412
FXUS61 KGYX 211851
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
251 PM EDT SUN JUN 21 2026
WHAT HAS CHANGED
RAINFALL AMOUNTS HAVE TRENDED UPWARDS FOR THE LATE MONDAY INTO
TUESDAY SYSTEM. THESE TRENDS WILL HAVE TO BE WATCHED CLOSELY FOR
POTENTIAL FLOOD RISKS.
KEY MESSAGES
1. SCATTERED SHOWERS AND STORMS DIMINISH BY SUNSET THIS EVENING.
SLOW MOVING STORMS HAVE PRODUCED HEAVY RAINFALL AND A LOCALIZED
RISK FOR FLASH FLOODING.
2. LOW PRESSURE CROSSES LATE MONDAY INTO TUESDAY MORNING
BRINGING WIDESPREAD RAINFALL. A SWATH OF HEAVY RAINFALL IS
POSSIBLE WITH THIS SYSTEM BRINGING THE RISK OF FLOODING.
3. WEATHER IS LIKELY TO REMAIN UNSETTLED THROUGH THE REST OF
NEXT WEEK.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
LATEST RADAR SHOWS SCATTERED THUNDERSTORMS ACROSS MAINE AND NEW
HAMPSHIRE WITH THESE STORMS HAVING A HISTORY OF PRODUCING
RAINFALL RATES OF 1-2 INCHES PER HOUR. AMPLE CAPE ACROSS THE
AREA HAS ALLOWED FOR SOME STRONGER CELLS TO CONTAIN SMALL HAIL
WHILE THE LACK OF SHEAR HAS LARGELY KEEP STORMS SUB-SEVERE.
SCATTERED STORMS WILL CONTINUE INTO THIS EVENING AND WILL WANE
WITH THE LOSS OF HEATING. THE PRIMARY HAZARD WITH THESE STORMS
WILL BE LOCALIZED HEAVY RAINFALL AND POSSIBLY THE NEED FOR
ADDITIONAL FLASH FLOOD WARNINGS.
KEY MESSAGE 2 DESCRIPTION...
MESOSCALE MODELS ARE IN DECENT AGREEMENT IN AN AREA OF LOW
PRESSURE TRACKING ACROSS SOUTHERN NEW ENGLAND LATE MONDAY INTO
TUESDAY MORNING BRINGING A SWATH OF MODERATE TO HEAVY RAINFALL
ACROSS THE AREA. ON THE OTHER HAND, GLOBAL MODELS AND THEIR
ENSEMBLES (MAINLY THE GEFS) STILL HAVE SEVERAL MEMBERS THAT KEEP
THE HEAVIEST RAINFALL TO THE SOUTH OF THE FORECAST AREA. THESE
SOUTHERN TRACK ENSEMBLE MEMBERS ARE LIKELY HOLDING DOWN THE NBM
QPF FORECAST AND COULD SEE RAINFALL AMOUNTS TREND HIGHER OVER
THE NEXT FORECAST CYCLE IF THE AGREEMENT AMONGST MESOSCALE
MODELS CONTINUES.
THE SYNOPTIC SETUP IS NOT OVERLY IMPRESSIVE WITH A LOW
AMPLITUDE WAVE EMERGING FROM THE OHIO VALLEY THAT PARTIALLY
PHASES WITH AN UPPER LOW OVER SE CANADA. THERE IS A SIGNAL FOR
THE RIGHT ENTRANCE REGION OF THE UPPER JET TO BE NEAR BY AND
THIS COULD AID IN SYNOPTIC ASCENT. MOST MODEL SOLUTIONS BRING A
PLUME OF PWATS NEARING 1.75 INCHES ACROSS SOUTHER AREAS WITH
PWATS GREATER THAN 2 INCHES CLOSE BY. ULTIMATELY, THE
VARIABILITY IN RAINFALL AMOUNTS WILL HINGE ON HOW FAR NORTH THE
LOW TRACKS THAT WILL ALLOW FOR HIGHER PWATS INTO THE AREA ALONG
WITH BETTER INSTABILITY. WARM CLOUD DEPTHS NEARING 12KFT WILL
ALSO AID IN RAINFALL EFFICIENCY. THE LATEST HREF DOES RAISE SOME
CONCERNS THE MEAN QPF OF 2-3 INCHES ACROSS CENTRAL NH INTO THE
WHITE MOUNTAINS EXTENDING INTO THE FOOTHILLS OF WESTERN MAINE.
