGH FRIDAY/
THROUGH 00Z TUESDAY...CONDITIONS ARE CURRENTLY VFR, BUT WE
SHOULD SEE A DETERIORATING TREND THROUGH THE NEXT SEVERAL HOURS
AS SNOW OVERSPREADS THE REGION FROM WEST TO EAST. ONSET TIME
FOR SNOW LOOKS TO BE MAINLY 9PM TO MIDNIGHT, AND SHOULD BEGIN
FIRST AT ALB/GFL/POU FOLLOWED BY PSF. ONCE SNOW BEGINS, MAINLY
IFR VSBYS AND MVFR TRENDING TO IFR CIGS EXPECTED THROUGH THE
REMAINDER OF THE OVERNIGHT PERIOD.
UP TO AN INCH OR TWO OF SNOW POSSIBLE THROUGH TOMORROW MORNING.
PRECIPITATION TAPERS OFF SHORTLY AFTER SUNRISE, AND MAY END AS
A BRIEF PERIOD OF LIGHT FREEZING DRIZZLE, WHICH COULD RESULT IN
A LIGHT GLAZE OF ICE. EVEN AFTER PRECIP ENDS, EXPECTING LOW
STRATUS AND MIST TO LINGER WELL INTO TOMORROW, WITH
PREDOMINANTLY IFR CIGS AND MVFR TO IFR VSBYS THROUGH TOMORROW
MORNING. CIGS AND VSBYS SHOULD IMPROVE TO LOW-END MVFR FOR MOST
OF TOMORROW AFTERNOON, ALTHOUGH PSF MAY SEE IFR CIGS CONTINUE
THROUGH THROUGH TOMORROW EVENING.
WINDS WILL GENERALLY BE AT 5 KT OR LESS TONIGHT, AND WITH WEAK
SFC WINDS A PERIOD OF LLWS IS EXPECTED AT ALB AND GFL AS WINDS
AT 2000 FT INCREASE TO AROUND 30-35 KT FROM THE SOUTH. LLWS
CONCERNS DIMINISH AFTER SUNRISE TOMORROW, BUT ARISE ONCE AGAIN
AT ALL TERMINALS DURING THE AFTERNOON, ESPECIALLY AFTER SUNSET,
AS WINDS AT 2000 FT INCREASE AGAIN TO 35-40 KT FROM THE SOUTH.
SFC WINDS TOMORROW WILL INCREASE TO 5-8 KT FROM THE SOUTHEAST
DURING THE AFTERNOON.
OUTLOOK...
MONDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY. DEFINITE RA.
TUESDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...SHSN.
THURSDAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
ALY WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM EST MONDAY FOR
CTZ001-013.
NY...WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM EST MONDAY FOR
NYZ064>066.
MA...NONE.
VT...NONE.
SYNOPSIS...KL/PICARD
NEAR TERM...KL/MAIN
SHORT TERM...KL
LONG TERM...MAIN
AVIATION...MAIN
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