837
FXUS61 KALY 210532
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1232 AM EST SAT DEC 21 2024
SYNOPSIS
LIGHT SNOW THIS AFTERNOON INTO TOMORROW MORNING RESULTING IN
SLIPPERY TRAVEL, INCLUDING TODAY'S EVENING COMMUTE. AFTER SNOW
ENDS TOMORROW MORNING, WINDS TURN BREEZY WITH CLEARING SKIES AND
TEMPERATURES TURNING COLD. COLD TEMPERATURES PERSIST THROUGH
MONDAY BEFORE OUR NEXT LIGHT SNOW EVENT ARRIVES MONDAY NIGHT
INTO CHRISTMAS EVE.
NEAR TERM /THROUGH TODAY/
KEY MESSAGE:
- LIGHT SNOW MAY RESULT IN SLIPPERY TRAVEL THROUGH THIS MORNING.
MOTORISTS ARE ENCOURAGED TO EXERCISE CAUTION WHILE DRIVING AND
ALLOW ADDITIONAL TIME TO ARRIVE AT THEIR DESTINATION.
- SNOW WILL LIKELY TURN BRIEFLY STEADY FOR THE PRE-DAWN HOURS
INTO SATURDAY MORNING (4AM TO 10AM) PRODUCING UP TO AN
ADDITIONAL QUICK 1 TO 2 INCHES.
DISCUSSION:
UPDATE...AS OF 12:30 AM EST
AFTER A LULL IN THE SNOW EARLIER
THIS EVENING, WE ARE BEGINNING TO SEE SNOWFALL REDEVELOP AND
INCREASE IN INTENSITY ACROSS THE MOHAWK VALLEY, NORTHEASTERN
CATSKILLS, CAPITAL DISTRICT, AND UPPER HUDSON VALLEY AHEAD OF
THE APPROACHING UPPER TROUGH. WE SHOULD SEE THIS STEADY LIGHT
SNOW CONTINUE THROUGH THE NEXT SEVERAL HOURS AS THE UPPER TROUGH
AXIS APPROACHES FROM THE WEST AND CVA INCREASES. SNOWFALL RATES
HAVE GENERALLY TOPPED OUT AROUND 1/2 INCH PER HOUR OVER THE LAST
HOUR OR SO, BUT NEVERTHELESS SLIPPERY TRAVEL CONDITIONS WILL
REMAIN POSSIBLE THROUGH TONIGHT AND TOMORROW MORNING, ESPECIALLY
ON UNTREATED ROADWAYS. WHILE WE EXPAND THE LIKELY POPS THROUGH
THE NEXT FEW HOURS, MOST OF THE ADJUSTMENTS WITH THIS FORECAST
UPDATE WERE MINOR, AS THE PREVIOUS FORECAST OVERALL REMAINS IN
GOOD SHAPE. PLEASE SEE PREVIOUS DISCUSSION BELOW FOR MORE
DETAILS...
PREVIOUS
AS A SECONDARY UPPER LEVEL TROUGH APPROACHES FROM
WESTERN NY LATE TONIGHT (09-10UTC), A MOHAWK HUDSON CONVERGENCE
(MHC) SIGNAL IDENTIFIED IN CSTAR RESEARCH DEVELOPS RESULTING IN
A SECOND PERIOD OF SNOW OVER THE CAPITAL DISTRICT THROUGH ABOUT
14-16 UTC. THIS WILL LIKELY PRODUCE A QUICK 1-2 INCHES OF
LIGHT/FLUFFY SNOW (SLRS 14-16:1) WITH SNOWFALL RATES BRIEFLY
REACHING 0.5" PER HOUR AS THE THERMAL PROFILES COOL BEHIND THE
ARCTIC FRONT AND FORCING INTERSECTS THE DGZ. SNOW ENDS BY MIDDAY
WITH NORTHWEST WINDS BEHIND OUR COLD FRONT USHERING IN MUCH
CHILLIER AIR. TOTAL SNOWFALL AMOUNTS RANGE 1 TO 3 INCHES WITH
THE HIGHEST AMOUNTS IN THE NORTHERN/EASTERN CATSKILLS AND
SCHOHARIE COUNTY WHERE AMOUNTS RANGE 3-4 INCHES. THERE IS 40 TO
70% CONFIDENCE FOR MUCH OF THE REGION TO RECEIVE AT LEAST 2
INCHES OF SNOW BUT UNDER 10% FOR GREATER THAN 4 INCHES. SOME
UPSLOPE ENHANCEMENTS BRING LIGHT SNOW FOR THE SOUTHERN GREENS
AND NORTHERN TACONICS THROUGH TOMORROW AFTERNOON.
