678
FXUS61 KGYX 192000
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
400 PM EDT Wed Jun 19 2024

.SYNOPSIS...
High pressure will remain east of New England through much of
this week, continuing our period of hot and humid conditions
through Thursday. Record high temperatures and potentially
dangerous heat index values are likely. A cold front will
slowly cross through the region on Thursday and Friday with an
increasing chance for scattered strong thunderstorms and cooler
temperatures starting on Friday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Showers and thunderstorms, a few severe, will continue into the
early evening hours per latest radar trends and latest NamNest
solution. HRRR continues to have an issue deriving the
convection today. This precipitation will diminish by around
sunset as the atmosphere gradually stabilizes.

Excessive heat today will lead towards another very warm night
tonight. Last night, lows were in the lower to mid 70s in many
interior areas and this will likely occur again. This sustained
heat leading into tomorrow will allow for increased heat stress
in buildings and areas without proper air conditioning.

Patchy fog can be expected tonight, especially in areas that
received heavy rainfall today. The latest HREF hints at possible
maritime fog along the Midcoast region tonight by late tonight.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
The latest 12Z operational runs and ensemble solutions continue
to suggest a more westerly component to the flow on Thursday.
This may delay the sea breeze along the immediate shoreline
allow for hazy, hot and humid conditions all the way to the
coastline for a longer period than today. In any case, this
large scale upper level ridge that has been leading to the heat will
still be intact. Expect apparent temperatures to reach or
exceed 105 degrees in many areas once again on Thursday.
Surrounding this warning, have issued Heat Advisories for the
period 15Z-23Z.

A front does cross through the region during the afternoon
hours, a little faster than guidance has suggested. However,
temperatures will soar very quickly during the morning hours to
allow for high CAPE values to develop and improved dynamics
along and near the passing cold front. Most of the area remains
in a Marginal Risk and have included strong, gusty winds and
locally very heavy rainfall in the forecast. There will be high
PWATs near 2 inches in a steep low level level lapse rates
leading to the severe weather potential.

Patchy fog once again can be expected Thursday night. Showers
will take a few more hours to diminish than today with a chance
for precipitation throughout the night.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
With ongoing heat headlines and severe weather, the long term
forecast was populated with the NBM, with only minor adjustments
made.

The heat breaks by Friday as a cold front presses southward
Thursday night. Highs are mostly expected to range from the
upper 70s to mid 80s. Showers and storms are likely across as
least southern areas as convection rides along the front.
Periods of showers and storms are likely at times through the
weekend and into early next week as we find ourselves on the
northern side of the ridge. Cooler conditions are expected on
Saturday, but a warming trend resumes on Sunday with temps
warming into the 80s and continuing into early next week. Drier
conditions likely return by midweek next week as highs warm
back into the low 90s.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
Short Term...Mainly VFR conditions after the convection
diminishes this evening. However, there will be the potential
for valley fog. Maritime fog is possible along the Midcoast.

More showers and thunderstorms, some with strong gusty winds
and possible hail will return on Thursday afternoon leading to
localized IFR conditions. Scattered showers and thunderstorms
may linger into Thursday night.

Long Term...Periods of showers and storms bring restrictions at
times Friday through Monday, especially in the afternoon hours.
Otherwise, mainly VFR conditions are expected. VFR conditions
likely then prevail next Tuesday and Wednesday.

&&

.MARINE...
Short Term...South to southwesterly winds will continue tonight
into Thursday, just below SCA criteria. Winds back to the west
Thursday night as slightly drier air enters the region.

Long Term...A cold front presses southward through the waters
early Friday, with high pressure gradually building in for the
weekend. SCA conditions are then possible next week as southerly
flow increases as the high moves offshore.


&&

.CLIMATE...
RECORD HIGHS FOR JUNE 20: Concord-98, 1993 Augusta-95, 1953
Portland-93, 2020

RECORD WARM LOWS FOR June 20: Concord-73 in 1931; Augusta-67 in
1974; Portland-69 in 2020

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory until 8 PM EDT this evening for MEZ007>009-
     022>028.
     Excessive Heat Warning until 8 PM EDT this evening for
     MEZ012>014-018>021-033.
     Heat Advisory from 11 AM to 7 PM EDT Thursday for MEZ012>014.
     Excessive Heat Warning from 11 AM to 7 PM EDT Thursday for
     MEZ018>028-033.
NH...Heat Advisory until 8 PM EDT this evening for NHZ001>003-005-
     007-011-014.
     Excessive Heat Warning until 8 PM EDT this evening for NHZ004-
     006-008>010-012-013-015.
     Heat Advisory from 11 AM to 7 PM EDT Thursday for NHZ002>005-
     007-011.
     Excessive Heat Warning from 11 AM to 7 PM EDT Thursday for
     NHZ006-008>010-012>015.
MARINE...None.

&&

$$

NEAR/SHORT TERM...Cannon
LONG TERM...Clair