094  
FXUS61 KALY 291759  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
159 PM EDT THU JUL 29 2021  
   
SYNOPSIS
 
 
HIGH PRESSURE OVER THE REGION EARLY THIS MORNING WILL SHIFT  
EASTWARD OFF THE NEW ENGLAND COAST BY THIS AFTERNOON. AN AREA OF  
LOW PRESSURE AND AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS  
THE REGION THIS AFTERNOON INTO THE EVENING, BRINGING SHOWERS AND  
THUNDERSTORMS. ANOTHER DISTURBANCE AND A COLD FRONT WILL MOVE  
THROUGH TONIGHT WITH ADDITIONAL SHOWERS AND THUNDERSTORMS. SOME  
OF THE STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. A FALL-LIKE  
AIR MASS WILL BUILD IN FOR FRIDAY, WITH BREEZY CONDITIONS AND  
BELOW NORMAL TEMPERATURES.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
   
UPDATE
 
AS OF 1:40 PM EDT, SHOWERS AND EMBEDDED THUNDERSTORMS  
HAVE OVERSPREAD MUCH OF THE REGION, WITH AREAS THAT HAVE SO FAR  
REMAINED DRY EXPECTED TO SEE RAIN WITHIN THE NEXT HOUR OR 2.  
PRECIPITATION AMOUNTS HAVE GENERALLY BEEN BETWEEN A TENTH AND A  
QUARTER OF AN INCH, WITH AROUND A HALF INCH IN PARTS OF FULTON  
AND MONTGOMERY COUNTIES WHERE THE HEAVIER RAIN HAS FALLEN  
WITHIN EMBEDDED THUNDERSTORMS. ADDITIONAL SHOWERS AND POSSIBLY  
SOME THUNDER ARE DEVELOPING IN PORTIONS OF ULSTER, DUTCHESS, AND  
LITCHFIELD COUNTIES AHEAD OF THE MAIN LINE OF RAIN. AT THIS  
TIME, THE HEAVIEST RAIN LOOKS TO STAY SOUTH OF OUR REGION THIS  
AFTERNOON, BUT WILL CONTINUE TO MONITOR AREAS THAT SEE TRAINING  
OF STORMS FOR FLASH FLOOD POTENTIAL.  
 
OVERALL, DID NOT MAKE ANY SUBSTANTIAL CHANGES TO THE FORECAST  
WITH THIS UPDATE. MADE SOME ADJUSTMENTS TO POPS, QPF, WINDS, AND  
TEMPERATURES TO REFLECT CURRENT TRENDS. OTHERWISE, PREVIOUS  
FORECAST FOR A SEASONABLE COOL AND WET AFTERNOON LOOKS TO BE ON  
TRACK.  
   
PREVIOUS
 
AS OF 10:45 AM EDT, RADAR REFLECTIVITY SHOWS A  
LINE OF SHOWERS WITH SOME EMBEDDED THUNDERSTORMS IN WESTERN NY  
MOVING EASTWARD TOWARDS OUR REGION. A FEW SHOWERS HAVE ALSO  
DEVELOPED OVER PARTS OF ULSTER, DUTCHESS, AND LITCHFIELD  
COUNTIES ASSOCIATED WITH ISENTROPIC LIFT/WARM ADVECTION AHEAD OF  
THE 850 MB WARM FROM APPROACHING FROM THE SOUTHWEST. COVERAGE  
OF SHOWERS AND THUNDERSTORMS SHOULD INCREASE OVER THE NEXT  
SEVERAL HOURS , WITH RAIN LIKELY THIS AFTERNOON AS THE MAIN LINE  
MOVES THROUGH THE REGION. PREVIOUS FORECAST LOOKED PRETTY GOOD  
REGARDING PRECIPITATION, SO ONLY MADE SOME MINOR ADJUSTMENTS TO  
POPS AND QPF TO REFLECT CURRENT OBSERVATIONS. WILL CONTINUE TO  
MESSAGE THREAT FOR HEAVY RAIN/ISOLATED FLASH FLOODING THIS  
AFTERNOON AS MULTIPLE ROUNDS OF SHOWERS/THUNDERSTORMS COULD  
RESULT IN LOCALLY HEAVY RAINFALL. OTHER CHANGE WITH THIS UPDATE  
WAS TO LOWER DAYTIME HIGH TEMPERATURES A DEGREE OR TWO AS  
INCREASING CLOUD COVER OVER THE NEXT SEVERAL HOURS SHOULD HELP  
PREVENT TEMPS FROM INCREASING TOO MUCH THIS AFTERNOON.  
OTHERWISE, PREVIOUS FORECAST REMAINS ON TRACK.  
   
