018  
FXUS61 KBGM 181536  
AFDBGM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BINGHAMTON NY  
1036 AM EST SAT JAN 18 2025  
   
SYNOPSIS
 
 
THE NEXT COLD FRONT WILL BRING A MIX OF RAIN AND SNOW TO THE  
AREA TODAY. COLDER AIR MOVES IN TONIGHT AND THE NEXT CHANCE OF  
SNOW ARRIVES SUNDAY. SOME AREAS OF NORTHEAST PA AND SOUTHERN NY  
WILL SEE ACCUMULATING SNOWFALL. VERY COLD ARCTIC AIR WILL SETTLE  
INTO THE REGION MONDAY THROUGH AT LEAST WEDNESDAY.  
 

 
   
NEAR TERM /THROUGH SUNDAY/
 
 
1035 AM UPDATE:  
 
THE NEAR TERM FORECAST REMAINS ON TRACK AND NO CHANGES WERE MADE  
WITH THIS UPDATE. WILL BE TAKING A CLOSER LOOK AT SUNDAY'S STORM  
WITH THE UPCOMING AFTERNOON FORECAST PACKAGE.  
 
415 AM UPDATE..  
PRIMARY CONCERNS IN THE NEAR TERM ARE FOCUSED ON THE WEAK  
SYSTEM MOVING THROUGH TODAY, COLD AIR PUSHING IN TONIGHT AND THE  
COASTAL LOW DEVELOPING AND MOVING ALONG THE EAST COAST ON  
SUNDAY WITH THE POTENTIAL FOR SIGNIFICANT ACCUMULATING SNOW.  
 
THE WINTER STORM WATCH IN EFFECT FOR PORTIONS OF NORTHEAST PA  
AND SULLIVAN COUNTY NY WAS EXPANDED SLIGHTLY TO INCLUDE DELAWARE  
COUNTY NY AND ALSO WYOMING AND SUSQUEHANNA COUNTIES IN PA.  
 
FOR TODAY, THE AMPLIFIED RIDGE AXIS THAT MOVED THROUGH  
YESTERDAY IS WELL OFF THE NEW ENGLAND COAST AS OF THIS MORNING,  
BUT THERE IS STILL THE REMNANTS OF THE LOW LEVEL JET AND WARM  
NOSE LINGERING ACROSS PARTS OF THE INTERIOR NORTHEAST. THIS  
POCKET OF WARM SOUTHERLY WINDS IS ALLOWING FOR SOME RELATIVELY  
WARM TEMPERATURES (UPPER 20S TO MID 30S) ACROSS THE REGION ALONG  
WITH OCCASIONALLY GUSTY SOUTH WINDS (UP TO 20-25 MPH). AN  
INCOMING UPPER SHORT WAVE AND ASSOCIATED SURFACE COLD FRONT WILL  
PUSH THROUGH DURING THE DAY TODAY AND INITIALLY PRODUCED LIGHT  
SNOW ON THE FRONT END THIS MORNING. HOWEVER, WITH WEAK HEATING  
DURING THE AFTERNOON, ESPECIALLY IN THE VALLEY AND LOWER-  
ELEVATION LOCATIONS, SURFACE TEMPERATURES WILL WARM SLIGHTLY  
ABOVE FREEZING AND ALLOW FOR A MIX OF RAIN AND SNOW SHOWERS.  
THERE COULD BE POCKETS OF HEAVIER PRECIPITATION IN THE  
AFTERNOON, WHICH COULD SWITCH THE MIX OVER TO ALL SNOW. HOWEVER,  
SNOWFALL ACCUMULATIONS SHOULD REMAIN BELOW AN INCH EXCEPT  
ACROSS NORTHERN ONEIDA COUNTY IN NY WHERE THE PRECIP MAY REMAIN  
SNOW ALL DAY AND 1-3 INCHES OF SNOW IS POSSIBLE.  
 
FOR TONIGHT, AN COOLING AIR MASS AND PATTERN SHIFT WILL OCCUR  
AS THE WIND FLOW SHIFTS TO THE NORTHWEST AND COLDER AIR STARTS  
TO FILTER IN. TEMPERATURES IN THE UPPER 20S AND LOWER 30S THIS  
EVENING WILL COOL INTO THE LOWER 20S BY SUNDAY MORNING. THE  
LINGERING SNOW SHOWERS THIS EVENING WILL TAPER OFF AND MOST OF  
THE SNOW SHOULD END DURING THE OVERNIGHT HOURS.  
 
