635  
FXUS61 KBTV 161739  
AFDBTV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BURLINGTON VT  
1239 PM EST MON DEC 16 2024  
   
SYNOPSIS  
 
RELATIVELY QUIET WEATHER CONDITIONS ARE EXPECTED TODAY AS LIGHT  
SNOW COMES TO A CLOSE TODAY. THERE IS A CHANCE FOR SOME DRIZZLE  
THIS EVENING ACROSS PARTS OF EASTERN VERMONT. BE AWARE OF  
TEMPERATURES FOR THE EVENING COMMUTE AS DRIZZLE SHIFTS INTO THE  
REGION. STRONG SOUTHERLY GUSTS WILL DEVELOP TONIGHT OVER THE  
NORTHERN SLOPES OF THE ADIRONDACKS AND IN THE NORTHERN CHAMPLAIN  
VALLEY, WHERE GUSTS OF 35 TO 45 MPH ARE EXPECTED. PERIODS OF  
RAIN SHOWERS ON TUESDAY WILL TRANSITION TO LAKE EFFECT LATER IN  
THE EVENING. SEVERAL FAST MOVING WEATHER DISTURBANCES WILL  
TRAVERSE THE REGION THROUGHOUT THE WEEK WITH ADDITIONAL RAIN AND  
SNOW CHANCES.  
 
 
   
NEAR TERM /THROUGH TUESDAY/  
 
AS OF 1228 PM EST MONDAY...NO SIGNIFICANT CHANGES WITH EARLY  
AFTERNOON UPDATE. TEMPS HAVE WARMED INTO THE LOWER 40S IN THE  
CPV, BUT STILL ARE HOVERING NEAR FREEZING ACRS THE DEEPER  
VALLEYS OF EASTERN VT. WE CONTINUE TO WATCH FOR PATCHY FREEZING  
DRIZZLE TO DEVELOP AROUND SUNSET ACRS OUR EASTERN SECTIONS,  
WHICH MAY REQUIRE A SPS. OTHERWISE, REST OF FCST IN GOOD SHAPE.  
 
PREVIOUS DISCUSSION BELOW:  
THE TRICKY PART THIS EVENING IS HOW MUCH COOL AIR REMAINS LOCKED IN  
EASTERN VERMONT AS MARITIME MOISTURE TRACKS NORTHWARDS. TEMPERATURES  
COULD BE HOVERING AROUND THE FREEZING MARK LATER THIS EVENING, AND  
DEPENDING ON HOW EARLY LOW-LEVEL MOISTURE ARRIVES, THERE COULD BE A  
FEW POCKETS OF FREEZING DRIZZLE. FOR NOW, WILL CONTINUE TO MONITOR  
TRENDS AND HOW WARM TEMPERATURES GET.  
 
OVERNIGHT, A STRONG 55-65 KNOT LOW-LEVEL JET WILL DEVELOP ACROSS THE  
REGION. THIS SHOULD PROMOTE INCREASING GUSTS OVERNIGHT.  
PROBABILISTIC GUIDANCE FROM THE HREF IS SURPRISINGLY AGGRESSIVE,  
INDICATING 70-100 PERCENT PROBABILITIES OF GUSTS GREATER THAN 50  
MPH. HOWEVER, FORECAST SOUNDINGS ARE EITHER NEUTRAL OR FEATURE AN  
INVERSION BELOW THE CORE OF STRONGEST WINDS THAT IS BELOW RIDGE  
TOPS. ANALYZING CROSS SECTIONS OF DOWNSLOPE REGIONS DOES NOT APPEAR  
TO MATCH SIGNALS FOR MOUNTAIN WAVE BREAKING. CROSS SECTIONS  
HIGHLIGHT THE DOWNSLOPE WINDS WELL, BUT DEEP MOISTURE IS ALREADY IN  
PLACE WHERE WE ARE USUALLY LOOKING FOR DRY SUBSIDENCE, AND  
PRECIPITATION LOOKS TO ARRIVE WITH THE JET FORMATION. THE  
FORECAST WILL SOMEWHAT RELY ON HAVING THE JET DEVELOP AS WELL.  
A DELAY IN ITS DEVELOPMENT BEFORE IT LIFTS NORTH COULD LEAVE US  
LESS WINDY AS WELL. THE SHORT OF IT IS THAT THERE ARE SEVERAL  
FORECAST INDICATORS THAT SUGGEST KEEPING THINGS FROM GUSTING TOO  
STRONGLY. PRESSURE GRADIENTS WILL ALLOW FOR STRONG CHANNELING  
IN THE CHAMPLAIN VALLEY WITH SOME DOWNSLOPE ENHANCEMENT THAT  
PLACES AN EXPECTED FORECAST OF 35 TO 45 MPH GUSTS IN THE  
NORTHERN CHAMPLAIN VALLEY AND NORTHERN SLOPES OF THE  
ADIRONDACKS. THERE COULD BE A LOCALIZED GUST TO 50 AT COMMON  
TROUBLE SPOTS LIKE MALONE, ELLENBURG, AND THE MILTON SANDBAR.  
WILL GIVE ANOTHER CYCLE TO ASSESS WHETHER HEADLINES ARE NEEDED.  
ANY INCREASE IN LOW-LEVEL INSTABILITY OR LOWERING OF WHERE THE  
STRONGEST WINDS ARE LOCATED WOULD NECESSITATE HEADLINES.  
 