PREVIOUS...AS OF 6:42 AM
 
LOW LEVEL STRATUS CLOUDS HAVE  
EXPANDED INTO THE TACONICS AND BERKSHIRES OVER THE PAST FEW  
HOURS, SO INCREASED CLOUD COVER IN THESE AREAS EARLY THIS  
MORNING. OTHERWISE, SOME PATCHY FOG EVIDENT WHICH SHOULD  
DISSIPATE IN THE NEXT 1-2 HOURS. OBSERVATIONS INDICATING COOL  
TEMPERATURES MAINLY IN THE 50S, ALTHOUGH SOME MID/UPPER 40S WERE  
NOTED IN PARTS OF THE ADIRONDACKS. OUTSIDE OF THE STRATUS  
CLOUDS, SKIES WERE PARTLY/MOSTLY SUNNY ELSEWHERE.  
   
PREVIOUS [0351]
 
TRANQUIL CONDITIONS TO START THE DAY WITH  
SOME PATCHY FOG IN SHELTERED VALLEYS AND PATCHES OF LOW STRATUS  
CLOUDS EAST OF POUGHKEEPSIE IN LITCHFIELD COUNTY. CURRENTLY  
WATCHING AN MCS TRACKING SOUTHEAST ACROSS SOUTHERN  
WISCONSIN/LAKE MICHIGAN. THE TRAJECTORY OF THIS SYSTEM SHOULD  
PASS BY WELL SOUTH OF OUR AREA. HOWEVER, WE ARE EXPECTING  
SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON AS A  
SEPARATE UPPER LEVEL DISTURBANCE (CLEARLY EVIDENT IN GOES-EAST  
WATER VAPOR IMAGERY) FARTHER NORTH APPROACHES FROM THE UPPER  
GREAT LAKES. LARGE SCALE FORCING WILL INCREASE ACROSS OUR AREA,  
WITH SOME INSTABILITY DEVELOPING. FORTUNATELY, FORECAST SBCAPE  
FROM GFS, NAM AND HREF INDICATING ONLY AROUND MAX SBCAPE VALUES  
OF 500-1000 J/KG, WITH A WARM FRONT AND GREATER INSTABILITY  
REMAINING SOUTH OF OUR AREA. HREF SHOWING HIGHEST PROBS FOR MAX  
UPDRAFT HELICITY ACROSS PA/NJ. ISOLATED STRONG TO SEVERE STORMS  
MAY SCRAPE PARTS OF ULSTER, DUTCHESS AND LITCHFIELD COUNTIES  
WHICH IS WHERE A MARGINAL RISK OF SEVERE STORMS FROM THE STORM  
PREDICTION CENTER REMAINS IN PLACE.  
 
THE GREATER HAZARD IN OUR AREA WILL BE LOCALLY HEAVY RAINFALL  
ASSOCIATED WITH CONVECTIVE CELLS. MOIST GROUND CONDITIONS IN  
PLACE, SO WILL HAVE TO WATCH FOR STORMS REPEATEDLY MOVING OVER  
THE SAME AREAS FOR POSSIBLE ISOLATED FLASH FLOODING. STORM  
MOTIONS SHOULD BE RELATIVELY QUICK TODAY, WITH INCREASING MID  
LEVEL FLOW AND DEEP LAYER SHEAR AROUND 30-40 KT. HOWEVER DUE TO  
ANTECEDENT WET CONDITIONS AND MULTIPLE ROUNDS OF SHOWERS AND  
STORMS, MOST OF OUR AREA HAS BEEN UPGRADED TO A SLIGHT RISK FOR  
EXCESSIVE RAINFALL. MINOR FLOODING OF URBAN, POOR DRAINAGE AND  
LOW LYING AREAS IS EXPECTED, WITH SCATTERED FLASH FLOODING.  
 
