909
FXUS61 KGYX 181328
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
928 AM EDT MON MAY 18 2026
WHAT HAS CHANGED
LIGHT RAIN CONTINUES TO LIFT THROUGH THE WESTERN FORECAST AREA,
WITH A FEW ISOLATED SHOWERS DEVELOPING FURTHER SOUTH AND EAST.
THE LIGHTNING THREAT HAS LARGELY DIMINISHED AS THE SYSTEM MOVES
INTO A MORE STABLE ENVIRONMENT.
KEY MESSAGES
1. COOLER TODAY IN ME WITH SOUTHEASTERLY WINDS, BUT STILL VERY WARM
ACROSS MUCH OF NH. A FEW SHOWERS POSSIBLE THIS MORNING IN
CENTRAL AND NORTHERN NH INCLUDING THE WESTERN ME MOUNTAINS.
2. TUESDAY AND WEDNESDAY SHOULD FEATURE THE WARMEST
TEMPERATURES OF THE YEAR THUS FAR WITH CHANCES OF ISOLATED TO
SCATTERED THUNDERSTORMS, SOME POTENTIALLY STRONG.
3. EXPECT COOLER AND DRY CONDITIONS TO END THE WORK WEEK WITH
TEMPERATURES AROUND OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF
YEAR THROUGH THE WEEKEND.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
HIGH PRESSURE WILL SLIDE OFFSHORE EARLY THIS MORNING ALLOWING
SFC WINDS TO HAVE AN EASTERLY COMPONENT GOING THROUGH THE DAY
TODAY. WITH OCEAN TEMPERATURES STILL IN THE 40S, MOST MAINE
ZONES OUTSIDE OF THE MOUNTAINS SHOULD BE A GOOD DEAL COOLER
TODAY. TEMPERATURES WILL CONTINUE TO BE QUITE WARM IN MUCH OF NH
AS THE OCEAN WILL OBVIOUSLY HAVE LESSER OF A COOLING INFLUENCE.
A MODEST BURST OF WAA ALOFT WILL AID IN A CHANCE FOR SHOWERS
ACROSS CENTRAL AND NORTHERN NH THIS MORNING, WITH PERHAPS EVEN A
RUMBLE OF THUNDER WILL RELATIVELY STEEP LAPSE RATES ALOFT. THIS
ACTIVITY SHOULD LIFT NORTHEASTWARD INTO THE WESTERN ME
MOUNTAINS AND FOOTHILLS BY LATE MORNING THEN DRY OUT. THE REST
OF THE FORECAST AREA SHOULD REMAIN DRY.
SHOWERS AND PERHAPS A FEW RUMBLES OF THUNDER MAY AFFECT
NORTHERNMOST NH AND THE WESTERN ME MOUNTAINS TONIGHT BUT THE
BULK OF THE ACTIVITY SHOULD REMAIN IN CANADA AS WARM FRONT
RETURNS NORTHWARD THERE.
KEY MESSAGE 2 DESCRIPTION...
A PROGRESSIVE LOW AMPLITUDE SHORTWAVE TROUGH WILL PASS NORTH OF THE
FORECAST AREA ON TUESDAY, FLATTENING THE RIDGE A BIT AND LEADING TO
SOME MODEST HEIGHT FALLS. A BAND OF MID-LEVEL WESTERLYS IN THE 40 TO
50 KNOT RANGE WILL SPREAD ACROSS THE REGION THROUGH EARLY AFTERNOON,
WHICH COULD LEAD TO SOME EARLY DAY STORMS IN THE VICINITY OF THE
SOUTHERN KENNEBEC VALLEY AND PORTIONS OF THE MIDCOAST. A SECOND WAVE
WILL APPROACH NEW HAMPSHIRE LATE AFTERNOON OR EARLY EVENING. STORMS
MAY BE ONGOING OVER VERMONT BEFORE MOVING INTO NEW HAMPSHIRE AND WE
COULD ALSO HAVE SOME ADDITIONAL DEVELOPMENT OVER THE MOUNTAINS. IN
BOTH POTENTIAL STORM REGIMES, STORM COVERAGE REMAINS UNCERTAIN GIVEN
NEBULOUS FORCING MECHANISMS AND LESS THAN IDEAL DIURNAL TIMING
(EARLY IN THE DAY FOR THE EASTERN STORMS AND CLOSER TO EVENING FOR
THE WESTERN/NORTHERN STORMS). ALL IN ALL, BOTH ENVIRONMENTS COULD
SEE CAPE VALUES IN THE 500 TO 1000 J/KG RANGE AND DEEP LAYER SHEAR
UP TO 35 KNOTS OR SO. THUS, ANY STORMS THAT DO FORM COULD
BECOME STRONG OR MARGINALLY SEVERE WITH THE PRIMARY THREATS OF
SMALL HAIL, GUSTY WINDS, AND FREQUENT LIGHTNING. SHOWERS AND
STORMS SHOULD DIMINISH MID TO LATE EVENING.
