210  
FXUS61 KALY 312347  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
747 PM EDT THU JUL 31 2025  
   
SYNOPSIS
 
 
MUCH COOLER TODAY WITH PERIODS OF STEADY RAIN. AS A DISTURBANCE  
RIDES ALONG A STALLED BOUNDAY, PERIODS OF MODERATE TO HEAVY RAIN  
ARE EXPECTED IN THE EASTERN CATSKILLS, MID-HUDSON VALLEY AND  
LITCHFIELD COUNTY THROUGH THIS EVENING AND, IF HEAVY RAIN  
PERSISTS, CAN RESULT IN ISOLATED TO SCATTERED FLASH FLOODING.  
A STRETCH OF SEASONABLY COOL AND COMFORTABLE WEATHER ENSUES  
TOMORROW AND SATURDAY BEFORE TEMPERATURES TREND WARMER THROUGH  
EARLY NEXT WEEK.  
 

 
   
DISCUSSION
 
 
KEY MESSAGE  
 
- HEAVY RAINFALL RATES REACHING UP TO 1 TO 2 INCHES PER HOUR  
THIS AFTERNOON INTO THIS EVENING IN THE EASTERN CATSKILLS,  
MID-HUDSON VALLEY, AND LITCHFIELD COUNTY, CT, CAN RESULT IN  
ISOLATED TO SCATTERED FLASH FLOODING, ESPECIALLY IF HEAVY  
RAIN PERSISTS OVER A GIVEN AREA. A FLOOD WATCH WILL BE IN  
EFFECT FOR THESE AREAS FROM 2PM TODAY TO 8AM FRIDAY.  
 
WIDESPREAD RAINFALL CONTINUES TO STREAM EASTWARD ACROSS MUCH OF  
EASTERN NY AND WESTERN NEW ENGLAND THIS AFTERNOON AS SURFACE ANAFRONT  
HAS ALREADY SETTLED WELL TO OUR SOUTH ACROSS NJ/PA WITH NORTHERLY  
WINDS IN ITS WAKE. WE HAVE ALREADY HIT OUR HIGH TEMPERATURE FOR  
THE DAY AND THANKS TO WET-BULBING PROCESSES, WILL CONTINUE TO  
STAY IN THE 60S THE REST OF THE DAY. LATEST ADVANCED LAYER  
PRECIPITABLE WATER (ALPW) SATELLITE IMAGERY SHOWS TWO SOURCES OF  
RICH MOISTURE STREAMING INTO THE NORTHEAST WITH ONE PLUME  
STEMMING FROM THE EASTERN PACIFIC AND A SECOND PLUME FROM THE  
SOUTHEAST IMPINGING INTO THE MID-ATLANITC/SOUTHERN NEW ENGLAND.  
WHERE THESE TWO SOURCES CONVERGE WILL BE THE FOCUS FOR THE  
HEAVIEST RAINFALL RATES AND FLASH FLOODING CONCERNS AND LATEST  
HIGH RES GUIDANCE POINTS TO AREAS MAINLY SOUTH OF OUR AREA IN  
THE NJ/NYC METRO WHICH REMAIN IN THE WARM SECTOR AND HAVE HIGHER  
AVAILABLE INSTABILITY.  
 
HOWEVER, THE STRONG TEMPERATURE GRADIENT OVER SOUTHEASTERN NY  
(60S IN THE EASTERN CATSKILLS/MID-HUDOSN VALLEY AND MID TO UPPER  
70S IN NW CT TO 80S IN NYC) HAS SUPPORTED STRONG MID-LEVEL  
FGEN. AS A SHORTWAVE IN THE OHIO VALLEY RIDES ALONG THE  
BOUNDARY THIS AFTERNOON INTO THIS EVENING AND ENCOUNTERS  
ENHANCED FORCING FOR ASCENT FROM A 125 - 140KT JET POSITIONED  
IN EASTERN QUEBEC, THE FGEN IN THE 850 - 700HPA LAYER LIKELY  
TIGHTENS SUPPORTING PERIODS OF MODERATE TO EVEN HEAVY RAIN.  
WHILE STRATIFORM RAIN WILL CONTINUE OVER MUCH EASTERN NY AND  
WESTERN NEW ENGLAND AS WE REMAIN ON THE "COOL SIDE" OF THE  
BOUNDARY, GUIDANCE STILL SUGGESTS THAT THE LEADING EDGE OF THE  
STRATIFORM RAIN OVER THE MID- HUDSON VALLEY, NW CT, AND THE  
EASTERN CATSKILLS WILL FEATURE HIGHER RAINFALL RATES REACHING  
1-2 INCHES PER HOUR. AS A SFC LOW DEVELOPS IN THE MID-ATLANTIC  
AND TRACKS ACROSS NJ THIS AFTERNOON INTO THIS EVENING, THE BAND  
OF STRATIFORM RAIN OVER UPSTATE NY LOOKS TO PIVOT FROM NORTHEAST  
TO SOUTHWEST. THIS COULD SUPPORT HEAVY RAINFALL PERSISTING OR  
TRAINING OVER PARTS OF THE MID- HUDSON VALLEY, EASTERN CATSKILLS,  
AND LITCHFIELD COUNTY, CT, ESPECIALLY GIVEN SLIGHTLY MORE  
INSTABILITY AVAILABLE IN DUTCHESS/LITCHFIELD AND WHERE FORWARD  
PROPAGATING CORFIDI VECTORS REMAIN PARALLEL TO THE MEAN CLOUD  
LAYER FLOW.  
 
