124
FXUS61 KGYX 162020
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
320 PM EST MON DEC 16 2024
SYNOPSIS
SOUTH WINDS WILL BRING INCREASING MOISTURE TONIGHT WITH AREAS OF
FLURRIES AND DRIZZLE DEVELOPING THROUGH MIDNIGHT. SOME OF THE
NORTHERN PEAKS AND VALLEYS MAY BE BELOW FREEZING AS SEE SOME
BRIEF FREEZING RAIN, BUT OTHERWISE RAIN IS EXPECTED FOR THE REST
OF THE FORECAST AREA. A FRONT WILL SWEEP THROUGH EARLY TUESDAY
AND BRING AN END TO PRECIPITATION FOR EVERYWHERE BUT THE
MOUNTAINS, WHERE SNOW SHOWERS CONTINUE THROUGH THE DAY. THE
SECOND HALF OF THE WEEK WILL FEATURE ANOTHER CHANCE FOR
PRECIPITATION WITH A STRONGER STORM SYSTEM. A COLDER, SNOWIER
STORM IS POSSIBLE WITH THIS ONE. THE COLDEST AIR OF THE SEASON
MOVES IN FOR THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
CLOUDS CONTINUE TO LOWER AND THICKEN THIS EVENING. PRECIP WILL
GENERALLY BE VERY LIGHT THRU MIDNIGHT. THERE WILL BE WAVES OF
EITHER DRIZZLE OR FLURRIES...DEPENDING ON THE DEPTH OF MOISTURE.
THERE ARE SOME HIGH CLOUDS STREAMING OVER THE LOWER DECK...AND
THIS IS LEADING TO A POTENTIAL FOR SEEDER-FEEDER MECHANISM TO
LIMIT DRIZZLE. BUT OVERALL IT IS QUITE DRY ALOFT...ESPECIALLY IN
THE SNOW GROWTH ZONE. TEMPS ALSO CONTINUE TO SLOWLY WARM
UP...BUT SOME POCKETS OF SUB-FREEZING AIR REMAIN. SO AT LEAST AT
ONSET SOME FREEZING RAIN OR FREEZING DRIZZLE IS LIKELY. I HAVE
ISSUED A WINTER WEATHER ADVISORY FOR THE AREAS MOST LIKELY TO
SEE A LIGHT GLAZE ON SURFACE BEFORE ANY WARMING OCCURS. ONE
THING TO WATCH WILL BE ROAD SURFACE TEMPS. RECENT COLD WEATHER
MAY LEAD TO ROAD SURFACES REMAINING BELOW FREEZING BRIEFLY
DESPITE AIR TEMPS BEING ABOVE. THIS COULD LEAD TO RAIN FREEZING
EVEN IF OBSERVING EQUIPMENT IS NOT REPORTING IT. THAT SHOULD NOT
LAST LONG OVERNIGHT HOWEVER...WITH WAA EXPECTED TO LEAD TO A
NON-DIURNAL TEMP TREND. I USED HI-RES GUIDANCE TO BLEND 2 M
TEMPS UP THRU THE NIGHTTIME.
SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/
TUE MORNING THE FRONT/OCCLUSION WILL SWEEP THRU THE FORECAST
AREA AND BRING AN END TO STEADY PRECIP RATHER QUICKLY FROM WEST
TO EAST. UPSLOPING FLOW WILL LEAD TO SCATTERED MTN SNOW SHOWERS
THRU MUCH OF THE REST OF THE DAY INTO THE EVENING...LIGHT
ACCUMULATIONS ARE POSSIBLE.
IT WILL AT LEAST BRIEFLY WARM UP AS THE LOW LEVEL COLD AIR IS
MIXED OUT BEHIND THE FRONT...THEN A STEADY FALL IS EXPECTED THRU
THE REST OF THE DAY. IT WILL ALSO BE BREEZY...BUT WIND GUSTS ARE
GENERALLY ANTICIPATED TO BE LESS THAN 25 MPH. THE PRESSURE
GRADIENT WILL KEEP THINGS MORE MIXED THAN NOT GOING INTO TUE
NIGHT...SO TEMPS WILL BE WARMER THAN NORMAL FOR THIS TIME OF
YEAR.
LONG TERM /WEDNESDAY THROUGH MONDAY/
OVERVIEW...