THE HREF MAX QPF BRINGS AMOUNTS UP TO 5 INCHES IN THESE SAME
AREAS. THEREFORE, STAY TUNE TO THE LATEST FORECAST UPDATES
BECAUSE THESE HIGHER END AMOUNTS WILL LIKELY WARRANT A FLOOD
WATCH.
LOW PRESSURE EXITS TUESDAY LATE TUESDAY MORNING WITH A DRYING
TREND INTO TUESDAY AFTERNOON.
KEY MESSAGE 3 DESCRIPTION...
A RELATIVELY ZONAL MID-LEVEL PATTERN IS LIKELY THROUGH THE END OF
THIS WEEK. THIS WILL ALLOW FOR THE POTENTIAL TO SEE ROUTINE BOUTS OF
UNSETTLED WEATHER BY THURSDAY AND FRIDAY ACROSS NORTHERN NEW
ENGLAND.
THROUGH THE SECOND HALF OF THE WEEK, INSTABILITY OVER THE AREA IS
LIKELY TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS. TEMPERATURES
ALSO LOOK A LITTLE WARMER, WITH HIGH TEMPERATURES IN THE UPPER 70S
AND LOWER 80S THROUGH THE REST OF THE WEEK. WEDNESDAY HAS THE BEST
CHANCE TO BE THE DRIEST DAY OF THE THREE, WITH SCATTERED
THUNDERSTORMS APPEARING MORE LIKELY FOR THURSDAY AND FRIDAY.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
THROUGH MONDAY... SCATTERED SHOWERS AND TS WILL CONTINUE UP TO
00Z THIS EVENING BRINGING BRIEF AND LOCALIZED RESTRICTIONS.
OUTSIDE OF SHOWERS AND TS WILL BE MAINLY VFR INTO THE FIRST HALF
OF TONIGHT. PATCHY FOG IS POSSIBLE ACROSS THE ENTIRE AREA WITH
RESTRICTIONS LIKELY AT LEB, HIE, RKD, AND AUG. CONFIDENCE
DECREASES FARTHER SOUTH IN FOG POTENTIAL, BUT HAVE MENTIONED IT
IN THE PWM AND CON TAF. CONDITIONS LIKELY BECOME VFR MONDAY
MORNING. CLOUDS THICKEN AND LOWER FROM SW TO NE MONDAY AFTERNOON
WITH RAIN LIKELY BY MONDAY EVENING WITH CONDITIONS DROPPING TO
MVFR AND THEN IFR.
OUTLOOK:
MONDAY NIGHT-TUESDAY: IFR LIKELY MONDAY NIGHT INTO TUESDAY
MORNING IN LOW CIGS AND RAIN. CONDITIONS IMPROVE INTO TUESDAY
AFTERNOON.
WEDNESDAY: MAINLY VFR.
THURSDAY-FRIDAY: SHOWERS BRING POTENTIAL FOR RESTRICTIONS.
MARINE
WINDS AND SEAS REMAIN BELOW SCA THRESHOLDS THROUGH MONDAY. LOW
PRESSURE CROSSING SOUTHERN NEW ENGLAND WILL BRING INCREASING
SOUTH WINDS APPROACHING 25 KTS TUESDAY MORNING. WINDS SHIFT
OFFSHORE TUESDAY AFTERNOON WITH WINDS AND SEAS LARGELY REMAINING
BELOW SCA THRESHOLDS THROUGH LATE WEEK.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
DISCUSSION...PALMER/SCHROETER
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