THE LATEST HREF SHOWS A 50-70% CHANCE FOR RAINFALL RATES AT OR  
ABOVE 1 INCH IN 3 HOURS FROM 18 UTC THURS - 03 UTC FRI WHERE WE  
HAVE THE FLOOD WATCH WITH EVEN A 10% CHANCE FOR AT OR ABOVE 3  
INCHES IN 3 HOURS. HOWEVER, THE HIGHEST PROBABILITIES FOR  
HIGHER RAINFALL RATES/AMOUNTS REMAIN TO OUR SOUTH IN NJ/NYC AREA  
WHERE THE ERO MODERATE RISK WAS EXPANDED. LATEST FLASH FLOOD  
GUIDANCE FROM THE NERFC STILL SHOWS 2 - 3 INCHES IN 1 HOUR AND 3  
- 3.5 INCHES IN 3 HOURS (SLIGHTLY LOWER OVER THE EASTERN  
CATSKILLS) FOR THESE AREAS SO IT WILL TAKE HEAVY RAIN PERSISTING  
OVER A GIVEN AREA BEFORE FLOODING OCCURS. LATEST TOTAL RAINFALL  
AMOUNTS STILL RANGES FROM 1 TO 3 INCHES WITH LOCALLY UP TO 3 TO  
5 INCHES NOT RULED OUT WHERE HEAVY RAIN TRAINS/PERSIST, PER  
LATEST 24 HOUR MAX AND LPMM ENSEMBLE GUIDANCE FROM THE HREF. A  
SHARP CUT-OFF IN RAINFALL TOTALS EXPECTED NORTH OF THE I-90  
CORRIDOR WITH NEAR OR UNDER 0.25 INCHES IN THE SOUTHERN/WESTERN  
ADIRONDACKS AND UPPER HUDSON VALLEY. THE HEAVIEST RAIN WINDS  
DOWN BY 03 - 06 UTC WITH LINGERING SHOWS EXITING FROM NORTHWEST  
TO SOUTHEAST BY 12 UTC FRIDAY.  
 
A STRETCH OF DRY AND SEASONABLY COOL WEATHER ENSUES TOMORROW  
THROUGH SATURDAY AS CANADIAN HIGH PRESSURE BUILDS OVER THE  
NORTHEAST SUPPORTING LOW HUMIDITY WITH ABUNDANT SUNSHINE ON  
SATURDAY. FRIDAY NIGHT AND SATURDAY NIGHT TEMPERATURES WILL BE  
COOLER THAN NORMAL FALLING INTO THE 40S AND 50S THANKS TO IDEAL  
RADIATIONAL COOLING. WE TREND WARMER SUNDAY THROUGH THE MIDDLE  
OF NEXT WEEK WITH DAYTIME HIGHS BACK IN THE 70S AND 80S AND  
HIGHER HUMIDITY RETURNING.  
 

 
   
AVIATION /00Z FRIDAY THROUGH TUESDAY/
 
 
THROUGH 00Z SATURDAY...WE START THE TAF PERIOD WITH A MIX OF  
VFR, MVFR, AND IFR CONDITIONS FOR ALL TAF SITES DUE TO LOW  
CLOUD CEILINGS OR PERIODS OF LIGHT TO MODERATE RAINFALL.  
MVFR/IFR CONDITIONS CONTINUE THROUGH 12Z DUE TO LOW CLOUD  
CEILINGS OR PATCHY FOG DEVELOPMENT AS RAINFALL GRADUALLY ENDS  
BETWEEN 03Z AND 12Z. VFR CONDITIONS RETURN FOR TOMORROW  
AFTERNOON. WINDS CONTINUE TO BE NORTHERLY TO NORTHEASTERLY  
THROUGH THE OVERNIGHT HOURS INTO TOMORROW AFTERNOON BETWEEN 3  
AND 8 KNOTS.  
 
OUTLOOK...  
 
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.  
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
 

 
   
ALY WATCHES/WARNINGS/ADVISORIES
 
 
CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ001-013.  
FLOOD WATCH THROUGH FRIDAY MORNING FOR CTZ001-013.  
NY...FLOOD WATCH THROUGH FRIDAY MORNING FOR NYZ063>066.  
MA...NONE.  
VT...NONE.  
 

 
 

 
 
SYNOPSIS...RATHBUN/SPECIALE  
DISCUSSION...SPECIALE  
AVIATION...WEBB  
 
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