640  
FXUS61 KALY 161028  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
628 AM EDT TUE SEP 16 2025  
   
SYNOPSIS
 
 
ABOVE NORMAL TEMPERATURES CONTINUE THROUGH FRIDAY WITH A  
WEAKENING COASTAL LOW SLOWLY APPROACHING TONIGHT INTO WEDNESDAY  
RESULTING A FEW LIGHT SHOWERS MAINLY SOUTH OF I-90. THEN, A  
MOISTURE STARVED COLD FRONT ON FRIDAY USHERS IN BREEZY WINDS  
FOLLOWED BY COOLER TEMPERATURES FOR SATURDAY. TEMPERATURES TREND  
WARMER FOR THE START OF THE NEW WORK WEEK.  
 

 
   
DISCUSSION
 
 
OUR REX BLOCK BEGINS TO BREAKDOWN TODAY AS OUR ~590DAM UPPER  
LEVEL ANTICYCLONE WEAKENS AS IT SHIFTS EASTWARD OUT OF THE GREAT  
LAKES. THIS OCCURS WHILE OUR VERTICALLY STACKED COASTAL LOW  
CURRENTLY SEEN ON WATER VAPOR IMAGERY OFF THE MID-ATLANTIC COAST  
SLOWLY PRESSES NORTHWARD. THUS, INITIAL SUNSHINE TODAY WILL  
BECOME FILTERED THROUGH INCREASING CIRRUS CLOUDS THAT GRADUALLY  
EXPAND FROM SOUTH TO NORTH AHEAD OF THE APPROACHING COASTAL  
LOW. TEMPERATURES TODAY ONCE AGAIN RISE ABOVE NORMAL AS DEEP  
BOUNDARY LAYER MIXING IN A DRY ENVIRONMENT WITH 850HPA  
ISOTHERMS +10C TO +13C AND INSOLATION SUPPORTS TEMPERATURES IN  
THE MID TO UPPER 70S WITH EVEN LOW 80S IN THE UPPER HUDSON  
VALLEY WHERE MORE SUNSHINE WILL LIKELY OCCUR. CIRRUS CLOUDS  
EXPANDS AND THICKENS TONIGHT AS OUR COASTAL CONTINUES ITS SLOW  
APPROACH.  
 
AS MID AND UPPER LEVEL MOISTURE INCREASES, ISOLATED TO WIDELY  
SCATTERED SHOWERS ON THE NORTHERN PERIPHERY OF THE LOW START TO  
IMPINGE UPON THE MID-HUDSON VALLEY AND NW CT DURING THE PRE-DAWN  
HOURS (09 - 12 UTC) AND WE CONTINUE TO SHOW SLIGHT CHANCE POPS  
HERE WHICH MATCHES WITH THE ECMWF ENSEMBLE AND NBM  
PROBABILITIES. PREVIOUS MODEL RUNS SUGGESTED THE INCOMING  
COASTAL LOW WOULD WEAKEN ENOUGH DURING ITS APPROACH THAT SLIGHT  
CHANCE AND LOW END CHANCE POPS WOULD MAINLY BE CONFINED TO OUR  
FAR SOUTHERN ZONES. WHILE THE HIGHEST CONFIDENCE IN MEASURABLE  
SHOWERS REMAINS OVER SOUTHERN ZONES (20-35%), LATEST TRENDS  
SUGGEST UP TO A 15% CHANCE THAT ISOLATED SHOWERS EXPAND AS FAR  
NORTH AS THE I-90 CORRIDOR GIVEN THAT THE LOW'S 500HPA  
CIRCULATION REMAINS CLOSED THROUGH 00 THURS. OTHERWISE,  
WEDNESDAY WILL FEATURE CLOUDIER SKIES, ESPECIALLY FROM I-90  
SOUTHWARD WITH MORE FILTERED SUN TO THE NORTH. THUS, HIGH  
TEMPERATURES WILL FALL A FEW DEGREES SHORT COMPARED TO THE DAYS  
LEADING UP TO IT WITH 70-80% CHANCE THAT TEMPERATURES EXCEED 75  
DEGREES NORTH OF I-90 WITH JUST 25-50% CHANCE TO THE SOUTH WHERE  
CLOUDS WILL BE THICKER. TOTAL QPF AMOUNTS REMAIN LOW AND WILL  
NOT PUT A DENT IN THE ONGOING RAINFALL DEFICIT AS THERE IS JUST  
A 20-40% CHANCE THAT TOTAL RAINFALL EXCEEDS A TENTH IN THE MID-  
HUDSON VALLEY AND NW CT AND UNDER 10% CLOSER TO I-90.  
 
