124  
FXUS61 KBGM 181109  
AFDBGM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BINGHAMTON NY  
709 AM EDT MON OCT 18 2021  
   
SYNOPSIS
 
 
COOLER WEATHER WITH ON AND OFF LAKE ENHANCED RAIN SHOWERS ARE  
EXPECTED TO CONTINUE THIS MORNING, THEN SLOWLY DIMINISH BY LATER  
IN THE DAY. WARMER AND DRIER WEATHER LOOKS TO RETURN TUESDAY,  
AS HIGHS REACH BACK INTO THE 60S. THE NEXT SHOT OF RAIN ARRIVES  
THURSDAY AND FRIDAY WITH COOLER CONDITIONS EXPECTED THIS  
WEEKEND.  
 

 
   
NEAR TERM /THROUGH TUESDAY/
 
 
437 AM UPDATE...  
WATER VAPOR IMAGERY SHOWS AN IMPRESSIVE CHAIN OF SHORTWAVE  
TROUGHS/VORT MAXES ON THE BACKSIDE OF A LONGWAVE TROUGH PARKED  
OVER QUEBEC AND NORTHERN NEW ENGLAND. THE MOST SIGNIFICANT UPPER  
LEVEL SHORTWAVE (FOR US) IS THE ONE ROLLING INTO EASTERN LAKE  
ONTARIO. A SURFACE TROUGH ASSOCIATED WITH THIS FEATURE EXTENDS  
ACROSS NY STATE, JUST INLAND OF LAKE ONTARIO. WHILE THERE ISN'T  
MUCH OF AN AIRMASS CHANGE NORTH OF THIS BOUNDARY, WINDS DO SHIFT  
FROM THE W TO NW, AND THERE IS SIGNIFICANT COOLING JUST ALOFT,  
PARTICULARLY AT 850 MB. ALSO OF NOTE IS ANOTHER DISTURBANCE  
ROLLING INTO NE PA THAT WAS NOT WELL HANDLED BY MODELS  
OVERNIGHT, AND IS SOON TO BRING SOME BRIEF RAIN SHOWERS TO THE  
WYOMING VALLEY.  
 
EXPECT TO SEE ANOTHER SIGNIFICANT UPTICK IN PRECIP COVERAGE AS  
THE SURFACE TROUGH MOVES THROUGH, WITH THE BEST COVERAGE OVER  
AN AREA NORTH AND EAST OF A PEO-BGM LINE (AND ON INTO OTSEGO AND  
DELAWARE COUNTIES).  
 
IN THE WAKE OF THE TROUGH, PRECIP COVERAGE AND INTENSITY WILL  
DIMINISH, BUT WILL NONETHELESS REMAIN WIDELY SCATTERED DOWNWIND  
OF THE LAKES THROUGH EARLY AFTERNOON. GIVEN THE LOW LEVEL NW  
WINDS, THE MOST FAVORED AREA WILL BE OVER SOUTHERN CAYUGA,  
EASTERN TOMPKINS, ONONDAGA, AND CORTLAND COUNTIES. THOSE  
NORTHWEST WINDS WILL BE A BIT FRESH AT TIMES, GUSTING TO AROUND  
20-25 MPH.  
 
CLOUDS WILL DIMINISH FROM EAST TO WEST TONIGHT, WITH THE MOST  
CLEARING OCCURRING WEST OF I-81 WHERE LOW LEVEL WINDS WILL  
SHIFT, INTERRUPTING THE LAKE TRAJECTORY. THE PRESSURE GRADIENT  
LOOKS TO BE A LITTLE LIGHTER OUT THAT WAY AS WELL, THOUGH WINDS  
SHOULD BE JUST HIGH ENOUGH TO PREVENT MUCH FOG. STILL,  
TEMPERATURES WILL DROP INTO THE UPPER-30S, WITH SOME SHELTERED  
AND TYPICALLY- COLDER VALLEYS AND HOLLOWS REACHING FOR THE MID-  
30S. SOME FROST IS POSSIBLE IN THESE AREAS.  
 
UPPER LEVEL RIDGING WILL QUICKLY PUSH THE CORE OF THE COLDER  
AIR ALOFT EAST OF THE AREA, WITH LOW LEVEL WINDS SHIFTING TO  
WESTERLY AREA-WIDE ON TUESDAY. WITH MOSTLY SUNNY SKIES  
PREVAILING, EXPECT TEMPERATURES TO CLIMB BACK UP INTO THE  
MIDDLE-60S MAINLY WEST OF I-81, WITH LOWER-60S EAST, AND UPPER-  
50S IN THE HIGHER ELEVATIONS OF THE CATSKILLS.  
 

