373  
FXUS61 KALY 191734  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
134 PM EDT TUE MAR 19 2019  
   
SYNOPSIS
 
 
AN UPPER LEVEL DISTURBANCE WILL BRING SOME ISOLATED TO  
SCATTERED SNOW SHOWERS TODAY, OTHERWISE IT WILL BE FAIR AND DRY  
WITH HIGH PRESSURE BUILDING IN. THE SURFACE HIGH WILL BRING COLD  
AND DRY CONDITIONS TONIGHT. ON WEDNESDAY, THE HIGH MOVES EAST  
OF NEW ENGLAND WITH A SOUTHERLY FLOW OF MILDER AIR ALLOWING  
TEMPERATURES TO RISE ABOVE NORMAL. THE NEXT LOW PRESSURE SYSTEM  
ARRIVES FROM THE WEST LATE WEDNESDAY NIGHT INTO THURSDAY WITH  
WIDESPREAD RAIN AND SNOW SHOWERS.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
AS OF 12:15 PM EDT, CLOUDINESS IS INCREASING DUE TO DAYS  
HEATING AND NOW EXTENDS FROM MOHAWK VALLEY EAST TO SOUTHERN  
VERMONT AND BERKSHIRES SOUTHWEST TO EASTERN CATSKILLS.  
ELSEWHERE, SKIES ARE MAINLY CLEAR. RADAR SHOWS SOME SCATTERED  
SNOW SHOWERS AND FLURRIES WHERE CLOUDY. TEMPERATURES RANGE FROM THE  
UPPER 20S IN THE HILL TOWNS TO AROUND 40 IN THE MID HUDSON  
VALLEY. WINDS ARE GENERALLY FROM A NORTHWEST DIRECTION AND  
BEGINNING TO BECOME GUSTY. PITTSFIELD GUSTING TO AROUND 30 MPH  
THIS HOUR.  
 
PREVIOUS... A CYCLONIC FLOW OF CHILLY AIR ALOFT WILL CONTINUE  
OVER THE REGION ONE MORE DAY. THE H500 UPPER LEVEL TROUGH WILL  
STILL HAVE A COLD POOL OF -30C TO -36C AIR OVER MUCH OF UPSTATE  
NY AND NEW ENGLAND. IN THE WEST TO NORTHWEST FLOW, SOME  
INSTABILITY DIURNAL CUMULUS WILL LIKELY FORM, AND SOME LAKE  
ONTARIO MOISTURE WILL BE TAPPED FOR SOME ISOLATED TO SCATTERED  
LAKE ENHANCED SNOW SHOWERS AND FLURRIES, ESPECIALLY WEST OF THE  
HUDSON RIVER VALLEY.  
 
A WEAK H500 IMPULSE WILL ATTEMPT TO FOCUS ANY ISOLATED SNOW  
SHOWERS AND FLURRIES. WE INCREASED THE POPS WITH THIS UPDATE FOR  
THE WESTERN ADIRONDACKS, WESTERN MOHAWK VALLEY, AND NORTHERN  
CATSKILLS BASED ON THE UPSTREAM RADAR TRENDS WHERE THE SNOW  
SHOWERS ARE INCREASING ACROSS WESTERN AND CENTRAL NY. THE  
BOUNDARY LAYER MAY WARM ENOUGH FOR LIGHT RAIN TO MIX WITH THE  
SNOW IN THE VALLEY AREAS. SOME LIGHT DUSTINGS TO A HALF INCH ARE  
POSSIBLE OVER THE HIGHER TERRAIN. ISOLATED ONE INCH AMOUNTS ARE  
POSSIBLE OVER THE WESTERN DACKS. HIGH PRESSURE AT THE SURFACE  
WILL BE BUILDING IN FROM THE OH VALLEY, AND PENNSYLVANIA LATE IN  
THE DAY. H850 TEMPS WILL BE IN THE -8C TO -12C RANGE.  
 
SUNSHINE WILL MIX WITH CLOUDS, AND MAX TEMPS WILL BE IN THE  
UPPER 20S TO MID 30S OVER THE MTNS, AND MAINLY UPPER 30S TO  
LOWER 40S IN THE LOWER ELEVATIONS, THOUGH SOME MID 40S ARE  
POSSIBLE IN THE MID HUDSON RIVER VALLEY AND SOUTHERN LITCHFIELD  
CO. CT. WEST TO NORTHWEST WINDS WILL BE IN THE 5 TO 15 MPH  
RANGE.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/
 
 
TONIGHT...THE SFC ANTICYCLONE BUILDS IN FROM FROM JUST OFF THE  
NJ COAST OVER NY AND NEW ENGLAND WITH MOSTLY CLEAR SKIES AND  
LIGHT TO CALM WINDS FOR NEAR IDEAL RADIATIONAL COOLING  
CONDITIONS. THE MID AND UPPER LEVEL FLOW BECOMES FLATTER, AS THE  
UPPER TROUGH MOVES DOWNSTREAM. LOWS WILL BE IN THE MID TEENS TO  
MID 20S ACROSS THE FORECAST AREA.  
 
