122  
FXUS61 KALY 171748  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
1248 PM EST SUN FEB 17 2019  
   
SYNOPSIS
 
 
HIGH PRESSURE OVER SOUTHERN QUEBEC WILL CONTINUE A DRY,  
BUT COLD AFTERNOON, AS CLOUDS WILL BEGIN TO INCREASE FROM THE SOUTH  
AND WEST. A STORM SYSTEM WILL BRING SNOW TO THE REGION TONIGHT INTO  
MONDAY, WITH A LIGHT TO MODERATE ACCUMULATION IN MOST AREAS.  
TEMPERATURES WILL CONTINUE TO BE NEAR NORMAL LEVELS FOR MID FEBRUARY  
THIS WEEK WITH SOME MORE WINTRY PRECIPITATION EXPECTED LATE  
WEDNESDAY INTO THURSDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
AS OF 1233 PM EST...HIGH PRESSURE CENTERED OVER SOUTHERN QUEBEC  
WILL CONTINUE TO PROVIDE A COLD, BUT DRY AFTERNOON. HIGH CLOUDS  
ARE STARTING TO INCREASE FROM THE SOUTH AND WEST, AS SEEN ON  
THE GOES-16 IR IMAGERY. LOW PRESSURE IS ORGANIZING OVER THE TN  
VALLEY WITH A WARM FRONT EXTENDING INTO THE CENTRAL APPALACHIANS  
AND MID ATLANTIC STATES. CLOUDS WILL CONTINUE TO INCREASE,  
THICKEN AND LOWER BY SUNSET, AS THE SFC HIGH SLIDES EASTWARD,  
AND A STORM SYSTEM APPROACHES FROM THE SOUTHWEST.  
 
TEMPS ARE ON THE CHILLY SIDE DESPITE THE SUNSHINE WITH HIGHS A  
TAD BELOW NORMAL WITH A STRONG SUBSIDENCE AND RADIATIVE  
INVERSION ON THE 12Z KALY SOUNDING. HIGHS WILL BE IN THE UPPER  
20S TO LOWER 30S IN THE LOWER ELEVATIONS, EXCEPT SOME MID 30S  
OVER THE MID HUDSON VALLEY AND NW CT. 20S TO AROUND 30F OVER THE  
HILLS AND MOUNTAINS.  
 
IT STILL LOOKS LIKE THE ONSET OF ANY LIGHT SNOW AHEAD OF THE  
PRIMARY WAVE AND A FRONTAL BOUNDARY WILL BE AFTER DARK. THE  
CURRENT HEADLINES LOOK ON TRACK. WE MAY HAVE TO ADD A LITTLE  
FREEZING DRIZZLE/FREEZING RAIN MONDAY MORNING FOR THE EXTREME  
SOUTHERN REACHES OF THE FORECAST AREA /ULSTER...DUTCHESS...AND  
LITCHFIELD COUNTIES/...AS WE LOSE THE ICE NUCLEI IN THE CLOUDS  
AS THE MAIN THRUST OF ISENTROPIC LIFT. MORE DETAILS IN THE NEXT  
UPDATE.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/
 
 
WINTER WEATHER ADVISORY 9 PM EST TO 1 PM MON FROM THE MOHAWK  
VALLEY, CAPITAL REGION, AND THE BERKSHIRES SOUTHWARD...  
 
CLOSED UPPER LEVEL LOW OVER THE MIDWEST WILL BE OPENING UP AND  
WEAKENING AS IT HEADS NORTHEAST WITHIN THE FAST SOUTHWEST FLOW  
ALOFT. THE FLOW OVER THE NORTHEAST IS RATHER CONFLUENT, WHICH  
WILL BE CAUSING THIS UPPER LEVEL ENERGY TO START TO SHEAR OUT.  
DESPITE THIS WEAKENING OF THE FORCING AT 500 HPA, WE ARE  
ANTICIPATING SOME PRECIPITATION IN THE FORM OF SNOW TO BREAK  
OUT ACROSS THE REGION LATE THIS EVENING, AS A SOUTHWESTERLY LOW  
LEVEL JET AROUND 30 KTS ALLOWS FOR SOME WARM  
ADVECTION/ISENTROPIC LIFT. WITH PLENTY OF COLD AIR IN PLACE BOTH  
AT THE SURFACE AND ALOFT, SOME LIGHT SNOW MAY BEGIN AS EARLY AS  
00Z-02Z, WITH PRECIP SPREADING NORTHEAST INTO THE OVERNIGHT.  
 