THE PRECIPITATION ASPECT OF THIS REMAINS UNCHANGED. A BRIEF  
CONVERGENCE OF FAVORABLE INGREDIENTS FOR PRECIPITATION SHOULD  
PRODUCE 0.10-0.50" WITH LOCALLY MORE OR LESS DEPENDING ON TERRAIN.  
RAIN IS GOING TO RACE EAST, AND WILL BE OUT OF HERE BY TUESDAY  
MORNING. AFTERWARDS, WE WILL AGAIN NEED TO WATCH GUSTS. RISING  
HEIGHTS BEHIND THE FRONT AND THE PRESENCE OF 50 KNOT WINDS AROUND  
3500-4500 FEET WILL BEAR SOME WATCHING. THERE COULD BE ANOTHER  
WINDOW FOR STRONG WINDS BEFORE THINGS SETTLE TUESDAY AFTERNOON. SOME  
LAKE EFFECT SHOWERS WILL DEVELOP, BUT A LACK OF COOL AIR WILL  
KEEP LAPSE RATES RELATIVELY LOW. TEMPERATURES WILL STILL BE IN  
THE 40S FOR MOST ON TUESDAY, BUT NOT FEELING PLEASANT WITH GUSTY  
SOUTHWEST WINDS.  
 
 
   
SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/  
 
AS OF 313 AM EST MONDAY...WE'VE GOT A BRIEF BREAK IN THE ACTIVE  
WEATHER PATTERN TUESDAY NIGHT AND WEDNESDAY AS THE FRONTAL SYSTEM  
WILL QUICKLY BE RACING EASTWARD. DIMINISHING WINDS AND RAIN CHANCES  
WILL BE THE HIGHLIGHT OF THE TUESDAY NIGHT PERIOD. SLIGHTLY COOLER  
TEMPERATURES ARE EXPECTED ON WEDNESDAY WITH HIGHS IN THE UPPER 30S  
TO LOWER 40S DUE TO A COMBINATION OF WEAK COLD ADVECTION AND A  
PLETHORA OF CLOUD COVER. WE WILL BEGIN TO SEE PRECIPITATION CHANCES  
INCREASE CLOSE TO SUNSET ON WEDNESDAY ACROSS NORTHERN NEW YORK AS A  
MORE AMPLIFIED UPPER LEVEL TROUGH AND STRONGER COLD FRONT DEVELOP  
ACROSS THE REGION. MORE ON THIS IN THE LONG TERM SECTIONS BELOW.  
 