FOR SUNDAY, THE STAGE WILL BE SET FOR A PERIOD OF ACCUMULATING  
SNOW DUE TO THE DEVELOPMENT AND STRENGTHENING OF A COASTAL  
SURFACE LOW JUST OFF THE NJ COAST.  
 
ANTECEDENT COLD, SUB-FREEZING AIR NEAR THE SURFACE AND  
THROUGHOUT THE COLUMN WILL CREATE FAVORABLE CONDITIONS FOR SNOW  
PRODUCTION AS THIS SYSTEM PASSES BY TO THE EAST. FROM THE  
SYNOPTIC LEVEL, A POSITIVELY TILTED UPPER TROUGH OVER THE OHIO  
VALLEY/GREAT LAKES WILL BECOME NEGATIVELY TILTED DURING THE DAY  
SUNDAY AND LIFT NEWD THROUGH THE NORTHEAST US. AN EMBEDDED SHORT  
WAVE AND 300MB JET STREAK WILL INDUCE AN AREA OF STRONG  
VERTICAL MOTION ON THE LEADING EDGE OF THIS TROUGH AND ACT TO  
DEEPEN THE SURFACE LOW WITH TIME. THIS ENTIRE SYSTEM WILL  
TRANSLATE NORTHEASTWARD LATER SUNDAY AND SUNDAY NIGHT AND SEEMS  
TO BE WELL SIMULATED WITH MOST OF THE DETERMINISTIC MODEL  
GUIDANCE.  
 
THE DETAILS OF THE MESOSCALE FORCING FEATURES REMAIN THE AREA  
OF GREATEST CHALLENGE. THE EXACT POSITION OF THE STRENGTHENING  
SURFACE LOW WILL PLAY A LARGE ROLE IN THE LOCATION OF THE LOW  
LEVEL BAROCLINIC ZONE AND FORMATION OF THE FRONTOGENETIC LAYER.  
THE CONSENSUS SEEMS TO BE ALONG A SW TO NE LINE EXTENDING FROM  
E-CENTRAL PA INTO NEW ENGLAND, WITH WARM AIR TO THE SOUTHEAST  
AND THE COLD AIR REMAINING IN PLACE TO THE NORTHWEST. THIS  
POSITION OF THE F-GEN LAYER WOULD THEN ALLOW THE HEAVIEST SNOW  
TO SET UP JUST TO THE NORTH/NW...ROUGHLY FROM THE POCONOS INTO  
THE SOUTHERN CATSKILLS.  
 
THE UNCERTAINTIES REMAIN CENTERED AROUND THE EXACT LOCATION OF  
THIS LAYER OF FGEN. ANY EAST OR WEST MOVEMENT OF THIS FORCING  
COULD SHIFT THE BAND SIGNIFICANTLY. WE ARE ALSO STARTING TO SEE  
SOME INDICATION OF MESOSCALE BANDING AND WEAK CSI. THE NAM/GFS  
AND CANADIAN MODEL GUIDANCE IS INDICATING THE PRESENCE OF  
NEGATIVE EPV OVERLAPPING WITH SOME OF THE AFOREMENTIONED LOW-  
LEVEL FGEN, WHICH IS USUALLY AN INDICATION OF POTENTIAL BANDING  
SNOWFALL AND ENHANCED SNOWFALL RATES. THE HREF WPC SNOWBAND  
PROBABILITY TRACKER IS WITHIN SPATIAL RANGE OF THIS EVENT AND IS  
STARTING TO PICK UP ON THIS POTENTIAL AS WELL.  
 
DUE TO SOME OF THE ITEMS MENTIONED HERE AND THE FACT THAT THERE  
IS A SLIGHTLY INCREASED CONCERN FOR WESTWARD EXTENT OF THE  
HEAVY SNOW, WE HAVE DECIDED TO EXPAND THE WINTER WEATHER WATCH  
SLIGHTLY TO THE WEST/NW. THIS STILL DOES APPEAR TO BE A VERY  
QUICK-HITTING STORM, WITH THE MOST FAVORABLE TIME OF HEAVY SNOW  
FALLING FROM AROUND 12 PM TO 7 PM...EARLIER IN THE WYOMING  
VALLEY AND LATER IN THE CATSKILLS.  
 
WE WILL LIKELY NEED SOME WINTER WEATHER ADVISORIES IN A TIER OF  
COUNTIES TO THE WEST/NW, BUT GIVEN THE UNCERTAINTY, WE WILL  
HOLD OFF AT THIS TIME. A TIGHT GRADIENT OF SNOWFALL APPEARS  
LIKELY WITH AREAS FARTHER TO THE WEST AND NORTH POSSIBLY SEEING  
A VERY MINIMAL AMOUNT OF SNOW WITH THIS SYSTEM.  
 