IT THEN TURNS BREEZY TOMORROW AFTERNOON WITH NORTHWEST WINDS
BECOMING SUSTAINED 10-15KTS AND GUSTS UP TO 20-25KTS. WITH
TEMPERATURES ONLY IN THE 20S, THE WINDS WILL MAKE IT FEEL EVEN
CHILLIER IN THE SINGLE DIGITS AND TEENS. GIVEN HOW LIGHT/FLUFFY
THE FRESH SNOW WILL BE, SOME BLOWING SNOW IS NOT RULED OUT.
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/
KEY MESSAGE:
- HIGH CONFIDENCE (GREATER THAN 75%) FOR COLD TEMPERATURES THIS
WEEKEND WITH FRIGID OVERNIGHT LOWS BOTH SATURDAY AND SUNDAY
NIGHT. THE COMBINATION OF COLD TEMPERATURES AND LIGHT WINDS
SATURDAY WILL LEAD TO WIND CHILL OR "FEEL-LIKE" TEMPERATURES
RANGING FROM -20C TO 0C.
DISCUSSION:
CLEARING SKIES AND NORTHWEST WINDS USHERING IN 850HPA ISOTHERMS
2 TO 2.5 STANDARD DEVIATIONS BELOW NORMAL PER THE NAEFS (-15C
TO -18C) WILL PROMOTE VERY COLD OVERNIGHT LOWS SAT NIGHT. WITH
THE PRESSURE GRADIENT BETWEEN THE INCOMING HIGH AND EXITING COLD
FRONT REMAINING TIGHT ENOUGH, NORTHWEST WINDS REMAIN SUSTAINED
5 - 15KTS. THE COMBINATION OF A CONTINUED BREEZE PLUS PLUMMETING
TEMPERATURES INTO THE SINGLE DIGITS AND EVEN SUB-ZERO IN THE
SOUTHERN ADIRONDACKS, SOUTHERN VT, AND NORTHERN CATSKILLS WILL
SUPPORT WIND CHILL VALUES OR "FEEL-LIKE" TEMPERATURES BETWEEN 0
AND -20C. SOME ZONES IN THE NORTHERN CATSKILLS, HELDERBERGS,
TACONICS AND BERKSHIRE COUNTY MAY APPROACH COLD WEATHER ADVISORY
CRITERIA AND WE WILL CONTINUE TO MONITOR TRENDS.
OUR 1035-1040 HPA CANADIAN HIGH BUILDS DIRECTLY OVERHEAD SUNDAY
SUPPORTING CLEAR/SUNNY SKIES. WINDS WILL BE DECREASING THROUGH
THE DAY AS THE PRESSURE GRADIENT WEAKENS BUT STILL EXPECTING A
SLIGHT NORTHWEST BREEZE (SUSTAINED WINDS 5-9KTS). WITH THE CORE
OF OUR CHILLY AIR MASS IN PLACE, DAYTIME TEMPERATURES WILL
REMAIN VERY COLD AS 850 HPA TEMPERATURES ONLY RANGE -12 TO -18C.
THIS WILL RESULT IN TEMPERATURES ONLY CLIMBING INTO THE TEENS
AND SINGLE DIGITS. CLEAR SKIES, DECREASING WINDS, AND A FRESH
SNOW PACK SUNDAY NIGHT WILL SUPPORT IDEAL RADIATIONAL COOLING
CONDITIONS. PROBABILISTIC GUIDANCE SHOWS GREATER THAN 70% CHANCE
FOR TEMPERATURES SUN NIGHT TO FALL BELOW 10 DEGREES ACROSS EASTERN
NY AND WESTERN NEW ENGLAND AND EVEN 30 TO 40% FOR TEMPERATURES
TO FALL BELOW 5 DEGREES IN THE HUDSON VALLEY. THUS, SUN NIGHT
WILL LIKELY BE THE COLDEST NIGHT OF THE SEASON AS WE EXPECT
OVERNIGHT LOWS TO FALL TOWARDS 0 IN THE VALLEY WITH -10 TO 0 FOR
AREAS AT AND ABOVE 1000FT. SOME ZONES IN THE NORTHERN/EASTERN
CATSKILLS, TACONICS, AND BERKSHIRES ARE CLOSE TO COLD WEATHER
ADVISORY (-15F TO -24F) AND WILL BE CONTINUE TO EVALUATE
TRENDS.
STAYING DRY INTO MONDAY AS HIGH PRESSURE SHIFTS INTO NEW ENGLAND
WITH EARLY SUN FADING BEHIND INCREASING CLOUDS AS OUR NEXT
DISTURBANCE APPROACHES FROM THE GREAT LAKES. NOT QUITE AS COLD
AS THE WEEKEND BUT STILL EXPECTING BELOW NORMAL DAYTIME HIGHS
RISING ONLY INTO THE 20S.
