851  
FXUS61 KBTV 201941  
AFDBTV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BURLINGTON VT  
341 PM EDT MON AUG 20 2018  
   
SYNOPSIS
 
 
AFTER ANOTHER ROUND OF PATCHY FOG OVERNIGHT AND EARLY TUESDAY  
MORNING, ANOTHER BEAUTIFUL DAY IS EXPECTED ACROSS MUCH OF THE NORTH  
COUNTRY. CONDITIONS WILL BEGIN TO DETERIORATE TUESDAY EVENING AS AN  
UPPER LEVEL TROUGH DISPLACES THE HIGH PRESSURE OVER THE REGION AND  
BRINGS THE RETURN OF RAINFALL TO THE REGION. RAIN WILL CONTINUE  
THROUGH WEDNESDAY AFTERNOON BEFORE EXITING TO THE EAST. SKIES WILL  
CLEAR HEADING INTO THURSDAY AND WILL CONTINUE TO REMAIN MOSTLY CLEAR  
THROUGH THE FIRST HALF OF THE WEEKEND. TEMPERATURES WILL REMAIN NEAR  
NORMAL WITH TEMPERATURES A DEGREE OR TWO WITH EACH PASSING DAY.  
 

 
   
NEAR TERM /THROUGH TUESDAY NIGHT/
 
 
AS OF 309 PM EDT MONDAY...AFTERNOON SATELLITE IMAGERY SHOWS A PLETHORA  
OF FAIR WEATHER CUMULUS ACROSS THE NORTH COUNTRY. BASED ON THE  
ALBANY RAOB AT 12Z, A STOUT INVERSION HAS CAPPED THESE CUMULUS  
CLOUDS AND THESE CLOUDS SHOULD DISSIPATE WITH THE LACK OF  
DIURNAL HEATING THIS EVENING. THIS WILL ALLOW FOR ANOTHER TRUE  
RADIATIONAL COOLING NIGHT WITH TEMPERATURES DROPPING INTO THE  
UPPER 40S AT SARANAC LAKE TO THE LOWER 60'S IN THE CHAMPLAIN  
VALLEY. CROSSOVER TEMPS FOR FAVORABLE FOG LOCATIONS TONIGHT ARE  
IN THE LOWER TO MID 50'S WHICH MEANS THAT THERE IS ONCE AGAIN A  
DECENT CHANCE OF FOG ACROSS NORTHERN NEW YORK AND THE  
CONNECTICUT RIVER VALLEY WITH FORECAST LOWS IN THESE AREAS IN  
THE UPPER 40S TO LOWER 50'S. ANY FOG THAT DOES DEVELOP LATE  
NIGHT INTO WEDNESDAY MORNING WILL QUICKLY DISSIPATE AFTER  
SUNRISE.  
 
TUESDAY WILL LARGELY BE ANOTHER BEAUTIFUL SUMMER DAY ACROSS THE  
NORTH COUNTRY AS TEMPERATURES ONCE AGAIN WARM INTO THE MID 70'S TO  
LOWER 80'S. THROUGHOUT THE DAY, THE UPPER LEVEL RIDGE AND SURFACE  
LOW PRESSURE WILL BEGIN TO BE DISPLACED EASTWARD AS A DEEPENING  
UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION TRACKS NORTHEASTWARD.  
AS WE SHIFT FROM THE UPPER LEVEL RIDGE TO THE UPPER LEVEL TROUGH,  
SOUTHWESTERLY FLOW ALOFT WILL TAP INTO A VERY MOISTURE RICH AIR MASS  
WHICH WILL ALLOW DEWPOINTS TO QUICKLY RISE INTO THE LOWER TO MID  
60'S ON TUESDAY AS PWAT VALUES INCREASE TO ABOUT 2 INCHES. CONTRARY  
TO PREVIOUS MODEL RUNS, THE MAIN MOISTURE AXIS IS NOW EXPECTED TO  
COME THROUGH WITH THE MAIN UPPER LEVEL SUPPORT WHICH WILL FAVOR SOME  
HEAVIER RAIN AMOUNTS. RAINFALL IS EXPECTED TO MOVE INTO THE ST.  
LAWRENCE VALLEY LATE TUESDAY AFTERNOON INTO THE EVENING HOURS AND  
ULTIMATELY INTO VERMONT JUST BEFORE MIDNIGHT. HOWEVER, A STRONG  
SOUTHWESTERLY LLJ OF ABOUT 35 TO 40 KTS WILL DEVELOP AT THE SAME  
TIME AS THE STRONGEST UPPER LEVEL SUPPORT PUSHES THROUGH WHICH WILL  
LIKELY INITIALLY DOWNSLOPE RAINFALL ACROSS THE CHAMPLAIN VALLEY WHILE  
THE WESTERN SLOPES OF THE ADIRONDACK AND GREEN MOUNTAINS. THIS WILL  
LIMIT VALUES ACROSS THE CHAMPLAIN VALLEY WHILE THE WESTERN PEAKS  
COULD RECEIVE A BIT MORE RAINFALL THAN IS CURRENTLY FORECASTED.  
 
