840
FXUS61 KGYX 170905
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
405 AM EST FRI JAN 17 2025
SYNOPSIS
A FRONTAL SYSTEM WILL BRING CHANCES FOR RAIN SHOWERS AND
MOUNTAIN SNOW SATURDAY INTO SUNDAY MORNING. A WAVE OF LOW
PRESSURE TRACKING OFFSHORE WILL BRING CHANCES FOR LIGHT TO
MODERATE SNOW SUNDAY NIGHT. AN ARCTIC AIR MASS ARRIVES TUESDAY
THROUGH THURSDAY.
NEAR TERM /UNTIL 6 PM THIS EVENING/
WEAK INVERTED TROUGH CONTINUES TO BRING SOME NEARSHORE SNOW
SHOWERS IN VERY SOUTHERN ME AND COASTAL NH. THESE REMAIN LIGHT
AND SWING OFFSHORE THROUGH THE EARLY MORNING HOURS.
WARMER TODAY WITH LIGHT WINDS AS RIDGING BUILDS INTO NEW
ENGLAND. TEMPS PUSH INTO THE LOWER TO MID 30S ALONG THE SOUTHERN
ME COAST AND SOUTHERN NH. WHAT LITTLE MOISTURE WAS IN THE COLUMN
OVERNIGHT AND THIS MORNING WILL HAVE PULLED EAST BY MIDDAY,
BRINGING MORE SUN FOR THE COAST AND INTERIOR. CLOUDS WILL TEND
TO LINGER IN THE MOUNTAINS WHERE BLOCKED FLOW WON'T FLUSH LOWER
LEVEL MOISTURE AS READILY.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/
THE TREND TONIGHT WILL FAVOR INCREASING CLOUDS AS MID AND UPPER
RIDGE CRESTS AND LOW LEVELS BECOME SW. CLOUDS AND WIND WILL TEND
TO KEEP TEMPS FROM FALLING OFF OVERNIGHT, REMAINING NEARLY
STEADY FOR THE SOUTHERN HALF OF THE CWA FROM LATE EVENING
ONWARD. WINDS OFF THE SURFACE WILL INCREASE, AND EXPECT A LARGE
GUST GRADIENT FROM THE VALLEYS TO THE HIGHER TERRAIN OVERNIGHT.
SUBTLE MIXING INTO SATURDAY MORNING WILL EVEN THIS SOMEWHAT.
A QUICK MOVING SYSTEM IS EXPECTED TO BRING PRECIPITATION TO THE
AREA FOR THE SECOND HALF OF SATURDAY, BUT LIGHT PRECIP MAY
BEGIN LATE MORNING. GUIDANCE IS IN FAIRLY GOOD AGREEMENT OF
PRECIP FOCUS FOR THE AFTERNOON AND EVENING, BUT I DO HAVE SOME
CONCERN OF SCATTERED RAIN/SNOW SHOWERS PREEMPTING THIS MID TO
LATE MORNING. SOUTHERLY LOW LEVEL MOISTURE ADVECTION IS ROBUST
BEGINNING IN THE MORNING, AND EXPECT UPPER LEVEL MOISTURE TO BE
PRESENT. SHOULD THE IN-BETWEEN DRY LAYER BE THINNER THAN
MODELED, MUCH OF THE AREA COULD SEE SPOTTY SHOWERS BEGINNING
EARLIER. WHILE THE NAM TENDS TO OVERDO BL MOISTURE, SHOULD THIS
LOW LEVEL MOISTURE ADVANCE WHILE SFC TEMPS ARE STILL BELOW
FREEZING, A PERIOD OF FREEZING DRIZZLE MAY BE POSSIBLE SAT AM
FOR MAINLY INTERIOR LOCATIONS.