 
   
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/  
 
AS OF 313 AM EST MONDAY...A FAST MOVING STORM SYSTEM IS EXPECTED TO  
BRING A MIX OF RAIN AND SNOW TO THE NORTH COUNTRY WEDNESDAY NIGHT  
THROUGH THURSDAY MORNING. THIS SYSTEM IS GOING TO BE ON THE TRICKY  
SIDE FOR TWO REASONS. ONE, THE LOW PRESSURE SYSTEM WILL BE MOVING  
AROUND 50 MPH WHICH WILL LIMIT THE AMOUNT OF TIME THAT PRECIPITATION  
WILL FALL ACROSS THE REGION. TWO, THE THERMAL PROFILES FOR THIS  
EVENT ARE GOING TO BE ON THE MARGINAL SIDE FOR BOTH RAIN AND SNOW.  
LET'S TAKE A DEEPER LOOK AT THE THERMAL PROFILES TO GET A BETTER  
UNDERSTANDING ON WHAT IS EXPECTED TO OCCUR. TUESDAY AND WEDNESDAY  
ARE BOTH EXPECTED TO BE WELL ABOVE FREEZING ACROSS THE REGION WHICH  
STARTS US OFF ABOVE FREEZING WHICH IS ALWAYS A RECIPE FOR TRICKY  
PRECIPITATION TYPE AND AMOUNTS. GIVEN STRONG UPPER LEVEL DYNAMICS  
WITH GOOD UPPER LEVEL DIFFLUENCE, WE SHOULD SEE IMPRESSIVE WET-  
BULBING AT THE ONSET OF PRECIPITATION WHICH MAY BE ENOUGH TO SWITCH  
PRECIPITATION TYPE TO SNOW IN SOME LOCATIONS ALTHOUGH TEMPERATURES  
WILL INITIALLY BE ABOVE FREEZING. STRONG COLD ADVECTION ALOFT IN THE  
MID-LEVELS WILL QUICKLY OVERSPREAD THE NORTH COUNTRY WEDNESDAY NIGHT  
ALLOWING FOR MID-LEVEL AND SURFACE TEMPERATURES TO RAPIDLY COOL  
ALLOWING FOR MORE PRECIPITATION TO CHANGE OVER TO RAIN.  
 
AT HIGHER ELEVATIONS, LIKE MOUNT MANSFIELD, WE WILL SEE MORE SNOW  
THAN RAIN GIVEN THE COLD ADVECTION ALOFT HAPPENS WELL BEFORE THE  
BOUNDARY LAYER. GIVEN THE ABOVE INFORMATION, WE ARE CONFIDENT MOST  
PLACES WILL SEE ACCUMULATING SNOW BUT THE AMOUNT REMAINS IN  
QUESTION. IN PREVIOUS EVENTS WHERE WE ARE WAITING ON THE COLD  
ADVECTION TO HELP CHANGE RAIN TO SNOW, WE TYPICALLY WASTE SOME OF  
THE PRECIPITATION AMOUNTS (QPF) IN THAT TRANSITION PERIOD WHICH CUTS  
OUR SNOW TOTALS. IN ADDITION, ISOTHERMAL LOW-LEVEL THERMAL PROFILES  
AROUND 30-32 DEGREES WILL LIKELY LEAD TO A 8-1 TO 10-1 SNOW RATIO.  
AS IT STANDS NOW, IT LOOKS LIKE SNOW AMOUNTS MAY STAY JUST BELOW  
ADVISORY LEVEL BUT IT'S POSSIBLE A FEW PLACES COULD SEE 3-5" OF SNOW  
BELOW 1500 FT WITH SUMMITS POSSIBLY PICKING UP 8 TO 12 INCHES OF  
FRESH SNOW.  
 
THE BULK OF THE PRECIPITATION WILL TAPER OFF THROUGH THE MORNING  
HOURS ON THURSDAY BUT A NICE SET-UP FOR A BACKSIDE BONUS OF UPSLOPE  
SNOW SHOWERS ACROSS THE WESTERN SLOPES OF THE GREEN AND ADIRONDACK  
MOUNTAINS LOOKS LIKELY. OTHER THAN A CHANCE FOR SOME SNOW SHOWERS ON  
FRIDAY, THE FORECAST THROUGH EARLY NEXT WEEK LOOKS RATHER QUIET BUT  
WILL BE ON THE COLD SIDE. HIGHS IN THE TEENS AND LOWS IN THE SINGLE  
DIGITS ABOVE AND BELOW ZERO LOOK LIKELY SATURDAY AND SUNDAY.  
 