IN ADDITION TO RAINFALL, SOME GUSTY WINDS ARE EXPECTED ACROSS  
PORTIONS OF THE NORTH COUNTRY TUESDAY AFTERNOON. A DECENT GRADIENT  
WIND WILL SET UP AS A SURFACE LOW TRACKS OF THE GREAT LAKES REGION  
INTO THE OTTAWA VALLEY TUESDAY AFTERNOON AND ULTIMATELY INTO THE  
CANADIAN MARITIMES. MODELS ARE ALSO PICKING UP ON A DECENT  
ISALLOBARIC COUPLET JUST NORTH OF THE INTERNATIONAL BORDER WHICH  
SHOULD HELP EVEN MORE WITH THE GUSTY WINDS. OVERALL, THE STRONGEST  
WINDS ARE EXPECTED OVER THE HIGHER TERRAIN WITH WINDS IN THE 30 TO  
45 KNOT RANGE AND OVER LAKE CHAMPLAIN WITH WINDS IN THE 15 TO 25 KT  
RANGE.  
 

 
   
SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/
 
 
AS OF 309 PM EDT MONDAY...RAINFALL IS EXPECTED TO CONTINUE THROUGH THE  
AFTERNOON HOURS ON WEDNESDAY. A COLD FRONT WILL COME SWEEPING  
ACROSS THE NORTH COUNTRY DURING THE LATE MORNING AND AFTERNOON  
HOURS WHICH WILL HELP BRING AN END TO RAINFALL DURING THE  
AFTERNOON AND EVENING HOURS ON WEDNESDAY. A FEW RUMBLES OF  
THUNDER ARE POSSIBLE FROM EARLY WEDNESDAY MORNING THROUGH THE  
AFTERNOON AS COLDER AIR ALOFT HELPS TO INCREASE MID- LEVEL LAPSE  
RATES AND INSTABILITY. STILL, NO STRONG THUNDERSTORMS ARE  
EXPECTED AS THE ATMOSPHERE STILL REMAINS SATURATED AND STABLE  
(MAINLY MOIST ADIABATIC LAPSE RATES THROUGH THE COLUMN). SKIES  
WILL BEGIN TO CLEAR BEHIND THE COLD FRONT WEDNESDAY NIGHT WHICH  
WILL LIKELY LEAD TO ANOTHER BOUT OF FOG ACROSS A GOOD PORTION OF  
THE NORTH COUNTRY.  
 

 
   
LONG TERM /THURSDAY THROUGH MONDAY/
 
 
AS OF 338 PM EDT MONDAY...A DRY UPPER LEVEL TROUGH WILL BE  
TRACKING THROUGH THE NORTH COUNTRY THURSDAY PUSHING OUT THROUGH  
THE REGION AS HIGH PRESSURE BUILDS IN OVER THE NORTH COUNTRY.  
ANTICYCLONIC FLOW WILL BRING SOUTHWESTERLY WINDS TO THE REGION  
BRINGING SLIGHTLY MILDER TEMPERATURES BACK IN FOR FRIDAY.  
THANKFULLY HOWEVER THE MOISTURE WILL STILL BE NEAR NORMAL AS  
RELATIVE HUMIDITIES WILL BE IN THE 35-40% RANGE. GIVEN THE LONG  
STRING OF WARMER DAYS IT SHOULD FEEL LIKE A NICE REFRESHING  
DAY.  
 
HEADING INTO THE WEEKEND QUIET WEATHER CONTINUES AS HEIGHTS  
CONTINUE TO BUILD THROUGH SATURDAY MORNING. OUR NEXT CHANCE FOR  
SHOWERS BEGINS SOMETIME OVER THE WEEKEND AS A WEAK SHORTWAVE  
SLOWLY CREEPS IN FROM THE WEST. WITH THE STRENGTH OF THE HIGH  
PRESSURE SYSTEM THE SHORTWAVE MAY END UP PUSHING UP AND OVER  
THE RIDGE AND SO FOR THE TIME BEING I'VE ONLY OFFERED UP 20-30%  
CHANCE FOR SHOWERS OVER NORTHERN NEW YORK WITH 10-20% ACROSS THE  
CHAMPLAIN VALLEY AND AREAS SOUTH AND EAST. TEMPERATURES WILL  
REMAIN FAIRLY STEADY, WITH HIGHS IN THE UPPER 70S/LOW 80S AND  
LOWS IN THE 50S TO MID 60S FRIDAY THROUGH SUNDAY.  
 

 
   
AVIATION /20Z MONDAY THROUGH SATURDAY/
 
 
THROUGH 18Z TUESDAY...VFR CONDITIONS ARE EXPECTED TO PERSIST  
THROUGH THE FORECAST PERIOD EXCEPT FOR THE POSSIBILITY OF IFR  
FOG AT KSLK AND KMPV ONCE AGAIN BETWEEN 08Z AND 14Z TUESDAY.  
ANY FOG THAT DEVELOPS WILL MIX OUT BY 14Z ON TUESDAY UNDER AMPLE  
SUNSHINE. WINDS WILL BEGIN TO STRENGTHEN ON TUESDAY WITH WINDS  
IN THE 8 TO 15 KT RANGE EXPECTED BY 18Z.  
 
OUTLOOK...  
 
TUESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. DEFINITE  
SHRA.  
WEDNESDAY: MAINLY MVFR, WITH AREAS VFR POSSIBLE. CHANCE SHRA.  
WEDNESDAY NIGHT: VFR. NO SIG WX.  
THURSDAY: VFR. NO SIG WX.  
THURSDAY NIGHT: VFR. NO SIG WX.  
FRIDAY: VFR. NO SIG WX.  
FRIDAY NIGHT: VFR. NO SIG WX.  
SATURDAY: VFR. SLIGHT CHANCE SHRA.  
 

 
   
BTV WATCHES/WARNINGS/ADVISORIES
 
 
VT...NONE.  
NY...NONE.  
 

 
 

 
SYNOPSIS...CLAY  
NEAR TERM...CLAY  
SHORT TERM...CLAY  
LONG TERM...DEAL  
AVIATION...CLAY  
 
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