903
FXUS61 KGYX 261830
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
130 PM EST FRI DEC 26 2025
SYNOPSIS
WEAK LOW PRESSURE LOOKS TO PASS MOSTLY TO OUR SOUTH TONIGHT,
BUT LIGHT SNOW IS LIKELY OVER SOUTHERN NEW HAMPSHIRE TONIGHT
INTO SATURDAY MORNING. NEXT POTENTIAL STORM ARRIVES FOR SUNDAY
NIGHT AND MONDAY AND WILL LIKELY BE MORE OF A MIXED BAG WITH ALL
PRECIPITATION TYPES POSSIBLE DURING THE EVENT. WINDS RAMP UP
TUESDAY IN THE WAKE OF THE SYSTEM AND BELOW NORMAL TEMPERATURES
CONTINUE THROUGH THE NEW YEAR'S HOLIDAY WINDOW.
NEAR TERM /THROUGH TONIGHT/
SHORTWAVE TROF CROSSING THE GREAT LAKES TONIGHT WILL SPREAD WARM
ADVECTION OVER THE NORTHEAST. ON THE LEADING EDGE THERE WILL BE
DECENT FRONTOGENESIS, AND PRETTY MUCH ALL GUIDANCE HAS IT
REACHING SOUTHWESTERN PORTIONS OF THE FORECAST AREA. THE
LIMITING FACTOR WILL BE BLOCKING LOW PRESSURE OVER THE ATLANTIC
SOUTH OF NEWFOUNDLAND, WHICH WILL SHUNT THE APPROACHING
SHORTWAVE SOUTH AND EAST. THE GLOBAL NWP TENDS TO WASH THE WARM
ADVECTION OUT FASTER THAN THE HIGHER-RES MESOSCALE GUIDANCE AT
THIS TIME. EXAMINING FORECAST SOUNDINGS ACROSS SOUTHWESTERN AND
SOUTHERN NH, THERE IS FORECAST TO BE A VERY DEEP LAYER FROM THE
SURFACE TO NEAR 500 MB OF TEMPS VERY CLOSE TO OPTIMAL SNOW
GROWTH. ANY LIFT WITHIN THAT LAYER WOULD SUPPORT SNOW GIVEN
SUFFICIENT SATURATION. SO WE WILL BE WATCHING RH, ESPECIALLY IN
THE MID LEVELS WHERE MWN CAN BE A PROXY. CURRENTLY IT IS QUITE
DRY UP AT THE OBSERVATORY, -44 DEWPOINT, BUT DEWPOINTS OVER AT
MOUNT MANSFIELD ARE CURRENTLY RISING AS PRECIP APPROACHES. THE
CURRENT EXPECTATION IS THAT LIGHT SNOW WILL BE POSSIBLE TONIGHT
MAINLY FROM LEB TO PSM AND AREAS SOUTH. GIVEN THOSE DEEP NEARLY
DENDRITIC SNOW GROWTH PROFILES THE SNOW TO LIQUID RATIOS SHOULD
BE QUITE HIGH. SO IT WILL NOT TAKE MUCH LIQUID EQUIVALENT TO GET
SOME ACCUMULATIONS OVER SOUTHERN NH. RIGHT NOW I HAVE A SOLID 2
TO 4 ACROSS MUCH OF THE AREA, WITH CHESHIRE COUNTY IN
PARTICULAR AVERAGING PRETTY CLOSE TO ADVISORY THRESHOLDS. IF
THINGS TREND A LITTLE MORE ROBUST OVER THE EVENING IT IS
POSSIBLE THAT A WINTER WEATHER ADVISORY COULD BE ISSUED.
SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/
REMAINING LIGHT SNOW TAPERS OFF MOSTLY BY MID MORNING ACROSS
SOUTHERN NH. IT WILL BE ANOTHER CHILLY BUT OTHERWISE FAIR
WEATHER DAY ONCE THAT SNOW CLEARS. HIGH PRESSURE SETTLES
OVERHEAD OVERNIGHT. WITH A FRESH BLANKET OF SNOW, CLEAR SKIES,
AND LIGHT WINDS, CONDITIONS WILL BE FAVORABLE FOR RADIATIONAL
COOLING. THE NBM LOOKS RATHER WARM GIVEN THIS SET UP, SO I
PREFERRED TO BLEND THE 10TH PERCENTILE AND MOS GUIDANCE TO
CAPTURE THE TYPICALLY COOLER LOCATIONS. THIS DROPPED MIN TEMPS
IN THOSE AREAS SOME 10 DEGREES, BUT I COULD SEE FURTHER REFINING
NEEDED IN SUBSEQUENT FORECASTS.
