488
FXUS61 KGYX 161831
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
231 PM EDT SAT AUG 16 2025
SYNOPSIS
A COLD FRONT WILL BRING THE CHANCE FOR SOME SHOWERS AND STORMS
ON SUNDAY, FOLLOWED BY COOLER FALL-LIKE WEATHER FOR THE START OF
THE WORK WEEK. AN AREA OF LOW PRESSURE WILL APPROACH THE REGION
BY MID-WEEK, BRINGING A PERIOD OF UNSETTLED WEATHER. HIGH
PRESSURE BUILDS IN FROM THE NORTH THROUGH THE END OF NEXT WEEK
AS HURRICANE ERIN PASSES BY WELL OFFSHORE.
NEAR TERM /THROUGH TONIGHT/
IMPACTS AND KEY MESSAGES:
* NO SIGNIFICANT WEATHER IMPACTS EXPECTED.
VISIBLE SATELLITE AND RADAR THIS AFTERNOON SHOW A DECENT
CUMULUS FIELD HAS DEVELOPED OVER THE AREA WITH SOME SHOWERS
FORMING IN SOUTHERN VERMONT ALONG A SHORTWAVE. THESE WILL MOVE
EASTWARD AND GRAZE THE FAR SOUTHEASTERN CORNER OF NEW HAMPSHIRE
OVER THE NEXT COUPLE HOURS, SO ADDED SOME LOW POPS THERE TO
CAPTURE THAT. OTHERWISE THE REMAINDER OF THE AFTERNOON LOOKS
QUIET.
EXPECT SOME PATCHY FOG DEVELOPMENT AGAIN TONIGHT, ESPECIALLY IN
THE VALLEYS AS WE BEGIN TO SEE LOW LEVEL MOISTURE INCREASE
OVERNIGHT. WE SHOULD ALSO ONCE AGAIN SEE SOME DECENT RADIATIONAL
COOLING SO BLENDED IN SOME MAV TO REFLECT THAT. THIS BRINGS LOW
TEMPERATURES DOWN TO THE MID-TO UPPER 50S NORTH OF THE
MOUNTAINS AND LOW 60S TO THE SOUTH. SOME HIGH CLOUDS MAY REACH
AS FAR NORTH AS SOUTHERN NEW HAMPSHIRE AND KEEP THEM A LITTLE
BIT WARMER (MID-60S).
SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/
IMPACTS AND KEY MESSAGES:
* SOME STRONG TO MARGINALLY SEVERE THUNDERSTORMS ARE POSSIBLE
SUNDAY AFTERNOON AND EARLY EVENING WITH STRONG WINDS BEING THE
MAIN THREAT.
A TROUGH DEEPENS OVER THE AREA SUNDAY WITH AN ACCOMPANYING COLD
FRONT SET TO CROSS AS WELL. THIS WILL PROVIDE THE FORCING FOR
SHOWERS AND A FEW STRONG STORMS IN THE AFTERNOON AND EARLY
EVENING HOURS. THE MORNING SHOULD START MOSTLY CLEAR SOUTH OF
THE MOUNTAINS ALLOWING FOR TEMPERATURES TO CLIMB INTO THE UPPER
80S IN THE FOOTHILLS TO AROUND 90F IN SOUTHERN NEW HAMPSHIRE AND
SOUTHWESTERN MAINE. SOUTHWESTERLY FLOW EARLY WILL HELP
DEWPOINTS CLIMB INTO MID- 60S WHICH MAY BRING HEAT INDICES CLOSE
TO 95F IN A FEW LOCATIONS IN INTERIOR SOUTHEASTERN NEW
HAMPSHIRE, BUT DON'T REALLY HAVE THE AREAL EXTENT OR DURATION TO
JUSTIFY A HEAT ADVISORY. INSTEAD, I THINK THE HIGHER DEWPOINTS
WILL BE MORE IMPACTFUL IN REGARDS TO THE SEVERE WEATHER THREAT
AS THEY WILL INCREASE LIFT CONSIDERING THE DRY AIR ALOFT.
LOCATIONS NORTH OF THE MOUNTAINS ARE THE FIRST TO SEE MORE IN
THE WAY OF CLOUD COVER AND SHOWERS/STORMS, SO HIGH TEMPERATURES
THERE WILL LIKELY BE LIMITED TO THE UPPER 70S AND LOW 80S.
