741
FXUS61 KGYX 022336
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
736 PM EDT SUN AUG 2 2026
WHAT HAS CHANGED
MINOR CHANGES WERE MADE TO THE NEAR TERM PORTION OF THE FORECAST
AND THE AVIATION SECTION HAS BEEN UPDATED FOR THE 00Z TAF
PACKAGE.
KEY MESSAGES
1.SHOWERS AND THUNDERSTORMS INCREASE IN COVERAGE LATER TONIGHT
AND PERSIST INTO MONDAY AS A COLD FRONT CROSSES THE REGION.
2. HUMID CONDITIONS PERSIST THROUGH THE REMAINDER OF THE WEEK
WITH CHANCES FOR SCATTERED AFTERNOON THUNDERSTORMS.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
AN UPPER-LEVEL TROUGH OVER EASTERN CANADA WILL DEEPEN AND
CARVE SOUTH INTO NEW ENGLAND TONIGHT INTO MONDAY. GUIDANCE
CONTINUES TO FAVOR A SLIGHTLY SLOWER EASTWARD PROGRESSION, WITH
THE TROUGH POTENTIALLY CLOSING OFF. DEEP SOUTHERLY TO
SOUTHWESTERLY FLOW WILL ADVECT A PLUME OF MOISTURE RICH AIR INTO
THE REGION, DRIVING PWATS VALUES AROUND 2.0 INCHES, WITHIN AN
ENVIRONMENT WITH DEEP WARM-CLOUD DEPTHS (>13KFT). THE OVERNIGHT
TIMING WILL LIMIT OVERALL INTENSITY, AND SHOULD START MONDAY
OFF WITH MOSTLY CLOUDY CONDITIONS. THE CLOUD COVER WILL BE A
DEFINING DRIVER ON INTENSITY OF ANY STORMS THROUGHOUT MONDAY AS
UPPER LEVELS BECOME MORE FAVORABLE WITH ASCENT INCREASING
THROUGHOUT THE DAY. INCREASING LARGE-SCALE ASCENT ON MONDAY
WILL INTERACT WITH MODEST INSTABILITY (CAPE 500-1000J/KG) WILL
PRODUCE MULTIPLE ROUNDS OF HEAVY SHOWERS AND THUNDERSTORMS. AS
THINGS CURRENTLY LOOK, WE CAN EXPECT TALL, SKINNY CAPE PROFILES,
WITH A HIGH MOISTURE CONTENT, AND EFFICIENT WARM RAIN
COLLISION-COALESCENCE PROCESSES. TRANSLATION, WHEN IT RAINS IT
WILL POUR. THE STORMS SHOULD BE PROGRESSIVE, WHICH SHOULD KEEP
MOST STORM TOTAL ACCUMULATIONS AROUND 0.5-1. HOWEVER, THE STORM
MOVEMENTS WILL BE RUNNING PARALLEL TO THE FRONTAL BOUNDARY,
INCREASING THE POTENTIAL FOR STORM TRAINING AND BACKBUILDING
WITH FROPA. DRY ANTECEDENT CONDITIONS WITH AMPLE RUNOFF STORAGE
REDUCES THE WIDESPREAD FLOOD RISK, HOWEVER LOCALIZED AREAS COULD
QUICKLY ACCUMULATE 3+, SO WE CANT RULE OUT AN ISOLATED RISK
OF FLASH FLOODING. HIGHER TERRAIN MAY EXPERIENCE LOCALIZED
UPSLOPE ASCENT, FURTHER ELEVATING RAINFALL EFFICIENCY AND FLASH
FLOOD THREATS. WPC HAS THE REGION IN A LEVEL 1 OF 4, A MARGINAL
RISK FOR LOCALIZED FLASH FLOODING. AT THIS TIME IT IS HARD TO
PIN POINT EXACTLY WHERE THE HIGHEST RISK FOR FLOODING WOULD
OCCUR, AND GIVEN DRY ANTECEDENT CONDITIONS, HAVE HELD OFF ON A
FLOOD WATCH.
IN ADDITION TO THE EXCESSIVE RAINFALL THREAT, SPC MAINTAINS A
MARGINAL RISK (LEVEL 1/5) FOR SEVERE WEATHER FOR MONDAY
AFTERNOON; THE PRIMARY HAZARD WILL BE LOCALIZED DAMAGING WIND
GUSTS FROM WATER- LOADED DOWNBURSTS. CAMS CONTINUE TO SUGGEST
THAT STORMS WILL DEVELOP ALONG THE COLD FRONT MOVING WEST TO
EAST ACROSS THE AREA, STRENGTHENING IN NEW HAMPSHIRE TOWARDS
PEAK HEATING. AS MENTIONED ABOVE, WE WILL SEE SOME MODEST
INSTABILITY WITH MLCAPE IN THE 500 TO 1000 J/KG RANGE.