WEDNESDAY...A NICE DAY IS EXPECTED TO OPEN ASTRONOMICAL SPRING  
WITH THE RETURN FLOW FROM THE RETREATING SFC HIGH OFF THE NEW  
ENGLAND COAST ALLOWING TEMPS TO RISE ABOVE NORMAL. SPRING  
BEGINS AT 558 PM EDT. IN THE WARM ADVECTION PATTERN, H850 TEMPS  
INCREASE TO -3C TO -5C. SOME CIRRUS MAY INCREASE DURING THE MID  
TO LATE AFTERNOON, BUT EXPECT PARTLY TO MOSTLY SUNNY  
CONDITIONS, AND MAX TEMPS TO BE ABOUT 5 TO 7 DEGREES ABOVE  
NORMAL WITH SOUTHERLY WINDS IN THE 10 TO 15 MPH RANGE. HIGHS  
WILL GET INTO THE UPPER 40S TO LOWER 50S IN THE LOWER ELEVATIONS  
WITH UPPER 30S TO MID 40S OVER THE HIGHER TERRAIN.  
 
WED NIGHT INTO THU...A NORTHERN STREAM POSITIVELY TILTED MID AND  
UPPER LEVEL TROUGH WILL BE APPROACHING NY AND NEW ENGLAND WED  
NIGHT. THE TROUGH DIGS EQUATORWARD AND ATTEMPTS TO PHASE WITH  
SOUTHERN STREAM ENERGY MOVING ACROSS THE SOUTHEAST AND INTO THE  
OHIO VALLEY. SOUTHWEST FLOW SETS UP ACROSS THE REGION. A LOW-  
LEVEL JET AT 850 HPA INCREASES TO 40-50 KTS ACROSS THE REGION  
BETWEEN 06Z-12Z. THE INCREASING LOW-LEVEL JET WILL TAP SOME GULF  
MOISTURE AND HELP ENHANCE THE ISENTROPIC LIFT FOR SOME RAIN AND  
SNOW SHOWERS TO THE OVERSPREAD THE REGION IN THE EARLY TO MID  
MORNING HOURS. WE SLOWED THE TREND OF THE PCPN THIS CYCLE BASED  
ON THE SLOWER TIMING WITH THE GUIDANCE AND THE PHASING OF THE  
TWO TROUGHS POTENTIALLY. LOWS WILL BE IN THE MID 20S TO MID 30S.  
WE HAVE THE HIGHEST POPS PRIOR TO DAYBREAK WEST OF THE HUDSON  
RIVER VALLEY IN THE HIGH CHANCE TO LIKELY RANGE.  
 
THE SOUTHWEST FLOW WILL ALSO FAVOR SOME OROGRAPHIC ENHANCEMENT  
OVER THE SOUTHWEST ADIRONDACKS IN N-CNTRL HERKIMER TO SOUTHWEST  
HAMILTON COUNTIES THROUGH THURSDAY MORNING WHERE 1-3" OR  
POSSIBLY SOME ISOLATED 2-4" OF WET SNOW ACCUMULATION ARE  
POSSIBLE. THE SOUTHERN ADIRONDACKS AND SOUTHERN GREENS COULD  
RECEIVE 1-3" OF SNOW WITH AN INCH OR LESS OVER THE BERKSHIRES  
AND EASTERN CATSKILLS. ANY SNOW IN THE LOWER ELEVATIONS WOULD BE  
A LIGHT COATING ON THE GRASSY SURFACES AS THE BOUNDARY LAYER  
WARMS CONSIDERABLY. OTHERWISE, THE WARM ADVECTION AND INCREASING  
SOUTHERLY FLOW AHEAD OF WEAKENING LOW PRESSURE OVER THE EASTERN  
GREAT LAKES REGION, AND THE DEVELOPING SECONDARY LOW OVER  
EASTERN VA AND THE DELMARVA REGION THU AFTERNOON WILL BRING  
PERIODS OF SHOWERS DURING THE AFTERNOON. WE HAVE POPS IN THE  
LIKELY RANGE DURING THE AFTERNOON, AS AN INVERTED SFC TROUGH  
NORTH OF THE SECONDARY CYCLONE WILL FOCUS THE PCPN. HIGHS MAY  
ONLY GET INTO THE MID 30S TO AROUND 40F OVER THE MTNS WITH 40S  
TO LOWER 50S IN THE VALLEYS AND OVER THE HILLS.  
 