TIMING OF SHOWERS AND STORMS IS PRETTY UNANIMOUS BETWEEN CAMS
WITH A LINE OF SHOWERS/STORMS CROSSING THE INTERNATIONAL BORDER
IN THE 2-3PM WINDOW WITH CONVECTION BEGINNING TO FIRE OUT AHEAD
OF IT NEAR THE FOOTHILLS AS WELL. THE HREF SUGGESTS AROUND
500-800 J/KG OF SBCAPE DEVELOPS BY THIS TIME WITH 25-35 KTS OF
BULK SHEAR. CAMS HAVE BACKED OFF ON MID- LEVEL LAPSE RATES WITH
THE LATEST RUNS, SUGGESTING THEM BEING MORE IN THE WAY OF 5.5
C/KM, BUT EVEN SO FORECAST SOUNDINGS DO HAVE SOME NICE INVERTED
VS. WOULD EXPECT STORMS TO TAKE A CELLULAR STORM MODE WITH,
STRONG DOWNDRAFT WINDS THE MAIN HAZARD. THE SPC HAS INTRODUCED A
MARGINAL RISK FROM SOUTHERN NEW HAMPSHIRE UP THROUGH THE
MIDCOAST. OVERALL COVERAGE CONTINUES TO LOOK MOSTLY SCATTERED,
BUT ONE OF THE AREAS THE CAMS HAVE BEEN CONSISTENTLY AND
UNANIMOUSLY DEVELOPING THE MORE ROBUST CONVECTION IS OVER THE
MIDCOAST. I WOULD EXPECT THIS AREA TO BE THE MOST LIKELY TO SEE
THUNDERSTORMS, WITH LOCATIONS TO THE WEST SEEING MUCH MORE HIT-
OR-MISS TYPE STUFF. UNFORTUNATELY, I WOULD NOT BE SURPRISED IF
THERE ARE MANY LOCATIONS THAT MISS OUT ON MUCH NEEDED RAIN
COMPLETELY, ESPECIALLY IN NEW HAMPSHIRE WHERE CAMS HAVE BEEN
VERY SPORADIC WITH SHOWER/STORM COVERAGE. GENERALLY QPF IN THE
LOWER CONFIDENCE AREAS IS LESS THAN A TENTH OF AN INCH AND
AROUND 0.25" IN THE MOUNTAINS WHERE ROBUST CONVECTION SEEMS LESS
LIKELY. IN THE MIDCOAST AREA WHERE THE MODELS HAVE BEEN MORE
CONSISTENT, IT'S UP AROUND 0.75-1". THE ENSEMBLE MAX SUGGESTS
THAT SOME OF THE MORE ROBUST CONVECTION COULD DROP UPWARDS OF 2"
IN SPOTS AND WITH PWATS MODELED UP AROUND 1.50-1.75", I FIND
THAT REASONABLE. THE BOTTOM LINE IS THAT SOME LOCATIONS WILL
SCORE MUCH NEEDED RAIN, WHILE MANY OTHERS CONTINUE TO GET LITTLE
OR NONE.
SHOWERS AND STORMS SINK SOUTH OFF THE COAST IN THE 8-9PM WINDOW
AND BETWEEN LOSS OF DAYTIME HEATING AND DRIER AIR WORKING IN
BEHIND THE FRONT THEY SHOULD BE GETTING CHOKED OFF PRETTY
QUICKLY. THE DRIER AIR AND CLEARING SKIES NORTH OF THE MOUNTAINS
SHOULD ALLOW THAT AREA TO DROP INTO THE LOW TO MID 40S. SOUTH
OF THE MOUNTAINS, WHERE INFLUENCE FROM THE FRONT MAY TAKE A
LITTLE LONGER, HAS A BETTER CHANCE OF BOTTOMING OUT IN THE LOW
TO MID 50S, WITH SOME UPPER 50S ALONG THE SOUTHERN COAST. WINDS
SOUTH OF THE MOUNTAINS ALSO LOOK QUITE BREEZY POST FRONT SOUTH
OF THE MOUNTAINS WITH SOME 15-20MPH GUSTS POSSIBLE THROUGH THE
MIDNIGHT HOUR.