THE COLUMN FINALLY SATURATES FULLY IN THE AFTERNOON WHEN THE
BEST CHANCE OF MORE STRATIFORM PRECIP ARRIVES. FROM THIS PHASE
OF THE SYSTEM, STILL EXPECT LIGHT SNOW ACCUMS IN THE MOUNTAINS,
NORTH OF THE FOOTHILLS, WITH ALL RAIN SOUTH OF HERE. THE QUICK
MOVING SYSTEM WILL BRING GENERALLY LESS THAN 0.2" TO THE AREA,
WITH SOME COASTAL ENHANCEMENT POSSIBLE WHERE VALUES MAY APPROACH
0.4"
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
05Z LONG TERM FORECAST UPDATE... LATEST ENSEMBLE BASED GUIDANCE
CONTINUES TO BE IN BETTER AGREEMENT FOR A LIGHT TO MODERATE
SNOWFALL FROM A DEVELOPING COASTAL LOW ON SUNDAY NIGHT. POPS
INCREASED FOR THIS PERIOD AS CONFIDENCE IS INCREASING FOR A
POTENTIALLY PLOWABLE SNOWFALL IN MOST LOCATIONS. BEHIND THIS
SYSTEM, THERE IS STRONG CONFIDENCE FOR A PERIOD OF WELL BELOW
AVERAGE TEMPERATURES TUESDAY THROUGH THURSDAY WITH BELOW ZERO
LOW TEMPERATURES LIKELY AND WINDCHILLS APPROACHING 15-20 BELOW.
PREVIOUSLY...
OVERVIEW: THE CONTINENTAL SCALE PATTERN ACROSS NORTH AMERICA
DURING THE LONG TERM PERIOD WILL BE DOMINATED BY A NEGATIVE EPO
WITH PERSISTENT RIDGING IN THE NE PACIFIC INTO ALASKA. A LONG
WAVE TROUGH WILL REMAIN DOWNSTREAM OF THIS RIDGE ACROSS THE
CENTRAL CONUS WITH EMBEDDED WAVES BRINGING A COUPLE OF CHANCES
FOR PRECIPITATION LATE SATURDAY INTO SUNDAY AND SUNDAY NIGHT
INTO MONDAY. CONFIDENCE IS HIGH THAT AN ARCTIC AIRMASS WILL
DESCEND INTO THE CENTRAL CONUS AND SPREADS EAST BEHIND THE
MONDAY SYSTEM. ADDITIONAL WAVES WILL DIVE DOWN THE EASTERN FLANK
OF THE PERSISTENT RIDGE THROUGH MID WEEK AND DEPENDING ON THEIR
TRAJECTORY AROUND THE TROUGH, THERE WILL BE CHANCES FOR
ADDITIONAL WINTER SYSTEMS LATE NEXT WEEK. THE PATTERN OVER THE
PAST TWO WEEKS HAS BEEN ONE WHERE THESE SYSTEMS MISS TO OUR
SOUTH WITH THE PAST FEW ENSEMBLE RUNS FAVORING LIGHT
PRECIPITATION EVENTS OR MISSES OUT TO SEA.
IMPACTS:
*LIGHT TO MODERATE SNOW SUNDAY NIGHT INTO MONDAY WILL BRING THE
POTENTIAL FOR SLICK TRAVEL THROUGH THE MONDAY MORNING COMMUTE.
*AN ARCTIC AIR MASS ARRIVING ON NORTHWEST WINDS WILL BRING WIND
CHILLS WELL BELOW ZERO MONDAY NIGHT WITH WIND CHILLS AROUND -25F
ACROSS NORTHERN ZONES. HIGH TEMPERATURES WILL BE RESTRICTED TO THE
TEENS AND SINGLE DIGITS THROUGH MID WEEK WITH LOWS TUESDAY NIGHT
DROPPING WELL BELOW ZERO ACROSS MUCH OF THE AREA.
DETAILS: SATURDAY WILL BE THE WARMEST DAY OF THE FORECAST PERIOD
AS WARM AIR ADVECTION AHEAD OF A COLD FRONT WILL BRING HIGHS
INTO THE 30S AND 40S. THE APPROACHING COLD FRONT WILL BRING
MOSTLY RAIN SHOWERS SOUTH OF THE MOUNTAINS STARTING SATURDAY
AFTERNOON AND ENDING SUNDAY MORNING. IN THE MOUNTAINS AND NORTH
THERMAL PROFILES WILL SUPPORT MOSTLY SNOW WITH ACCUMULATIONS OF
1-3 INCHES. THE COLD WILL SETTLE NEAR THE SOUTHERN NEW ENGLAND
COASTLINE SUNDAY. HIGHS ON SUNDAY WILL RANGE FROM THE 20S NORTH
TO 30S SOUTH.