 
   
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
 
 
MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT REGARDING THE  
DEVELOPMENT OF A POTENTIAL COASTAL LOW PRESSURE SYSTEM THURSDAY  
NIGHT INTO FRIDAY MORNING, ALTHOUGH THERE ARE SIGNIFICANT  
POSITION/TRACK DIFFERENCES AMONG THE GFS/ECMWF/NAM/CMC. THE GFS AND  
THE GEFS ENSEMBLE MEAN ARE ON THE EASTERN ENVELOPE OF SOLUTIONS WITH  
A TRACK MAINLY OFF SHORE TO NEAR CAPE COD, WHILE THE NAM AND ECMWF  
ARE FARTHER THE WEST FROM THE DELMARVA TO SOUTHEAST NEW ENGLAND. THE  
NAM/ECMWF CAMP WOULD RESULT IN GREATER QPF AND PRECIP LASTING  
THROUGH MUCH OF THURSDAY NIGHT, WHILE THE GFS HAS MUCH LIGHTER QPF  
AND IS MORE PROGRESSIVE. MAIN POINT AT THIS TIME IS THERE IS  
CONSENSUS FOR A COASTAL STORM WITH HIGH ENOUGH CONFIDENCE TO MENTION  
LIKELY POPS ACROSS THE SE 2/3 OF OUR AREA. PRECIP TYPE WILL BE  
ANOTHER CHALLENGE, AS MODELS INDICATING LOW LEVEL THERMAL PROFILES  
TO BE RATHER WARM REGARDLESS OF STORM TRACK. EXPECTING SNOW OR  
RAIN/SNOW MIX TO BE ACROSS HIGHER TERRAIN AREAS, WITH THE THREAT OF  
ACCUMULATING SNOW CONFINED TO MOUNTAIN AREAS AT THIS TIME. HOWEVER,  
THIS IS STILL A LOW CONFIDENCE FORECAST DUE TO TRACK/QPF/P-TYPE  
ISSUES SO A LOT COULD STILL CHANGE FROM NOW UNTIL THURSDAY NIGHT.  
 
ON FRIDAY, THERE IS GROWING MODEL CONSENSUS THAT A STRONG NORTHERN  
STREAM UPPER LEVEL LOW WILL RAPIDLY DIG SOUTHWARD ACROSS SE CANADA  
AND THE EASTERN GREAT LAKES. CYCLONIC VORTICITY ADVECTION ALONG WITH  
TERRAIN FORCING ASSOCIATED WITH NW FLOW WILL RESULT IN SCATTERED  
VALLEY RAIN SHOWERS AND NUMEROUS MOUNTAIN SNOW SHOWERS. THERE COULD  
BE SOME LIGHT SNOW ACCUMULATIONS, ESPECIALLY FOR FAVORED UPSLOPE  
AREAS OF THE WESTERN ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS.  
 
AS THE UPPER LOW MERGES WITH THE TROUGH FROM THE COASTAL STORM, THE  
SURFACE CYCLONE IS FORECAST TO DEEPEN CONSIDERABLY BY FRIDAY NIGHT  
IN THE VICINITY OF NORTHERN MAINE. THIS WILL RESULT IN A  
STRENGTHENING PRESSURE GRADIENT AND POTENTIALLY STRONG NORTHWEST  
WINDS DEVELOPING ACROSS OUR REGION FRIDAY NIGHT AND LASTING THROUGH  
SATURDAY, AS THE STORM SYSTEM STARTS TO BECOME VERTICALLY STACKED  
AND DOES NOT MAKE MUCH EASTWARD PROGRESS. BLUSTERY AND COLD  
CONDITIONS EXPECTED ON SATURDAY, ALTHOUGH SNOW SHOWER ACTIVITY  
SHOULD BE DIMINISHING AS THE FLOW PATTERN BECOMES MORE NEUTRAL.  
 
DRY AND COLD CONDITIONS IN STORE FOR SATURDAY NIGHT, AS THE STORM  
SYSTEM PULLS FARTHER AWAY IN THE CANADIAN MARITIMES. SUNDAY LOOKS TO  
FEATURE WARMER TEMPERATURES AS HEIGHTS ALOFT ARE FORECAST TO RISE  
ALONG WITH ABUNDANT SUNSHINE. THE NEXT CHANCE OF SHOWERS ARRIVES ON  
MONDAY, AS A STRONG COLD FRONT SAGS SOUTHWARD FROM CANADA WHILE SOME  
MOISTURE POOLS ALONG THE FRONT AS A WEAK WAVE OF LOW PRESSURE MAY  
DEVELOP.  
 