LONG TERM /MONDAY THROUGH SATURDAY/
KEY MESSAGES
-FALL LIKE WEATHER FOR EARLY NEXT WEEK
-SOME OPPORTUNITIES FOR RAINFALL MIDWEEK
-DRY & WARMING TREND FOR LATE WEEK INTO THE WEEKEND
A FALL-LIKE AIRMASS ASSOCIATED WITH UPPER LEVEL TROUGHING AND
SURFACE CANADIAN HIGH PRESSURE WILL SET-UP ACROSS THE REGION BY
MONDAY. THE MOISTURE STARVED AIRMASS (RH<40%) WILL LIMIT CLOUD
COVER APART FROM SOME FAIR WEATHER CU. THE DEWPOINTS IN THE
40S/50S WILL SUPPORT COLD NIGHTS WITH MANY SITES BOTTOMING OUT
AT OUR CROSS-OVER TEMPS IN THE LOWS 40S TO LOW 50S, COOLER IN
THE HIGHER TERRAIN. THE COLDER AIR OVER WARM WATERS WILL LEAD TO
VALLEY FOG IN THE MORNINGS. EXPANSIVE SURFACE HIGH PRESSURE
WILL REMAIN OVER THE AREA THROUGH TUESDAY WITH DRY AIR AND
STRONG SUBSIDENCE, SUPPORTING MOSTLY SUNNY SKIES AND LIGHT
WINDS. A SHORTWAVE TROUGH IS PROJECTED TO SWING ACROSS THE AREA
MIDWEEK, BRINGING SOME SHOWERS BACK INTO THE FORECAST (20-50%),
WITH THE GREATEST CHANCE ACROSS NH, AND LOWEST NEAR THE MIDCOAST
WHERE IT HAS BEEN DRIEST RECENTLY. THE AIRMASS WILL HAVE
RECOVERED SOME MOISTURE AHEAD OF THIS SHORTWAVE, WITH PWATS
>1.25", SO RAINFALL WILL BE ABLE TO ACCUMULATE TO ~0.25" SOUTH
OF THE MOUNTAINS, AROUND 0.5" OR GREATER IN THE HILLS. THIS
EVENT IS THE BEST OPPORTUNITY FOR MEASURABLE RAINFALL IN THE
LONG TERM, SO DROUGHT CONDITIONS LIKELY TO WORSEN OVER THE NEXT
7-10 DAYS. SURFACE HIGH PRESSURE LEADS US INTO THE WEEKEND, WITH
GRADUAL DAY-TO-DAY WARMING WHICH CONTINUES INTO THE WEEKEND AS
ZONAL FLOW TO WEAK RIDING ALOFT DEVELOPS.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
SHORT TERM...RESTRICTIONS ARE LIKELY AGAIN OVERNIGHT AT LEB AND
HIE IN VALLEY FOG, AND POSSIBLE AT AUG AND RKD WITH LOW
STRATUS/FOG. ANYTHING THAT DOES DEVELOP WILL QUICKLY CLEAR BY
AROUND 13Z (MAYBE CLOSER TO 16Z AT RKD) BACK TO VFR. SUNDAY
AFTERNOON AND EVENING WILL FEATURE SCATTERED THUNDERSTORMS WITH
TERMINALS SOUTH OF THE MOUNTAINS MOST LIKELY TO BE EFFECTED.
SOME LOW LEVEL WIND SHEAR IS POSSIBLE SUNDAY NIGHT ALONG THE
COAST BEHIND A FRONTAL PASSAGE.
LONG TERM...THERE WILL BE LOCALIZED RIVER VALLEY FOG THROUGH
THE FIRST PART OF NEXT WEEK THAT WILL CAUSE LOCALIZED
REDUCTIONS, ESPECIALLY ACROSS THE NORTHERN TERMINALS. OTHERWISE,
LARGE AREA OF CANADIAN-SOURCED HIGH PRESSURE WILL EXPAND ACROSS
THE REGION PROVIDING WIDESPREAD VFR CONDITIONS THROUGH THE
ENTIRE TAF PERIOD.
MARINE
SHORT TERM...SEAS AND WIND GUSTS STAY MOSTLY BELOW SCA CRITERIA
THROUGH THIS PERIOD. THE EXCEPTION IS OVERNIGHT SUNDAY WHEN
GUSTS AROUND 25KTS BEHIND THE A FRONT MOVING OVER THE WATERS MAY
NECESSITATE AN SCA. SHOWERS AND THUNDERSTORMS ARE POSSIBLE
SUNDAY LATE EVENING/NIGHT AS THE FRONT MAKES IT'S APPROACH. THE
FRONT WILL SHIFT WINDS FROM SOUTHERLY TO NORTHERLY OVERNIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/... THE LONG TERM WILL START
WITH N/NE WINDS AT 10-20 KT N/NE AND 3-4 FT SEAS, BUT GRADUALLY
IMPROVING CONDITIONS AS HIGH PRESSURE BUILDS OVERHEAD. HIGH
PRESSURE WILL DOMINATE INTO TUESDAY WITH FAIR SEAS. INCREASING
POTENTIAL FOR SCA CONDITIONS THU/FRI DUE TO THE APPROACH OF
SWELLS FROM WHAT IS CURRENTLY HURRICANE ERIN. ERIN IS PROJECTED
TO PUSH EAST OF THE U.S. COAST BY MIDWEEK, HOWEVER SOME OF THE
LARGER SEAS AND SWELLS 15-17 SECONDS COULD REACH THE LOCAL AREA
DESPITE THE STORM MOVING WELL AWAY FROM THE AREA. SEAS ARE
LIKELY TO EXCEED 5 FT, HOWEVER THIS IS HIGHLY DEPENDENT ON THE
TRACK AND STRENGTH OF ERIN AS IT DRIFTS NORTHWARD THE NEXT FEW
DAYS.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
SYNOPSIS...JAMISON
NEAR/SHORT TERM...BARON
LONG TERM...JAMISON
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