768
FXUS61 KGYX 190432 AAC
AFDGYX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAY ME
1132 PM EST SAT JAN 18 2025
SYNOPSIS
A COLD FRONT WILL CROSS THE AREA LATE AFTERNOON INTO TONIGHT.
RAIN AND SNOW WILL MOVE THROUGH AHEAD OF THE FRONT, WITH SNOW
ACCUMULATING A FEW INCHES IN THE MOUNTAINS. ANOTHER WAVE FORMS
ALONG THE FRONT AND WILL TRACK NORTHEASTWARD TOWARDS THE GULF OF
MAINE SUNDAY NIGHT. SNOW WILL SPREAD INTO THE AREA TO THE
NORTHWEST OF THE TRACK. MODERATE ACCUMULATIONS ARE POSSIBLE.
THEN ARCTIC AIR POURS INTO THE COUNTRY AND LINGERS THROUGH
MIDWEEK.
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
UPDATE...PRECIP BEGINNING TO DEPART THE AREA AT THIS HOUR. POP
FORECAST LOOKS GOOD...SO ONLY CHANGE WAS TO ADD AREAS OF FOG.
PRIMARILY LOW CLOUD AT THE MOMENT...BUT SOME OF THE HILLS AND
HIGHER ELEVATIONS ARE IN THOSE CLOUDS...BUT SOME LOWER
ELEVATIONS OF NH ARE ALSO SHOWING VISIBILITY BELOW 1 SM. THIS
SHOULD BEGIN MIXING OUT AROUND 2 AM.
PREVIOUS DISCUSSION...A WEAK WAVE IN THE BROAD 500 MB EXTENDING
EQUATORWARD FROM LARGE CLOSED LOW OF HUDSON BAY. MOVES THROUGH
THE CWA TONIGHT DRAGGING A COLD FRONT THE REGION LATER TONIGHT.
AHEAD OF THE PRECIP IS BREAKING OUT AND WILL SEE A BAND OF
SHOWERS /AND PROBABLY A FEW HOURS OF STEADY PRECIP THIS EVENING.
THIS RESULT IN RAIN ACROSS THE SOUTH, AND SNOW IN THE MTNS. THE
MOUNTAIN VALLEYS COULD SEE AN INCH OR TWO OF TWO SNOW WITH
HIGHER AMOUNTS AS YOU MOVE IN ELEVATION. THE PRECIP WILL END
ACROSS MOST OF THE CWA AROUND OR SHORTLY AFTER MIDNIGHT. THERE
IS POTENTIAL FOR SKIES TO CLEAR AND RAD COOLING TO ALLOW FOR
RAIN ON THE ROADS TO ICE UP IN SOME AREAS EARLY SUNDAY MORNING.
LOWS RANGE FROM THE MID 20S IN THE MTNS TO THE LOW 30S IN THE S.
SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/
SOME RIDGING SHIFTS IN BRIEFLY FROM THE NW BEHIND THE FRONT
SUNDAY MORNING, AND WILL LIKELY SEE SOME THOUGH ABOUT MIDDAY
BEFORE THE CLOUDS ROLL IN AGAIN FROM THE SW SUNDAY AFTERNOON. IT
LOOKS LIKE PRECIP HOLD OFF ACROSS THE CWA UNTIL AROUND SUNSET
IN S NH, AND SPREADING NE ACROSS THE AREA THROUGH THE EVENING.
IT SHOULD BE ALL SNOW DESPITE HIGHS IN THE S IN THE MID TO UPPER
30S AS TDS WILL BE LOW AND WET BULB PROCESSES SHOULD COOL THE
COLUMN QUICKLY.