AN ACTIVE PATTERN CONTINUES THROUGH THE MIDDLE AND LATER PORTIONS OF
THE WORK WEEK WITH MULTIPLE CHANCES FOR RAIN OR SNOW. COLD WEATHER
RETURNS FOR THE END OF THE WEEK AND NEXT WEEKEND AS A TROUGH DEEPENS
ACROSS THE NORTHEAST.
DETAILS...
MILD WEATHER PRECEDES A SYSTEM ON WEDNESDAY WITH HIGHS MAINLY
IN THE 40S OUTSIDE OF THE HIGHER TERRAIN. A SHORTWAVE SWINGS
THROUGH THE OHIO VALLEY AND BY WEDNESDAY LOW PRESSURE DEEPENS AS
IT LIKELY TRACKS ACROSS OR JUST SOUTH OF SOUTHERN NEW ENGLAND.
WITH A LACK OF COLD AIR IN PLACE, A RAIN/SNOW LINE IS EXPECTED
TO SET UP ACROSS THE COASTAL PLAIN WEDNESDAY NIGHT AND INTO
EARLY THURSDAY. INTERIOR AND NORTHERN AREAS STAND THE BEST
CHANCE TO PICK UP A LIGHT TO MODERATE SNOWFALL, WHILE THE COAST
AND SOUTHERN NH LOOKS TO BE MOSTLY RAIN AT THIS POINT. THE
SYSTEM MOVES AWAY THURSDAY MORNING, WITH HIGHS RANGING FROM NEAR
30 ACROSS THE NORTH, TO THE MID 40S ALONG THE COAST.
SEASONABLY COOL AIR RETURNS FOR FRIDAY, WITH HIGHS RANGING FROM THE
LOW 20S ACROSS THE NORTH, TO THE MID 30S ALONG THE COASTLINE. WITH
COLD AIR IN PLACE, WE THEN WATCH THE NEXT POTENTIAL SYSTEM FOR
LATE FRIDAY AND FRIDAY NIGHT.
MODELS CONTINUE TO DIVERGE GREATLY ON THIS SYSTEM FROM RUN TO RUN,
AND SOMEWHAT BETWEEN DIFFERENT MODEL SUITES. THE OVERALL SET UP
FEATURES AN ALBERTA CLIPPER MOVING EASTWARD THROUGH THE GREAT LAKES,
AS RICH MOISTURE MOVES NORTHWARD OFF THE EAST COAST. THE
DISCREPANCY CONTINUES TO BE WHETHER OR NOT THESE TWO FEATURES
PHASE IN TIME TO BRING A SIGNIFICANT SNOWFALL TO THE AREA. AT
THIS POINT THE MODELS ARE SUGGESTING THIS DOES NOT HAPPEN IN
TIME, WITH ATLANTIC CANADA SEEING THE BRUNT OF A POWERFUL LOW
PRESSURE SYSTEM. HOWEVER, THIS DOESN'T MEAN IT SHOULD BE RULED
OUT YET, AS WE'RE STILL ABOUT 5 DAYS OUT. IT WOULD ONLY TAKE A
SLIGHTLY MORE AMPLIFIED SHORTWAVE TO PHASE SOONER AND BRING A
MORE SIGNIFICANT SNOWFALL TO THE AREA. ONE MODEL THAT DOES SHOW
THIS HAPPENING A LITTLE SOONER AND BRINGING SNOW IT AT LEAST
EASTERN AREAS IS THE NEW EURO AIFS MODEL. IT'S STILL TOO EARLY
TO KNOW IF THIS IS JUST AN OUTLIER, OR THE START OF A TREND, BUT
WE'LL NEED TO CONTINUE TO WATCH THIS SYSTEM FOR A COUPLE MORE
DAYS BEFORE A HIGHER CONFIDENCE OUTCOME CAN BE REACHED.