 
   
AVIATION /18Z MONDAY THROUGH SATURDAY/  
 
THROUGH 18Z TUESDAY...CHALLENGING WITH CHANGEABLE CONDITIONS  
EXPECTED AT OUR TAF SITES FOR THE NEXT 12 TO 24 HOURS. CURRENTLY  
A MIX OF VFR/MVFR CIGS WITH VFR VIS. AS SOUTHEAST UPSLOPE FLOW  
DEVELOPS EXPECT LOWERING CIGS TO IFR CONDITIONS AT MPV BY 00Z,  
WITH SOME INTERVALS OF IFR CIGS AT EFK/SLK POSSIBLE. A STRONG  
SOUTHWEST 2500 TO 4000 FEET ABOVE GROUND LEVEL JET OF 50 TO 65  
KNOTS DEVELOPS THIS EVENING, WHICH WILL RESULT IN AREAS OF  
MODERATE TO LOCALLY SEVERE TURBULENCE AND WIND SHEAR. THESE  
WINDS ARE EXPECTED TO STAY MOSTLY ABOVE GROUND LEVEL TONIGHT,  
BUT AS MIXING IMPROVES TOWARD SUNRISE ON TUESDAY MORNING, EXPECT  
LOCALIZED GUSTS 25 TO 35 KNOTS POSSIBLE, ESPECIALLY  
EFK/SLK/PBG AND MSS, ELSEWHERE SLIGHTLY LESS WIND IS  
ANTICIPATED. A PERIOD OF RAIN SHOWERS WILL QUICKLY MOVE FROM  
WEST TO EAST OVERNIGHT WITH BRIEF MVFR VIS LIKELY IN THE HEAVIER  
SHOWERS. CONDITIONS GRADUALLY IMPROVE FROM IFR/MVFR AT  
SLK/EFK/MPV TO MVFR WHILE VFR DEVELOPS IN THE VALLEYS. A PERIOD  
OF IFR CIGS IS ALSO POSSIBLE THIS EVENING AT PBG ASSOCIATED WITH  
SOUTHEAST FLOW OFF LAKE CHAMPLAIN.  
 
OUTLOOK...  
 
TUESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. NO SIG WX.  
WEDNESDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. CHANCE RA,  
CHANCE SN.  
WEDNESDAY NIGHT: MAINLY IFR, WITH AREAS MVFR POSSIBLE. DEFINITE  
SN, LIKELY SHSN, DEFINITE RA.  
THURSDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. CHANCE SHSN.  
THURSDAY NIGHT: VFR. NO SIG WX.  
FRIDAY: MAINLY MVFR, WITH AREAS VFR POSSIBLE. CHANCE SHSN.  
FRIDAY NIGHT: MAINLY MVFR, WITH AREAS VFR POSSIBLE. CHANCE SHSN.  
SATURDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHSN.  
 
 
   
MARINE  
 
SOUTH WINDS INCREASE 15 TO 30 KNOTS THIS EVENING WITH LOCALIZED  
GUSTS 40 TO 45 KNOTS POSSIBLE AFTER MIDNIGHT. WINDS SHIFT TO THE  
WEST ON TUESDAY MORNING AND DECREASE AT 15 TO 25 KNOTS. WAVES 1  
TO 3 FEET WILL BUILD 3 TO 6 FEET BY TONIGHT AND SLOWLY SUBSIDE  
ON TUESDAY AS WINDS SHIFT TO THE WEST.  
 
 
   
EQUIPMENT  
 
PLATTSBURGH ASOS IS MISSING VISIBILITY IN REPORTS AND IS  
AWAITING A PART TO FIX THIS ISSUE, WHICH SHOULD ARRIVE LATER  
TODAY AND IF ALL GOES AS PLANNED, SHOULD BE FIXED BY THIS  
EVENING.  
 
 
   
BTV WATCHES/WARNINGS/ADVISORIES  
 
VT...WIND ADVISORY FROM 7 PM THIS EVENING TO 4 PM EST TUESDAY FOR  
VTZ001>003-016.  
NY...WIND ADVISORY FROM 7 PM THIS EVENING TO 4 PM EST TUESDAY FOR  
NYZ027-028-030-031-034.  
 
 
 
 
SYNOPSIS...HAYNES  
NEAR TERM...HAYNES/TABER  
SHORT TERM...CLAY  
LONG TERM...CLAY  
AVIATION...TABER  
MARINE...TEAM BTV  
EQUIPMENT...TEAM BTV  
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