315  
FXUS61 KALY 300825  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
425 AM EDT SUN APR 30 2017  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM SOUTHWEST QUEBEC THIS  
MORNING WITH COOL LATE APRIL WEATHER, AS A WEAK DISTURBANCE MAY  
FOCUS SOME ISOLATED TO SCATTERED SHOWERS, AS WELL AS A FEW RUMBLES  
OF THUNDER ESPECIALLY WEST OF THE HUDSON RIVER VALLEY THIS  
AFTERNOON. A WARM FRONT WILL INCREASE THE THREAT OF ISOLATED TO  
SCATTERED SHOWERS TONIGHT INTO EARLY MONDAY AS IT SLOWLY LIFTS  
NORTH OF THE REGION. A WARM AND MORE HUMID AIR MASS WILL BE OVER  
THE REGION ON MONDAY, BUT A COLD FRONT WILL BRING WIDESPREAD  
SHOWERS AND A CHANCE OF THUNDERSTORMS LATE IN THE AFTERNOON INTO  
TUESDAY MORNING.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
AS OF 425 AM EDT...A COOL START TO THE LAST DAY OF APRIL, AS A  
CHILLY CANADIAN AIR MASS CONTINUES TO BUILD INTO THE REGION FROM  
NEAR JAMES BAY, AS IT WILL DRIFT SOUTHEAST ACROSS  
WEST/SOUTHWEST QUEBEC BY THE AFTERNOON. THE COLD FRONT THAT  
MOVED THROUGH YESTERDAY HAS BECOME STATIONARY NEAR THE OH VALLEY  
AND MID ATLANTIC STATES. A SHORT-WAVE MOVING OVER THE WESTERN  
PERIPHERY OF THE H500 CLOSED ANTICYCLONE CENTERED EAST OF THE  
CAROLINAS THIS MORNING ON THE GOES-16 WATER VAPOR CHANNELS WILL  
DRIFT INTO WESTERN-CENTRAL NY. THE SHORT-WAVE AND A SFC TROUGH  
WILL FOCUS SOME ISOLATED-SCATTERED SHOWERS WITH THE BETTER  
FORCING DUE TO THE ISENTROPIC LIFT ROUGHLY FROM THE CAPITAL  
REGION/NORTHERN CATSKILLS NORTH AND WEST. THE 00Z ECMWF/NAM/CAN  
GGEM ARE THE MOST AGGRESSIVE WITH THIS FEATURE IN THE LATE  
MORNING INTO THE AFTERNOON. THE 00Z GFS HAS A SECONDARY SFC  
ANTICYCLONE BUILDING FROM EAST OF THE GULF OF MAINE. WE HAVE  
PLACED ISOLATED TO SCATTERED SHOWERS IN THE FORECAST WITH THE  
HIGHER POPS WEST OF THE HUDSON RIVER VALLEY. THE SHOWALTER  
STABILITY INDICES LOOKED MORE STABLE WITH LESS MUCAPE ON THE GFS  
COMPARED TO THE NAM. OUR CONFIDENCE WAS GREATEST FOR ISOLATED  
THUNDERSTORM OR A FEW RUMBLES OF THUNDER AGAIN WEST OF THE  
CAPITAL REGION. THE LATEST HRRR HINTS AT THE CAPITAL REGION  
NORTH FOR THE MORE ROBUST SHOWERS/ISOLATED THUNDERSTORMS.  
 
TEMPS CONTINUE TO TREND DOWN COOLER TODAY DUE TO THE SHALLOW  
COLD AIR FUNNELED INTO THE REGION FROM THE SFC ANTICYCLONE TO  
THE NORTH, AND THE POSSIBILITY OF THE SHOWERS PRODUCING RAIN  
COOLED AIR. AS THE WIND VEER FROM THE NORTH/NORTHWEST IN THE SFC  
AND BOUNDARY LAYER TO THE EAST SOUTHEAST ENOUGH WARMING MAY  
OCCUR FOR HIGHS TO GET CLOSER TO THE AN ECMMOS/GFSMOS BLEND OVER  
THE COOLER NAM MOS HIGHS. HIGHS WILL GENERALLY BE IN THE UPPER  
40S TO MID 50S OVER THE HILLS/MOUNTAINS AND UPPER 50S TO LOWER  
60S IN THE VALLEY AREAS.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/
 
 
TONIGHT...THE WARM FRONT STARTS TO MAKE PROGRESS NORTHWARD, AS  
THE BETTER LIFT AND SYNOPTIC FORCING CONTINUES TO BE WITH THE  
THERMAL TROUGH EARLIER IN THE DAY WELL NORTH OF THE REGION ALONG  
THE RIM OF THE H500 RIDGE OFF THE COAST. NONETHELESS, SOME  
ISOLD-SCATTERED SHOWERS AND PATCHY DRIZZLE WILL LIKELY OCCUR  
FORM THE HUDSON RIVER VALLEY NORTH AND EAST AHEAD OF THE WARM  
FRONT WITH THE LOW-LEVEL BOUNDARY LAYER FLOW BEING FROM THE  
SOUTHEAST. SOME LOW-LEVEL STRATUS WILL LIKELY BLANKET MOST OF  
THE REGION. A GRAY AND COOL OVERNIGHT PERIOD IS EXPECTED WITH  
LOWS PREDOMINATELY IN THE 40S.  
 
