470  
FXUS61 KALY 231949  
AFDALY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ALBANY NY  
349 PM EDT SUN APR 23 2017  
   
SYNOPSIS
 
 
A DELIGHTED END TO THE WEEKEND WILL BE FOLLOWED BY ANOTHER MILD  
DAY FOR THE START OF THE WORK AND SCHOOL WEEK. OUR DRY WEATHER  
WILL GRADUALLY COME TO AN END OVERNIGHT MONDAY AS TUESDAY INTO  
WEDNESDAY APPEARS TO BE RATHER CLOUDY AND DAMP AS LOW PRESSURE  
TRACKS ALONG THE EASTERN SEABOARD.  
 

 
   
NEAR TERM /UNTIL 6 AM MONDAY MORNING/
 
 
WE WILL REMAIN WITHIN A NARROW REGION OF CONFLUENCE ACROSS THE  
COUNTY WARNING AREA (CWA) WHICH SHOULD RESULT IN MAINLY CLEAR  
SKIES AND LIGHT WINDS THROUGH THE REMAINDER OF TODAY INTO  
TONIGHT. A WEAK FRONTAL BOUNDARY ACROSS THE UPPER GREAT LAKES  
WILL APPROACH THE ST LAWRENCE VALLEY OVERNIGHT WHICH MAY BRING  
SOME HIGH AND MID LEVEL CLOUD COVERAGE INTO THE ADIRONDACKS  
OVERNIGHT. OTHERWISE, CUT-OFF UPPER LOW IN THE VICINITY OF THE  
TENNESSEE VALLEY WILL CONTINUE TO SLOWLY TRACK EASTWARD AS  
SURFACE LOW SPAWNS OFF THE SOUTHEAST CONUS. THIS TOO MAY BRING  
SOME HIGHER LEVEL CLOUDS INTO OUR SOUTHERN PORTIONS OF THE CWA  
OVERNIGHT. THERE COULD BE SOME PATCHY FOG ALONG AREA RIVERS AND  
LAKES OVERNIGHT THAT WILL NEED TO BE WATCHED AND POSSIBLY  
INCLUDED INTO THE GRIDS WITH FUTURE ESTF'S. AS FOR TEMPERATURES  
OVERNIGHT, MOS NUMBERS ARE QUITE CLOSE AND NEAR CURRENT FORECAST  
VALUES SO LITTLE CHANGES NEEDED AT THIS TIME...MAINLY MID-UPR  
30S ACROSS THE TERRAIN TO LOWER 40S FOR VALLEY LOCATIONS.  
 

 
   
SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/
 
 
MONDAY WE WILL SEE AN INCREASE IN MAINLY HIGHER LEVEL CLOUDS AS  
WEAK FRONTAL ZONE TO OUR NORTH STALLS JUST NORTH OF OUR  
ADIRONDACK REGION AND SOUTHEAST CONUS UPPER AND SURFACE LOWS  
SLOWLY TRACK UP THE EASTERN SEABOARD. SO FILTERED SUNSHINE AS  
TEMPERATURES SHOULD RETURN BACK INTO THE 60S FOR MANY LOCATIONS  
WITH COOLER 50S NEAR THE FRONTAL ZONE ACROSS THE NORTHERN DACKS  
WITHIN OUR CWA.  
 
OVERALL MODEL CONSENSUS CONTINUES TO FAVOR THE MAIN CULPRIT TO  
OUR WEATHER PATTERN WILL BE THE SOUTHEAST CONUS LOW WHICH WILL  
TRACK NORTHWARD ALONG THE SEABOARD. THE FIRST SHOT OF ISENTROPIC  
LIFT ARRIVES OVERNIGHT MONDAY WITH THE NAM THE MOST PRONOUNCED.  
SO WE WILL INCREASE POPS THROUGH THE OVERNIGHT PERIOD FROM SOUTH  
TO NORTH. THEN THROUGH TUESDAY, A RATHER DAMP DAY AS COUPLE  
WAVES OF ISENTROPIC LIFT TRANSVERSES THE REGION WITH PERIODS OF  
LIGHT RAIN AND/OR DRIZZLE UNFOLDS ACROSS A GOOD PORTION OF THE  
REGION. DUE TO THE CLOUD COVERAGE AND PRECIPITATION,  
TEMPERATURES WILL TOUGH TO CLIMB INTO THE MIDDLE 50S.  
 