THE BULK OF ANY PRECIP FALLS SUNDAY NIGHT AND MOSTLY SUNDAY
EVENING IN THE 00-06Z RANGE. MODELS HAVE COME TOGETHER A LITTLE
BIT BETTER ALTHOUGH THE GFS SUITE STILL A COUPLE INCHES OF SNOW
HIGHER THEN THE EURO SUITE. EURO SHOW DECENT BANDING SIGNATURE
RIGHT ON THE COAST, ALTHOUGH CLOSE ENOUGH THAT IF ITS OFFSHORE
WILL DEFINITELY SEE LESS SNOW, BUT MANY OF THE MODELS HAVE
CONVERGED ON SFC LOW TRACK NEAR OR JUST OUTSIDE THE 40/70
BENCHMARK. THE BIGGEST OUTLIER ATTM IS THE NAM12 AND THE NAM 3,
WHICH WOULD ONLY BE BE BORDERLINE ADVISORY SNOW. DECIDED TO KEEP
THE WATCH GOING ONE MORE CYCLE, TO SEE IF THE RECENT MODEL
TRENDS WILL CONTINUE ONE WAY OR THE OTHER, OR IF THEY HAVE
LATCHED ONTO TO SOMETHING. WILL ALSO LIKELY NEED SOME ADVISORIES
OUTSIDE THE WATCH AREA. STILL I THINK IN THE WATCH AREA THE
REASONABLE FORECAST FOR NOW SEEMS TO BE IN THE 4-8” RANGE.
INCREASING SNOW RATIOS DURING TOMORROW WILL AID IN INCREASING
SNOW AMTS AND ALSO ADD THE FLUFF FACTOR. TEMPS WILL BEGIN TO
DROP QUICKLY MONDAY NIGHT WITH LOWS GENERALLY 5-15 ABOVE
LONG TERM /MONDAY THROUGH SATURDAY/
500MB SHORTWAVE AND ASSOCIATED SURFACE LOW WILL ALREADY BE IN THE
PROCESS OF LIFTING NORTHWARD INTO THE CANADIAN MARITIMES MONDAY
MORNING WITH BREEZY NORTHWEST WINDS KICKING IN AND BRINGING IN DRIER
AND COLDER AIR. SO ANY LINGERING LIGHT SNOW ACROSS EASTERN AREAS
SHOULD QUICKLY COME TO AN END WITH CONTINUED DECREASING CLOUDINESS
GOING INTO THE AFTERNOON ALONG WITH BLUSTERY CONDITIONS. WINDS
GUSTING TO 25 TO 30 MPH THROUGH THE DAY WILL LIKELY START WIND
CHILLS BELOW ZERO IN THE MORNING (WELL BELOW ZERO IN THE MOUNTAINS),
AND THESE WON'T RECOVER MUCH THROUGH THE DAY AS TEMPERATURES LIKELY
REMAIN IN THE TEENS AND EVEN SINGLE DIGITS IN THE MOUNTAINS WITH
STRONG COLD AIR ADVECTION.
WINDS ARE FORECAST TO GRADUALLY EASE MONDAY EVENING AND MONDAY AS
THE GRADIENT RELAXES, BUT THERE WILL STILL BE ENOUGH OF A BREEZE TO
PRODUCE VERY COLD WIND CHILLS AS TEMPERATURES CONTINUE TO FALL WITH
THE ARCTIC AIR MASS. FORECAST WIND CHILLS SOUTH OF THE MOUNTAINS ARE
-5 TO -10F AND -15 TO -25F IN THE MOUNTAINS, WHERE COLD WEATHER
HEADLINES MAY BE REQUIRED.
THE ARCTIC AIR STAYS PUT THROUGH THURSDAY BEFORE TEMPERATURES
MODERATE TO FINISH UP THE WEEK AND TO START THE WEEKEND. IN GENERAL,
WIND CHILLS LIKELY WILL BE BELOW ZERO IN THE EVENINGS THROUGH THE
MORNING HOURS SOUTH OF THE MOUNTAINS AND THEN LIMITED TO THE SINGLE
DIGITS DURING THE AFTERNOON AS HIGHS ARE ONLY FORECAST TO REACH THE
TEENS WITH SOMEWHAT BREEZY CONDITIONS. WIND CHILLS IN THE MOUNTAINS
ARE FORECAST TO REMAIN WELL BELOW ZERO FROM THE EVENINGS THROUGH
MORNING AND MAY NOT MAKE IT ABOVE ZERO DURING THE AFTERNOON AS TEMPS
ONLY FORECAST TO REACH THE SINGLE DIGITS.