MONDAY...A POTENT CLOSED UPPER LOW CONTINUES TO CHURN NORTH TO  
NORTHEAST INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES REGION.  
MEANWHILE, DOWNSTREAM OVER THE NORTHEAST THE THE MID AND UPPER  
LEVEL FLOW AMPLIFIES FROM THE SOUTHWEST WITH THE SFC RIDGE  
SHIFTING SLIGHTLY FURTHER OFFSHORE. IT WILL TAKE A LITTLE TIME  
FOR THE LOW STRATUS TO BURN OFF IN THE MORNING, BUT THERE ARE  
HINTS IN THE GUIDANCE OF SOME SUNSHINE BY THE EARLY AFTERNOON AS  
WE BUST INTO THE WARM SECTOR. H850 TEMPS OF +12C TO +14C WOULD  
SUPPORT EVEN HIGHER TEMPS THAT WE ARE FORECASTING, BUT THE  
CLOUDS MAY BE TOUGH TO ERODE ESPECIALLY EAST OF THE HUDSON RIVER  
VALLEY. ALSO, SOME SHOWERS AND THUNDERSTORMS WILL LIKELY FLARE  
UP QUICKLY IN THE AFTERNOON WITH A POTENTIAL PREFRONTAL SFC  
TROUGH AHEAD OF THE COLD FRONT. WE HAVE MAINLY A CHANCE OF  
SHOWERS AND THUNDERSTORMS IN THE LATE AFTERNOON WITH THE BETTER  
COVERAGE AT NIGHT. HIGHS WILL GENERALLY BE IN THE MID 60S TO MID  
70S ACROSS THE REGION WITH THE COOLER TEMPS ACROSS WESTERN NEW  
ENGLAND AND OVER THE MOUNTAINS.  
 
MONDAY NIGHT...THE LOW-LEVEL JET AHEAD OF THE COLD FRONT  
INCREASES WITH A DEEPER FETCH OF MOISTURE OUT OF THE GULF. THE  
SOUTH TO SOUTHWEST H850 LOW-LEVEL JET INCREASES TO AROUND 50  
KTS. THE CONVERGENCE AND SYNOPTIC LIFT INCREASES WITH THE FRONT  
COUPLED WITH GOOD UPPER JET DYNAMICS. LOCATIONS NORTH AND WEST  
OF THE CAPITAL REGION WILL LIKELY BE NEAR THE REAR ENTRANCE  
REGION OF AN H250 JET STREAK OF 100-110 KTS PER THE LATEST  
NAM40. THE FRONT COMES THROUGH AT NIGHT WITH WANING INSTABILITY.  
SOME STRONG THUNDERSTORMS MAY BE POSSIBLE WITH GUSTY WINDS  
ESPECIALLY NEAR THE WESTERN MOHAWK VALLEY AND SOUTHERN  
ADIRONDACKS. THE LATEST SPC DAY 2 GRAPHIC HAS THE MARGINAL RISK  
BARELY CLIP HERKIMER COUNTY. THE BETTER CHANCE FOR SEVERE  
THUNDERSTORMS LOOKS TO BE WEST WITH THE BETTER HEATING, SHEAR  
AND INSTABILITY SET UP. WE WILL CONTINUE TO MONITOR ANY  
POTENTIALLY SEVERE THREAT, BUT FOR NOW WILL CALL IT WIDESPREAD  
SHOWERS WITH A CHANCE OF THUNDERSTORMS. WITH SFC DWPTS SURGING  
INTO THE 50S TO AROUND 60F AND PWATS A COUPLE OF STANDARD  
DEVIATIONS ABOVE NORMAL...IN THE 1-1.50"+ INCH RANGE, AS A  
DECENT BURST OF RAIN IS POSSIBLE WITH AROUND THREE QUARTERS OF  
AN INCH OVER THE NORTHWEST ZONES /SOUTHERN DACKS/ TO QUARTER  
INCH OVER NW CT/MID HUDSON VALLEY. LOWS WILL BE MILDER IN THE  
UPPER 40S TO UPPER 50S.  
 
