138  
FXUS61 KBGM 210913  
AFDBGM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BINGHAMTON NY  
413 AM EST THU NOV 21 2024  
   
SYNOPSIS  
 
A STRONG LOW PRESSURE SYSTEM DEVELOPS NEAR LONG ISLAND LATER  
TODAY AND ROTATES THROUGH THE REGION ON FRIDAY BRINGING MORE  
RAIN AND SNOW. THIS LOW LOOKS TO LINGER NEAR NEW ENGLAND THROUGH  
THE WEEKEND. ANOTHER COLD FRONT THEN FOLLOWS WITH ANOTHER  
CHANCE OF RAIN AND SNOW SHOWERS EARLY NEXT WEEK.  
 
 
   
NEAR TERM /THROUGH FRIDAY/  
 
A RATHER COMPLEX WINTER STORM IS ONGOING ACROSS THE REGION THIS  
MORNING. A BAND OF RAINFALL IS MOVING EASTWARD AND SHOULD EXIT  
AROUND SUNRISE OR SO. THIS SHOULD BRING A SHORT BREAK TODAY  
BEFORE AN ADDITIONAL SURFACE LOW DEVELOPS LATE THIS AFTERNOON  
NEAR LONG ISLAND. THIS LOW PRESSURE SYSTEM WILL THEN RETROGRADE  
NORTHWEST AND LOOP THROUGH OUR REGION UNDER AN UPPER LEVEL  
TROUGH.  
 
CONSIDERABLE LIFT NEAR AND WEST OF THE LOW SHOULD START TO  
REDEVELOP RAINFALL ACROSS THE REGION THIS AFTERNOON FROM EAST TO  
WEST. SLIGHTLY DRIER AIR WILL ALSO START TO ADVECT INTO THE  
REGION THIS MORNING. DYNAMICAL AND EVAPORATIONAL COOLING  
PROCESSES SHOULD ALLOW FOR RAIN TO CHANGE TO SNOW FROM THE  
HIGHER ELEVATIONS TO THE VALLEYS AS PRECIPITATION FALLS. AS THE  
LOW MOVES FURTHER NORTHWEST INTO OUR REGION PRECIPITATION LOOKS  
FAIRLY WIDESPREAD TONIGHT.  
 
LATER THIS EVENING AND OVERNIGHT A LOOK AT 700 MB MODELED FGEN  
SHOWS VERY STRONG SIGNALS FOR BANDING MOVING INTO SULLIVAN AND  
PIKE COUNTY THAT BASICALLY TRACKS ALONG ROUTE 17/ I-86 THROUGH  
THE OVERNIGHT TOWARD BROOME COUNTY.SNOWFALL RATES UNDER THE BAND  
HAVE THE POTENTIAL TO BE 1-3+ INCHES PER HOUR FOR SEVERAL  
HOURS. SOME UNCERTAINITY IS STILL PRESENT IN THE EXACT LOCATION  
OF THE BANDING BUT GUIDANCE FROM WPC AND HI-RES GUIDANCE FAVORS  
THESE LOCATIONS AT THIS TIME. THE BANDING SIGNAL BECOMES MORE  
DIFFUSE TOWARD SUNRISE WITH WEAKER BANDS LIKELY ROTATING TOWARD  
ITHACA AND CORTLAND AND FURTHER SOUTHWEST INTO BRADFORD PA.  
 
SNOWFALL RATIOS LOOK TO VARY QUITE A BIT AS WELL. WITH LIGHTER  
PRECIPITATION AND A WARM GROUND INITIALLY VALUES MAY BE UNDER  
5:1. THIS IS PARTICULARLY TRUE IN VALLEY LOCATIONS THAT TAKE  
LONGER TO CHANGEOVER. WHEN HEAVIER SNOWFALL RATES OCCUR WE SHOULD  
BE ABLE TO GET A MORE TYPICAL OF A 10:1 RATIO. THIS SHOWS ON  
MODEL SOUNDINGS AS FAVORABLE SNOW GROWTH IN THE -10 TO 20C  
LAYER, STEEP MID- LEVEL LAPSE RATES AND PLENTY OF OMEGA.  
SNOWFALL TOTALS LOOK TO BE MAXIMIZED AT HIGHER ELEVATIONS UNDER  
THE INTENSE BANDS. AMOUNTS OF OVER A FOOT TO LOCALLY 18 INCHES  
ARE NOT OUT OF THE QUESTION IN THE WARNING WITH VALLEY LOCATIONS  
GETTING SEVERAL INCHES.  
 