TEMPERATURES WILL BE ON THE COOL SIDE TODAY DUE TO THE  
INCREASING CLOUDS AND COVERAGE OF SHOWERS AND THUNDERSTORMS  
DURING THE AFTERNOON. HIGHS ONLY EXPECTED TO BE IN THE 70S FOR  
VALLEYS TODAY. HUMIDITY LEVELS WILL INCREASE, WITH DEWPOINTS  
RISING INTO THE 60S.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/
 
 
IT APPEARS WE MAY GET A BRIEF BREAK (OR AT LEAST LESS COVERAGE)  
FROM THE SHOWERS AND THUNDERSTORMS, AS THE FIRST DISTURBANCE  
MOVES EAST OF THE REGION. HOWEVER, WITH A CONTINUED BROAD UPPER  
LEVEL TROUGH IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST,  
ANOTHER UPPER LEVEL SHORT WAVE WILL BE RAPIDLY APPROACHING FROM  
THE NORTH/WEST BY LATER THIS EVENING. THIS WILL RESULT IN  
ANOTHER ROUND OF SHOWERS AND EMBEDDED THUNDERSTORMS. CONVECTION  
SHOULD BE ELEVATED, SO THE MAIN THREAT WILL CONTINUE TO BE  
LOCALLY HEAVY RAINFALL AND SCATTERED FLASH FLOODING. THIS WILL  
ESPECIALLY BE OF CONCERN FOR AREAS THAT HAVE REPEATED DOWNPOURS.  
AGAIN WE ARE EXPECTING RELATIVELY QUICK STORM MOTIONS, BUT SOME  
AREAS WILL EXPERIENCE MULTIPLE ROUNDS OF SHOWERS AND STORMS  
WHICH WOULD INCREASE THE FLOOD THREAT IN THOSE AREAS. SLIGHT  
RISK OF EXCESSIVE RAINFALL PERSISTS THROUGH THE NIGHT. FOLLOWING  
TRENDS IN THE CAMS, SHOWERS AND STORMS SHOULD FINALLY TAPER OFF  
TOWARDS EARLY FRIDAY MORNING AS THE SHORT WAVE AND ASSOCIATED  
COLD FRONT PUSH SOUTH/EAST THROUGH THE REGION.  
 
WE WILL GET A TASTE OF FALL IN LATE JULY ON FRIDAY, WITH A  
BROAD UPPER LEVEL TROUGH REMAINING IN PLACE AND A NORTHWEST FLOW  
REGIME. COLD ADVECTION IMPRESSIVE FOR THIS TIME OF YEAR, WITH  
850 MB TEMPERATURE ANOMALIES DECREASING TO AROUND -2 TO -3 STDEV  
DURING THE DAY. THIS WILL TRANSLATE TO TEMPERATURES 10-15  
DEGREES BELOW NORMAL. A GUSTY NORTHWEST WIND WILL MAKE IT FEEL  
EVEN COOLER, WITH GUSTS OF 20-30 MPH DEVELOPING BY AFTERNOON. A  
FEW BRIEF/LIGHT SHOWERS WILL BE POSSIBLE FRIDAY MORNING AS THE  
UPPER TROUGH AXIS MOVES THROUGH, BUT DRY CONDITIONS EXPECTED  
DURING THE AFTERNOON. CLOUDS WILL BE PREVALENT THROUGH THE  
MORNING, WITH INCREASING SUNSHINE IN THE AFTERNOON. CLOUD COVER  
WILL HANG ON LONGER ACROSS THE HIGHER TERRAIN.  
 
MAINLY CLEAR AND COOL CONDITIONS IN STORE FOR FRIDAY NIGHT.  
THERE WILL STILL BE A BIT OF A BREEZE DUE TO A PRESSURE GRADIENT  
REMAINING, WITH HIGH PRESSURE BUILDING IN ACROSS THE OHIO  
VALLEY. SO WHILE IT WILL BE QUITE COOL, SOME MIXING SHOULD LIMIT  
TEMPS REACHING RECORD COLD LEVELS. STILL, MOST OF THE AREA WILL  
HAVE LOWS IN THE 40S TO LOWER 50S.  
 