LONG TERM /TUESDAY THROUGH FRIDAY/
KEY MESSAGES:
- CONFIDENCE IS INCREASING FOR A WIDESPREAD LIGHT SNOWFALL MONDAY
NIGHT INTO CHRISTMAS EVE BEFORE DRIER WEATHER ARRIVES FOR CHRISTMAS
DAY
DISCUSSION:
A POSITIVELY TILTED UPPER LEVEL TROUGH AND WEAKENING SURFACE LOW
WILL CROSS THE REGION MONDAY NIGHT INTO CHRISTMAS EVE BRINGING A
PERIOD OF SNOW TO THE REGION. THERE STILL REMAINS SOME UNCERTAINTY
WITH THE AMOUNT OF QPF WITH THIS SYSTEM WHICH WOULD IMPACT SNOWFALL
TOTALS. A CURRENT BLEND OF THE GUIDANCE SUGGESTS SNOWFALL AMOUNTS OF
A COATING TO 2 INCHES MAY BE COMMON. SOUTHERLY FLOW MAY RESULT IN
SOME UPSLOPE ENHANCEMENT ACROSS THE FOOTHILLS OF THE SOUTHERN
ADIRONDACKS COULD RECEIVE 3 OR 4 INCHES. WILL CONTINUE TO MONITOR
TRENDS AND FINE TUNE SNOWFALL TOTALS OVER THE COMING DAYS.
IN THE WAKE OF THIS SYSTEM, HIGH PRESSURE CENTERED ACROSS QUEBEC AND
NORTHERN NEW ENGLAND NOSES INTO THE REGION AND LOOKS TO BRING A
PERIOD OF MAINLY DRY WEATHER FOR CHRISTMAS DAY THROUGH THE REMAINDER
OF THE WEEK. HIGHS EACH DAY WILL BE IN THE 30S WITH SOME UPPER 20S
ACROSS THE HIGHER ELEVATIONS. LOWS WILL BE MAINLY IN THE TEENS TO
LOWER 20S.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
UPPER LEVEL SHORTWAVE TROUGH IS LOCATED OVER THE NORTHEAST AND THE
TROUGH AXIS WILL BE CROSSING THE AREA DURING THE LATE OVERNIGHT
HOURS. RADAR IMAGERY CONTINUES TO SHOW A LARGE AREA OF LIGHT
SNOWFALL OVER THE REGION AND EXPECTATION IS THAT THIS WILL CONTINUE
THROUGH THE LATE NIGHT HOURS WITH THE FORCING OVERHEAD. SNOWFALL
RATES WILL BE FAIRLY LIGHT, SO VISIBILITY WILL GENERALLY BE IN THE
MVFR RANGE (3-5SM), ALTHOUGH BRIEF BURST AROUND 2SM CANNOT TOTALLY
BE RULED OUT, ESPECIALLY FOR KALB. NORTHERLY WINDS WILL BE AROUND 5-
10 KTS THROUGH THE REST OF THE OVERNIGHT HOURS.
SNOW WILL TAPER OFF AFTER DAYBREAK AS THE TROUGH AXIS PUSHES
EASTWARD. WILL CONTINUE TO MENTION A VCSH FOR A FEW HOURS IN CASE A
FEW SNOW SHOWERS LINGER AROUND (ESPECIALLY NEAR KALB), BUT
VISIBILITY WILL BE IMPROVING. NORTHWEST WINDS WILL BE PICKING UP
BEHIND THE DEPARTING SYSTEM WITH SUSTAINED WINDS AROUND 10-15 KTS.
THESE WINDS WILL PEAK IN THE LATE MORNING THROUGH LATE AFTERNOON
HOURS, WITH SOME GUSTS UP TO 25 KTS POSSIBLE, ESPECIALLY AT
KALB/KPSF. FLYING CONDITIONS WILL GO BACK TO VFR BY THE MID TO LATE
MORNING HOURS AS CEILINGS IMPROVE BACK TO AROUND 3500-5000 FT.
CLOUDS WILL DECREASE, WITH A MOSTLY CLEAR TO CLEAR SKY BY EVENING
INTO SATURDAY NIGHT. VFR CONDITONS ARE EXPECTED FOR ALL OF SATURDAY
NIGHT. WINDS WILL DECREASE SLIGHTLY, BUT STILL REMAIN BREEZY AROUND
10 KTS FROM A NORTHWESTERLY DIRECTION INTO SATURDAY NIGHT.
OUTLOOK...
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN...SN.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX.
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
SYNOPSIS...SPECIALE
NEAR TERM...MAIN/NAS/SPECIALE
SHORT TERM...SPECIALE
LONG TERM...RATHBUN
AVIATION...FRUGIS
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