MORE UNCERTAINITY IS PRESENT FOR THE HEAVY PRECIPITATION TO  
REACH THE REMAINING COUNTIES STILL UNDER A WINTER STORM WATCH IN  
THE FINGER LAKES/STEUBEN COUNTY EASTWARD TO CORTLAND AND  
COOPERSTOWN. VALLEY LOCATIONS COULD GET JUST LIGHT PRECIPITATION  
RESULTING IN ONLY LIGHT ACCUMULATIONS LEADING TO SHARP CUTOFFS.  
 
STEADY SNOWFALL SHOULD CONTINUE TO AROUND NOON IN NE PA.  
PRECIPITATION THEN BECOMES MORE SHOWERY LATER FRIDAY. THE LOSS  
OF THE PRECIPITATION RATES SHOULD ALLOW TEMPERATURES TO RISE  
FROM AROUND FREEZING FOR LOWS WELL INTO THE 30'S. AREAS THAT  
SEE MUCH LESS PRECIPITATION SUCH AS SYRACUSE MAY NOT FALL BELOW  
THE MID 30'S AND GET WELL INTO THE 40'S FRIDAY.  
 
 
   
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/  
 
300 AM UPDATE...  
 
THE CENTER OF THE LOW PRESSURE SYSTEM THAT BROUGHT THE WINTER  
STORM TO THE REGION WILL SLOWLY SLIDE TO THE EAST FRIDAY NIGHT.  
NORTHERLY FLOW WILL PUSH A MARGINALLY DRY SLOT INTO THE AREA.  
THERE WILL BE SOME LINGERING SNOW SHOWERS ACROSS THE REGION, BUT  
SHOWERS SHOULD DISSIPATE AS THE NIGHT PROGRESSES. LOWS WILL FALL  
INTO THE UPPER 20S TO LOW 30S ACROSS THE REGION.  
 
SATURDAY, THE UPPER LEVEL TROUGH THAT HAS BEEN MOSTLY STATIONARY  
AND SPINNING OVER THE REGION WILL FINALLY OPEN UP AND SPEED UP  
ITS PROGRESSION TO THE EAST. THIS WILL BRING NW FLOW ACROSS THE  
REGION AND CONTINUE TO ADVECT IN COOL AIR FROM CANADA. LAKE  
EFFECT PRECIPITATION IS EXPECTED TO DEVELOP LATE SATURDAY  
MORNING INTO THE AFTERNOON. AN UPSTREAM CONNECTION TO THE  
GEORGIAN BAY ON LAKE HURON WILL ENHANCE LAKE EFFECT  
PRECIPITATION ACROSS THE NORTHERN FINGER LAKES INTO THE MOHAWK  
VALLEY SATURDAY EVENING INTO SUNDAY MORNING. TEMPERATURES WILL  
BE WARM ENOUGH FOR MOST OF THE PRECIPITATION TO FALL AS RAIN.  
HIGHER ELEVATIONS IN THE FINGER LAKES AND SOUTH OF THE MOHAWK  
VALLEY SHOULD SEE SNOW MIX IN SATURDAY NIGHT, BUT ACCUMULATIONS  
ARE NOT EXPECTED AT THIS TIME. TEMPS ON SATURDAY WILL BE IN  
THE LOW TO MID 40S ACROSS THE REGION.  
 
LAKE EFFECT SHOWERS WILL CONTINUE THROUGH SATURDAY NIGHT INTO  
SUNDAY AFTERNOON. A RIDGE WILL BUILD INTO THE AREA LATE SUNDAY  
AFTERNOON, WHICH WILL CUT OFF THE LAKE EFFECT PROCESS AND BRING  
COOL AND QUIET WEATHER TO THE REGION SUNDAY NIGHT. ALL TOLD,  
UP TO 0.25IN OF RAIN COULD FALL, CENTERED ON AN AREA FROM  
SENECA TO ONEIDA COUNTY. TEMPS ON SUNDAY WILL ONCE AGAIN BE IN  
THE 40S, WITH OVERNIGHT LOWS IN THE UPPER 20S TO LOW 30S.  
 