THE INSTABILITY ALONG THE FRONT WILL BE COLLOCATED WITH 40 TO
45 KNOTS OF EFFECTIVE LAYER SHEAR. THUS, THE MORE ESTABLISHED
UPDRAFTS WILL HAVE THE POTENTIAL TO PRODUCE SOME ISOLATED
DAMAGING WIND GUSTS. AS IS OFTEN THE CASE AROUND HERE, MUCH OF
THE SEVERE POTENTIAL WILL DEPEND ON HOW MUCH NEW HAMPSHIRE CAN
CLEAR OUT AFTER THE MORNING CONVECTION MOVES THROUGH. IF WE GET
SOME MORE BREAKS, WE COULD SEE POCKETS OF MLCAPE CLOSER TO THAT
1000 J/KG VALUE BUT IF WE REMAIN SOCKED IN, INSTABILITY WILL BE
MORE LIMITED.
KEY MESSAGE 2 DESCRIPTION...
TUESDAY THROUGH FRIDAY...
THE FRONTAL BOUNDARY WILL WEAKEN SOUTH OF THE REGION ON TUESDAY,
PROVIDING FAIR CONDITIONS AND A BRIEF REDUCTION IN THE
HEAT/HUMIDITY. BY WEDNESDAY THROUGH THE WEEKEND, THE BROAD
UPPER LEVEL TROUGH SHIFTS BACK OVER THE GREAT LAKES, AND WITH
THE BERMUDA HIGH OFFSHORE ESTABLISHING DEEP SOUTHWESTERLY FLOW
ACROSS THE AREA. THIS WILL SUPPORT WARM AND HUMID CONDITIONS,
WITH SHOWER AND THUNDERSTORM CHANCES (2535%) DIURNALLY DRIVEN.
SOME GUIDANCE IS SHOWING EMBEDDED SHORTWAVE ENERGY THURSDAY
THAT COULD ENHANCE COVERAGE, SO HAVE HIGHEST POPS AT THAT POINT
IN THE EXTENDED PERIOD. WHILE EXACT TIMING AND INTENSITY REMAIN
UNCERTAIN THIS FAR OUT, DIURNAL HEATING WILL FAVOR THE HIGHEST
STORM COVERAGE DURING THE AFTERNOON AND EVENING HOURS.
AVIATION /00Z MONDAY THROUGH FRIDAY/
THROUGH 00Z TUESDAY: AN APPROACHING SYSTEM WILL LEAD TO
LOWERING CEILINGS, FOG, AND INCREASING PRECIPITATION CHANCES
OVERNIGHT INTO MONDAY. ALL SITES SHOULD DIP INTO IFR CATEGORIES
OR LOWER OVERNIGHT BEFORE GRADUALLY IMPROVING LATER IN THE DAY.
EXPECT WIDESPREAD SHOWERS TONIGHT THROUGH MONDAY MORNING WITH
SOME SCATTERED SHOWERS AND THUNDERSTORMS ALONG A COLD FRONT
MONDAY AFTERNOON. A FEW STRONGER STORMS WITH GUSTY WINDS WILL BE
POSSIBLE IN THE AFTERNOON OVER NEW HAMPSHIRE, POTENTIALLY
IMPACTING HIE, LEB, CON, AND MHT. A PERIOD OF LLWS IS ALSO
POSSIBLE ACROSS COASTAL TAF SITES MONDAY AFTERNOON INTO MONDAY
EVENING.
OUTLOOK...
MONDAY NIGHT-WEDNESDAY NIGHT: GENERALLY VFR CONDITIONS DURING
THE DAY WITH POTENTIAL FOR IFR FOG AT SOME TERMINALS DURING THE
NIGHT AS WE ENTER A PERIOD OF INCREASING HUMIDITY THROUGH NEXT
WEEK.
THURSDAY-FRIDAY: MVFR OR LOWER RESTRICTIONS POSSIBLE UNDER
ISOLATED TO SCATTERED SHOWERS AND STORMS.
MARINE
WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA THRESHOLDS TODAY.
HOWEVER, AN INCREASE IN WINDS AND SEAS WILL LIKELY LEAD TO SCA
CONDITIONS DEVELOPING BY LATE MONDAY MORNING THROUGH MONDAY
NIGHT. AREAS OF FOG WILL DEVELOP AGAIN TONIGHT, LOCALLY DENSE
AT TIMES. ADDITIONALLY, CHANCES FOR WIDESPREAD SHOWERS AND
STORMS INCREASE OVERNIGHT INTO MONDAY.
AFTER SEAS AND WIND RELAX TUESDAY MORNING, WE SHOULD REMAIN
BELOW SCA CRITERIA THROUGH THE EXTENDED.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM MONDAY TO 8 AM EDT TUESDAY FOR
ANZ150-152-154.
SMALL CRAFT ADVISORY FROM 2 PM MONDAY TO 8 AM EDT TUESDAY FOR
ANZ151-153.
DISCUSSION...TUBBS/HARGROVE/JAMISON
AVIATION...TUBBS
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