THERE MAY BE SOME UPSLOPE MOUNTAINS SNOW SHOWERS FROM TIME TO TIME
TUES-WED, BUT IN GENERAL CONDITIONS LOOK MOSTLY DRY DURING THIS
PERIOD. GOOD MIXING WILL PROMOTE STEEP LOW-LEVEL LAPSE RATES, AND
FROUDE NUMBERS DO LOOK TO INCREASE DURING THE AFTERNOONS. THIS
SUGGESTS IT COULD BE CLOUDIER THAN CURRENTLY FORECAST SOUTH OF THE
MOUNTAINS ALONG WITH A FEW SNOW SHOWERS IF WE HAVE ENOUGH LOW-LEVEL
MOISTURE. WORTH MENTIONING: MODELS ARE SHOWING A DEEPENING LOW OVER
THE WESTERN ATLANTIC AS A SHORTWAVE APPROACHES TUESDAY NIGHT INTO
WEDNESDAY. NBM SLIGHT CHANCE POPS SUGGEST SOUTHERN/COASTAL AREAS
COULD SEE VERY LIGHT SNOW OUT OF THIS, BUT THERE IS MUCH MORE
SUPPORT IN THE ENSEMBLES TO KEEP THIS LOW WELL TO THE SOUTH AND
EAST.
THURSDAY STARTS COLD, BUT DAYTIME HIGHS WILL RECOVER A BIT AS HIGH
PRESSURE SHIFTS EAST BRINGING A RETURN TO SOUTHERLY FLOW. TEMPS
CONTINUE TO MODERATE FOR FRIDAY AND SATURDAY, AND THERE ARE HINTS OF
ANOTHER COASTAL LOW MOVING LATE WEEK AS A NORTHERN STREAM SHORTWAVE
ATTEMPTS TO PHASE WITH SOUTHERN STREAM ENERGY. THIS WILL NEED TO BE
MONITORED AS IT COULD BRING SNOW TO PORTIONS OF THE AREA, BUT
ENSEMBLES CURRENTLY FAVOR A MORE OFFSHORE TRACK AND KEEP THE BULK OF
THE QPF TO THE SOUTH AND EAST.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
SHORT TERM...IFR EXPECTED THIS EVENING, WITH SOME IMPROVEMENT TO
MVFR AFTER MIDNIGHT IN SOME AREAS, AND TO VFR BY EARLY SUNDAY
MORNING. HOWEVER, EXPECTING MVFR CONDS TO RETURN LATE AFTERNOON
SUNDAY WITH IFR OR LOWER IN SN AT ALL TERMINALS SUNDAY NIGHT.
LONG TERM...CLOUDS CONTINUE TO CLEAR OUT FROM WEST TO EAST MONDAY
MORNING WITH MAINLY VFR PREVAILING THROUGH THURSDAY. A COUPLE OF
EXCEPTIONS WILL BE THE POSSIBILITY OF MVFR CEILINGS AND SNOW SHOWERS
AT HIE FROM TIME TO TIME
MARINE
SHORT TERM...WINDS DROP OFF LATER TONIGHT BUT WON’T FALL MUCH
BELOW SCA DURING THE DAY SUNDAY BEFORE NW FLOW PICKS BACK UP
AGAIN LATE SUNDAY INTO SUNDAY NIGHT. WITH MUCH COLDER AIR MOVING
IN COULD SEE LIGHT FREEZING SPRAY DEVELOP TOWARD DAYBREAK ON
MONDAY.
LONG TERM...SCA CONDITIONS WILL LIKELY CONTINUE MONDAY INTO MONDAY
NIGHT (MAYBE TUESDAY AS WELL) AS LOW PRESSURE LIFTS INTO THE
CANADIAN MARITIMES, AND THERE MAY BE A BRIEF PERIOD OF GALES ON
MONDAY. A DISTANT LOW PRESSURE PASSING TO THE SOUTH AND EAST OF THE
WATERS MAY THEN BRING ANOTHER PERIOD OF SCA CONDITIONS AS WINDS TURN
TO THE NORTH/NORTHWEST, BUT THAT DEPENDS ON ITS TRACK. HIGH PRESSURE
BUILDS TOWARD THE NORTHEAST THURSDAY. BY LATE WEEK OR THE START OF
NEXT WEEKEND, THERE IS SOME SIGNAL FOR A COASTAL LOW PRESSURE...BUT
CONFIDENCE IN ANY PARTICULAR TRACK IS LOW AS TO WEATHER IT CROSSES
THE WATERS OR REMAINS TO THE SOUTH AND EAST.
GYX WATCHES/WARNINGS/ADVISORIES
ME...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
MORNING FOR MEZ014-018>028.
NH...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
MORNING FOR NHZ005>015.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR ANZ150-152-154.
NEAR TERM...LEGRO
SHORT TERM...CEMPA
LONG TERM...COMBS
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