WITH THE INITIAL SURFACE LOW HEADING TOWARDS THE EASTERN OHIO  
VALLEY, THE 00Z HREF SUGGEST THE BEST SNOWFALL RATES WITHIN THE  
WARM ADVECTION WILL LIKELY BE 04Z-08Z, AS SNOWFALL RATES MAY  
EXCEED 0.50 INCH PER HOUR (ALTHOUGH NOT OVER 1" PER HOUR RATES  
EXPECTED).  
 
BY SHORTLY AFTER DAYBREAK, THE BEST ISENTROPIC LIFT WILL BE  
SHIFTING NORTH AND EAST AWAY FROM THE AREA. HOWEVER, WE ARE  
EXPECTING LIGHT SNOW TO LINGER INTO THE DAY MONDAY, AS A  
SECONDARY SURFACE LOW DEVELOPS SOUTH OF LONG ISLAND AND LIFTS  
NORTHEAST. THE COMBINATION OF AN INVERTED SURFACE TROUGH, ALONG  
WITH ELONGATED UPPER LEVEL ENERGY AND A POWERFUL 180 KT JET  
STREAK OVERHEAD, SHOULD CONTINUE SOME SPOTTY LIGHT SNOWFALL  
THROUGH AT LEAST THE MORNING ON MONDAY (WITH SOME EASTERN AREAS  
EVEN SEEING OCCASIONAL LIGHT SNOW LINGERING INTO THE AFTERNOON  
AS WELL).  
 
ALTHOUGH THERE ARE SOME SUBTLE DIFFERENCE IN MODEL GUIDANCE, ALL  
GUIDANCE SUGGESTS JUST A LIGHT TO LOCALLY MODERATE AMOUNT OF  
SNOW. FOLLOWING CLOSELY TO WPC WWD SNOW FORECAST, AS WELL AS THE  
00Z HREF, TOTAL SNOWFALL FOR AREAS FROM THE MOHAWK VALLEY/I-90  
ON SOUTHWARD LOOKS TO BE 2 TO 5 INCHES, WITH THE HIGHEST TOTALS  
OVER THE EASTERN CATSKILLS. BASED ON THIS FORECAST AND IN  
COLLABORATION WITH NEIGHBORING OFFICES, WE ARE HAVE PLACED THIS  
AREA WITHIN A WINTER WEATHER ADVISORY. FURTHER NORTH, THE  
ADIRONDACKS, LAKE GEORGE SARATOGA REGION AND SOUTHERN VT SHOULD  
SEE 1 TO 3 INCHES OF SNOWFALL (LOCALLY AROUND 4 INCHES IN THE  
FAR SOUTHERN GREENS).  
 
ALTHOUGH NOT HEAVY AMOUNTS, THIS SNOW WILL STILL MAKE FOR  
SLIPPERY TRAVEL TONIGHT INTO MONDAY. THE HOLIDAY MAY LIMIT  
IMPACTS SOMEWHAT, BUT ANYONE NEEDING TO TRAVEL SHOULD ANTICIPATE  
SNOW COVERED ROADWAYS AND LOW VISIBILITY FOR MONDAY MORNING.  
 
WITH SOME MID LEVEL DRYING, ITS POSSIBLE THAT ICE NUCLEI IS LOST  
FOR FAR SOUTHERN AREAS, ALLOWING PRECIP TO END AS SOME SPOTTY  
LIGHT FREEZING DRIZZLE ON MONDAY MORNING, BUT THIS WOULD ONLY  
BE A TRACE TO A FEW HUNDREDTHS AND WOULD OCCUR AFTER SNOW HAS  
OCCURRED, SO ADDITIONAL IMPACTS WOULD BE MINOR. HAVE NOT  
INCLUDED THIS IN THE FORECAST AT THIS TIME, BUT MAY BE SOMETHING  
TO MONITOR.  
 