 
   
AVIATION /18Z TUESDAY THROUGH SUNDAY/
 
 
HIGH PRESSURE CONTINUES TO BUILD IN TONIGHT, PROVIDING MAINLY  
DRY CONDITIONS. WITH COLD AIR ALOFT, SCT-BKN AFTERNOON CUMULUS  
CLOUDS WILL CONTINUE WITH VFR CONDITIONS PREVAILING THROUGH THE  
24 HOUR TAF PERIOD ENDING 18Z WEDNESDAY. A BRIEF SNOW SHOWER OR  
FLURRY IS POSSIBLE AT KPSF BETWEEN 18 AND 22Z, BUT SHOULD NOT  
RESTRICT VISIBILITY BELOW 6SM.  
 
WINDS TODAY WILL MOSTLY BE NORTHWEST AROUND 10-15 KT, BECOMING  
CALM AFTER DARK THIS EVENING. HOWEVER, THIS AFTERNOON, DEEP  
MIXING OF THE LOWER ATMOSPHERE WILL MIX DOWN SOME 30 KT  
NORTHWESTERLY WIND GUSTS FROM ALOFT. GUSTY NW WINDS HAVE BEEN  
INCLUDED IN THE TAFS IN A TEMPO FROM 18-22Z.  
 
OUTLOOK...  
 
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.  
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA.  
THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA.  
FRIDAY: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA.  
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY SLIGHT CHANCE OF SHRA...SHSN.  
SATURDAY: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.  
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.  
SUNDAY: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.  
 

 
   
FIRE WEATHER
 
 
AN UPPER LEVEL DISTURBANCE WILL BRING SOME ISOLATED SNOW  
SHOWERS AND FLURRIES MAINLY WEST OF THE HUDSON RIVER VALLEY TODAY,  
OTHERWISE IT WILL BE FAIR AND DRY WITH HIGH PRESSURE BUILDING IN. THE  
SURFACE HIGH WILL BRING COLD AND DRY CONDITIONS TONIGHT, BEFORE  
MOVING EAST OF THE NEW ENGLAND COAST WITH A SOUTHERLY FLOW OF MILDER  
AIR ALLOWING TEMPERATURES TO TREND ABOVE NORMAL FOR WEDNESDAY.  
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION WILL BE LATE  
WEDNESDAY NIGHT THROUGH THURSDAY.  
 
MOST OF THE HIGHER TERRAIN REMAINS SNOW COVERED. THE RH VALUES  
WILL LOWER TO 30 TO 60 PERCENT THIS AFTERNOON, AND THEN RECOVER  
TO 75 TO 100 PERCENT WEDNESDAY MORNING. THE MINIMUM RH VALUES  
WILL BE IN THE 30 TO 55 PERCENT RANGE WEDNESDAY AFTERNOON.  
 
THE WINDS WILL BE WEST TO NORTHWEST AT 5 TO 15 MPH TODAY AND  
LIGHT AND VARIABLE AT LESS THAN 5 MPH TONIGHT. EXPECT SOUTHERLY  
WINDS ON WEDNESDAY OF 5 TO 15 MPH.  
 

 
   
HYDROLOGY
 
 
NO WIDESPREAD HYDROLOGY PROBLEMS ARE ANTICIPATED THROUGH MUCH OF  
THE THE NEXT WEEK.  
 
FORECAST LIQUID EQUIVALENT PRECIPITATION FOR THE NEXT 7 DAYS IS  
THREE QUARTERS OF AN INCH OR LESS. HOWEVER, SOME OF THE MEDIUM  
RANGE GUIDANCE (ECMWF) AS WELL AS THE NAM DOES BRING A HALF AN  
INCH TO AN INCH OR MORE OF LIQUID EQUIVALENT THURSDAY INTO  
FRIDAY FROM A SLOW MOVING LOW PRESSURE SYSTEM. THIS CONTINUES TO  
BE MONITORED CLOSELY, AS SOME WITHIN BANK RISES ON RIVERS WOULD  
BE POSSIBLE WITH HIGHER QPF.  
 
OVERALL, FORECAST TEMPERATURES WILL GENERALLY BE NEAR TO BELOW  
NORMAL. LOW TEMPERATURES ARE FORECAST BELOW FREEZING ON MOST  
NIGHTS  
 
THE COMBINATION OF THE POSSIBILITY OF LOW PRECIPITATION, LOW  
MAXIMUM TEMPERATURES AMD DEW POINT TEMPERATURES BELOW FREEZING  
SHOULD LEAD TO ORDERLY SNOW MELT AND MINOR CHANGES IN RIVER  
FLOWS.  
 
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...SND/WASULA  
NEAR TERM...SND/WASULA  
SHORT TERM...WASULA  
LONG TERM...JPV  
AVIATION...SND  
FIRE WEATHER...WASULA  
HYDROLOGY...SND/WASULA  
 
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