REGARDLESS OF THE DEVELOPMENT OF THE COASTAL LOW, AT LEAST SOME SNOW
SHOWER ACTIVITY IS POSSIBLE LATE FRIDAY AS THE CLIPPER MOVES THROUGH
NEW ENGLAND. BEHIND THIS SYSTEM, ARCTIC AIR POURS INTO NEW ENGLAND
FOR NEXT WEEKEND, BRINGING THE COLDEST TEMPERATURES OF THE SEASON SO
FAR. HIGHS IN THE TEENS AND 20S WITH LOWS IN THE SINGLE DIGITS TO
BELOW ZERO LOOK INCREASINGLY LIKELY. IF THERE DOES END UP BEING A
MORE WIDESPREAD SNOW COVER THESE TEMPERATURES WOULD GO EVEN LOWER,
SO THIS IS ONE MORE REASON TO KEEP MONITORING THE FRIDAY SYSTEM.
AVIATION /20Z MONDAY THROUGH SATURDAY/
SHORT TERM...WIDESPREAD MVFR CONDITIONS CONTINUE TO MOVE
NORTHWARD THRU THE FORECAST AREA AT THIS HOUR. GRADUALLY IFR
CONDITIONS WILL CREEP IN FROM THE SOUTHWEST AND OVERSPREAD MOST
OF THE TAF SITES BY MIDNIGHT AT THE LATEST ACROSS THE FARTHEST
EAST AREAS. TEMPS APPEAR TO BE WARM ENOUGH THAT ANY PRECIP
SHOULD BE RA THRU THE OVERNIGHT. THE ONE CONCERN MAY BE IF ROAD
SURFACE TEMPS REMAIN SUB-FREEZING AFTER RECENT COLD WEATHER...A
BRIEF ICE MAY FORM BEFORE MELTING WITH ADDITIONAL OVERNIGHT
WARMING AND PRECIP. SOME LLWS IS LIKELY TONIGHT AROUND 1500 FT
AS A LLJ SWEEPS NORTHWARD TOWARDS DAYBREAK. VFR CONDITIONS
RETURN FOR ALL TAF SITES EXCEPT HIE ON TUE...WHERE LINGERING
MVFR CIGS ARE LIKELY BECAUSE OF UPSLOPE FLOW.
LONG TERM...VFR CONDITIONS ON WEDNESDAY GIVE WAY TO IFR TO LIFR
AND RESTRICTIONS WEDNESDAY NIGHT WITH RAIN SOUTH AND SNOW
NORTH. MVFR TO VFR RETURNS FOR THURSDAY AND INTO FRIDAY.
CONDITIONS THEN BECOME DEPENDENT ON THE TRACK OF A STORM FOR
LATE FRIDAY AND FRIDAY NIGHT, WITH COASTAL TERMINALS SEEING THE
GREATEST CHANCE FOR RESTRICTIONS. VFR THEN LIKELY RETURNS FOR
NEXT WEEKEND.
MARINE
SHORT TERM...SOUTH WINDS CONTINUE TO GRADUALLY INCREASE TONIGHT.
BRIEFLY AROUND SUNRISE WINDS OUTSIDE OF THE BAYS NORTH OF CAPE
ELIZABETH MAY GUST TO GALE FORCE. A GALE WARNING HAS BEEN ISSUED
FOR THESE ZONES...WITH SCAS IN EFFECT FOR ALL OTHER WATERS.
WINDS AND SEAS WILL BE SLOW TO DIMINISH...LINGERING ABOVE SCA
THRESHOLDS ESPECIALLY OUTSIDE OF THE BAYS THRU TUE NIGHT.
LONG TERM...LOW PRESSURE CROSSES THE WATERS WEDNESDAY NIGHT,
WITH WESTERLY WINDS POSSIBLY BRINGING SCA CONDITIONS BEHIND THE
SYSTEM ON THURSDAY. CONDITIONS THEN BECOME DEPENDENT ON THE
TRACK OF A DEVELOPING COASTAL LOW LATE FRIDAY. NORTHERLY GALES
AND ARCTIC SEA SMOKE ARE THEN POSSIBLE OVER THE WEEKEND.
GYX WATCHES/WARNINGS/ADVISORIES
ME...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 4 AM EST
TUESDAY FOR MEZ007>009-012-013.
NH...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 4 AM EST
TUESDAY FOR NHZ004.
MARINE...GALE WARNING FROM 4 AM TO 11 AM EST TUESDAY FOR ANZ150-152.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 PM EST
TUESDAY FOR ANZ151-153-154.
NEAR TERM...LEGRO
SHORT TERM...LEGRO
LONG TERM...CLAIR
AVIATION...CLAIR/LEGRO
MARINE...CLAIR/LEGRO
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