LONG TERM /SUNDAY THROUGH FRIDAY/
PATTERN OVERVIEW: A RIDGE SLIDES OVERHEAD SUNDAY STARTING THE
PERIOD WITH FAIR WEATHER, BUT THAT WILL CHANGE HEADING INTO
MONDAY AS A POTENT UPPER LOW APPROACHES THE REGION PROVIDING THE
FORCING FOR A WINTRY STORM. THE UPPER LOW PASSES TO OUR NORTH
TUESDAY AND THEN WE REMAIN IN A BROAD TROUGH THROUGH THE END OF
THE PERIOD. THERE IS SOME SUGGESTION OF WAVES ROTATING THROUGH
THE BROADER TROUGH, BUT WITH LACK OF FRONTAL FORCING, NOTHING
LOOKS OVERLY IMPACTFUL AT THIS TIME.
IMPACTS AND KEY MESSAGES:
* A MIXED PRECIPITATION EVENT IS LIKELY TO IMPACT POST-HOLIDAY
TRAVEL SUNDAY NIGHT AND MONDAY.
DETAILS: SUNDAY: THE AXIS OF SURFACE HIGH PRESSURE MOVES
OVERHEAD SUNDAY WITH RIDGING ALOFT. THIS WILL ALLOW FOR A SUNNY
START TO THE DAY, AND WITH 850 TEMPERATURES RISING INTO THE
+1-5C RANGE, SURFACE TEMPERATURES END UP IN THE LOW TO MID 30S
SOUTH OF THE MOUNTAINS, AND IN THE MID TO UPPER 20S NORTH.
CLOUDS BEGIN TO THICKEN SUNDAY EVENING AS LOW PRESSURE
APPROACHES FROM THE WEST, BUT PRECIPITATION TIMING IS A LITTLE
MORE UNCERTAIN. THE EURO AND CANADIAN CONTINUE TO BE THE QUICKER
OUTLIERS WITH PRECIPITATION ENTERING IN THE MIDNIGHT HOUR
SUNDAY NIGHT, BUT THE GFS AND NOW THE NAM HOLD OFF UNTIL EARLY
MONDAY MORNING (MORE IN THE 2AM-4AM WINDOW). LOW TEMPERATURES
ARE GOING TO OCCUR EARLY ON IN THE NIGHT SUNDAY, DROPPING IN TO
UPPER TEENS AND LOW 20S TO THE SOUTH (LOW TO MID-TEENS NORTH)
BEFORE WE CLOUD OVER AND WARM NOSE STARTS PUSHING IN.
MONDAY: PRECIPITATION STARTS EARLY ON MONDAY AND INITIALLY IT
IS GOING TO BE A MIXED BAG AS A WARM NOSE PUSHES IN ALOFT, WITH
COLD AIR STILL IN PLACE AT THE SURFACE. BUFKIT PROFILES IN NEW
HAMPSHIRE AND FAR SOUTHERN MAINE ARE SUGGESTING A PERIOD OF
FREEZING RAIN AS THE SURFACE COLD LAYER IS VERY SHALLOW.
SOUTHERN ZONES MAY SWITCH OVER TO PLAIN RAIN AS EARLY AS MID-
MORNING WHICH WOULD LIMIT ICE ACCUMULATIONS AND TRAVEL IMPACTS
THERE. CENTRAL AND NORTHERN NEW HAMPSHIRE MAY SEE THE GREATER
ICE ACCUMULATIONS AS A SOLID COLD AIR DAMMING SIGNATURE IS
ALREADY SHOWING UP ON THE NAM. BUFKIT PROFILES HEADING INTO
INTERIOR MAINE SUGGEST A STRONGER COLD AIR DAM WITH A DEEPER
COLD LAYER (~4000 FT) THAT WOULD SUGGEST TO ME THAT SLEET WOULD
BE THE MORE DOMINANT PRECIP TYPE HERE, RATHER THAN THE FREEZING
RAIN THE GLOBAL MODELS ARE GOING FOR. STILL NOT GREAT FOR
TRAVEL, BUT BETTER FOR KEEPING ACCUMULATING ICE DOWN. THERE IS
STILL A LOT OF UNCERTAINTY REGARDING WHAT THE TEMPERATURE
PROFILES ARE GOING TO LOOK LIKE LATER IN THE DAY. MODELS WANT TO
SCOUR OUT THE COLD AIR AND SWITCH MUCH OF THE AREA SOUTH OF THE
MOUNTAINS TO RAIN, BUT HISTORICALLY THE COLD AIR DAM ALWAYS
WINS AND INTERIOR ZONES MAY SEE SLEET AND/OR FREEZING RAIN
PERSIST. THERE IS GOING TO BE CHANGES AS THIS SYSTEM MOVES INTO
THE HI-RES MODEL WINDOW, BUT IF YOU ARE USING THIS INFORMATION
FOR PLANNING POST-HOLIDAY TRAVEL I WOULD SAY SUNDAY IS
DEFINITELY THE DAY TO DO IT. WHATEVER ENDS UP HAPPENING, MONDAY
DOES NOT LOOK LIKE THE DAY TO BE ON THE ROAD. I CONTINUED WITH
MIXED PRECIPITATION IN THE WEATHER GRIDS TO HIGHLIGHT
UNCERTAINTY IN ONE TYPE OR THE OTHER, BUT ALSO TO HIGHLIGHT THE
UNFAVORABLE TRAVEL CONDITIONS.
