139
FXUS61 KGYX 220311
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1111 PM EDT TUE JUL 21 2026
WHAT HAS CHANGED
BACK EDGE OF STEADY RAINFALL IS PUSHING EAST THROUGH WESTERN
MAINE AND HAVE ADJUSTED POPS TO ALIGN WITH OBSERVED TRENDS. FOG
HAS BECOME MORE PREVALENT IN THE WAKE OF THE RAIN SO HAVE
EXPANDED FOG COVERAGE THROUGH THE REST OF TONIGHT.
KEY MESSAGES
1. RAIN WITH EMBEDDED THUNDER INCREASES IN COVERAGE SOUTH TO
NORTH THIS EVENING. RAIN RATES MAY BE HEAVY AT TIMES, WITH
LOCALIZED AMOUNTS GREATER THAN 1 INCH POSSIBLE.
2. A PASSING COLD FRONT WILL INITIATE SHOWERS AND THUNDERSTORMS
WEDNESDAY AFTERNOON. A FEW OF THESE STORMS MAY BE STRONG TO
SEVERE, WITH GUSTY WINDS THE PRIMARY THREAT.
3. HIGH PRESSURE BRINGS A PERIOD OF MOSTLY DRY WEATHER THROUGH
THE WEEKEND BEFORE THE PATTERN BECOMES MORE UNSETTLED INTO EARLY
NEXT WEEK.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
CAMS HAVE BEEN SPORADIC WITH PRECIPITATION COVERAGE INTO THIS
EVENING. THIS LEADS TO LOWER CONFIDENCE IN EXACT RAIN TIMING,
BUT THE GENERAL AIRMASS STILL SUPPORTS A PERIOD OF SYNOPTIC
RAINFALL TONIGHT.
AN AREA OF RAIN THAT MOVE THROUGH THE MORNING HOURS HAS HELPED
KEEP EARLY AFTERNOON TEMPERATURES A FEW DEGREES OFF PREVIOUS
FORECAST HIGHS. THIS HAS ALSO LIKELY PUT A DENT IN POSSIBLE
DESTABILIZATION AHEAD OF A WARM FRONT LIFTING INTO SOUTHERN NEW
ENGLAND. THIS REGION OF SHOWERS DID EVENTUALLY SUCCUMB TO DRY
AIR ACROSS CENTRAL MAINE, BUT EXPECT A MOISTENING AIRMASS TO
ARRIVE WITH PWATS NEAR 2 INCHES.
UPSTREAM CONVECTION SHOULD MAKE ITS WAY TOWARDS SOUTHERN NH THIS
EVENING. WILL NEED TO MONITOR MESOANALYSIS FOR ANY UPTICKS IN
SURFACE CAPE. THIS WOULD ALLOW CONVECTION TO CONTINUE TO CYCLE
INTO THE SOUTHERN PORTION OF THE FORECAST AREA. FOR NOW, THIS
LOOKS TO STOP AROUND THE NH/MA BORDER, WITH ELEVATED
INSTABILITY BUILDING UP THROUGH THE ME COAST. THIS MUCH SHOULD
BE USEFUL FOR INCREASING RAINFALL RATES THROUGH MID EVENING. THE
ABOVE AVERAGE PWATS, SATURATED PROFILES, AND DEEP WARM CLOUD
LAYERS SHOULD COMPLIMENT THIS WITH EFFICIENT RAIN PROCESSES. ANY
TALLER CORES THAT DEVELOP COULD PRODUCE RAIN RATES AROUND 1 TO
2 INCHES PER HOUR. ANY TRAINING MAY LEAD TO ISOLATED INSTANCES
OF FLASH FLOODING, MAINLY FOCUSED SOUTH AND EAST OF THE
FOOTHILLS. HOWEVER ANTECEDENT DRY CONDITIONS IS KEEPING FLASH
FLOOD GUIDANCE PRETTY HIGH.
FORCING FOR THE MAIN PERIOD OF RAIN IS PROGRESSIVE, AND
DIMINISHING COVERAGE IS EXPECTED AROUND MIDNIGHT SW TO NE. THERE
MAY BE A FEW ADDITIONAL SHOWERS OR RUMBLES OF THUNDER AFTER
THIS, BUT PWATS WILL BE DIMINISHING AMID LESS MOISTURE.
KEY MESSAGE 2 DESCRIPTION...
A COLD FRONT WILL BE APPROACHING WESTERN NH COME WEDNESDAY
MORNING. THIS WILL BE BRINGING IN MUCH DRIER AIR BEHIND IT, BUT
SOME MID LEVELS WILL HAVE ALREADY DRIED BEHIND OVERNIGHT RAIN.
