003
FXUS61 KGYX 011848
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
248 PM EDT WED JUL 1 2026
WHAT HAS CHANGED
TEMPERATURES ADJUSTMENTS WERE MADE FROM THURSDAY THROUGH
SATURDAY. ANY WATCHES WERE UPGRADED TO EXTREME HEAT WARNINGS OR
HEAT ADVISORIES.
KEY MESSAGES
1. HEAT CONTINUES TO BUILD INTO THURSDAY, AND THEN LINGER INTO
AT LEAST FRIDAY. OVERALL THE HEAT REMAINS ON TRACK, WITH MINOR
TWEAKS TO TEMPERATURES AND HEAT INDICES OVER THE NEXT FEW DAYS.
2. HEAT AND HUMIDITY WILL PROVIDE FUEL FOR THUNDERSTORMS
THROUGH THURSDAY WITH STORMS POSSIBLE DURING THE DAY AND
OVERNIGHT. PLACEMENT, TIMING, AND COVERAGE OF STORMS REMAINS
VARIABLE. SPC HAS A SLIGHT RISK ACROSS PORTIONS OF NH AND A
MARGINAL RISK ELSEWHERE FOR SEVERE STORMS THROUGH TONIGHT. THERE
IS A MARGINAL RISK FOR SEVERE STORMS ON THURSDAY. THE MAIN
HAZARDS WITH ANY SEVERE STORMS ARE DAMAGING WINDS AND HAIL.
3. THE RIDGE RESPONSIBLE FOR THE EXTREME HEAT BREAKS DOWN LATE
FRIDAY THROUGH THE WEEKEND ALLOWING FOR A DOWN TREND IN
TEMPERATURES. CHANCES FOR SHOWERS AND STORMS REMAIN IN THE
FORECAST INTO MIDWEEK.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
THE HEAT IS UNDERWAY ACROSS THE AREA. OVERALL TODAY'S TEMPS
LOOK LIKELY TO LAND A FEW DEGREES COOLER THAN THE ORIGINAL
FORECAST, AND THIS OUTCOME WAS KEPT IN MID FOR THE NEXT FEW
DAYS. THE FORECAST WAS MOSTLY JUST FINED TUNED FROM PREVIOUS
VERSIONS, BUT WITH THESE HIGH END READINGS THE MINOR CHANGES CAN
MAKE THE DIFFERENCE IN HEADLINE DECISIONS.
SO WITH THE FORECAST ADJUSTMENTS, AN EXTREME HEAT WARNING HAS
BEEN ISSUED INTO CENTRAL MAINE AND THE MIDCOAST FOR THURSDAY,
AND ADVISORIES FURTHER NORTH. HEAT ADVISORIES WILL LIKELY BE
NEEDED IN THESE NEW WARNING AREAS FOR FRIDAY, BUT WILL BE
ADDRESSED ONCE THE PEAK OF THE HEAT IS DEALT WITH TOMORROW.
IN GENERAL, HEAT INDICES OF 105-110 ARE EXPECTED IN THE WARNING
AREAS, AND HEAT INDICES OF 95-104 ARE EXPECTED IN THE ADVISORY
AREAS. TOMORROW FEATURES BOTH THE HIGHEST TEMPERATURES, AND
WIDESPREAD DEW POINTS IN THE LOW TO MID 70S. DEW POINTS LIKELY
DROP BACK INTO THE UPPER 60S TO LOW 70S ACROSS INTERIOR NEW
HAMPSHIRE DURING THE AFTERNOON HOURS, WHICH WILL ALLOW TEMPS TO
CLIMB HIGHER. FRIDAY THEN LOOKS TO PRODUCE SLIGHTLY LOWER
TEMPERATURES, AND LOWER DEW POINTS. A WEST WIND KEEPS ALL THE
COASTLINES HOT ON FRIDAY AS WELL, WITH WIDESPREAD HIGHS IN THE
90S.
SIGNIFICANT CHANGES WERE MADE TO THE HIGH TEMPERATURES FOR
SATURDAY, THE 4TH OF JULY. EARLIER NBM FORECASTS OF HIGHS IN THE
UPPER 90S WERE NOT CONSISTENT WITH EXPECTED 850MB TEMPS, AND
WERE ADDRESSED IN THIS FORECAST UPDATE. THIS STILL BRINGS ONE
MORE VERY WARM DAY WITH HIGHS IN THE UPPER 80S TO LOW 90S, BUT
WILL MARK A DOWNWARD TREND FROM THE PEAK OF THE HEAT. DEW POINTS
WILL ALSO BE LOWER ON SATURDAY, KEEPING HEAT INDICES WITHIN A
FEW DEGREES OF THE AIR TEMPS.
KEY MESSAGE 2 DESCRIPTION...
NOT MUCH HAS CHANGED WITH REGARDS TO SEVERE POTENTIAL OVER THE
NEXT 48 HOURS AS MODELS CONTINUE TO DO A POOR JOB OF TRACKING
THE CONVECTIVE WAVES ROLLING THE RIDGE. THE LATEST RUNS OF THE
CAMS AREN'T CONVINCED IN MUCH DEVELOPING THIS AFTERNOON WITH
LACK OF FORCING IN THE AREA, BUT ALSO DEVELOP 2000-3000 J/KG OF
CAPE OVER THE AREA. AS MENTIONED PREVIOUSLY, ANYTHING THAT DOES
DEVELOP (THINK TERRAIN FORCED CONVECTION) WOULD HAVE THE
INGREDIENTS TO QUICKLY STRENGTHEN. THE OTHER REASON THIS IS
SIGNIFICANT IS BECAUSE THAT MEANS THAT THE CONVECTIVE SYSTEMS
DEVELOPING ALONG THE FRONT DRAPED OVER THE GREAT LAKES REGION
HAVE A SUPPORTIVE ENVIRONMENT TO SUSTAIN THEMSELVES AS THEY
JOURNEY INTO OUR AREA. AT THE TIME OF THIS WRITING THERE IS
ROBUST CONVECTION NORTHEAST OF OTTAWA (THAT YOU WON'T FIND ON
ANY OF THE CURRENT CAM RUNS) THAT MAY REACH NEW HAMPSHIRE LATER
THIS AFTERNOON AND MAY VERY WELL BE SEVERE IF IT DOES. A PERFECT
EXAMPLE OF THE ANALOGY I USED YESTERDAY WHERE VERY OFTEN CAMS
STRUGGLE TO CAPTURE THESE FEATURES IN THESE SETUPS AND WE HAVE
TO WAIT TO SEE WHAT ACTUALLY FORMS BEFORE WE CAN START TALKING
ABOUT IT WITH CONFIDENCE.