HIGHS ON MONDAY LOOK TO REACH THE MID 20S TO MID 30S WITH THE  
EXPECTED SNOW AND CLOUDS. SOME BRIGHTENING OF THE SKIES IS  
POSSIBLE BY LATE IN THE DAY, BUT ANY BREAKS IN THE CLOUDS LIKELY  
WON'T OCCUR UNTIL AT LEAST MONDAY EVENING.  
 
PRECIP SHOULD BE BASICALLY TAPERED OFF BY SUNSET MONDAY FOR THE  
REGION. THE EXCEPTION MAY BE ACROSS THE WESTERN MOHAWK VALLEY,  
WHERE A WEAK LAKE RESPONSE COULD KEEP A FEW LIGHT SNOW SHOWERS  
OR FLURRIES AROUND INTO MONDAY NIGHT, BUT LITTLE TO NO  
ADDITIONAL ACCUMULATION IS EXPECTED.  
 
ANOTHER LARGE HIGH PRESSURE AREA BUILDING INTO THE AREA FROM  
THE GREAT LAKES IS EXPECTED FOR TUESDAY INTO TUESDAY NIGHT.  
THIS WILL KEEP DRY WEATHER IN PLACE OVER THE AREA. TEMPS MAY BE  
SLIGHTLY BELOW NORMAL FOR TUESDAY, WITH HIGHS IN THE 20S AND  
LOWS IN THE SINGLE DIGITS TO LOW TEENS FOR TUESDAY NIGHT.  
 

 
   
LONG TERM /WEDNESDAY THROUGH SATURDAY/
 
 
WE START OFF WITH A DEPARTING SURFACE HIGH OFF THE NEW ENGLAND  
COASTLINE AS UPSTREAM SYSTEM APPROACHES. WHILE MOISTURE TRANSPORT  
WILL BE RICH FROM THE GULF OF MEXICO, THERE ARE INCREASING SIGNS OF  
CONVECTION ACROSS THE OHIO/TENNESSEE VALLEY AND INTO THE MID-  
ATLANTIC. THIS MAY RESULT IN MOISTURE TRANSPORT DISRUPTION AND  
LOWER PRECIPITATION AMOUNTS ACROSS THE REGION AS SUGGESTED BY THE  
ECMWF. HOWEVER, IT REMAINS RATHER LOW CONFIDENCE WITH THIS PORTION  
OF THE FORECAST AS SECONDARY SURFACE WAVE DEVELOPMENT JUST OFF THE  
MID-ATLANTIC COAST TOWARD 12Z THURSDAY DEVELOPS WITHIN THIS ENHANCED  
REGION OF POTENTIAL CONVECTION ALONG THE BAROCLINIC ZONE.  
FURTHERMORE, TEMPERATURE PROFILES WILL ALSO ADJUST AS WHAT INITIALLY  
FALLS OUT OF THE SKY WILL BE SNOW THEN TRANSITION TOWARD A WINTRY  
MIX AS WARM ADVECTION ALOFT ON THE SOUTHWEST LOW LEVEL JET  
INCREASES.  
 
THE GOOD NEWS IS THIS SYSTEM IS RATHER PROGRESSIVE PER THE 00Z NCEP  
MODEL SUITE AND INTERNATIONAL GLOBAL GUIDANCE AS PRECIPITATION WILL  
TAPER OFF MY THURSDAY AFTERNOON. COULD BE RATHER MILD BEFORE THE  
COLD FRONT CROSSES THE REGION THROUGH THE AFTERNOON HOURS. THEN  
BRISK AND COOLER WEATHER RETURNS AS WE ROUND OUT THE WEEK.  
 
