637
FXUS61 KGYX 042318
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
718 PM EDT TUE AUG 4 2026
WHAT HAS CHANGED
LOWERED FORECAST LOW TEMPERATURES TONIGHT ACROSS MOST LOCATIONS
GIVEN THE EXPECTED STRONG RADIATIONAL COOLING CONDITIONS.
OTHERWISE, ADJUSTED THE AVIATION SECTION FOR THE 00Z TAF
PACKAGE.
KEY MESSAGES
1. WARMER AND MORE HUMID WEATHER BUILDS THROUGH THE WEEK AS
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER PATTERN.
2. INCREASING MOISTURE THURSDAY INTO THE WEEKEND WILL BRING DAILY
CHANCES FOR SHOWERS AND THUNDERSTORMS.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
THE BERMUDA HIGH BUILDS WESTWARD TOWARD THE EASTERN SEABOARD
THIS WEEK, BRINGING WARMER AND MORE HUMID CONDITIONS BY MID TO
LATE WEEK. TEMPERATURES GENERALLY REACH INTO THE MID 80S BY
WEDNESDAY, WITH UPPER 80S TO LOW 90S EXPECTED FOR MOST AREAS
FROM THURSDAY THROUGH AT LEAST SATURDAY. DEW POINTS WILL ALSO BE
ON THE RISE THROUGH THE WEEK, AND LIKELY BEGIN TO PUSH 70
DEGREES BY THURSDAY, AND EXPAND ON FRIDAY AND THE WEEKEND.
THE COMBINATION OF HEAT AND HUMIDITY LIKELY PUSHES HEAT INDICES
INTO THE LOW TO MID 90S ACROSS PARTS OF SOUTHERN NEW HAMPSHIRE
AND JUST BACK FROM THE COAST OF MAINE. THE HEAT OVERALL DOESN'T
LOOK LIKE A HIGH END EVENT, BUT AN EXTENDED PERIOD OF MULTIPLE
DAYS WITH HEAT INDICES INTO THE LOW TO MID 90S.
COOLER TEMPERATURES LIKELY DON'T ARRIVE UNTIL EARLY TO MID WEEK
NEXT WEEK WITH A COLD FRONT. THERE REMAINS A WIDESPREAD TIME
RANGE ON THE POSSIBLE ARRIVAL OF THIS FRONT ANYWHERE FROM LATE
MONDAY TO WEDNESDAY OF NEXT WEEK.
KEY MESSAGE 2 DESCRIPTION...
A LONG WAVE TROUGH OVER THE CANADIAN PRAIRIES WILL GRADUALLY
DEEPEN AND SLIDE EAST THE SECOND HALF OF THE WEEK. ENSEMBLES ARE
IN DECENT AGREEMENT THAT SOUTHWEST FLOW AHEAD OF THE TROUGH
WILL ADVECT DEEP MOISTURE INTO THE REGION WITH PWATS NEARING 2.0
INCHES BY THURSDAY. THE TROUGH AXIS DOES NOT CROSS THE AREA
THROUGH THE WEEKEND ALLOWING FOR DEEP MOISTURE TO PERSIST. DEW
POINTS IN THE UPPER 60S TO LOW 70S THURSDAY THROUGH SATURDAY
COMBINED WITH SURFACE HEATING WILL LIKELY GENERATE SUFFICIENT
INSTABILITY FOR THUNDERSTORMS DURING THE AFTERNOONS. ENSEMBLES
ARE HIGHLIGHTING FRIDAY AND SATURDAY AS THE DAYS WITH HIGH
PROBABILITIES OF CAPE GREATER THAN 500 J/KG ACROSS MUCH OF THE
AREA WITH CAPE MAINLY FOCUSED OVER NH THURSDAY. DEEP LAYER
SHEAR THROUGH THE PERIOD MAY APPROACH 35 KTS, WHICH WILL BE
SUFFICIENT FOR ORGANIZED CONVECTION. THE LACK OF A WELL DEFINED
SURFACE FEATURE FOR FORCING AND RIDGING JUST TO THE EAST
SUGGESTS COVERAGE OF ANY SHOWERS AND STORMS WILL BE LIMITED
THURSDAY AND FRIDAY. EMBEDDED SHORT WAVES HELP KNOCK THE RIDGE
DOWN SATURDAY WITH BETTER FORCING FOR ASCENT OVERSPREADING THE
AREA. SATURDAY IS WHEN POPS WILL CLIMB INTO THE 50 TO 70 PERCENT
RANGE SOUTH TO NORTH WITH POPS LOWERING INTO NEXT WEEK. MACHINE
LEARNING GUIDANCE OUT OF CSU IS HIGHLIGHTING POTENTIAL FOR
STRONG TO SEVERE STORMS FRIDAY THROUGH SUNDAY WITH THE HIGHEST
PROBABILITIES ON SATURDAY. IT WILL LIKELY TAKE A FEW MORE MODEL
CYCLES TO PIN DOWN THE FINER DETAILS ON STORMS FRIDAY INTO THE
WEEKEND WHILE THERE DOES APPEAR SOME POTENTIAL FOR TORRENTIAL
RAINFALL GIVEN THE HIGH PWATS AND STRONG TO SEVERE STORMS.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
THROUGH WEDNESDAY NIGHT: MAINLY VFR. VALLEY FOG BRINGS
POTENTIAL FOR RESTRICTIONS AT LEB AND HIE TONIGHT AND AGAIN
WEDNESDAY NIGHT. WINDS WILL BE LIGHT AND VARIABLE TONIGHT BEFORE
BECOMING S-SW ON WEDNESDAY AT 5-15 KTS. NO LLWS IS ANTICIPATED
THROUGH THE PERIOD.
OUTLOOK:
THURSDAY - TUESDAY: MAINLY VFR PREVAILS AT MOST TERMINALS. A
BRIEF AFTERNOON SHOWER OR THUNDERSTORM IS POSSIBLE EACH DAY.
NIGHTTIME VALLEY FOG WILL BE POSSIBLE EACH NIGHT, ESPECIALLY AT
LEB AND HIE.
MARINE
HIGH PRESSURE CONTINUES TO BUILD OVER THE WATERS AND PERSISTS
INTO THURSDAY WITH WINDS AND SEAS REMAINING BELOW SCA
THRESHOLDS. A SLOW MOVING FRONT APPROACHES FROM THE WEST FRIDAY
INTO THE WEEKEND WHILE WINDS AND SEAS REMAIN BELOW SCA
THRESHOLDS. MAINLY FAIR CONDITIONS PREVAIL AS HIGH PRESSURE
REMAINS IN CONTROL OF THE WEATHER PATTERN THROUGH THE WEEKEND,
BRINGING A STEADY SOUTHWESTERLY FLOW.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
DISCUSSION...TUBBS/CLAIR/SCHROETER
AVIATION...TUBBS
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