TUESDAY NIGHT, VERTICALLY STACKED LOW APPROACHES AS SOUTHEAST  
LOW LEVEL WIND FIELD INCREASES. THIS WILL INCREASE MOISTURE  
ENTRAINMENT FROM THE ATLANTIC WHERE ADDITIONAL LIGHT RAINFALL IS  
EXPECTED. DURING THE OVERNIGHT, THETA-E FIELDS AND DEFORMATION  
AXIS BEGIN TO LINE UP FOR THE EASTERN 2/3RDS OF THE CWA  
OVERNIGHT INTO WEDNESDAY WHERE WE WILL KEEP POPS RATHER HIGH. A  
FURTHER EXAMINATION OF THE FORECAST SOUNDINGS INDICATE WE BEGIN  
TO LOSE THE MID LEVEL MOISTURE FIELDS FROM WEST TO EAST WHILE  
LOW LEVEL SHEAR AND LIFT CONTINUE. SO WE WILL INTRODUCE SOME  
DRIZZLE TO THE FORECAST/GRIDS. TEMPERATURES SHOULD REMAIN RATHER  
COOL WITH THE UNSETTLED CONDITIONS AS HIGHS TUESDAY AFTERNOON  
RANGE FROM 55F TO 65F.  
 

 
   
LONG TERM /WEDNESDAY THROUGH SUNDAY/
 
 
ACTIVE PACIFIC JET WILL CARVE OUT A DEEP TIME-MEAN LONGWAVE TROUGH  
OVER THE WESTERN CONUS. DOWNSTREAM, DEAMPLIFYING WAVES EMANATING  
FROM THIS TROUGH WILL BATTLE A BUILDING RIDGE CENTERED ACROSS THE  
SOUTHEASTERN US. MODEL CONSENSUS FAVORS POSITIVE UPPER HEIGHT  
ANOMALIES OVER THE EASTERN THIRD OF THE US, SO ABOVE-NORMAL  
TEMPERATURES ARE FAVORED DURING THE LONG-TERM PERIOD.  
 
ON WEDNESDAY NIGHT, MODEL CONSENSUS DEPICTS A COMPACT CUTOFF LOW  
MOVING NORTHEASTWARD A LITTLE WAYS OFF THE NEW ENGLAND COASTLINE.  
SOME REMNANT MOISTURE AND SHOWERS FROM THIS WAVE MAY STILL BE  
IMPACTING SOUTHERN NEW ENGLAND WEDNESDAY NIGHT. THE WAVE WILL  
QUICKLY EXIT THE AREA AS SHORTWAVE RIDGING AND WARM SOUTHERLY FLOW  
BUILDS INTO NEW YORK FOR THURSDAY. THEN, ATTENTION TURNS TO A  
SURFACE LOW TRACKING NORTH-NORTHEAST THROUGH THE WESTERN GREAT LAKES  
AS THE LONGWAVE TROUGH ATTEMPTS TO EXPAND EASTWARD. MODEL CONSENSUS  
KEEPS US IN THE WARM SECTOR AND DELAYS SHOWER/STORM CHANCES UNTIL  
THE THURSDAY NIGHT. ECMWF STALLS THE FRONT OUT INTO FRIDAY OVER OUR  
REGION, SO HAVE KEPT CHANCE POPS IN PLACE FOR THIS SCENARIO.  
 