TUESDAY-FRIDAY: STRONG COLD AIR ADVECTION RAMPS UP WINDS
TUESDAY WITH WEST-NORTHWESTERLY GUSTS REACHING THE 25-35 MPH
RANGE. AS IS USUAL WITH THIS PATTERN, EXPECT THE MOUNTAINS TO
SEE PERSISTENT SNOW SHOWERS. THIS LOOKS TO CONTINUE THROUGH THE
END OF THE LONG TERM PERIOD AS A BROAD TROUGH DOMINATES THE
WEATHER PATTERN, BUT A LACK OF ANY FRONTAL FORCING SUGGESTS
LIGHT SHOWERS, MAINLY IN THE MOUNTAINS, IS ALL WE MAY SEE AS WE
HEAD INTO THE NEW YEAR.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
SHORT TERM...VFR CONDITIONS PREVAIL OVER THE MAJORITY OF THE
FORECAST AREA THRU SAT NIGHT. LIGHT SNOW WILL OVERSPREAD PARTS
OF SOUTHERN NH AROUND MIDNIGHT AND CONTINUE INTO SAT MORNING.
AREAS OF IFR, MAINLY DUE TO LOW VIS, WILL BE POSSIBLE ROUGHLY
FROM A LEB TO PSM LINE AND POINTS SOUTH. THIS MOVES SOUTHEAST BY
MIDDAY SAT AND A RETURN TO VFR CONDITIONS IS EXPECTED.
LONG TERM...VFR CONDITIONS PREVAIL THROUGH THE DAY SUNDAY
BEFORE CEILINGS BEGIN TO LOWER SUNDAY NIGHT. OVERNIGHT SUNDAY
WIDESPREAD MIXED PRECIPITATION ENTERS THE AREA MAKING CONDITIONS
VARIABLE, BUT WIDESPREAD IFR SEEMS PRETTY LIKELY INTO MONDAY
MORNING. CONDITIONS ARE MOST LIKELY TO IMPROVE BACK TO MVFR AT
COASTAL TERMINALS MONDAY AS THEY STAND THE BEST CHANCE OF
TRANSITIONING TO LIGHT RAIN AT SOME POINT. CONDITIONS AT INLAND
TERMINALS ARE MORE UNCERTAIN. WE SHOULD SEE VFR CONDITIONS
RETURN FOR TUESDAY AND WEDNESDAY. WESTERLY WIND GUSTS ON TUESDAY
MAY REACH 25-30 KTS.
MARINE
SHORT TERM...WINDS AND SEAS CONTINUE TO DIMINISH THIS AFTERNOON
AS HIGH PRESSURE BUILDS INTO THE REGION. I HAVE DROPPED THE BAYS
FROM THE SCA AND WINDS ARE NO LONG GUSTING ABOVE 25 KT. OUTSIDE
THE BAYS THE SCA CONDITIONS WILL LINGER INTO EARLY THIS EVENING
BEFORE DIMINISHING. LIGHT SNOW IS EXPECTED TO MOVE OVER THE
WATERS AFTER MIDNIGHT TONIGHT, WITH THE SEACOAST WATERS OUT TO
JEFFREYS LEDGE POTENTIALLY SEEING REDUCED VISIBILITY. LIGHT
FREEZING SPRAY WILL REMAIN POSSIBLE THRU THE PERIOD, ESPECIALLY
NORTH OF CAPE ELIZABETH.
LONG TERM...SUB-SCA CRITERIA CONDITIONS ARE EXPECTED ON SUNDAY,
BUT WINDS AND SEAS WILL RAMP UP MONDAY AS A FRONTAL SYSTEM
TRAVERSES THE AREA. BY MONDAY AFTERNOON FREQUENT WIND GUSTS
25KTS+ ARE GOING TO BE PRESENT, POTENTIALLY REACHING GALE FORCE
MONDAY NIGHT. THE STRONGER WIND GUSTS BEGIN TO TAPER OFF
WEDNESDAY, BUT WON'T FALL BELOW 25KTS UNTIL MAYBE FRIDAY. DURING
THIS SAME TIME PERIOD SEAS BUILD TO 8-10 FT, AGAIN NOT FALLING
BELOW 5FT UNTIL MAYBE FRIDAY.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ150-
152-154.
NEAR/SHORT TERM...LEGRO
LONG TERM...BARON
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