596  
FXUS61 KGYX 201140  
AFDGYX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAY ME  
640 AM EST FRI DEC 20 2024  
   
SYNOPSIS
 
 
A WEAK CLIPPER PASSES NORTH OF THE AREA TODAY AND TONIGHT,  
WHILE ANOTHER LOW PASSES WELL OFFSHORE TONIGHT, BRING SOME SNOW  
SHOWERS OR LIGHT SNOW. VERY COLD AIR MOVES INTO NEW ENGLAND  
SATURDAY NIGHT AND SUNDAY. ALTHOUGH IT WILL GRADUALLY MODERATE  
TO NEAR NORMAL BY THE MIDDLE OF NEXT WEEK, AS STRONG HIGH  
PRESSURE SETTLES OVER THE REGION.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
640 AM...NO CHANGES TO THE OVERALL FORECAST FOR TODAY, JUST  
SOME MINOR CHANGES THIS MORNING BASED ON OBS. STILL SOME  
POSSIBILITY OF LOCALIZED HIGHER ACCUMS SOMEWHERE ON THE COAST  
IF INVERTED TROUGH DEVELOPS GIVEN THE HIGH FLUFF FACTOR, BUT NO  
CLEAR SIGNALS SHOWING UP YET.  
 
PREVIOUSLY...500MB TROUGH EXTENDING FROM JAMES BAY SOUTHWARD  
TOWARD THE GREAT LAKES THIS MORNING, AND SRN STREAM WAVE DIVING  
OUT OF THE LOWER OHIO VALLEY TOWARD THE CAROLINA COAST ARE OUR  
TWO SYSTEMS OF INTEREST TODAY AND TONIGHT, ALTHOUGH THEY NEVER  
QUITE GET TOGETHER TO PHASE, THERE WILL BE SOME INTERACTION  
BETWEEN THAT WILL BRING LIGHT SNOW OR SHSN TO THE REGION THIS  
AFTERNOON INTO TONIGHT. THE SRN STREAM WILL SEE A DEVELOPING  
COASTAL LOW OFF THE MID-ATLANTIC COAST, THAT TRACKS WELL  
OFFSHORE TO A POINT S OF NOVA SCOTIA BY SATURDAY MORNING. THIS  
SHOULD BRING SOME LIGHT SN OR SNOW SHOWERS INTO S NH AND ALONG  
THE ME COAST DURING THE AFTERNOON. MEANWHILE THE BROADER TROUGH  
TO OUR W WILL BRING SOME SHSN INTO THE MTNS, AND THE CT VLY THIS  
AFTERNOON AS WELL. NONE OF THIS WILL BE SIGNIFICANT BUT IT WILL  
IMPACT THE EVENING COMMUTE. COULD SEE UP TO AN INCH OF SNOW IN  
SE NH AND ALONG THE ME COAST S OF PORTLAND BY SUNSET, WITH SOME  
LOCALIZED COATINGS OF SNOW IN MOST OTHER SPOTS, ALTHOUGH EASTERN  
ZONES MAY BOT SEE MUCH SNOW UNTIL SUNSET. IT’LL GENERALLY BE  
CLOUDY ALL DAY, AND HIGHS WILL RANGE FROM THE LOW TO MID 20S IN  
THE N TO AROUND 30 IN THE S.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/
 
 
THE OFFSHORE LOW DEEPENS THOUGH TONIGHT, BUT ALSO TRACK NE AND  
FURTHER AWAY FROM THE CWA OVERNIGHT. THIS SHOULD BRING ANY SNOW  
TO AN END ACROSS ALL BIT THE MID COAST AND CAPITAL DISTRICT  
BEFORE MIDNIGHT, BUT IN THAT AREA, COULD SEE A PERIOD OF LIGHT  
SNOW DEVELOP LATER THIS EVENING AND OVERNIGHT CLOSER TO THE LOW.  
HERE COULD GET AN INCH OR TWO IN SOME SPOTS TONIGHT. OTHERWISE  
WINDS SHIFT FROM NE TO NW IN THE NH AND W ME, WHICH WILL SEE  
UPSLOPE SHSN REDEVELOP IN THE MTNS AND END THE SNOW IN THE  
DOWNSLOPE AREAS. LOW DROP TO 10-15 IN THE MTNS, TO AROUND 20 IN  
THE S, ALTHOUGH SOME LOW TO MID 20S ALONG MID COAST WITH THE  
SNOW AND CLOUDS IN PLACE. HIGHS WILL MAINLY BE IN THE IN THE 20S  
TO AROUND 30 IN SE NH AND ON THE COAST, WITH PARTLY SUNNY  
SKIES.  
 