TUE-TUE NIGHT...THE CLOSED CYCLONE UPSTREAM OVER THE NORTHERN  
GREAT LAKES REGION, AND SOUTHERN ONTARIO WILL CONTINUE TO IMPACT  
THE AREA WITH BREEZY AND COOL CONDITIONS WITH SCATTERED SHOWERS  
AS SEVERAL SHORT-WAVE IMPULSES SWING THROUGH THE CYCLONE ACROSS  
THE REGION. THE MOST WIDESPREAD SHOWERS WILL LIKELY BE NORTH AND  
WEST OF THE CAPITAL REGION IN THE CYCLONIC FLOW WITH SOME WEST-  
SOUTHWEST OROGRAPHIC ENHANCEMENT OFF THE WESTERN ADIRONDACKS AND  
SOUTHERN GREENS. PLENTY OF GREAT LAKE MOISTURE WILL BE TAPPED IN  
THE CYCLONIC FLOW. HIGHS WILL BE MAINLY IN THE 50S TO LOWER 60S  
WEST OF THE HUDSON RIVER VALLEY...AND MID 60S TO AROUND 70F FROM  
THE HUDSON RIVER VALLEY EASTWARD EXCEPT SOME COOLER READINGS IN  
THE UPPER 50S TO LOWER 60S OVER THE SOUTHERN GREENS. LOWS FALL  
BACK TO THE MID 30S TO MID 40S OVER THE REGION TUE NIGHT, AS THE  
STRONGER COLD ADVECTION SWEEPS ACROSS THE REGION.  
 

 
   
LONG TERM /WEDNESDAY THROUGH SATURDAY/
 
 
THE LONG TERM PERIOD WILL BE DOMINATED BY GENERAL UPPER LEVEL  
TROUGHINESS AND BELOW NORMAL TEMPERATURES. AND ALTHOUGH THE MODELS  
CONTINUE TO STRUGGLE WITH THE EVOLUTION OF THE CUT OFF LOW DURING  
THE LATTER PART OF THE WEEK, THERE SEEMS TO BE INCREASING CONFIDENCE  
FOR DAILY RAIN CHANCES AND PLENTY OF CLOUDINESS.  
 
ON WEDNESDAY, SOME TRAILING UPPER LEVEL ENERGY WILL ALLOW FOR A  
CHANCE OF SHOWERS MAINLY NORTH AND WEST OF THE GREATER CAPITAL  
REGION AS THE MAIN UPPER LEVEL LOW CONTINUES TO LIFT FURTHER  
NORTHEAST. VERY BRIEF AND WEAK SHORTWAVE RIDGING PASSES THROUGH THE  
REGION WEDNESDAY NIGHT AS THE NEXT LOW PRESSURE SYSTEM TAKES SHAPE  
IN THE MID-MISSISSIPPI VALLEY. TEMPERATURES WEDNESDAY NIGHT COULD BE  
QUITE CHILLY DEPENDING ON THE CLOUD COVER AS THE 850MB TEMPS ARE -1  
TO -4 C ACROSS MOST OF THE AREA, WITH 700 MB TEMPS RANGING FROM -6  
TO -10 C.  
 
THE 00Z/30 GFS AND ECMWF CONTINUE TO STRUGGLE WITH THE EVOLUTION OF  
A CUT OFF LOW AND ITS INTERACTION WITH SHORTWAVE ENERGY DIVING  
SOUTHWARD OUT OF CANADA DURING THE THURS-SUN TIME FRAME. BOTH MODELS  
DEVELOP A SURFACE LOW OVER THE TENNESSEE VALLEY THURSDAY AFTERNOON,  
SPREADING RAINFALL NORTHEASTWARD INTO OUR REGION. EVEN THOUGH THERE  
CONTINUES TO BE DISCONTINUITY IN THE MODEL SOLUTIONS BEYOND THURSDAY  
AFTERNOON, THERE IS INCREASING CONFIDENCE FOR RAIN CHANCES THROUGH  
AT LEAST FRIDAY. POTENTIAL FOR ADDITIONAL RAIN OVER THE WEEKEND WILL  
DEPEND ON THE POSITION OF THE UPPER LOW AND TROUGH.  
 
BELOW NORMAL TEMPERATURES SHOULD CONTINUE THURSDAY THROUGH SATURDAY,  
WITH DAYTIME HIGHS MAINLY IN THE 50S, AND OVERNIGHT LOWS IN THE 40S,  
ALTHOUGH SOME 30S COULD OCCUR ACROSS HIGHER ELEVATIONS.  
 

