116  
FXUS61 KALY 180846  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
346 AM EST WED DEC 18 2024  
   
SYNOPSIS  
 
A FAST MOVING STORM SYSTEM WILL RETURN THE THREAT FOR  
RAIN AND HIGHER ELEVATION SNOW TO THE REGION FOR THIS AFTERNOON INTO  
TONIGHT. DRIER AND MORE SEASONABLE WEATHER IS EXPECTED FOR THURSDAY  
BEFORE A WIDESPREAD LIGHT SNOW IMPACTS THE AREA FOR FRIDAY INTO  
FRIDAY NIGHT. MUCH COLDER TEMPERATURES ARE EXPECTED ACROSS THE  
REGION FOR THE WEEKEND.  
 
 
   
NEAR TERM /THROUGH TONIGHT/  
 
KEY MESSAGE:  
 
- FAST MOVING STORM SYSTEM WILL IMPACT THE REGION THIS AFTERNOON  
INTO TONIGHT WITH A LIGHT SNOW ACCUMULATION ACROSS THE HIGH  
TERRAIN.  
 
DISCUSSION:  
 
AS OF 345 AM EST...IR SATELLITE IMAGERY CONTINUES TO SHOW FAIRLY  
WIDESPREAD CLOUDS OVER MUCH OF THE REGION, WITH STRATUS AND  
STRATOCU ACROSS NORTHERN AREAS WITHIN THE WEST-SOUTHWEST FLOW  
ALOFT. FURTHER SOUTH, THERE ARE MORE BREAKS, ALTHOUGH THERE ARE  
PLENTY OF PASSING HIGH CLOUDS.  
 
WHILE THE MORNING WILL START OFF DRY, CLOUDS WILL CONTINUE TO BE  
IN PLACE, AS UPSTREAM SATELLITE IMAGERY SHOWS CLOUDS WILL  
CONTINUE TO SPREAD TOWARDS THE AREA THROUGH THE MORNING HOURS,  
ALLOWING FOR ALL AREAS TO BECOME OVERCAST BY THE LATE MORNING  
HOURS. TEMPS HAVE BEEN VARIABLE TO START THE DAY, AS NORTHERN  
AREAS SEEING THE THICKER CLOUD COVER ARE STARTING OUT IN THE 30S  
TO LOW 40S, WHILE SOUTHERN AREAS THAT SAW MORE BREAKS OVERNIGHT  
ARE STARTING OUT IN THE MID 20S TO LOW 30S.  
 
UPPER LEVEL DISTURBANCE WILL BE MOVING ACROSS THE GREAT LAKES  
FOR TODAY AND WILL APPROACH THE AREA FOR TONIGHT. MEANWHILE, A  
SURFACE STORM IS LOCATED OVER THE TENNESSEE VALLEY AND IT WILL  
BE LIFTING NORTHEAST ACROSS THE MID ATLANTIC FOR LATER TODAY.  
THE SURFACE LOW LOOKS TO PASS JUST SOUTHEAST OF THE AREA ALONG  
THE NORTHEAST COAST FOR THIS EVENING, BEFORE PASSING OFF THE  
COAST OF NEW ENGLAND FOR LATER TONIGHT.  
 
DESPITE THE CLOUDS, A LIGHT SOUTHERLY FLOW WILL HELP TEMPS WARM  
THIS MORNING. MOST AREAS WILL REACH THE UPPER 30S TO MID 40S  
TOWARDS MIDDAY, ALTHOUGH HIGH TERRAIN AREAS WILL ONLY BE IN THE  
LOW TO MIDDLE 30S.  
 