A COLD FRONT WILL MOVE ACROSS THE AREA OF WEDNESDAY AND GUIDANCE HAS
CONTINUED THE TREND OF SPEEDING THAT PASSAGE UP. IN FACT, THE NAM
ALMOST HAS THE FRONT AROUND THE MIDCOAST BY 18Z. SO, WE DO HAVE A
RISK FOR SOME STRONGER STORMS EARLIER IN THE DAY ON WEDNESDAY ALONG
AND AHEAD OF THE FRONT BUT THE WINDOW WILL BE SHORT BEFORE THE
BOUNDARY MOVES OUT OVER THE WATERS.
TUESDAY AND WEDNESDAY WILL ALSO BE THE WARMEST DAYS OF THE YEAR THUS
FAR WITH WIDESPREAD HIGHS IN THE 80S AND POTENTIALLY EVEN IN THE
LOWER 90S. TUESDAY'S HIGHS WILL RANGE FROM THE UPPER 70S AND LOWER
80S NORTH, TO THE UPPER 80S AND LOWER 90S SOUTH. COASTAL AREAS MAY
BE A LITTLE BIT COOLER GIVEN AN ONSHORE WIND COMPONENT. WEDNESDAY
WILL BE A TOUCH COOLER FOR MOST WITH THE PASSAGE OF THE COLD FRONT.
WE WILL STILL SEE WIDESPREAD HIGHS IN THE LOW TO MID 80S ALONG AND
SOUTH OF THE FOOTHILLS. TEMPERATURES OVER THE HIGHER TERRAIN WILL
MAX OUT IN THE LOWER 60S TO LOW/MID 70S.
KEY MESSAGE 3 DESCRIPTION...
WE WILL COOL DOWN BEHIND THE FRONT THROUGH THE REST OF THE WORK WEEK
AND INTO THE WEEKEND. THE COOLEST DAY WILL BE ON THURSDAY WHEN HIGHS
WILL MAINLY RANGE FROM THE LOW TO MID 50S NORTH, TO THE LOW TO MID
60S SOUTH. WE WARM JUST SLIGHTLY ON FRIDAY AND TEMPERATURES
GENERALLY STAY AROUND OR SLIGHTLY BELOW NORMAL THROUGH THE WEEKEND.
THE WEATHER PATTERN ALSO FAVORS DRY CONDITIONS DURING THIS TIME
FRAME.
AVIATION /13Z MONDAY THROUGH FRIDAY/
THROUGH 12Z TUESDAY...MAINLY VFR TODAY WITH SHOWERS AND
ISOLATED THUNDERSTORMS APPROACHING FROM THE WEST THIS MORNING.
VFR TONIGHT FOR MOST LOCATIONS. HOWEVER, WITH LOW LEVEL
EASTERLIES WE MAY SEE SOME MVFR TO IFR RESTRICTIONS IN FOG OR
LOW STRATUS, ESPECIALLY ON THE COASTAL PLAIN. LLWS IS ALSO
POSSIBLE OVERNIGHT TONIGHT.
OUTLOOK:
TUESDAY: AFTERNOON SHRA/TS CHANCES NEAR THE US/CAN BORDER. THERE IS
UNCERTAINTY HOW FAR EAST AND SOUTH SHRA/TS DEVELOP IN THE AFTERNOON.
TUESDAY NIGHT: COVERAGE OF SHRA DECREASES. VFR FORECAST.
WEDNESDAY: A COLD FRONT PASSES THROUGH THE REGION WITH SHRA/TS WEST
TO EAST THROUGH THE DAY. MVFR POSSIBLE W/ FRONTAL PASSAGE AND IN
SHOWERS/STORMS.
WEDNESDAY NIGHT: WINDS SHIFT NW WITH VFR BEHIND EXITING COLD FRONT.
THURSDAY AND THURSDAY NIGHT: VFR EXPECTED WITH NO SIG WX.
FRIDAY AND FRIDAY NIGHT: VFR EXPECTED WITH NO SIG WX.
MARINE
HIGH PRESSURE MOVES OVER THE WATERS TODAY WITH RELATIVELY LIGHT
EASTERLY TO SOUTHEASTERLY WINDS.
WINDS MAY APPROACH SCA CRITERIA ON THE COASTAL WATERS TUESDAY
AND WEDNESDAY AS SOUTHERLY FETCH BUILDS. WINDS THEN BECOME
OFFSHORE BEHIND A STRONGER COLD FRONT WED EVENING. HIGH PRESSURE
BUILDS IN FROM THE WEST MID TO LATE WEEK.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
DISCUSSION...CORNWELL/EKSTER/HARGROVE
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