 
   
LONG TERM /MONDAY THROUGH WEDNESDAY/  
 
315 AM UPDATE  
 
MONDAY LOOKS TO SEE HIGH PRESSURE SITTING OVERHEAD, BRINGING  
QUIET AND AND SEASONABLE TEMPS TO THE REGION. A CLIPPER SYSTEM  
LOOKS TO STREAM ACROSS THE GREAT LAKES AND IMPACT THE REGION  
MONDAY NIGHT INTO TUESDAY. TIMING AND LOCATION OF SAID SYSTEM IS  
STILL UNCERTAIN, BUT CURRENT THINKING IS A WARM AIRMASS AHEAD  
OF THE SYSTEM WILL ALLOW RAIN SHOWERS TO FALL ACROSS THE AREA  
MONDAY NIGHT INTO TUESDAY MORNING. COLD AIR WILL FILTER IN  
BEHIND THE CLIPPER, CHANGING PRECIP OVER TO SNOW OR A RAIN/SNOW  
MIX TUESDAY AFTERNOON. LAKE EFFECT SHOWERS WILL CONTINUE INTO  
WEDNESDAY WITH VALLEYS SEEING RAIN OR A RAIN SNOW MIX AND HIGHER  
ELEVATIONS SEEING MOSTLY SNOW SHOWERS.  
 
 
   
AVIATION /09Z THURSDAY THROUGH MONDAY/  
 
MVFR CONDITIONS ACROSS ALL TERMINALS AS RAIN SHOWERS ALONG A  
COLD FRONT MOVE ACROSS THE REGION TONIGHT. IFR CONDITIONS ARE  
EXPECTED FOR A FEW HOURS LATER TONIGHT AT RME/SYR/ITH/BGM/AVP AS  
SOME SNOW MAY DEVELOP AND CEILINGS FALL WITH THE INCOMING  
COLDER AIRMASS. ELM SHOULD REMAIN MVFR THROUGH THE MORNING  
HOURS.  
 
WE SHOULD SEE MVFR CONDITIONS AT MOST TERMINALS LATER THIS  
MORNING INTO THE EARLY AFTERNOON, WITH RME REMAINING IFR. IFR  
WILL RETURN TO MOST TERMINALS THIS AFTERNOON INTO THE OVERNIGHT  
HOURS AS A WINTER STORM IMPACTS THE REGION. ELM WILL BE ON THE  
FAR WESTERN EDGE OF THE STORM SO CONFIDENCE AT THIS TIME WAS NOT  
HIGH ENOUGH TO INCLUDE IFR CONDITIONS HERE.  
 
OUTLOOK...  
 
THURSDAY NIGHT THROUGH FRIDAY...RESTRICTIONS LIKELY WITH A  
WINTRY MIX OF RAIN AND SNOW OR JUST SNOW FOR MOST TERMINALS. SYR  
AND RME ARE EXPECTED TO REMAIN RAIN DURING THIS TIME.  
 
SATURDAY...CONTINUED POSSIBLE RESTRICTIONS IN RAIN AND SNOW  
SHOWERS, ESPECIALLY CENTRAL NY.  
 
SUNDAY...GRADUAL IMPROVEMENT. VFR PROBABLE FOR AVP WITH MVFR  
EXPECTED ELSEWHERE. MIXED RAIN/SNOW SHOWERS FAR NORTHERN AREAS.  
 
MONDAY... ANOTHER APPROACHING LOW PRESSURE SYSTEM COULD BRING  
POSSIBLE RESTRICTIONS.  
 
 
   
BGM WATCHES/WARNINGS/ADVISORIES  
 
PA...WINTER STORM WATCH FROM THIS AFTERNOON THROUGH FRIDAY  
AFTERNOON FOR PAZ038.  
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 PM EST  
FRIDAY FOR PAZ039-040-043-044-047-048-072.  
NY...WINTER STORM WATCH FROM THIS AFTERNOON THROUGH FRIDAY  
AFTERNOON FOR NYZ022>025-036-044>046-055.  
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 PM EST  
FRIDAY FOR NYZ056-057-062.  
 
 
 
 
 
SYNOPSIS...MWG  
NEAR TERM...MWG  
SHORT TERM...JTC  
LONG TERM...JTC  
AVIATION...JTC  
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