157
FXUS61 KGYX 120616
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
216 AM EDT SUN JUL 12 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST AT THIS TIME.
KEY MESSAGES
1. HIGH PRESSURE BRINGS MOSTLY DRY WEATHER AND SEASONABLY WARM
TEMPERATURES WITH COMFORTABLE HUMIDITY THROUGH TODAY.
2. HOT AND HUMID CONDITIONS BRING MODERATE TO MAJOR HEAT RISK MONDAY-
WEDNESDAY WITH THE PEAK OCCURING ON TUESDAY. HUMIDITY ABATES THE
SECOND HALF OF THE WEEK, WHILE TEMPERATURES CONTINUE TO RUN ABOVE
NORMAL.
3. A COLD FRONT BRINGS THE THREAT FOR SEVERE STORMS LATE TUESDAY
INTO TUESDAY NIGHT.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
PLEASANT CONDITIONS WILL PERSIST TODAY AS SURFACE HIGH PRESSURE
REMAINS OVER NEW ENGLAND. MOSTLY SUNNY SKIES ARE EXPECTED WITH
HIGH TEMPERATURES INTO THE LOWER TO MIDDLE 80S. LIGHT SURFACE
FLOW WILL LIKELY ALLOW FOR A SEA BREEZE TO DEVELOP BY EARLY
AFTERNOON BEFORE PUSHING INLAND THROUGH THE REMAINDER OF THE
AFTERNOON AND EARLY EVENING.
CLEAR TO PARTLY CLOUDY SKIES TONIGHT WILL ALLOW FOR ANOTHER
NIGHT OF RADIATIONAL COOLING WITH LOWS FALLING INTO THE UPPER
40S ACROSS THE NORTHERN VALLEYS WITH MIDDLE TO UPPER 50S
ELSEWHERE. VALLEY FOG IS ONCE AGAIN POSSIBLE AS WELL.
KEY MESSAGE 2 DESCRIPTION...
LONG WAVE RIDGING OVER THE CENTRAL U.S. WILL SPREAD EASTWARD
MONDAY INTO TUESDAY, ALLOWING H85 TEMPERATURES TO WARM TO AROUND
+20C WITH H925 TEMPERATURES NEARING +30C. THIS WILL ALLOW HIGH
TEMPERATURES TO REACH THE LOWER TO MIDDLE 90S ON MONDAY WITH
MIDDLE TO UPPER 90S ON TUESDAY. DEW POINTS WILL REMAIN
COMFORTABLE INTO THE 50S/LOWER 60S ON MONDAY BEFORE RISING INTO
THE MIDDLE TO UPPER 60S ON TUESDAY. THIS WILL ALLOW AFTERNOON
HEAT INDICES TO APPROACH THE 100 DEGREE MARK ON TUESDAY AND
THEREFORE HEAT ADVISORIES WILL LIKELY EVENTUALLY BE NEEDED FOR
PORTIONS OF THE FORECAST AREA. OVERNIGHT LOWS ON TUESDAY NIGHT
WILL LIKELY ONLY BE INTO THE 70S, RESULTING IN CUMULATIVE HEAT
STRESS.
A DRIER AIRMASS WILL ARRIVE ON WEDNESDAY BEHIND A COLD FRONT
WITH COMFORTABLE HUMIDITY LIKELY THROUGH THE REMAINDER OF THE
WEEK DESPITE CONTINUED WARM TEMPERATURES.
KEY MESSAGE 3 DESCRIPTION...