ON SATURDAY SHOULD SEE SNOW END EVERYWHERE BUT THE MOUNTAINS  
WHERE THE UPSLOPE SHSN WILL CONTINUE WITH SOME LIGHT ACCUMS IN  
THE FAVORED AREAS. HIGHS WILL MAINLY BE IN THE 20S, TO AROUND 30  
NEAR THE COAST.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
 
 
UPDATE...LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE ARRIVAL  
OF THE 01Z NBM. CHANCES FOR LIGHT SNOW CURRENTLY REMAINS IN THE CARDS  
FOR CHRISTMAS EVE.  
 
PREVIOUSLY...  
 
STRONG COLD AIR ADVECTION WILL BE IN FULL MODE DURING THE DAY  
ON SATURDAY. NEVERTHELESS, WE DO NOT START OUT THE DAY ALL THAT  
COLD ALLOWING TEMPERATURES TO REMAIN MOSTLY IN THE 20S NORTH TO  
THE LOWER 30S SOUTH. HIGH PRESSURE BUILDS TOWARDS THE REGION  
SATURDAY NIGHT WITH BREEZY CONDITIONS ALLOWING FOR A WELL MIXED  
LAYER. TEMPERATURES WILL STILL FALL TO NEAR ZERO IN THE NORTH  
WITH SINGLE DIGITS IN THE SOUTH. WIND CHILL VALUES WILL BE BELOW  
ZERO IN ALL AREAS BY MORNING.  
 
DESPITE LOW PRESSURE INTENSIFYING AND PASSING WELL TO OUR EAST, SNOW  
SHOWERS WILL CROSS THE REGION ON SATURDAY. THIS WILL MAINLY BE  
DUE TO FORCING FROM AN UPPER LEVEL TROUGH CROSSING THE REGION.  
THE HIGHEST CHANCE FOR PRECIPITATION WILL BE IN THE NORTHERN,  
HIGHER TERRAIN.  
 
BY SUNDAY AND SUNDAY NIGHT, THE CORE OF THE COLDEST AIR OF THE  
SEASON WILL BE OVER THE REGION. SOME AREAS WILL UNDERGO RADIATIONAL  
COOLING SUNDAY NIGHT, ALLOWING FOR TEMPERATURES TO DROP TO ZERO TO  
10 BELOW IN THE NORTH AND SINGLE DIGITS IN THE SOUTH.  
 
12Z MODELS AND LATEST ENSEMBLE SOLUTIONS SUGGEST THE DRY PATTERN  
CONTINUES EARLY NEXT WEEK WITH HIGH PRESSURE IN CONTROL OVER THE  
NORTHEAST. THIS WILL ALLOW FOR WEAK WEATHER SYSTEMS TO PASS BY TO  
OUR SOUTH.  
 

 
   
AVIATION /12Z FRIDAY THROUGH TUESDAY/
 
 
SHORT TERM...A PERIOD OF MVFR CIGS IS EXPECTED THIS AFTERNOON  
INTO TONIGHT, WITH SOME BRIEF PERIODS OF IFR IN -SN THIS  
AFTERNOON AND EVENING, ALTHOUGH KRKD COULD SEE MORE IFR  
OVERNIGHT THAN OTHER LOCATIONS. A RETURN VFR IS EXPECTED ON  
SATURDAY AT ALL BUT KHIE WHICH WILL BE MAINLY MVFR IN UPSLOPE  
CLOUDS/SHSN.  
 
LONG TERM...MVFR AND IFR CONDITIONS EXPECTED IN SNOW SHOWERS MAINLY  
IN THE NORTH ON SATURDAY. OTHERWISE, HIGH PRESSURE GRADUALLY BUILDS  
INTO THE REGION DURING THE PERIOD WITH VFR CONDITIONS AND DOWNSLOPE  
WINDS OVER MUCH OF THE AREA  
 

 
   
MARINE
 
 
SHORT TERM...NE FLOW INCREASES THIS MORNING WITH SCA WINDS  
EXPECTED THOUGH THE DAY INTO THIS EVENING BEFORE WINDS SWITCH N  
LATER TONIGHT AND EVENTUALLY NW ON SAT. AS COASTAL LOW DEEPENS  
WELL OFFSHORE COULD SEE A VERY BRIEF PERIOD OF GALES IN THE  
WATERS S OF PEN BAY LATE TONIGHT EARLY SAT. OTHERWISE SCA WINDS  
CONTINUE THROUGH AT LEAST SAT NIGHT.  
 
LONG TERM...WINDS AND SEAS WILL ONCE AGAIN EXCEED SCA THRESHOLDS  
OVER THE WEEKEND. WINDS WILL BACK OUT OF THE NORTH BEFORE  
BECOMING NORTHWESTERLY.  
 

 
   
GYX WATCHES/WARNINGS/ADVISORIES
 
 
ME...NONE.  
NH...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 3 PM EST SUNDAY FOR  
ANZ150-152-154.  
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 3 AM EST  
SUNDAY FOR ANZ151-153.  
 

 
 

 
 
NEAR TERM...CEMPA  
SHORT TERM...CEMPA  
LONG TERM...CANNON/EKSTER  
 
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