 
   
SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/
 
 
330 AM UPDATE...  
 
THE SUNDAY WINTER STORM WILL LINGER INTO THE OVERNIGHT HOURS AS IT  
SLIDES EAST. ANOTHER HALF INCH TO 2 INCHES OF SNOWFALL ACCUMULATION  
WILL BE POSSIBLE EAST OF I-81 DURING THE FIRST HALF OF SUNDAY  
NIGHT. BEHIND THE DEPARTING SYSTEM, COLD, WEST-NORTHWEST FLOW  
WILL KICK OFF SOME LAKE EFFECT SNOW SHOWERS. T850 TEMPS WILL BE  
AS LOW AS -20 DEG C. THERE IS SOME UNCERTAINTY ON HOW QUICKLY  
THE STORM SYSTEM MOVES OUT AND THEN HOW QUICKLY THE LAKE EFFECT  
SNOW DEVELOPS. THERE IS POTENTIAL FOR A COUPLE OF INCHES IN THE  
FINGER LAKES REGION SUNDAY NIGHT IF SNOW SHOWERS DEVELOP EARLIER  
THAN EXPECTED. CURRENTLY THE FORECAST HAS LESS THAN AN INCH FOR  
THIS REGION. THE 510 LINE (1000-500 MB THICKNESS) DROPS SOUTH  
OF THE REGION, INDICATING THE ARRIVAL OF AN ARCTIC AIR MASS.  
LOWS WILL BE IN THE SINGLE DIGITS, THOUGH BREEZY WINDS WILL PUSH  
WIND CHILLS BELOW ZERO.  
 
LAKE EFFECT SNOW WILL CONTINUE THROUGH MONDAY NIGHT. DURING THE  
DAYTIME, FLOW WILL FAVOR SNOW OVER PORTIONS OF CNY, THOUGH IT IS  
UNCERTAIN EXACTLY HOW THE BANDS WILL SET UP. MOST MODELS SHOW AN  
INITIAL BAND THAT WILL BE A COMBINATION OF A LAKE ERIE AND LAKE  
ONTARIO BAND. AS THE DAY PROGRESSES, SOME MODELS SHOW TWO SEPARATE  
BANDS, ONE FOR EACH LAKE WHILE OTHERS HANG ONTO ONE BAND UNTIL THE  
OVERNIGHT HOURS. EVENTUALLY, FLOW WILL BECOME MORE SOUTHWESTERLY AND  
THE BANDS WILL DRIFT NORTH OF THE REGION, THOUGH THE LAKE ONTARIO  
BAND WILL CLIP N. ONEIDA AT TIMES. DESPITE THE UNCERTAINTIES, THE  
DAYTIME WILL BE THE BEST CHANCE FOR ACCUMULATIONS WITH LOCALIZED  
AMOUNTS UP TO 2 INCHES POSSIBLE. THEN LIGHTER AMOUNTS ARE EXPECTED  
AS THE BAND(S) DRIFT NORTHWARD.  
 
TEMPERATURES WILL CONTINUE TO PLUMMET ON MONDAY. HIGHS WILL MAX OUT  
IN THE TEENS, THOUGH THE WYOMING VALLEY MAY JUST REACH THE 20S. WITH  
WINDS PICKING UP, WIND CHILLS WILL BE IN THE SINGLE DIGITS. CLEAR  
SKIES WILL SUPPORT GOOD RADIATIONAL COOLING OVERNIGHT, SO HOURLY  
TEMPERATURES WERE BUMPED DOWN USING AN EQUAL BLEND OF NBM AND NBM  
TENTH PERCENTILE GUIDANCE. THE LOWS WERE THEN DERIVED FROM THOSE  
CHANGES. BLUSTERY CONDITIONS ARE EXPECTED AS WIND CHILLS WILL FALL  
TO -15 TO -25 MONDAY NIGHT INTO TUESDAY MORNING. COLD WEATHER HAZARDS  
WILL LIKELY BE NEEDED, BUT GIVEN IT IS STILL A FEW DAYS OUT, THIS  
IS HIGHLIGHTED IN THE HWO FOR NOW.  
 

