Waterville Valley

000
FXUS61 KGYX 151023
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
623 AM EDT Tue Sep 15 2026

.WHAT HAS CHANGED...
Aviation section has been updated for the 12Z TAFs, but no 
no changes were needed to the forecast.

&&

.KEY MESSAGES...
1. It will be the coldest morning since last spring with Frost 
Advisories in effect across the North Country.

2. There is a chance for rain late this week, but otherwise it
will be generally dry with near to below normal temperatures.

&&

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

Clear skies prevail across the region this morning, with only a
subtle breeze delaying the drop in temps at this time. However
that is expected to continue to diminish thru sunrise and temps
should tumble into the 40s for much of the area. The primary
concern will be the North Country valleys where widespread 30s
are anticipated. A Frost Advisory remains in effect thru
morning. Elsewhere it would not surprise me to see a brief upper
30s reading in the typically cool locations like SFM. With a
cool start and subsidence inversion aloft, that will also make
it difficult to get too warm this afternoon. Despite full
sunshine it may be hard to escape the 60s today.

KEY MESSAGE 2 DESCRIPTION...

Much of the rest of the week will feature a fast jet to our
north with a strong upper ridge centered over the southeastern
CONUS to our south. That will be sufficient enough to prevent
any significant warmth from entering the region, but will also
lead to a frontal boundary at the very least draped near the
forecast area. This is what guidance continues to key on for the
next chance of rain. A cold front is forecast to wash out in the
vicinity Wed and then an area of rain may track along that into
our backyard for Thu. Given the uncertainty and lack of strong
forcing along the boundary, I am okay with the NBM PoP around 
50 percent for the local area.

The stronger signal is with the next wave that approaches over 
the weekend. The upper ridge over the Southeast is forecast to
retrograde from the late week thru the weekend. As it does so
and weakens, an opening upper low will eject from the northern
Rockies and head our way. Despite the fact that it is outside of
our QPF window, there is a plenty of ensemble support for
rainfall. NBM is already coming in with high likely PoP and that
seems reasonable given the event is occurring at the tail end of
the forecast range.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Through 12Z Wednesday...IFR to LIFR valley fog at HIE and LEB 
should clear by 13Z-14Z this morning with conditions returning 
to VFR. For the rest of the day, prevailing VFR at all sites. 
There may be enough cloud cover to disrupt or delay valley fog 
development tonight, but it is prime fog season so it may be 
more likely than not.

Outlook...

Wednesday: VFR conditions expected.

Thursday and Thursday night: Areas of rain showers and local
MVFR conditions possible.

Friday: VFR conditions expected.

Saturday: VFR conditions expected.

&&

.MARINE...
Breezy northwest winds continue to diminish overnight as high
pressure settles over the region. Winds and seas are expected to
remain below SCA thresholds thru the remainder of the week. A
stronger frontal wave will approach the waters over the weekend,
and this will be the window for some areas of SCA conditions.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Frost Advisory until 8 AM EDT this morning for MEZ007.
NH...Frost Advisory until 8 AM EDT this morning for NHZ001-002.
MARINE...None.

&&

$$

DISCUSSION...Legro
AVIATION...Combs/Legro
MARINE...Legro