131
FXUS61 KGYX 300626
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
226 AM EDT WED SEP 30 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE.
KEY MESSAGES
1. TEMPERATURES CONTINUE AN UPWARD TREND TODAY INTO THURSDAY
WITH HIGH PRESSURE PROVIDING FAIR WEATHER.
2. STRONG COLD FRONTS FRIDAY THEN AGAIN MONDAY CROSS THE REGION,
BRINGING BRIEF RAIN CHANCES AND BURSTS OF CRISP FALL WEATHER.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
BROAD HIGH PRESSURE ALONG THE EAST COAST WILL BECOME CENTERED
SOUTH OF NEW ENGLAND TODAY THROUGH THURSDAY. THIS WILL PROVIDE
FAIR WEATHER WHILE PARTS OF TODAY WILL FEATURE MORE CLOUDS THAN
SUN WITH MORE IN THE WAY OF SUNSHINE THURSDAY. AS HIGH PRESSURE
WILL BE CENTERED SOUTH OF THE REGION, TEMPERATURES AT 925 MB
WILL CLIMB TO AROUND +15C TODAY AND +19C THURSDAY. WHILE WINDS
WILL BE LIGHT, MODEL SOUNDINGS SHOW MIXING TO AT LEAST 925 MB
WILL BE POSSIBLE BOTH DAYS WHICH WILL TRANSLATE TO HIGHS IN THE
LOW 70S TODAY AND UPPER 70S THURSDAY. LIGHT WINDS AND SKIES
TRENDING MOSTLY CLEAR TONIGHT WILL LIKELY LEAD TO VALLEY FOG.
STEADY SW WINDS AND A WARM AIR MASS IN PLACE WILL LEAD TO A MILD
NIGHT THURSDAY NIGHT WITH LOWS FAILING TO DROP BELOW 60 DEGREES
ACROSS MUCH OF THE AREA.
KEY MESSAGE 2 DESCRIPTION...
A SHORTWAVE AND ATTENDANT COLD FRONT WILL CROSS THE REGION FRIDAY
AFTERNOON-NIGHT. TEMPERATURES ARE MORE UNCERTAIN OWING TO POTENTIAL
CLOUD COVER AND PRECIPITATION, BUT GUIDANCE HAS SLOWED DOWN THE
FRONT ENOUGH TO SUGGEST ONE MORE WARM DAY IN STORE, WITH 850 MB
TEMPS PUSHING 13-15 C ALONG WITH WARM SW SURFACE WINDS, WHICH
SUPPORTS HIGHS WELL INTO THE MID-UPPER 70S. WITH A FRONTAL PASSAGE
AROUND/JUST AFTER PEAK HEATING, CANNOT RULE OUT SOME HEAVIER
DOWNPOURS AND CONVECTION WITH AROUND 500 J/KG OF CAPE INDICATED ON
MULTIPLE SOURCES. PWATS ALSO SURGE TO 1.5-1.8"+ DEPENDING ON MODEL
OF CHOICE, WHICH IS 2-3 SD ABOVE CLIMATOLOGY, INDICATING THE
POTENTIAL FOR HEAVY DOWNPOURS. A VERY PROGRESSIVE SYSTEM LOOKS TO
CAP PRECIPITATION TOTALS HOWEVER, WITH ONLY A 30% OF EXCEEDING 0.5"
OF RAIN FOR THE FORECAST AREA ON THE ECMWF ENSEMBLE. OVERALL DOES
NOT LOOK LIKE A PARTICULARLY HIGH IMPACT EVENT AS OF NOW, BUT
SOMETIMES STRONGER DYNAMICS THIS TIME OF YEAR CAN COMPENSATE FOR
MORE MARGINAL INSTABILITY/MOISTURE.
SPEAKING OF, VERY STRONG CAA BEHIND THE COLD FRONT WITH 850 MB TEMPS
NOSEDIVING TO 2-5 C BY SATURDAY EVENING, WHICH WILL BE QUITE A
AIRMASS CHANGE. HIGHS IN THE 50S-60S THIS WEEKEND WILL BE
REPRESENTATIVE OF A COOLER SHIFT FROM THIS WEEK.
VERY STRONG AGREEMENT ON GLOBAL GUIDANCE IN ANOTHER DYNAMIC TROUGH
AND ATTENDANT COLD FRONT APPROACHING THE REGION LATE SUNDAY THEN
CROSSING THROUGH MONDAY. SIMILAR TO THE FIRST WAVE, A BIT OF A
GLANCING BLOW WITH THE SURFACE LOW AND ATTENDANT VORT MAX WELL TO
THE NORTH UP IN QUEBEC. THIS KEEPS THE SYSTEM PROGRESSIVE WITH ONLY
A WEAK SIGNAL FOR QUICK-HITTING PRECIPITATION ALONG THE COLD FRONT,
BUT THIS MAY EVEN BE A MOSTLY DRY FRONTAL PASSAGE DEPENDING ON HOW
IT ALL SHAKES OUT, AS ENSEMBLE SUPPORT FOR RAINFALL IS NOT HIGH
CURRENTLY. AN EVEN STRONGER COLD PUNCH IS POSSIBLE BEHIND THIS
SECOND FRONT WITH 850 MB TEMPS GOING NEGATIVE, WHICH AT A GLANCE
COULD SPELL QUITE CHILLY AND CRISP CONDITIONS FOR A FEW DAYS.
AVIATION /01Z WEDNESDAY THROUGH SUNDAY/
THROUGH 12Z THURSDAY...MVFR CIGS LIKELY ACROSS WESTERN ME INTO
THROUGH THIS MORNING WHILE SOUTHERN NH TERMINALS COULD BE VFR
OR MVFR. FOG REMAINS POSSIBLE AT ALL SITES THROUGH DAY BREAK
BUT IS MOSTLY LIKELY TO BRING IFR TO LIFR AT LEB, HIE, AND CON.
FOG SHOULD LIFT BY MID- MORNING TODAY WITH MOSTLY VFR THROUGH
00Z. MAINLY VFR TONIGHT WITH THE EXCEPTION BEING VALLEY FOG AT
LEB, HIE, AND POSSIBLY CON.
OUTLOOK:
THURSDAY: MAINLY VFR.
FRIDAY: VFR LIKELY IN THE MORNING WITH MVFR POSSIBLE LATE DUE
TO SHOWERS.
SATURDAY: VFR EXPECTED.
SUNDAY: MAINLY VFR WITH CHANCES FOR SHOWERS INCREASING SUNDAY
NIGHT.
MARINE
LOW PRESSURE WILL BE MOVING EAST OF NOVA SCOTIA THIS MORNING
WITH HIGH PRESSURE BUILDING ALONG THE EAST COAST TODAY AND
SETTLING SOUTH OF THE WATERS THURSDAY. THIS WILL ALLOW FOR WINDS
AND SEAS TO REMAIN BELOW SCA THRESHOLDS.
SW WINDS WILL FRESHEN THURSDAY NIGHT AS A COLD FRONT APPROACHES
FROM THE NW. THE FRONT CROSSES FRIDAY NIGHT SHIFTING WINDS OUT
OF THE NW WITH HIGH PRESSURE BUILDING IN OVER THE WEEKEND. WINDS
AND SEAS WILL CONTINUE TO REMAIN BELOW SCA THRESHOLDS WHILE SOME
GUSTS TO 20 KTS ARE LIKELY IN SW FLOW.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
DISCUSSION...BARKER/SCHROETER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page