A RATHER ROBUST TROUGH WILL TRACK ACROSS QUEBEC TUESDAY (WITH AN
ATTENDANT SURFACE LOW DOWN TO AROUND 990 MB). DUE TO THE
UPSTREAM RIDGE OVER THE CENTRAL U.S., OUR REGION WILL BE UNDER
NORTHWEST FLOW ALOFT. IN ADVANCE OF A SURFACE COLD FRONT (WHICH
LOOKS TO ARRIVE HERE WEDNESDAY MORNING), WE ARE EXPECTING TO SEE
A RATHER FAVORABLE ENVIRONMENT FOR SEVERE STORMS OVER OUR
REGION. THE FEATURE OF PARTICULAR INTEREST FOR THIS SETUP IS AN
ELEVATED MIXED LAYER (EML) MOVING OVER THE REGION; STEEP MID-
LEVEL LAPSE RATES ON THE ORDER OF 7-7.5 C/KM. COMBINED WITH
STRONG SURFACE HEATING AND DEW POINTS RISING TO THE UPPER
60S/LOW 70S, PLENTY OF INSTABILITY WILL BE AVAILABLE WITH MUCAPE
VALUES SURGING TO 2000-3000 J/KG, WHICH IS QUITE HIGH EVEN FOR
JULY. WHAT CONCERNS ME HOWEVER IS THIS INSTABILITY LOOKS TO BE
PAIRED WITH UNUSUALLY STRONG WIND ENERGY. 0- 6 KM BULK WIND
SHEAR IS ON THE ORDER OF 45-60 KTS, WHILE 0-3 KM SRH IS PROGGED
AT 200-300 M2/S2, INDICATING VERY FAVORABLE SPEED AND
DIRECTIONAL SHEAR. THIS COMBINATION OF INSTABILITY AND SHEAR
SUGGESTS A RATHER VOLATILE PARAMETER SPACE FOR ORGANIZED AND
LONG- LIVED SEVERE STORMS, SHOULD THEY ARRIVE, THAT WOULD BE
CAPABLE OF ALL SEVERE HAZARDS.
MAJOR UNCERTAINTY REMAINS ON STORM COVERAGE/TIMING. CONVECTION
SHOULD INITIALLY FIRE WELL TO OUR NORTH (CLOSER TO THE SURFACE
TROUGH INITIATING BOUNDARY) DURING THE AFTERNOON. STORMS, SHOULD
THEY MAKE IT TO NORTHERN NEW ENGLAND, WILL LIKELY BE ARRIVING IN THE
EVENING, WELL PAST PEAK HEATING HOURS. THIS MAKES FOR A TRICKY
FORECAST, AS CLIMATOLOGY TYPICALLY FAVORS WEAKENING AFTER THE LOSS
OF DAYTIME HEATING. HOWEVER, THE RARE SETUP OF HAVING AN EML AND
STRONG WIND SHEAR/FORCING MAKES FOR AN UNUSUAL SCENARIO WHERE STORMS
MAY PERSIST WELL INTO THE NIGHT, UNLIKE MOST OTHER EVENTS. GIVEN WE
ARE STILL AROUND THREE DAYS OUT, AND CAMS ARE NOT INTO RANGE YET, IT
STILL REMAINS A WAIT AND SEE FOR IMPACTS. THERE IS THE CHANCE THE
TROUGH ARRIVAL COULD SLOW DOWN, KEEPING THE STORM THREAT ALMOST
ENTIRELY IN CANADA. ON THE CONTRARY, A FASTER TROUGH ARRIVAL
SUGGESTS CONVECTION MAY IMPACT A LARGER SWATH OF NEW ENGLAND. SPC
HAS MAINTAINED A 15% CHANCE OF SEVERE, NORTH OF A CONCORD-PORTLAND-
ROCKLAND LINE.
AVIATION /02Z SUNDAY THROUGH THURSDAY/
THROUGH 06Z MONDAY: VFR CONDITIONS EXPECTED. THE EXCEPTION IS AT
KLEB AND KHIE WHERE VALLEY FG IS POSSIBLE AFTER 06Z SUNDAY
THROUGH AROUND 12Z SUNDAY AND THEN AGAIN TONIGHT. LIGHT AND
VARIABLE WINDS ARE EXPECTED, ALTHOUGH A SEA BREEZE IS LIKELY AT
KPWM, KPSM, AND KRKD WITH S WINDS AT 5-15 KTS. NO LLWS IS
ANTICIPATED THROUGH THE PERIOD.
OUTLOOK:
MONDAY/MONDAY NIGHT: VFR CONDITIONS.
TUESDAY/TUESDAY NIGHT: VFR CONDITIONS DURING THE DAYTIME BEFORE
POSSIBLE SHRA/TSRA ARRIVES LATE DAY OR AT NIGHT, BRINGING
LOCALIZED RESTRICTIONS.
WEDNESDAY-THURSDAY: VFR CONDITIONS LIKELY.
MARINE
S WINDS MAY GUST UP TO 25 KTS LATE MONDAY INTO EARLY TUESDAY
WITH SEAS OUTSIDE OF THE BAYS BUILDING TO 3-6 FT. W-SW WINDS MAY
THEN APPROACH 30 KTS LATE TUESDAY INTO TUESDAY NIGHT WITH SEAS
AT 3-6 FT OUTSIDE OF THE BAYS.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
DISCUSSION...TUBBS/BARKER
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