CONSENSUS FAVORS A DRY DAY FRIDAY INTO SATURDAY AS HIGH PRESSURE  
RETURNS BACK ACROSS THE GREAT LAKES AND INTO THE NORTHEAST CORRIDOR.  
SEASONABLE TEMPERATURES ARE EXPECTED AS WELL. LOOKING JUST BEYOND  
DAY 7, SEVERAL SIGNALS OF AN INCREASE AMPLIFICATION AND PHASING OF  
THE NORTHERN AND SOUTHERN STREAMS ACROSS THE GREAT LAKES REGION FOR  
AN ACTIVE END OF THE WEEKEND.  
 

 
   
AVIATION /18Z SUNDAY THROUGH FRIDAY/
 
 
HIGH PRESSURE ACROSS THE REGION WILL WEAKEN AND SHIFT OFF TO  
THE EAST THIS AFTERNOON INTO THE EVENING. IN THE MEANTIME,  
CLOUDS WILL THICKEN AND LOWER AS AN AREA OF LOW PRESSURE  
APPROACHES. OVERRUNNING SNOW EXPECTED TO DEVELOP AND SPREAD  
ACROSS THE AREA LATE THIS EVENING WITH IFR CONDITIONS QUICKLY  
DEVELOPING. THE SNOW IS THEN EXPECTED TO CONTINUE THROUGH THE  
OVERNIGHT AND MONDAY MORNING WITH THE SNOW LIGHTENING UP AS THE  
MORNING PROGRESSES AS LOW BEGINS TO MOVES AWAY FROM THE REGION.  
MVFR CONDITIONS ARE FORECAST TO DEVELOP AT KPOU, KALB AND KGFL  
AROUND MIDDAY WITH IFR PERSISTING INTO THE AFTERNOON AT KPSF.  
SNOWFALL ACCUMULATIONS OF 3-4 INCHES ARE EXPECTED AT KPOU, KALB  
AND KPSF WITH 2-3 INCHES AT KGFL.  
 
WINDS WILL BE VERY LIGHT THROUGH THE TAF PERIOD.  
 
OUTLOOK...  
 
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.  
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN.  
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SN.  
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.  
 

 
   
HYDROLOGY
 
 
DRY AND SEASONABLY COLD WEATHER IS EXPECTED THROUGH THE DAY  
TODAY. A STORM SYSTEM WILL BRING ACCUMULATING SNOWFALL TONIGHT  
INTO TOMORROW, WITH TOTAL LIQUID EQUIVALENT GENERALLY UNDER A  
THIRD OF AN INCH. ANOTHER SEASONABLY COLD AND DRY STRETCH IS  
LIKELY MONDAY NIGHT THROUGH MOST OF THE DAY WEDNESDAY.  
 
ANOTHER STORM SYSTEM IS EXPECTED LATE WEDNESDAY INTO THURSDAY  
AND THIS STORM WILL BRING SNOW CHANGING TO A WINTRY MIX AND/OR  
RAIN TO THE REGION. AS OF RIGHT NOW, ABOUT A QUARTER TO HALF  
INCH OF LIQUID EQUIVALENT IS EXPECTED WITH THIS STORM SYSTEM.  
 
TEMPERATURES LOOK TO REMAIN FAIRLY SEASONABLE INTO THE MIDDLE OF  
THE UPCOMING WEEK, WITH NO MAJOR WARM UPS OR HEAVY PRECIPITATION  
EVENTS EXPECTED. AS A RESULT, RIVER AND STREAM LEVELS WILL  
GENERALLY HOLD STEADY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK  
AND WIDESPREAD SNOW MELT, ICE MOVEMENT OR FLOODING IS NOT  
EXPECTED AT THIS TIME.  
 
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...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 1 PM EST  
MONDAY FOR CTZ001-013.  
NY...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 1 PM EST  
MONDAY FOR NYZ038>040-047>054-058>061-063>066-082.  
MA...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 1 PM EST  
MONDAY FOR MAZ001-025.  
VT...NONE.  
 

 
 

 
SYNOPSIS...FRUGIS/WASULA  
NEAR TERM...IAA/FRUGIS  
SHORT TERM...FRUGIS  
LONG TERM...BGM  
AVIATION...IAA  
HYDROLOGY...FRUGIS  
 
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