ALTHOUGH TEMPS ALOFT WILL BE COOLING TODAY, THE BOUNDARY LAYER  
WILL REMAIN SOMEWHAT MILD. AS THE LOW PRESSURE APPROACHES, AN  
AREA OF STEADY PRECIP WILL BE MOVING INTO THE AREA FROM THE  
WEST. PRECIP MAY ACTUALLY BEGIN ACROSS THE ADIRONDACKS FIRST BY  
THE EARLY TO MID AFTERNOON HOURS, BEFORE SPREADING ACROSS THE  
REST OF THE AREA FOR THE LATE AFTERNOON. ALTHOUGH TEMPS ALOFT  
WILL SUPPORT SNOWFALL, THE BOUNDARY LAYER WILL BE WARM FOR MANY  
AREAS. BECAUSE OF THIS, SNOWFALL WILL BE ELEVATION DEPENDENT,  
WITH ONLY THE WESTERN AND CENTRAL ADIRONDACKS AND SOUTHERN  
GREENS EXPECTED TO SEE ALL SNOW. MOST VALLEY AREAS WILL BE  
SEEING JUST RAIN, ALTHOUGH A BRIEF CHANGEOVER OR MIX WITH SNOW  
IS POSSIBLE LATE AS WET BULB EFFECTS ALLOWS THE SURFACE TO COOL  
OFF, ESPECIALLY FOR AREAS NORTH AND WEST OF THE CAPITAL REGION  
FOR LATE THIS EVENING.  
 
MOST OF THE STEADY PRECIP SHOULD BE ENDING AROUND MIDNIGHT OR  
SO, SO THIS WILL BE A QUICK STORM SYSTEM. QPF IS FAIRLY LIMITED,  
BUT 1-4 INCHES OF SNOW IS EXPECTED FOR THE ADIRONDACKS AND  
GREENS. ELSEWHERE FOR AREAS NORTH AND WEST OF THE CAPITAL REGION,  
A COATING TO AN INCH OR SO WILL BE POSSIBLE AS RAIN CHANGES TO  
SNOW BEFORE ENDING, WITH NO SNOW FOR AREAS SOUTH AND EAST OF THE  
CAPITAL REGION. LOCALLY SLICK TRAVEL IS POSSIBLE FOR THE HIGHEST  
TERRAIN. SNOW WILL BE WET, WITH LOW SNOW-TO-LIQUID RATIOS.  
 
ALTHOUGH THE STEADY PRECIP WILL END TOWARDS MIDNIGHT, THE  
PASSING UPPER LEVEL DISTURBANCE MAY STILL ALLOW FOR A FEW MORE  
SNOW SHOWERS OVERNIGHT, MAINLY ACROSS THE HIGH TERRAIN OF  
WESTERN NEW ENGLAND AND ACROSS LAKE-EFFECT FAVORED AREAS OF THE  
ADIRONDACKS. ANY ADDITIONAL SNOW ACCUMULATION WILL JUST BE A  
COATING TO AN INCH OR SO AND LIMITED TO JUST THE HIGHEST  
TERRAIN. LOWS WILL FALL INTO THE MID 20S TO LOW 30S, WITH SOME  
BREAKS EXPECTED IN THE CLOUD COVER BY LATE TONIGHT IN VALLEY  
AREAS.  
 
 
   
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/  
 
KEY MESSAGE:  
 
-INCREASING POTENTIAL FOR A LIGHT SNOW ACCUMULATION ACROSS MUCH  
OF THE REGION FRIDAY INTO FRIDAY NIGHT.  
 
DISCUSSION:  
 
BEHIND THE DEPARTING STORM SYSTEM, AN AREA OF HIGH PRESSURE WILL  
BE PASSING BY TO THE NORTH FOR THURSDAY INTO THURSDAY NIGHT. ANY  
LAKE EFFECT ACTIVITY SHOULD END EARLY THURSDAY, ALLOWING FOR  
MAINLY DRY AND SEASONABLE WEATHER FOR THURSDAY INTO THURSDAY  
NIGHT. NORTHWEST WINDS MAY BE A LITTLE BREEZY TO START ON  
THURSDAY, BUT WINDS SHOULD DECREASE BY LATER IN THE DAY AND INTO  
THURSDAY NIGHT.  
 
