536
FXUS61 KGYX 171021
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
621 AM EDT SUN MAY 17 2026
WHAT HAS CHANGED
UPDATED AVIATION SECTION FOR THE 12Z TAFS.
WITH THE VERY WARM TEMPERATURES ACROSS THE AREA TODAY, SOME OF
THE CAMS ARE SUGGESTING ENOUGH INSTABILITY FOR A FEW SHOWERS
OVER PORTIONS OF WESTERN AND SOUTHERN NH THIS AFTERNOON, BUT
DRY AIR ALOFT IS EXPECTED TO KEEP COVERAGE LOW. CAN'T
COMPLETELY RULE OUT A STORM BASED ON FORECAST SOUNDINGS FROM THE
NAM/RAP, BUT THE DRY AIR ALOFT MAY BE TOO MUCH TO OVERCOME.
HOWEVER, SHOULD A STORM DEVELOP, GUSTY WINDS ARE POSSIBLE.
KEY MESSAGES
1. OUTDOOR RECREATION IS BOUND TO BE IN HIGH DEMAND AND AREA
INLAND AND OCEAN WATERS REMAIN VERY COLD TODAY. SLIGHTLY COOLER
WEATHER IS EXPECTED AT THE COAST ON MONDAY AS WINDS GO ONSHORE.
THE FAR INTERIOR REMAINS IN THE 70S WITH EVEN SOME LOWER 80S
POSSIBLE IN SOUTHWESTERN NH.
2. ABOVE NORMAL TEMPERATURES CONTINUE TUESDAY INTO MID WEEK
WHICH SHOULD FEATURE THE WARMEST DAYS OF THE YEAR SO FAR. WITH
THE HEAT ALSO COMES THE CHANCE FOR SCATTERED SHOWERS AND
THUNDERSTORMS ON TUESDAY AND WEDNESDAY.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
ANY SHOWERS EARLY THIS MORNING SHOULD BE GONE BY SUNRISE
ALLOWING FOR ANOTHER WARM DAY TODAY. HIGH PRESSURE CRESTS OVER
NEW ENGLAND TONIGHT ALLOWING FOR A DECENT NIGHT FOR RADIATIONAL
COOLING, ESPECIALLY IN THE MOUNTAIN VALLEYS WHERE LOWS MAY DIP
INTO THE UPPER 30S IN SPOTS. THE MAIN ISSUE WILL BE GUSTS TODAY
WITH 25 TO 30 MPH POSSIBLE. AREA LAKES WILL BE WAVY.
ON MONDAY, SFC HIGH PRESSURE WILL MOVE JUST OFFSHORE. THIS WILL
SET UP SORT OF AN IN-SITU WARM FRONT WHICH WITH ONSHORE FLOW TO
ITS EAST WILL KEEP THE COASTAL PLAIN COOLER THAN SUNDAY. THIS
WILL ESPECIALLY BE TRUE LATE AFTERNOON AND EVENING WHEN THE
COLDEST SURFACE PUSH MOVES ONSHORE WITH THE HELP OF A SEABREEZE
CIRCULATION. WESTERN ZONES REMAIN WARM. THERE MAY BE A FEW
SHOWERS OR A BRIEF THUNDERSTORM DURING THE AFTERNOON HOURS IN
THE MOUNTAINS AS A WAVE MOVES EASTWARD NORTH OF WARM FRONT.
WITH THE ABUNDANTLY WARM WEATHER TODAY, IT IS IMPORTANT TO
RECOGNIZE THAT LAKE AND OCEAN WATER TEMPERATURES HAVE NOT WARMED
UP. OCEAN SEA-SURFACE TEMPERATURES ARE STILL IN THE LOWER TO
MID- 40S, WITH LAKE TEMPERATURES ONLY AROUND 50F. LAKE AND
OCEAN TEMPERATURES THIS COLD POSE A SIGNIFICANT HAZARD TO
SWIMMERS, BOATERS AND BEACHGOERS. HYPOTHERMIA AND COLD SHOCK CAN
OCCUR IN THESE WATER TEMPERATURES.