THE 12Z DETERMINISTIC GUIDANCE AND ENSEMBLES ARE SHOWING SIGNS
OF CONSOLIDATING AROUND A SOLUTION FOR A WAVE OF LOW PRESSURE
TRACKING SE OF CAPE COD SUNDAY NIGHT. ENSEMBLES ARE LOOSELY
CLUSTERING LOW LOCATIONS AROUND THE 40N/70W BENCHMARK. THE MULTI
MODEL CONSENSUS BRINGS CHANCES FOR LIGHT SNOW TO OVERSPREAD
MUCH OF THE AREA WITH MODERATE ACCUMULATIONS POSSIBLE ACROSS
SOUTHERN NH AND THE COASTAL PLAIN OF MAINE. BASED OFF A GENERAL
NORTHWARD SHIFT AND BETTER AGREEMENT IN THE 12Z GUIDANCE HAVE
NUDGED UP POPS VS THE NBM FOR THE SUNDAY NIGHT TIME FRAME.
CHANCES FOR SNOW WILL DIMINISH THROUGH THE DAY MONDAY. AN ARCTIC
AIR MASS WILL OVERTAKE MUCH OF THE CENTRAL CONUS AND SPREADS
EASTWARD INTO NEW ENGLAND BY TUESDAY. NEXT WEEK IS
CLIMATOLOGICALLY THE COLDEST WEEK OF THE YEAR AND IT WILL LIKELY
FEEL LIKE IT WITH HIGHS IN THE TEENS TO SINGLE DIGITS AND MUCH
OF THE AREA SEEING A COUPLE NIGHTS WITH LOW WELL BELOW ZERO.
AVIATION /08Z FRIDAY THROUGH TUESDAY/
SHORT TERM...SOME MVFR CEILINGS ALONG THE QUEBEC BORDER AND OVER
THE COASTAL WATERS THROUGH THIS MORNING. LIGHT SN POSSIBLE
AROUND PSM EARLY. OTHERWISE, VFR WITH LIGHT WINDS THROUGH
TONIGHT. SATURDAY, SW WINDS INCREASE WITH CLOUDS THICKENING AND
LOWERING. SN SPREADS ACROSS THE MOUNTAINS AND FOOTHILLS, WITH RA
ALONG THE COASTAL TERMINALS AND INTERIOR. CEILINGS TREND TO IFR
THROUGH THE DAY.
LONG TERM...SOME RESTRICTION IMPROVEMENT IS POSSIBLE SUNDAY
BEFORE LOW PRESSURE BRING -SN SUNDAY NIGHT INTO MONDAY. VFR
LIKELY MONDAY AFTERNOON THROUGH TUESDAY.
MARINE
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
THRESHOLDS THRU THE FIRST HALF OF TONIGHT. A FRONTAL SYSTEM WILL
THEN QUICKLY PROGRESS OVER THE WATERS THROUGH SATURDAY EVENING.
A PERIOD OF GALES IS POSSIBLE SATURDAY INTO THE EVENING, WITH
SCA IN THE BAYS AND OFF THE NH COAST.
LONG TERM...NNE WINDS INCREASE SUNDAY NIGHT AS LOW PRESSURE
TRACKS NEAR THE GULF OF MAINE. WINDS AND SEAS LIKELY REMAIN
ABOVE SCA THRESHOLDS SUNDAY NIGHT THROUGH MID WEEK. AN ARCTIC
AIRMASS MOVING OVER THE WATERS WILL LIKELY BRING LIGHT TO
MODERATE FREEZING SPRAY BY MONDAY.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...GALE WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING FOR
ANZ150-152.
NEAR TERM...CORNWELL
SHORT TERM...CORNWELL
LONG TERM...SCHROETER/TUBBS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page