THIS DRY AIR IS EXPECTED TO HINDER COVERAGE OF SHOWERS AND
THUNDERSTORMS INITIATED BY THE ARRIVING COLD FRONT. WHILE CAPE
BUILDS AND SHEAR IS SUPPORTIVE, THINK THE ASPECT OF SEVERE
WEATHER REMAINS FAIRLY ISOLATED. IT MAY NOT BE UNTIL EARLY
AFTERNOON THAT SHOWERS OR STORMS DEVELOP ALONG THE FRONT
BISECTING THE CWA. THESE MAY CONTAIN GUSTY WINDS AND LIGHTNING,
BUT MARGINAL WINDS IN THE LOW LEVELS PUT A CAP ON INTENSITY.
THESE SHOWERS AND STORMS LOOK TO MAKE THEIR WAY TOWARDS THE
ME/NH COASTS BY LATE AFTERNOON, MOVING OVER THE COASTAL WATERS
INTO THE EVENING.
A COOLER NIGHT IS THEN IN STORE AS DEW POINT TEMPS TUMBLE AND
CAA BRINGS OVERNIGHT LOWS IN THE UPPER 40S TO LOWER 50S ACROSS
THE AREA.
KEY MESSAGE 3 DESCRIPTION...
THE REST OF THE WEEK AND INTO THE WEEKEND LOOK TO BE MORE OF A
TRANQUIL SETTING AS HIGH PRESSURE BUILDS INTO THE REGION. A 500
MB BROAD TROUGH BRINGS IN MORE WESTERLY/NORTHWESTERLY FLOW
KEEPING TEMPERATURES AROUND NORMAL FOR THIS TIME OF YEAR.
THURSDAY WILL BE THE COOLEST OF THE DAYS, AS THE AIR MASS BEHIND
THE COLD FRONT SETTLES INTO OUR CWA. THE REMAINDER OF THIS WEEK
LOOKS TO HAVE OUR AREA KEEPING TO THE LOW 80S AS HIGHS, WITH
NIGHTTIME TEMPERATURES FALLING INTO THE MID TO UPPER 50S. WITH
THESE CONDITIONS AT NIGHT, IT MIGHT BE NICE TO OPEN THE WINDOWS!
LOOKING FURTHER AHEAD, THE GLOBAL MODELS ARE ALL IN DECENT
AGREEMENT THAT AT THE START OF NEXT WEEK, A WETTER AND MORE
UNSETTLED PATTERN WILL MAKE A RETURN TO OUR AREA. THIS IS DUE TO
HIGH PRESSURE, WHICH HAD BEEN DOMINATING, EXITING THE AREA. THE
EXACT WEATHER THIS FAR OUT CANNOT BE SET IN STONE FOR THE TIME
BEING, BUT I THINK IT IS FAIR TO SAY THAT THERE LOOKS TO BE A
TREND TOWARD SLIGHTLY COOLER (AND WETTER) WEATHER NEXT WEEK.
AVIATION /03Z WEDNESDAY THROUGH SUNDAY/
THROUGH 00Z THURSDAY...SHRA HAVE PUSHED EAST OF PWM WITH LOW
CIGS AND FOG BRINGING IFR/LIFR CONDITIONS FROM CON AND MHT TO
TAFS SITES EAST. VARYING RATES OF IMPROVEMENT TOWARDS 12Z WITH
VFR BECOMING MORE LIKELY AFTER 12Z.
WEDNESDAY SEE AS COLD FRONT MOVE ACROSS THE AREA WITH A WIND
SHIFT. SHRA/TS DEVELOP ALONG THIS FRONT IN THE EARLY AFTERNOON,
NEARING THE ME/NH COASTS BY 00Z THURS.
OUTLOOK...
THURSDAY-SUNDAY: GENERALLY VFR CONDITIONS ARE EXPECTED AS HIGH
PRESSURE SETTLES OVER THE REGION.
MARINE
WAVES BUILD INTO THIS EVENING WITH ONSHORE FLOW AHEAD AND BEHIND
A WARM FRONT. THESE WINDS CONTINUE MUCH OF WEDNESDAY BEFORE A
COLD FRONT CROSSES THE COASTAL WATERS WED EVENING. THIS WILL
BRING A WIND SHIFT AND GRADUAL DECREASE OF WAVE HEIGHTS
OVERNIGHT INTO EARLY THURSDAY MORNING.
5 TO 6 FT SEAS SLOWLY DECREASE ON THURSDAY, FALLING BELOW SCA
CRITERIA THURSDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION.
SUB-SCA CONDITIONS ARE THEN EXPECTED TO PREVAIL THROUGH THE
WEEKEND AS HIGH PRESSURE SLOWLY CONTINUES EASTWARD OVER THE
WATERS.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ150-152-
154.
DISCUSSION...BARON/CORNWELL/SCHROETER
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