UPPER LEVEL SHORTWAVE WILL BE MOVING TOWARDS THE AREA FROM THE  
GREAT LAKES FOR FRIDAY AND PASSING ACROSS THE AREA ON FRIDAY  
NIGHT. SURFACE CYCLOGENESIS WILL BE TAKING PLACE WELL OFFSHORE  
THE EASTERN SEABOARD. WHILE THE COASTAL STORM WILL BE TOO FAR  
AWAY TO HAVE MUCH OF A DIRECT IMPACT, IT MAY HELP ALLOW FOR SOME  
LIGHT PRECIP TO BREAK OUT WITHIN THE CYCLONIC FLOW OF THE  
PASSING UPPER LEVEL DISTURBANCE. WITH SURFACE TEMPS AND TEMPS  
ALOFT SUFFICIENTLY COLD, ANY PRECIP WILL BE IN THE FORM OF LIGHT  
SNOW. THE COLD AIR MASS IN PLACE SHOULD HELP PROMOTE DECENT  
SNOW- TO- LIQUID RATIOS. PRECIP RATES WILL BE LIGHT, BUT  
INTERMITTENT LIGHT SNOW IS EXPECTED BY LATE MORNING OR EARLY  
AFTERNOON FRIDAY THROUGH THE REST OF THE DAY AND INTO A GOOD  
PART OF FRIDAY NIGHT. NBM PROBABILITIES SHOW ABOUT A 20% TO 50%  
OF AT LEAST 1 INCH ACROSS THE REGION. LATEST MOST LIKELY  
FORECAST HAS ABOUT AN INCH OR TWO OF FLUFFY SNOW FOR MANY AREAS,  
ESPECIALLY FROM THE CAPITAL REGION ON WESTWARD ACROSS THE  
MOHAWK VALLEY AND CATSKILLS. DAYTIME TEMPS WILL ONLY BE IN THE  
UPPER 20S TO MID 30S, AND LOWS ON FRIDAY NIGHT LOOK CHILLY IN  
THE TEENS AND 20S.  
 
 
   
LONG TERM /SATURDAY THROUGH TUESDAY/  
 
KEY MESSAGES:  
 
- HIGH CONFIDENCE IN VERY COLD TEMPERATURES THIS WEEKEND.  
 
DISCUSSION:  
 
HIGH-AMPLITUDE UPPER-LEVEL TROUGHING WILL BE CENTERED OVER THE  
NORTHEAST SATURDAY MORNING BEHIND A DEPARTING UPPER SHORTWAVE AND  
ASSOCIATED COASTAL LOW. NORTHWESTERLY FLOW REINFORCED BY A WEAKER  
SHORTWAVE IMPULSE SATURDAY INTO SATURDAY NIGHT WILL DRIVE POTENT  
COLD ADVECTION YIELDING 850-HPA TEMPERATURES BETWEEN -15 AND -20C,  
AND PUSHING SURFACE TEMPERATURES 10 TO 20 DEGREES BELOW NORMAL FOR  
MID TO LATE DECEMBER. BREEZY CONDITIONS SATURDAY INTO SATURDAY NIGHT  
MAY PRODUCE BITTERLY COLD WIND CHILLS, WITH PORTIONS OF THE SOUTHERN  
ADIRONDACKS POSSIBLY SEEING DANGEROUSLY COLD VALUES BELOW -20F.  
 
SOME SNOW SHOWERS MAY LINGER INTO SATURDAY MORNING AS THE PREVIOUS  
COASTAL LOW EXITS EASTWARD, ESPECIALLY WEST OF THE HUDSON NEARER TO  
LAKE MOISTURE, AS WELL AS IN HIGHER TERRAIN EAST OF THE HUDSON DUE  
TO UPSLOPE ENHANCEMENT, BUT DRY WEATHER WILL OTHERWISE RETURN ACROSS  
THE REGION BY SATURDAY NIGHT. SATURDAY AFTERNOON HIGHS IN THE 10S TO  
20S FOR MOST WILL FALL TO THE SINGLE DIGITS BELOW ZERO IN HIGHER  
TERRAIN AND SINGLE DIGITS ABOVE ZERO AT LOWER ELEVATIONS SATURDAY  
NIGHT, BUT GUSTY NORTHWEST WINDS WILL MAKE TEMPERATURES FEEL MUCH  
COLDER. OVERNIGHT WIND CHILLS MAY FALL AS LOW AS 5F TO -10F WITHIN  
THE MAJOR VALLEYS, AND -10F TO -25F IN HIGHER TERRAIN. CANADIAN  
SURFACE HIGH PRESSURE BUILDING INTO THE REGION FROM THE NORTHWEST  
SUNDAY WILL SEE CONTINUED COLD TEMPERATURES, AS HIGH REACH ONLY THE  
SINGLE DIGITS TO MID TEENS IN HIGH TERRAIN AND MID-10S TO LOW 20S AT  
LOWER ELEVATIONS. SUNDAY NIGHT WILL FEATURE SIMILARLY COLD  
TEMPERATURES BETWEEN -10F AND 10F ACROSS THE REGION, BUT DIMINISHED  
WINDS WILL REDUCE THE RISK FOR DANGEROUSLY COLD WIND CHILLS.  
 