SATURDAY WILL BE ANOTHER COOL DAY, ALTHOUGH WITH LESS WIND THAN  
FRIDAY. TEMPERATURES WILL BE SIMILAR, WITH HIGHS IN THE  
LOWER/MID 70S IN VALLEYS AND 60S IN THE HIGHER TERRAIN. IT  
SHOULD REMAIN DRY, WITH HIGH PRESSURE CENTERED TO OUR SOUTH OVER  
THE MID ATLANTIC REGION.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
 
 
ALTHOUGH SATURDAY NIGHT WILL START OFF DRY, THE CHANCES FOR  
PRECIP WILL INCREASE THROUGH THE OVERNIGHT AND ESPECIALLY INTO  
THE DAY ON SUNDAY, AS A STRONG UPPER LEVEL SHORTWAVE ROTATES  
ACROSS THE AREA WITHIN THE LARGE SCALE TROUGH IN PLACE OVER THE  
NORTHEAST. HIGHEST POPS LOOK TO BE ON SUNDAY AFTERNOON,  
ESPECIALLY FOR NORTHERN AREAS. SOME RUMBLES OF THUNDER ARE  
POSSIBLE AS WELL AND SOME LOCALLY HEAVY DOWNPOURS WILL BE  
POSSIBLE. AFTER MORNING LOWS IN THE 50S, AFTERNOON HIGHS SHOULD  
REACH INTO THE MID 70S FOR MOST AREAS ON SUNDAY.  
 
A FEW SHOWERS COULD LINGER INTO SUNDAY NIGHT OR EARLY MONDAY AS  
THE UPPER LEVEL TROUGH AXIS MOVES THROUGH THE AREA. OTHERWISE,  
SKIES WILL BE CLEARING AND IT WILL BE DRYING OUT FOR THE EARLY  
PORTION OF NEXT WEEK. WITH SOMEWHAT LOWER HEIGHTS/COOLER TEMPS  
ALOFT IN PLACE, HIGHS WILL LIKELY BE A LITTLE BELOW NORMAL FOR  
MON THROUGH WED, WITH HIGHS ONLY IN THE 70S. DEWPOINTS WILL  
MAINLY BE IN THE 50S, SO IT WON'T FEEL TOO MUGGY AT ALL.  
 
ANOTHER UPPER LEVEL DISTURBANCE WILL BE APPROACHING TOWARDS  
MIDWEEK. THIS FEATURE IS DIFFICULT TO TIME, AS IT MAY CLOSE OFF  
AND/OR MOVE SLOWLY, BUT SOME SHOWERS COULD RETURN TOWARDS THE  
MIDDLE TO LATTER PORTION OF THE WEEK. FOR NOW, WILL KEEP POPS  
FAIRLY LOW, BUT WILL NEED TO MONITOR.  
 

 
   
AVIATION /18Z THURSDAY THROUGH TUESDAY/
 
 
SCATTERED SHOWERS AND THUNDERSTORMS HAVE MOVED INTO EASTERN NY  
AND WESTERN NEW ENGLAND. ONLY KGFL HAS SEEN MVFR FROM RAIN  
SHOWER. ACTIVITY WILL GENERALLY BE SCATTERED THIS AFTERNOON, BUT  
KGFL COULD SEE A FEW HOURS OF STEADY RAINFALL. THERE IS THE  
POTENTIAL FOR A BRIEF T-STORM LOWERING VISIBILITY TO IFR RANGE,  
SO WILL INCLUDE THIS IN A TEMPO FOR ALL SITES. OTHERWISE, IT  
WILL GENERALLY BE VFR OUTSIDE OF THE PRECIP WITH SOUTHERLY WINDS  
OF 5 TO 10 KTS.  
 
FLYING CONDITIONS LOOK TO LOWER DOWN TO MVFR/IFR FOR THIS  
EVENING FOR ALL SITES WITH LIGHT SOUTHERLY WINDS WITH MORE  
SHOWERS WILL BE MOVING IN FOR OVERNIGHT. MVFR/IFR VISIBILITY  
WILL BE POSSIBLE WITH THESE SHOWERS AS WELL WITH LINGERING LOW  
CLOUDS AND SOME FOG THROUGH DAYBREAK FRIDAY.  
 