 
   
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/
 
 
400 AM UPDATE  
 
STARTING OFF QUIET THIS PERIOD WITH HIGH PRESSURE IN PLACE JUST TO  
OUR SOUTH, ACROSS THE MID-ATLANTIC THROUGH WEDNESDAY. THIS WILL  
BRING MOSTLY CLEAR/SUNNY AND MILD WEATHER. OVERNIGHT LOWS WILL BE IN  
THE UPPER 40S TO LOWER 50S, WITH TEMPERATURES RISING INTO THE LOWER  
70S WEDNESDAY AFTERNOON. WE'LL HAVE LOW HUMIDITY AND A NICE WESTERLY  
BREEZY AT 6-12 MPH, SO OVERALL A VERY PLEASANT FALL DAY WEDNESDAY.  
BY WEDNESDAY NIGHT A WARM FRONT WILL LIFT NORTH ACROSS THE REGION,  
AS A LOW PRESSURE SYSTEM MOVES NORTHEAST INTO THE CENTRAL GREAT LAKES.  
THIS BOUNDARY WILL BRING AN INCREASE IN CLOUDS AND A FEW SPOTTY  
SHOWERS ARE ALSO POSSIBLE; MAINLY NORTH AND WEST OF BINGHAMTON...MILD  
OVERNIGHT LOWS AGAIN, IN THE MID-40S TO LOWER 50S.  
 
LATEST MODEL GUIDANCE SHOWS THE AFOREMENTIONED WARM FRONT LIFTING  
WELL OFF TO THE NORTH ON THURSDAY, AS OUR FORECAST AREA ENTERS THE  
WARM SECTOR OF THE APPROACHING LOW. THIS SHOULD ALLOW CONDITIONS TO  
BE PARTLY SUNNY, WARM AND BREEZY THURSDAY MORNING ACROSS THE REGION.  
LATER IN THE DAY THE COLD FRONT WILL APPROACH FROM THE WEST. EXACT  
TIMING REMAINS A BIT UNCERTAIN...BUT THE LATEST 00Z GUIDANCE HAS  
SLOWED IT DOWN BY A FEW HOURS. OVERALL, EXPECT INCREASING CLOUDS  
THURSDAY AFTERNOON, WITH SHOWERS BECOMING LIKELY ACROSS THE CENTRAL  
SOUTHERN TIER AND FINGER LAKES LATE IN THE DAY...THEN A CHANCE FOR  
LATE DAY SHOWERS AS FAR EAST AS THE I-81 CORRIDOR...BUT THESE MAY  
HOLD OFF UNTIL CLOSE TO SUNSET. MINOR AMOUNTS OF INSTABILITY NOTED  
IN THE GUIDANCE, SO CANNOT RULE OUT A STRAY THUNDERSTORM OR TWO...  
ADDED IN A SLIGHT CHANCE OF THUNDER INTO THE FORECAST GRIDS TO  
COVER THIS. ANOTHER WARM DAY, WITH HIGHS REACHING THE UPPER 60S  
TO LOWER 70S, DUE TO THE STRONG WARM AIR ADVECTION ON 6-12 MPH  
SOUTHERLY WINDS.  
 
THE LOW PRESSURE CENTER PASSES BY TO OUR NORTHWEST, UP ACROSS THE ST  
LAWRENCE VALLEY THURSDAY NIGHT; THIS WILL KEEP SHOWERS IN THE  
FORECAST, ESPECIALLY ACROSS CNY. SIMILAR OVER NIGHT LOWS BACK DOWN  
IN THE MID-40S TO LOWER 50S. WINDS TURN SOUTHWEST, WEST AND EVENTUALLY  
WEST-NORTHWEST OVERNIGHT AT 5 TO 10 MPH, BEHIND THE COLD FRONT.  
 

 
   
LONG TERM /FRIDAY THROUGH SUNDAY/
 
 
400 AM UPDATE  
 
THIS PERIOD WILL FEATURE SOMEWHAT UNSETTLED AND MORE FALL LIKE  
WEATHER FOR CNY AND NE PA. THERE IS QUITE A BIT OF UNCERTAINTY IN  
THE EXACT TIMING AND DETAILS OF THE FORECAST IN THIS TIMEFRAME. THE  
OVERALL SYNOPTIC SETUP WILL BE: A LARGE AND SLOW MOVING CLOSED UPPER  
LEVEL LOW STARTS OUT NEAR LAKE SUPERIOR FRIDAY INTO FRIDAY NIGHT  
SLOWLY SPINNING AND DROPPING SOUTH/EAST LATER SATURDAY, SATURDAY  
NIGHT AND SUNDAY. THERE WILL BE OTHER, HARD TO TIME, SHORTWAVE  
DISTURBANCES ROTATING AROUND, OR RIDING THE SOUTHERN SIDE OF THIS  
CLOSED LOW.  
 