 
   
LONG TERM /TUESDAY THROUGH FRIDAY/
 
 
330 AM UPDATE...  
 
THE CONTINUATION OF THE COLD CONDITIONS WILL BE THE MAIN CONCERN  
DURING THE LONG TERM PERIOD. THROUGH WEDNESDAY, TEMPERATURES WILL  
STRUGGLE TO CLIMB OUT OF THE SINGLE DIGITS DURING THE DAYTIME HOURS  
WHILE FALLING BELOW ZERO BOTH TUESDAY AND WEDNESDAY NIGHT. WIND  
CHILLS WILL ONCE AGAIN FALL BELOW -15 BOTH NIGHTS, THOUGH SLIGHT  
IMPROVEMENTS WILL BE SEEN WEDNESDAY NIGHT INTO THURSDAY MORNING. THE  
510 LINE WILL FINALLY MOVE BACK NORTH AS THE COLD AIR BEGINS TO  
RETREAT ON THURSDAY. HIGHS WILL CLIMB BACK INTO THE 20S BY THE END  
OF THE WEEK THOUGH SINGLE DIGITS WILL STILL BE POSSIBLE FOR SOME  
DURING THE OVERNIGHT HOURS.  
 
A NEARLY WEEK-LONG LAKE EFFECT EVENT IS IN STORE FOR THE LONG TERM  
PERIOD THOUGH WEST TO SOUTHWEST FLOW WILL KEEP MOST OF THE SNOW  
NORTH OF THE REGION. STILL, ON AND OFF SNOW SHOWERS WILL BE POSSIBLE  
ACROSS FAR NORTHERN PORTIONS OF THE REGION. MEANWHILE, HIGH PRESSURE  
WILL KEEP TWO SEPARATE COASTAL SYSTEMS JUST OUT OF THE REGION  
WEDNESDAY AND FRIDAY. HOWEVER, SHIFTS IN THESE TRACKS WILL BE  
POSSIBLE OVER TIME, SO BOTH WILL NEED TO BE MONITORED THROUGHOUT THE  
WEEK.  
 

 
   
AVIATION /16Z SATURDAY THROUGH WEDNESDAY/
 
 
A WEAK WAVE WILL MOVE INTO THE REGION LATER THIS MORNING AND  
CAUSE THE CURRENT VFR CONDITIONS TO DROP TO MVFR AFTER 15Z WITH  
SOME LIGHT RAIN MIXING WITH SNOW INTO THE AFTERNOON. THERE COULD  
BE PERIODS WHEN THE PRECIPITATION INTENSIFIES FOR SHORT PERIODS  
OF TIME. DURING THESE 1-2 HOUR WINDOWS IN THE AFTERNOON, VSBYS  
COULD DROP TO IFR OR LESS. THE RAIN/SNOW SHOWERS WILL SLOWLY  
TAPER OFF AFTER 22Z AND MAKE WAY FOR THE COLDER AND DRIER AIR  
EXPECTED TO MOVE IN AFTER 02Z. EAST/SOUTHEAST WINDS THIS MORNING  
WILL BECOME MORE SOUTHERLY LATER TODAY AND THEN VEER MORE TO  
THE NORTHWEST SATURDAY EVENING. A PERIOD OF DRY CONDITIONS IS  
EXPECTED AFTER 06Z TONIGHT BEFORE THE NEXT ROUND OF SNOW MOVES  
IN LATE SUNDAY MORNING.  
 
STILL EXPECTING A PERIOD OF LLWS AT MOST TERMINALS THROUGH 13-16Z  
THIS MORNING DUE TO A MODEST LOW LEVEL JET.  
 
OUTLOOK...  
 
SUNDAY...SNOW SPREADING NORTH WITH ASSOCIATED CIG AND VSBY  
RESTRICTIONS LIKELY. THE MOST FAVORABLE LOCATION WILL BE AVP  
DUE TO A PASSING COASTAL LOW. BGM, ITH AND ELM ALSO COULD BE  
IMPACTED.  
 
MONDAY THROUGH WEDNESDAY...LAKE EFFECT SNOW SHOWERS AND  
ASSOCIATED RESTRICTIONS POSSIBLE, ESPECIALLY FOR KSYR-KRME.  
 

 
   
BGM WATCHES/WARNINGS/ADVISORIES
 
 
PA...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY  
NIGHT FOR PAZ039-040-043-044-047-048-072.  
NY...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY  
NIGHT FOR NYZ057-062.  
 

 
 

 
 
SYNOPSIS...BJT  
NEAR TERM...BJG/BJT  
SHORT TERM...BTL  
LONG TERM...BTL  
AVIATION...BJT  
 
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