OUTLOOK...  
 
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.  
SUNDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.  
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.  
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.  
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
TUESDAY: LOW OPERATIONAL IMPACT. NO SIG WX.  
 

 
   
FIRE WEATHER
 
 
HIGH PRESSURE OVER THE REGION EARLY THIS MORNING WILL SHIFT  
EASTWARD OFF THE NEW ENGLAND COAST BY THIS AFTERNOON. AN AREA OF  
LOW PRESSURE AND AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS  
THE REGION THIS AFTERNOON INTO THE EVENING, BRINGING SHOWERS AND  
THUNDERSTORMS. ANOTHER DISTURBANCE AND A COLD FRONT WILL MOVE  
THROUGH TONIGHT WITH ADDITIONAL SHOWERS AND THUNDERSTORMS. SOME  
OF THE STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. A FALL-LIKE  
AIR MASS WILL BUILD IN FOR FRIDAY, WITH BREEZY CONDITIONS AND  
BELOW NORMAL TEMPERATURES.  
 
MINIMUM RELATIVE HUMIDITY VALUES TODAY WILL BE AROUND 60 TO 80  
PERCENT, INCREASING TO AROUND 100 PERCENT TONIGHT. MINIMUM RH  
VALUES ON FRIDAY WILL BE BETWEEN 50 TO 65 PERCENT.  
 
WINDS TODAY WILL BECOME SOUTHERLY INCREASING TO 5 TO 15 MPH,  
WITH SOME OCCASIONAL GUSTS TO 20 MPH. WINDS TONIGHT WILL REMAIN  
SOUTHERLY AROUND 5 TO 10 MPH. WINDS ON FRIDAY WILL SHIFT TO THE  
NORTHWEST AND INCREASE TO 10 TO 20 MPH WITH GUSTS UP TO 30 MPH.  
 

 
   
HYDROLOGY
 
 
DRY WEATHER IS EXPECTED TO PERSIST THROUGH THIS MORNING. THEN  
SHOWERS AND THUNDERSTORMS WILL BECOME LIKELY THIS AFTERNOON,  
WITH PERIODS OF SHOWERS AND STORMS LASTING THROUGH MUCH OF  
TONIGHT. LOCALLY HEAVY RAINFALL WILL OCCUR, RESULTING IN MINOR  
FLOODING OF URBAN, POOR DRAINAGE AND LOW LYING AREAS. SCATTERED  
FLASH FLOODING IS ALSO POSSIBLE, AS 30-DAY RAINFALL ESTIMATES  
INDICATE 150-400 PERCENT OF NORMAL PRECIP ACROSS THE REGION WITH  
MULTIPLE ROUNDS OF SHOWERS AND STORM WITH DOWNPOURS. MANY AREA  
RIVERS WILL EXPERIENCE A RISE IN WATER LEVELS TONIGHT INTO  
FRIDAY MORNING AS A RESULT OF THE RAIN, BUT RIVER FLOODING IS  
NOT EXPECTED AT THIS TIME, WITH MOST AREAS REMAINING BELOW  
ACTION STAGE.  
 
DRY WEATHER RETURNS FOR FRIDAY, WITH BREEZY AND COOLER  
CONDITIONS. IT SHOULD REMAIN DRY THROUGH SATURDAY, WITH  
INCREASING CHANCES FOR SHOWERS AND SOME THUNDERSTORMS BY SUNDAY  
AS A STRONG DISTURBANCE MOVES ACROSS THE REGION. ADDITIONAL  
HEAVY RAINFALL MAY OCCUR IN PARTS OF THE AREA, WHICH COULD  
RESULT IN SOME HYDRO ISSUES. STAY TUNED FOR FURTHER UPDATES.  
 
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES, INCLUDING  
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS, PLEASE  
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS  
ON OUR WEBSITE.  
 

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

 
 

 
SYNOPSIS...MAIN/JPV  
NEAR TERM...MAIN/JPV  
SHORT TERM...JPV  
LONG TERM...FRUGIS  
AVIATION...SND  
FIRE WEATHER...JPV  
HYDROLOGY...JPV  
 
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