OVERALL, EXPECT COOLER BUT MAINLY DRY WEATHER ON FRIDAY...BUT A  
STRAY SHOWER CANNOT BE RULED OUT FOR CNY. HIGHS FALL BACK INTO THE  
50S TO LOWER 60S WITH A COOL NORTHWEST WINDS 850MB TEMPERATURES ARE  
PROGGED AROUND +3 C...SO NOT VERY COLD YET. COOLER AIR ALOFT  
CONTINUES TO FILTER INTO THE REGION FRIDAY NIGHT INTO SATURDAY AS  
THE UPPER LOW SLOWLY APPROACHES. THERE ARE SOME INDICATIONS THAT A  
SHORTWAVE WILL ZIP ALONG, PERHAPS INDUCING SURFACE CYCLOGENESIS  
ACROSS THE MID-ATLANTIC REGION...IF THIS LOW DOES DEVELOP, THERE ARE  
STILL QUESTIONS ON IT TRACK AND MOISTURE AVAILABILITY. OVERALL, THE  
LOW TO MID LEVEL FLOW REMAINS WEST-SOUTH WEST OUT AHEAD OF THE EXPANSIVE,  
CLOSED UPPER LEVEL LOW. SO EVEN THROUGH 850MB TEMPERATURES ARE  
FORECAST TO COOL ENOUGH (+0C) TO GET THE SOME LAKE EFFECT SHOWERS  
GOING; RIGHT NOW THE DATA SHOWS MUCH OF THIS ACTIVITY REMAINING  
NORTH/WEST OF OUR CWA.  
 
THE CURRENT BEST TIMING ESTIMATE WOULD BE FOR THE UPPER LOW TO PASS  
BY JUST TO OUR NORTH EITHER SATURDAY NIGHT OR SUNDAY. THIS WILL  
BRING EVEN COLDER AIR INTO THE AREA, WITH 850MB TEMPERATURES FALLING  
TO AROUND -5C SUNDAY NIGHT OR MONDAY. WENT ABOVE NBM POPS SATURDAY  
NIGHT, SUNDAY AND SUNDAY NIGHT AS THE COLDER NORTHWEST FLOW GOES  
OVER THE WARM LAKES...EXPECTING LAKE EFFECT RAIN SHOWERS TO BE A  
GOOD BET. DID EVEN START TO MIX IN SOME LOW CHANCES FOR SNOW SHOWERS  
LATE SATURDAY NIGHT AND ESPECIALLY SUNDAY NIGHT OVER THE HIGHER  
ELEVATIONS IN CNY. RIGHT NOW THE BLENDED GUIDANCE DRIES THINGS OUT  
BY NEXT MONDAY, BUT THE DETERMINISTIC GUIDANCE IS STILL SHOWING THAT  
COLD NORTHWEST FLOW ACROSS OUR AREA ON THE BACK SIDE OF THE  
DEPARTING TROUGH...THEREFORE I WOULD NOT BE SURPRISED IF CLOUDS AND  
EVEN SOME LAKE EFFECT SHOWERS LINGER A BIT LONGER.  
 
MUCH COOLER TEMPERATURES OVER THE WEEKEND AND INTO EARLY NEXT WEEK.  
LOOK FOR HIGHS IN THE UPPER 40S TO MID-50S EACH DAY, WITH OVERNIGHT  
LOWS IN THE 30S AREAWIDE.  
 

 
   
AVIATION /12Z MONDAY THROUGH FRIDAY/
 
 
LAKE EFFECT CLOUDS WILL CONTINUE TO AFFECT MOST TERMINALS  
THROUGH THE DAY, WITH CEILINGS VARYING BETWEEN MVFR AND VFR, BUT  
LIKELY STEADYING OUT IN THE MVFR CATEGORY LATER THIS MORNING AS  
COLDER AIR ALOFT MOVES IN. RAIN SHOWERS HAVE BEEN LARGELY  
MODULATED BY A SERIES OF UPPER LEVEL IMPULSES DROPPING INTO THE  
AREA, AND WILL CONTINUE TO BE THE CASE THROUGH MID-MORNING, WITH  
SYR AND RME MOST FAVORED FOR RAINFALL. THEREAFTER, UPPER LEVEL  
SUPPORT DIMINISHES, AND SHOWERS WILL BECOME MORE WIDELY  
SCATTERED DOWNWIND OF LAKE ONTARIO, DIMINISHING IN COVERAGE  
TOWARDS THE EVENING. GUSTY NORTHWEST WINDS WILL PEAK THIS  
AFTERNOON BETWEEN 20 AND 24 KNOTS, DIMINISHING BEFORE SUNSET.  
 
VFR CONDITIONS AND LIGHT-BUT-STEADY WEST TO NORTHWEST WINDS  
WILL PERSIST OVERNIGHT.  
 
OUTLOOK...  
 
TUESDAY THROUGH WEDNESDAY...MAINLY VFR.  
 
THURSDAY AND FRIDAY...FLIGHT RESTRICTIONS LIKELY DUE TO THE NEXT  
ROUND OF RAIN SHOWERS STARTING LATER ON THURSDAY.  
 

 
   
BGM WATCHES/WARNINGS/ADVISORIES
 
 
PA...NONE.  
NY...NONE.  
 

 
 

 
SYNOPSIS...MPH  
NEAR TERM...MPH  
SHORT TERM...MJM  
LONG TERM...MJM  
AVIATION...MPH  
 
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