FOR THE WEEKEND, MODELS TRY TO EXPAND THE STRONG ANTICYCLONE  
CENTERED OVER THE SOUTHEASTERN US NORTHWARD, WHILE A DEEP UPPER LOW  
SETS UP OVER THE INTERMOUNTAIN WEST. MOISTURE RETURN IN BETWEEN  
THESE SYSTEMS LOOKS TO RESULT IN A LARGE WEST-EAST BAND OF PRECIP  
ALONG A WARM FRONT. THE POSITION OF THIS FRONT LOOKS TO BE THE KEY  
FOR PRECIPITATION CHANCES, AS THE EASTWARD EXTEND OF IT WILL BE  
NEARBY, BUT ENCOUNTERING SURFACE AND UPPER RIDGING OVER THE  
NORTHEAST. FOR NOW, PUT LOW CHANCE POPS IN THE FORECAST BOTH  
SATURDAY AND SUNDAY, REFLECTING LATEST MODEL CONSENSUS.  
 

 
   
AVIATION /19Z SUNDAY THROUGH FRIDAY/
 
 
VFR CONDITIONS SHOULD PREVAIL THROUGH THE FORECAST PERIOD ENDING  
18Z/MONDAY. MOSTLY CLEAR SKIES EXPECTED THROUGH THE EVENING  
HOURS WITH SOME HIGHER CLOUDS APPROACHING KGFL AND KPOU  
OVERNIGHT. THERE COULD BE SOME LOWER VISIBILITY POSSIBLE AT  
KGFL TOWARD MONDAY MORNING IN SHALLOW FOG, BUT CONFIDENCE NOT  
HIGH ENOUGH TO INCLUDE IN TAFS AT THIS TIME.  
 
LIGHT WINDS AT 8 KT OR LESS TO BECOME LIGHT AND VARIABLE  
TONIGHT.  
 
OUTLOOK...  
 
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA.  
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...RA.  
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.  
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.  
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.  
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX  
 

 
   
FIRE WEATHER
 
   
..LOW RELATIVE HUMIDITY VALUES MONDAY AFTERNOON
 
 
DRY WEATHER TONIGHT INTO MONDAY NIGHT AS HIGH PRESSURE  
DOMINATES THE REGION. CHANCES FOR RAIN WILL BE ON THE INCREASE  
LATE MONDAY NIGHT INTO TUESDAY MORNING AS COASTAL LOW MOVES UP  
THE EAST COAST. A WIDESPREAD RAINFALL IS EXPECTED FOR MUCH OF  
THE AREA TUESDAY INTO TUESDAY NIGHT WHICH MAY LINGER INTO  
WEDNESDAY.  
 
MINIMUM RELATIVE HUMIDITY VALUES WILL RECOVER TO 80 TO 95  
PERCENT TONIGHT. MINIMUMS MONDAY AFTERNOON ARE EXPECTED TO BE IN  
MAINLY THE 30S.  
 
WINDS WILL BE LIGHT AT LESS 10 MPH TONIGHT AND MONDAY.  
 

 
   
HYDROLOGY
 
 
DRY WEATHER INTO MOST OF MONDAY NIGHT AS HIGH PRESSURE  
DOMINATES. CHANCES FOR RAIN WILL BE ON THE INCREASE LATE MONDAY  
NIGHT INTO TUESDAY MORNING AS COASTAL STORM MOVES UP THE EAST  
COAST. A WIDESPREAD RAINFALL IS EXPECTED FOR MUCH OF THE AREA  
TUESDAY INTO TUESDAY NIGHT WHICH MAY LINGER INTO WEDNESDAY. AT  
THIS TIME, QPF AMOUNTS ARE ANTICIPATED TO RANGE FROM ABOUT A  
QUARTER OF AN INCH TO AROUND THREE-QUARTERS OF AN INCH ACROSS  
THE FORECAST AREA FROM NORTHWEST TO SOUTHEAST. A BRIEF BREAK IN  
THE WET WEATHER IS EXPECTED BEFORE COLD FRONT SWEEPS THROUGH  
THURSDAY NIGHT BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS TO  
THE AREA.  
 
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...BGM  
NEAR TERM...BGM  
SHORT TERM...BGM  
LONG TERM...JVM/ELH/SPECIALE/THOMPSON  
AVIATION...BGM/THOMPSON  
FIRE WEATHER...IAA/BGM  
HYDROLOGY...IAA/BGM  
 
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