717
FXUS61 KGYX 191023
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
623 AM EDT Wed Aug 19 2026

.WHAT HAS CHANGED...
Areas of dense fog continue to float around early this morning,
especially over much of New Hampshire and portions of coastal
Maine. No major changes were needed for this forecast update.

&&

.KEY MESSAGES...
1. Early morning fog today. A few showers and an isolated
thunderstorm possible by early this evening. Thursday should be
fair as well, but there is some minor forecast uncertainty.

2. The next chance for rain on a widespread basis arrives for
the second half of the weekend.

&&

.DISCUSSION...
KEY MESSAGE 1 DESCRIPTION...

After areas of early morning low clouds and fog we should see
increasing sunshine, especially on the coastal plain and across
southern NH. As a result, temperature will warm into the 80s at
most locations. A cold front will approach during the afternoon
hours, but the deeper forcing for ascent associated with it will
weaken considerably by early evening. Therefore, most showers
and any thunderstorms associated with it will probably weaken or
fall apart on approach from the west. However, heating of the
day may support a couple of convective showers or storms across
central and northern NH late in the afternoon and early evening.
Areas of fog are again likely later tonight, especially in the
CT River Valley and Midcoast of Maine.

The cold front continues to sag southward into southern New
England on Thursday. At this time most ensemble guidance
indicates that it will sag far enough south so that a developing
wave along said front remains well to our south also. This would
keep a possible round of showers and thunderstorms well to our
south later Thursday as well. However, there are some model
outliers that bring the wave farther north and thus a more
showery scenario late Thursday to our southern zones. However,
the forecast favors the drier majority at this time.


KEY MESSAGE 2 DESCRIPTION...

High pressure then builds in Friday and the first part of Saturday,
keeping the weather dry for much of the area. The high does move
off to the northeast later Saturday as low pressure emerges off
the Mid-Atlantic coast, and moisture will start to increase from
south to north over northern New England, potentially enough
for a few showers along the coast and southern NH during the day
Saturday. But again, most will be dry as the better chances
hold off until the second half of the weekend. Highs will in the
70s to low 80s and lows mostly in the 50s, except some embedded
upper 40s.

This initial low will keep a chance for showers along the coast and
southern NH Saturday night, but rain chances further increase
areawide Sunday into Sunday night as a 500mb approaches from
the west and encompasses much of the US East Coast. There`s a
strong signal in the ensemble for most of the area to see
measurable rain, although there are timing differences. If the
500 mb trough remains an open wave the rain looks more in the
Sunday-Sunday night timeframe, but if it closes off, then a
slower onset and end will likely be the result, making the
higher rain chances more in the Sunday night and Monday window.
By Tuesday, we should see a return to drier conditions, except
there may be some upslope showers in the mountains.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Fog may be locally dense for another hour or two, mainly in the
CT River Valley and perhaps even the Midcoast of Maine.
Elsewhere 2-5 miles in BR is expected through about 13z. VFR
conditions during the day today with fog returning to more or
less the same locations tonight. VFR Thursday.

Outlook:

Thursday night-Saturday: Mainly VFR, except nighttime/early
morning valley fog could produce IFR to LIFR at HIE and LEB.

Saturday night-Sunday: Increasing chances for rain. IFR to MVFR
possible.

&&

.MARINE...
Winds and seas generally stay below SCA thresholds today through
Thursday.

Thursday night-Tuesday...SCA conditions are currently not
expected through early next week. A weak front crosses the
waters Thursday and will be followed by high pressure building
in Friday and the start of the weekend. The high shifts to the
north and east as a couple of low pressures approach and cross
the waters from the west and southwest during the late Saturday
through Monday timeframe. High pressure returns by Tuesday of
next week.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$

DISCUSSION...Clair/Ekster/Hargrove