AS UPPER-LEVEL RIDGING BUILDS IN FROM THE WEST MONDAY INTO TUESDAY,  
DEVELOPING SOUTHWESTERLY MID-LEVEL WILL PUSH TEMPERATURES BACK  
TOWARD SEASONAL NORMS, WITH VALUES POSSIBLY RISING ABOVE FREEZING IN  
THE MID-HUDSON VALLEY BY CHRISTMAS EVE AFTERNOON. LONG-RANGE  
NUMERICAL GUIDANCE REMAINS IN GOOD AGREEMENT THAT A SHORTWAVE TROUGH  
ON THE BACKSIDE OF UPPER RIDGING WILL BRING LOW TO MEDIUM CHANCES  
(20-40%) FOR PRECIPITATION INTO CHRISTMAS EVE NIGHT, WITH SNOW  
REMAINING THE FAVORED P-TYPE FOR MUCH OF THE REGION.  
 
 
   
AVIATION /08Z WEDNESDAY THROUGH SUNDAY/  
 
THROUGH 06Z THURSDAY...LOW-VFR CIGS AT 3-5 KFT WITH UNRESTRICTED  
VSBYS ARE EXPECTED TO PREVAIL THROUGH THE OVERNIGHT PERIOD AT  
ALB/GFL/PSF WHILE CLEAR SKIES ASIDE FROM PASSING HIGH CIRRUS AT POU  
WILL ALLOW FOR PERIODS OF IFR VSBYS WITHIN FOG/MIST THROUGH SUNRISE.  
VFR CONDITIONS OTHERWISE CONTINUE THROUGH 18-21Z WED WITH PERSISTENT  
LOW CLOUD BASES AT 3-5 KFT AND INCREASING HIGHER CLOUDS AT 10-20  
KFT. CALM TO LIGHT SOUTHWEST WINDS ARE EXPECTED AT ALL TERMINALS  
BEFORE TURNING OUT OF THE SOUTH AT 3-6 KT AFTER 12-16Z WED.  
 
A COLD FRONT APPROACHING THE REGION FROM THE WEST WILL SEE RAIN AND  
SNOW SHOWERS SPREAD EASTWARD THROUGH THE AFTERNOON, 20-24Z WED.  
FLYING CONDITIONS WILL RAPIDLY DETERIORATE TO MVFR AND ULTIMATELY  
IFR/LIFR AS CIGS FALL TO 1-1.5 KFT OR LESS AND VSBYS TO 2SM TO LESS.  
VSBYS MAY FALL BELOW 1SM WHERE SNOW BECOMES THE DOMINANT P-TYPE,  
MOST LIKELY AT GFL/PSF. ALB/POU WILL MORE LIKELY SEE MORE RAIN AND  
MAINTAIN HIGHER, BUT STILL IFR OR LOW-MVFR, VSBYS. CALM TO LIGHT AND  
VARIABLE WINDS ARE EXPECTED DURING STEADY PRECIPITATION.  
 
OUTLOOK...  
 
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
FRIDAY: MODERATE OPERATIONAL IMPACT. LIKELY SN.  
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SN.  
SATURDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN.  
SATURDAY NIGHT: NO OPERATIONAL IMPACT. 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.  
 
 
   
ALY WATCHES/WARNINGS/ADVISORIES  
 
CT...NONE.  
NY...NONE.  
MA...NONE.  
VT...NONE.  
 
 
 
 
 
SYNOPSIS...FRUGIS  
NEAR TERM...FRUGIS  
SHORT TERM...FRUGIS  
LONG TERM...PICARD  
AVIATION...PICARD  
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