Cannon Mountain

000
FXUS61 KGYX 221416
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1016 AM EDT Sat Aug 22 2026

.WHAT HAS CHANGED...
Minor changes to reflect latest observational trends. It will
continue to be a mainly cloudy day with an increasing chance for
scattered showers towards early this evening. 

&&

.KEY MESSAGES...
1. Unsettled weather is expected through the weekend, but no
widespread significant rainfall amounts anticipated.

2. Isolated rain chances Monday-Tuesday with a lingering upper-
level low. Tranquil conditions by midweek, and loose signals for
increasing humidity late week ahead of another system.

&&

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

Low pressure south of southern New England will continue to
slowly lift northeast and weaken today. As it does so showers
will become more likely, especially over western Maine. Save for
the Seacoast it is possible most of NH remains dry today. NBM
handling the placement of best rain chance fairly I think, so no
planned changes there. Despite the relatively high PoP, QPF will
be on the low side. Most locations can expect less than a tenth
of an inch, but an especially lucky section of town could see up
to a quarter.

Overnight we will need to watch and see how marine fog/stratus
develops. The long range HRRR brings low visibility into coastal
areas, especially for western Maine. The set up would be
favorable as a warm front begins to lift into the region by
early Sun. 

Along that warm front showers and maybe a few thunderstorms are
forecast to form and lift north into the local area. This will
bring a scattered potential for beneficial rainfall amounts. I
do not anticipate this being a widespread soaker, but locations
that do see precip could see a decent amount given that this
will be more convective in nature. At this time I think
significant rainfall amounts will be too isolated to forecast,
so I will stick with the NBM QPF amounts, which more closely
match ensemble means around a quarter of an inch. 

Showery weather may continue into the afternoon and overnight,
as upper low begins to move overhead and keep conditions
unstable.

KEY MESSAGE 2 DESCRIPTION...

Upper-level low moving out of the Great Lakes will continue to 
pivot into southern Quebec early week while fully 
occluding/cutting off from the mean flow. This brings cyclonic 
westerly flow to New England. Most likely outcome will be 
falling dew points with diurnal clouds/brief showers Mon-Tue, 
especially focused in the higher terrain and closer to the 
upper-level low in the north.

Should see a nice dry punch on Monday especially across NH with
very dry mid-levels and dew points mixing down to as low as the
40s! Uncertain how much of this pushes into Maine. Depending on
how it all times out there may be an opportunity for some 
t-storms to develop in a juicy warm sector featuring rather 
steep lapse rates, MUCAPE values that may be pushing 1000 J/Kg, 
and close to 50 kts of deep-layer shear. It is possible the mid-
level dry punch could be a resistant against robust convection, 
but will keep a mention of iso to sct showers/thunder in the 
forecast at this time, with the primary focus from the Kennebec 
Valley down into the Midcoast.

On Wednesday the low loses its grip with brief height rises 
bringing tranquil conditions. By late week ensembles show 
another wave heading our way with possible surface cyclogenesis 
in the Michigan vicinity. With a developing trough to our west, 
likely will see southerly flow developing and returning 
humidity, but details are largely unknown at the 6+ day range.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
Through tonight...Mainly VFR conditions prevail today, but by 
mid to late afternoon CIGs will be lowering and MVFR conditions 
are anticipated. It is possible that some IFR CIGs work into 
coastal areas by evening along with some rain showers. Low CIGs
and more widespread fog will likely bring IFR to LIFR conditions
across much of the area tonight. 

Outlook:

Sunday: Fog scatters out as rain showers lift across the area
Sun. Some improvement to MVFR and VFR is possible by evening.

Sunday night: Continued improvement in conditions, except local
LIFR in valley fog.

Monday: Local MVFR or lower possible in showers.

Monday Night: VFR conditions expected.

Tuesday: Local MVFR or lower possible in showers.

Tuesday Night and Wednesday: VFR conditions expected.

&&

.MARINE...
Winds and seas are expected to remain below SCA thresholds thru
the extended period, despite weak low pressure moving thru the
Gulf of Maine today. Will have to watch the overnight window,
when areas of fog and low stratus may develop ahead of an
approaching warm front. Those foggy conditions are expected to
lift out on Sun.

&&

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

&&

$$

DISCUSSION...Tubbs 
AVIATION...Tubbs