KEY MESSAGE 2 DESCRIPTION...
MID/UPPER LEVEL RIDGING STARTS TO FLATTEN A BIT MONDAY NIGHT AS
A WAVE MOVES OVER THE TOP. MOST OF THE FORCING SHOULD REMAIN
NORTH OF OUR AREA, BUT A FEW SHOWERS WILL BE POSSIBLE ACROSS THE
MOUNTAINS OVERNIGHT.
PROGRESSIVE RIDGING WILL POP BACK UP EARLY TUESDAY BUT WILL BE
FOLLOWED BY SOME MODEST HEIGHT FALLS IN THE LATE AFTERNOON AND
INTO THE EVENING. WHILE SYNOPTIC FORCING REMAINS A BIT NEBULOUS,
THERE SHOULD BE ENOUGH LIFT TO SEE SOME ISOLATED TO SCATTERED
THUNDERSTORMS. THE BEST CHANCES WILL BE OVER NORTHERN NEW
HAMPSHIRE AND THE NORTHERN PORTIONS OF THE WESTERN MAINE
MOUNTAINS, BUT A BACKDOOR FRONT/SURFACE TROUGH COULD LEAD TO
SOME STORMS OVER THE INTERIOR AND MIDCOAST AS WELL. THE NAM AND
GFS DIFFER IN THEIR ESTIMATION OF HOW MUCH INSTABILITY WE WILL
SEE. THE NAM SUGGESTS WE COULD SEE UP TO 2000 J/KG MUCAPE BUT
THE GFS IS MORE IN THE 1000 TO 1500 J/KG RANGE. THE EUROPEAN
ENSEMBLE SPITS OUT MEDIUM TO HIGH CHANCES FOR MUCAPE GREATER
THAN 1000 J/KG IN THE AFTERNOON. THE GEFS AND GEPS ARE LESS
BULLISH. WITH DEEP LAYER SHEAR FORECAST AS HIGH AS 30 TO 35
KNOTS, THIS PARAMETER SPACE COULD POTENTIALLY BE ENOUGH FOR
SOME STRONG TO MARGINALLY SEVERE STORMS IN THE AFTERNOON AND
INTO THE EARLY EVENING. CSU MACHINE LEARNING GUIDANCE ALSO
CONTINUES TO HIGHLIGHT TUESDAY FOR LOW SEVERE WEATHER
PROBABILITIES.
A COLD FRONT THEN MOVES ACROSS THE REGION ON WEDNESDAY WHICH
COULD LEAD TO ANOTHER ROUND OF THUNDERSTORMS, POTENTIALLY A BIT
MORE WIDESPREAD THAN TUESDAY. THE MAGNITUDE OF STRONG TO SEVERE
STORM POTENTIAL ON WEDNESDAY WILL HEAVILY DEPEND ON THE FRONTAL
TIMING. THE LATER THE FRONT MOVES THROUGH, THE MORE AFTERNOON
INSTABILITY AND BETTER CHANCE FOR STRONGER STORMS. THERE HAS
BEEN A TREND OVER THE PAST COUPLE OF DAYS FOR THE FRONT TO MOVE
THROUGH EARLIER IN THE DAY WHICH WOULD KEEP THE STRONGER
THUNDERSTORM POTENTIAL CONFINED TO SOUTHERN NEW HAMPSHIRE, THE
INTERIOR/FOOTHILLS OF MAINE, AND POTENTIALLY INTO PORTIONS OF
THE MIDCOAST. CSU MACHINE LEARNING GUIDANCE HAS BACKED OFF ON
PROBABILITIES ON WEDNESDAY AS WELL. STILL, IT WILL BE ANOTHER
DAY TO MONITOR THE POTENTIAL FOR STRONG TO MARGINALLY SEVERE
STORMS, ESPECIALLY IF THE FRONTAL PASSAGE SLOWS DOWN OVER THE
NEXT FEW ROUNDS OF GUIDANCE. AFTER STORMS MOVE OUT ON WEDNESDAY
WE SHOULD SEE MAINLY DRY CONDITIONS THROUGH THE REST OF THE WEEK
AND INTO THE EARLY PART OF THE WEEKEND.
