Boothbay Harbor, Maine Weather Forecast Discussion

499
FXUS61 KGYX 192318
AFDGYX
Area Forecast Discussion
National Weather Service Gray ME
718 PM EDT Fri Sep 19 2025
.SYNOPSIS...
Winds will be diminishing this evening and tonight as high
pressure builds in. High pressure settles in for the weekend,
bringing a fresh cool and dry airmass to New England. Light
showers are possible for the first part of next week but
otherwise mainly dry conditions are expected to persist.
&&
.NEAR TERM /THROUGH SATURDAY/...
7pm Update:
A quiet evening continues across the region as northwest winds
start to relax. These winds should diminish even more over the
next couple of hours, becoming light overnight. No major changes
were needed for this update. Just blended in the latest
observations to the going forecast and updated the short term
Aviation discussion below.
Previous Discussion:
Clear skies and light winds will make for good radiational
cooling tonight for much of the area, especially across the
north where temperatures could reach the upper 20s to around 30
degrees in the northern valleys and lower to middle 30s in the
foothills. Freeze and Frost headlines remain in effect for these
areas.
Farther south, temperatures will range from the mid 30s to lower 40s
with the mid 30s mainly expected in the normally cooler spots, where
patchy frost will also be possible. More of a breeze along the
immediate coast may keep temps some areas in the middle 40s.
&&
.SHORT TERM /SATURDAY NIGHT/...
The high pressure settles on top of New England for Saturday, giving
the region a slightly cooler and sunny day with lighter winds,
followed by a clear, cold night with excellent radiational cooling.
High temperatures will be held to the 60s for most, but southern NH
may still get to around 70 degrees. Lows Saturday night are expected
to reach the mid 20s to around 30 degrees across the north, and with
the exception of the coast and southern NH, widespread temperatures
in the low-mid 30s are forecast for the rest of the area. Based on
the current forecast, additional Frost and Freeze headlines will
likely be needed for Saturday night, but to avoid confusion have
held off due to the current Frost Advisory and Freeze Warning
currently in effect for tonight.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
High pressure overhead Sunday morning will begin moving
offshore. The atmospheric column will still be plenty dry, with
RH less than 40% through 400mb. While mostly sunny skies are
expected as a result, could see some high cirrus working
through...moreso than Saturday. Winds remain light, but will
remain overnight as sfc winds shift south behind the high. Some
low level moisture advection could bring some lower clouds or
fog in overnight. The gentle breeze and chance of more clouds
will reduce time of good cooling, and not expecting as cold
temps Sunday night. Some patch frost may be possible in the
valleys in northern NH and mtns of western ME.
Dry weather continues Monday, but increase of clouds should be
apparent. Low pressure lifting north of the Great Lakes will
bring a warm front into the Northeast Monday and Monday night.
NE translation of the system means the slow arrival of deeper
moisture for the chance of showers, after sunset.
Broad area of unsettled weather will then cross Tuesday and
Wednesday. Main message here is on and off showers, with one or
two periods of rainfall possible in the forecast area. Global
models are still very much at odds of a more accurate depiction.
The lack of a more defined synoptic feature reduces
predictability as far as timing and amounts. But given PWATs and
lack of sharper forcing features, the likelihood of much more
than a quarter-inch of precipitation in any one remains below
40%.
This round of precipitation will be the last before another
round of dry conditions late week as a cold front passes and
low-RH air again takes residence in northern New England.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
Short Term...Mainly VFR, except fog may develop at HIE and LEB
tonight and again Saturday night. Winds will continue to relax
through the rest of tonight and Saturday as high pressure
builds into New England.
Long Term...VFR Sunday as high pressure pushes east. Return flow
overnight may bring low clouds or fog supporting IFR. This
should lift slightly into the day Monday, but patchy MVFR still
possible. Additional restrictions are possible into midweek with
SHRA moving into the region through Wednesday.
&&
.MARINE...
Short Term...High pressure begins to build in from the north
this evening and tonight, and the pressure gradient may briefly
tighten enough to support a period of N/NW wind gusts
approaching 25 kt this evening into the early overnight hours.
Otherwise, winds diminish the rest of tonight and Saturday as
the high pressure continues to build overhead.
Long Term...High pressure overhead Sunday morning will drift
over the Gulf of Maine into the afternoon and overnight. An
increase in low clouds will be possible, potentially reducing
vis into Monday morning. Unsettled weather arriving from the
west into midweek will tend to shift southerly winds NE. Wave
heights increase from 1-3 to 4-6 ft by Tuesday afternoon.
&&
.FIRE WEATHER...
Saturday will be less breezy but much drier as an Arctic
originating airmass builds into the region. Relative humidity
values are expected to drop into the 20-30 percent range which,
despite light winds, will continue elevated fire weather
concerns, especially if fuels are readily available. The next
chance for measurable rainfall arrives Monday night through
Wednesday, but forecast amounts remain light.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Freeze Warning from 2 AM to 8 AM EDT Saturday for MEZ007>009.
     Frost Advisory from 2 AM to 8 AM EDT Saturday for MEZ012>014-
     033.
NH...Freeze Warning from 2 AM to 8 AM EDT Saturday for NHZ001-002.
     Frost Advisory from 2 AM to 8 AM EDT Saturday for NHZ003-004.
MARINE...None.
&&
$$
NEAR TERM...Hargrove/Combs
SHORT TERM...Combs
LONG TERM...Cornwell

NWS GYX Office Area Forecast Discussion