SPEAKING OF CONFIDENCE, THE MAJORITY OF CAMS ONCE AGAIN HAVE
CONVECTION (CURRENTLY LOCATED OVER WISCONSIN) MAKING THE JOURNEY
TO WESTERN NEW HAMPSHIRE AROUND DAY BREAK, BUT AFTER THEIR
WHIFF LAST NIGHT I HAVE MY DOUBTS. BY THEN STABLE AIR NEAR THE
SURFACE WOULD LIKELY LESSEN THE SEVERE THREAT ANYHOW. THE
MAJORITY OF CAMS MAINTAIN A SEVERE THREAT THURSDAY
AFTERNOON/EVENING AS WELL, BUT THAT IS ANOTHER LOW CONFIDENCE,
WAIT AND SEE, SITUATION.
KEY MESSAGE 3 DESCRIPTION...
THE RIDGE BEGINS TO BREAK DOWN FRIDAY, BUT NOT BEFORE ONE MORE
VERY WARM DAY OF TEMPERATURES IN THE UPPER 90S. UNSURPRISINGLY,
MODELS HAVE BACKED OFF ON THE PROGRESSION OF THE COLD FRONT
UNTIL LATER ON FRIDAY OF EVEN SATURDAY BUT REGARDLESS WE SHOULD
BEGIN HEADING IN A MORE COMFORTABLE DIRECTION. THE HOLIDAY
WEEKEND WILL FEATURE SUMMER LIKE TEMPERATURES, BUT THE LOWER
DEWPOINTS BEHIND THE FRONT SHOULD MAKE IT LESS STICKY. GLOBAL
ENSEMBLES CONTINUE TO TREND TOWARD THE TRANSITION TO A BROAD
TROUGH FOLLOWING THIS RIDGE, WHICH WOULD CONTINUE THE COOLING
TREND EARLY NEXT WEEK, AS WELL AS KEEPING SHOWERS AND STORMS IN
THE FORECAST. WE THEN MAY SEE ANOTHER WARM UP MIDWEEK AS THERE
IS SURPRISING AGREEMENT ALREADY OF ANOTHER RIDGE TAKING SHAPE.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
MAINLY VFR PREVAILS AT MOST TERMINALS THROUGH THURSDAY NIGHT,
BUT SOME BRIEF RESTRICTIONS ARE POSSIBLE WITH ANY SHOWERS OR
STORMS FROM LATE THIS AFTERNOON THROUGH THURSDAY NIGHT. VALLEY
FOG OR LOW STRATUS IS ALSO LIKELY AT LEB AND HIE LATE TONIGHT.
SOME SHALLOW MARINE FOG IS ALSO POSSIBLE AT RKD TONIGHT.
OUTLOOK...
FRIDAY-MONDAY: GENERALLY VFR CONDITIONS ARE EXPECTED DURING
DAYLIGHT HOURS WITH TEMPO MVFR CONDITIONS POSSIBLE EACH
AFTERNOON IN SHOWERS AND THUNDERSTORMS.
MARINE
HIGH PRESSURE REMAINS CENTERED SOUTH OF NEW ENGLAND FOR THE NEXT
COUPLE DAYS. SEAS UP TO 5FT ARE POSSIBLE ACROSS THE FAR EASTERN
WATERS LATE TONIGHT IN SOUTHWEST FLOW. SOME PATCHES OF MARINE FOG
ARE POSSIBLE NEAR THE MIDCOAST SHORELINE TONIGHT. HIGH PRESSURE
SETTLES SOUTH OF THE WATERS LATE WEEK KEEPING WINDS AND SEAS
BELOW SCA LEVELS INTO MIDWEEK NEXT WEEK.
CLIMATE
HIGH TEMPERATURE RECORDS AT LONG TERM CLIMATE SITES...
JULY 2ND 3RD
AUG 93 (1963) 94 (2002)
PWM 98 (1941) 95 (2002)
CON 98 (1966) 102 (1966)
GYX WATCHES/WARNINGS/ADVISORIES
ME...HEAT ADVISORY UNTIL 8 PM EDT THURSDAY FOR MEZ007>009.
EXTREME HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR MEZ012-018>020-
023-033.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MEZ013-014-021-
022-024>026.
HEAT ADVISORY FROM 11 AM THURSDAY TO 8 PM EDT FRIDAY FOR
MEZ013-014.
EXTREME HEAT WARNING FROM 11 AM TO 8 PM EDT THURSDAY FOR
MEZ021-022-024>028.
AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MEZ023>028.
NH...HEAT ADVISORY UNTIL 8 PM EDT THURSDAY FOR NHZ001>003.
EXTREME HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR NHZ004>015.
AIR QUALITY ALERT UNTIL 10 PM EDT THIS EVENING FOR NHZ013-014.
MARINE...NONE.
DISCUSSION...BARON/CLAIR
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