RAIN SHOWERS DIMINISH IN COVERAGE WED NIGHT INTO EARLY THURSDAY  
AS THE COASTAL LOW'S 500HPA CIRCULATION OPENS UP AND EXITS INTO  
NEW ENGLAND. EARLY CLOUDS GIVE WAY TO INCREASING SUN ON  
THURSDAY AS WEAK HIGH PRESSURE BUILDS OVERHEAD. SLIGHTLY BREEZY  
WESTERLY WINDS BEHIND OUR DEPARTING COASTAL LOW ENHANCES  
BOUNDARY LAYER MIXING AND SUPPORTS ABOVE NORMAL TEMPERATURES  
ONCE AGAIN. IN FACT, THERE IS A 70-90% CHANCE THAT HIGHS EXCEED  
80 DEGREES IN VALLEY AREAS BUT NEARLY 0% CHANCE TO EXCEED 85.  
THURSDAY NIGHT. A MORE POTENT YET MOISTURE STARVED COLD FRONT  
THEN MARCHES SOUTH AND EASTWARD OUT OF CANADA LATE THURS NIGHT  
INTO EARLY FRIDAY MORNING. A TIGHTENING PRESSURE GRADIENT IN  
THE WAKE OF THE BOUNDARY WILL LIKELY SUPPORT BREEZY WINDS ON  
FRIDAY WITH NORTHWEST FLOW USHERING IN A MUCH DRIER AIR MASS  
(PWATS NEAR 0.5"). THUS, WE TRENDED DEW POINTS DOWNWARDS USING  
THE NBM 10TH PERCENTILE TO SHOW VALUES FALLING INTO 30S/40S.  
BETWEEN THE DRY AIR MASS (RH VALUES 30-45%), RECENT STRETCH OF  
DRY WEATHER, AND SLIGHTLY BREEZY WINDS, WE WILL MONITOR THE  
POTENTIAL FOR ENHANCED FIRE SPREAD ON FRIDAY. A ~1030HPA  
CANADIAN SFC HIGH AND UPPER LEVEL RIDGING BUILD INTO THE  
NORTHEAST FOR SATURDAY, SUPPORTING ABUNDANT SUNSHINE AND  
USHERING IN A FALL-LIKE AIR MASS. MORNING LOWS ON SATURDAY TURN  
QUITE CHILLY WITH A 50 - 75% CHANCE FOR LOWS IN THE SOUTHERN AND  
WESTERN ADIRONDACKS TO FALL TO 35 DEGREE OR LOWER SO WE WILL  
NEED TO MONITOR FROST POTENTIAL. HIGH PRESSURE SLIDES INTO NEW  
ENGLAND FOR SUNDAY, PROMOTING A SOUTHWEST RETURN FLOW AND  
ALLOWING TEMPERTURES TO TREND WARMER FOR THE NEW WORK WEEK.  
 

 
   
AVIATION /12Z TUESDAY THROUGH SATURDAY/
 
 
THROUGH 12Z/WED...FOG AT KGFL/KPSF WILL LIFT BY 13Z/TUE;  
OTHERWISE, VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE UPCOMING  
TAF PERIOD WITH SOME MID AND HIGH CLOUDS AROUND AS A COASTAL  
LOW PRESSURE SYSTEM SLOWLY LIFTS NORTHWARD. WITH THE ADDITIONAL  
CLOUDS TONIGHT, CONFIDENCE ON FOG DEVELOPMENT IS LOW SO DID NOT  
INCLUDE ANY MENTION AT THIS TIME. WIND WILL BECOME VARIABLE OR  
SOUTHEASTERLY AT 5 KT TODAY, THEN TREND LIGHT TO CALM AGAIN  
TONIGHT.  
 
OUTLOOK...  
 
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
 

 
   
ALY WATCHES/WARNINGS/ADVISORIES
 
 
CT...NONE.  
NY...NONE.  
MA...NONE.  
VT...NONE.  
 

 
 

 
 
SYNOPSIS...SPECIALE  
DISCUSSION...SPECIALE  
AVIATION...RATHBUN  
 
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