 
   
AVIATION /07Z SUNDAY THROUGH THURSDAY/
 
 
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST THIS AFTERNOON,  
WITH MAINLY MID LEVEL CLOUDS. THERE IS THE POTENTIAL FOR SOME  
SHOWERS/THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON HOURS BUT  
DUE TO LOWER CONFIDENCE, DECIDED TO ONLY INCLUDE VCSH AT THIS  
TIME. MODEL SOUNDINGS ALSO INDICATE THAT CIGS BUILD DOWN DURING  
THE LATE EVENING HOURS SO HAVE TRENDED CIGS TO MVFR BY THE END  
OF THE TAF PERIOD ACROSS ALL TAF SITES.  
 
SOME GUSTY WEST/NORTHWEST WINDS CONTINUE AT KALB EARLY THIS  
MORNING BUT THESE WINDS SHOULD LESSEN WITHIN THE NEXT COUPLE OF  
HOURS. WINDS WILL THEN BE OUT OF THE NORTH/NORTHEAST AT 5-10  
MPH AND SHOULD PERSIST THROUGH THE DAY TODAY. WINDS WILL THEN  
SHIFT BACK TO THE SOUTHEAST TOWARDS THE END OF THE PERIOD.  
 
OUTLOOK...  
 
MONDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY DEFINITE  
SHRA...CHC TSRA.  
TUESDAY: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA.  
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.  
WEDNESDAY: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF RA.  
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF RA.  
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA.  
THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA.  
FRIDAY: HIGH OPERATIONAL IMPACT. LIKELY RA.  
 

 
   
FIRE WEATHER
 
 
HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM SOUTHWEST QUEBEC THIS  
MORNING WITH COOL LATE APRIL WEATHER, AS A WEAK DISTURBANCE MAY  
FOCUS SOME ISOLATED TO SCATTERED SHOWERS, AS WELL AS A FEW  
RUMBLES OF THUNDER ESPECIALLY WEST OF THE HUDSON RIVER VALLEY  
THIS AFTERNOON. A WARM FRONT WILL INCREASE THE THREAT OF  
ISOLATED TO SCATTERED SHOWERS TONIGHT INTO EARLY MONDAY AS IT  
SLOWLY LIFTS NORTH OF THE REGION. A COLD FRONT WILL BRING  
WIDESPREAD SHOWERS AND A CHANCE OF THUNDERSTORMS LATE IN THE  
AFTERNOON INTO TUESDAY MORNING.  
 
THE RH VALUES WILL LOWER TO 35 TO 55 PERCENT TODAY WITH  
ISOLATED LIGHT SHOWERS AS THE WINDS WILL SHIFT TO EAST TO THE  
SOUTHEAST AT 5 TO 15 MPH. THE RH VALUES RECOVER TO 85 TO 100  
PERCENT TONIGHT AND FALL ONLY TO 55 TO 70 PERCENT MONDAY WITH  
SCATTERED SHOWERS AND THUNDERSTORMS LATE MONDAY AFTERNOON. WINDS  
WILL BECOME SOUTHEAST TO SOUTH TONIGHT INTO MONDAY AT 10 TO 15  
MPH.  
 

 
   
HYDROLOGY
 
 
A WARM FRONT WILL LIFT NORTH THROUGH TONIGHT. RAINFALL AMOUNTS  
WILL BE FAIRLY LIGHT ONCE AGAIN, WITH A FEW HUNDREDTHS TO A  
TENTH OF AN INCH OR SO.  
 
A STRONG COLD FRONT WILL CROSS THROUGH THE REGION LATE MONDAY  
AFTERNOON INTO TUESDAY MORNING. THIS FRONT MAY ALLOW FOR SOME  
LOCALLY HIGHER RAINFALL TOTALS DUE TO MORE WIDESPREAD SHOWERS  
AND A CHANCE OF THUNDERSTORMS IN A MORE HUMID AIR MASS. NO  
PROBLEMS ARE ANTICIPATED ON THE MAIN STEM RIVERS. RAINFALL  
AMOUNTS WILL RANGE FROM A QUARTER TO THREE QUARTERS OF AN INCH  
OVER THE HYDRO SERVICE AREA WITH SOME LOCALLY HIGHER AMOUNTS IN  
THUNDERSTORMS. PONDING OF WATER ON ROADWAYS OR LOW LYING AREAS  
AND POOR DRAINAGE WITHIN URBAN AREAS WILL BE POSSIBLE.  
 
SHOWERY AND UNSETTLED WEATHER CONTINUES TUESDAY INTO WEDNESDAY  
WITH ADDITIONAL LIGHT RAINFALL AMOUNTS OF A FEW HUNDREDTHS TO A  
QUARTER OF AN INCH.  
 
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...WASULA  
NEAR TERM...WASULA  
SHORT TERM...WASULA  
LONG TERM...JVM  
AVIATION...JVM  
FIRE WEATHER...NAS/WASULA  
HYDROLOGY...NAS/WASULA  
 
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