REGARDING TEMPERATURES, TUESDAY AND WEDNESDAY LOOK LIKELY TO BE
OUR WARMEST DAYS OF THE YEAR SO FAR FOR MOST (IF NOT ALL)
LOCATIONS. HIGHS ON TUESDAY WILL GENERALLY RANGE FROM THE UPPER
70S AND LOWER 80S NORTH, TO THE UPPER 80S AND LOWER 90S SOUTH.
SOME COASTAL AREAS WILL BE A LITTLE BIT COOLER WITH AN ONSHORE
COMPONENT TO THE WINDS. WITH THE COLD FRONT MOVING THROUGH ON
WEDNESDAY, HIGHS WILL BE A TOUCH COOLER NORTH (70S) BUT STILL
VERY WARM SOUTH AND ALONG THE COAST AHEAD OF THE COLD FRONT
(MID 80S TO LOWER 90S). WE WILL THEN COOL DOWN THROUGH THE END
OF THE WEEK AND INTO THE WEEKEND WITH WIDESPREAD HIGHS IN THE
50S NORTH, TO THE 60S SOUTH. A FEW LOWER 70S WILL REMAIN
POSSIBLE OVER SOUTHERN NEW HAMPSHIRE.
AVIATION /09Z SUNDAY THROUGH THURSDAY/
THROUGH 12Z MONDAY...VFR IS EXPECTED FOR ALL TERMINALS TODAY WITH
WESTERLY WIND GUSTS OF 20 TO 30 KT, POSSIBLY UP TO 35 KT. A COUPLE
OF SHOWERS MAY DEVELOP THIS AFTERNOON ACROSS CENTRAL AND SOUTHERN
NH, BUT CHANCES ARE TOO LOW FOR TAF INCLUSION AT THIS TIME. WINDS
DIMINISH THIS EVENING, AND VFR PREVAILS TONIGHT.
OUTLOOK:
MONDAY: LIGHTER WINDS AND VFR ON MONDAY AS WINDS GO ONSHORE.
TUESDAY: AM VFR, PM MVFR POSSIBLE DUE TO SHOWERS/THUNDERSTORMS.
WEDNESDAY: AM VFR, PM MVFR POSSIBLE DUE TO SHOWERS/THUNDERSTORMS.
THURSDAY: VFR LIKELY.
MARINE
SOUTHWESTERLY SCA-LEVEL WINDS WILL SUBSIDE EARLY THIS MORNING,
BUT SEAS MAY REMAIN AT OR ABOVE 5 FT FOR THE COASTAL WATERS
UNTIL LATER THIS MORNING OR EARLY AFTERNOON. LIGHT AND VARIABLE
WINDS ARE EXPECTED TO TURN EAST TONIGHT AND WILL CONTINUE
THROUGH MONDAY.
SOUTHERLY WINDS BUILD UP TO NEAR SCA LEVELS DURING THE DAY
TUESDAY, BUT SLOWLY START WEAKENING TUESDAY NIGHT AND INTO
WEDNESDAY. BELOW-SCA LEVEL WINDS AND SEAS WILL CONTINUE THROUGH
THE REMAINDER OF NEXT WEEK. SEAS ARE FORECAST TO GENERALLY BE IN
THE 2-5FT RANGE TUESDAY THROUGH THE REST OF THE WORK WEEK.
GYX WATCHES/WARNINGS/ADVISORIES
ME...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MEZ023>028.
NH...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR NHZ014.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EDT THIS AFTERNOON FOR ANZ150-
152.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ154.
DISCUSSION...COMBS/EKSTER/HARGROVE
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