300
FXUS61 KGYX 161203
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
803 AM EDT Fri Aug 16 2024

.SYNOPSIS...
Showers will be possible in the mountains today, but overall
coverage will be less than the last couple of days. Hurricane
Ernesto will pass well out to sea over the weekend, but that
will not stop swell from moving into the Gulf of Maine. That
could lead to a period of higher surf and rip currents into
early next week. The weather after Sunday looks unsettled with
showers and storms possible through much of early next week.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
Update...Minor changes to reflect latest observational trends.

Previous discussion...Locally dense fog remains across the
forecast area this morning...but visibility is slowly improving
and leaving behind just low clouds. I will not be expanding the
dense fog advisory...but will leave it in place thru sunrise.

Some showers across eastern ME will drift into portions of the
Kennebec Valley this morning but are not expected to make it
much farther west than that.

This afternoon we remain under the influence of the upper low
still spinning over the Canadian Maritimes. However the lack of
a clear forcing mechanism will likely confine showers to the
mtns where differential heating and orographic lift can do that
work. Lapse rates are weaker today and so convection overall
will not have the same punch as the past couple of days.

Will also see similar levels of wildfire smoke to the last
several days. HRRR smoke model suggests the highest
concentrations of near surface smoke will be north and
west...away from marine influences. I have haze in the forecast
for these areas.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Warm front will lift towards the forecast area tonight. North of
the boundary onshore flow will prevail and as a result at the
very least marine stratus will move back in tonight. Fog may not
be as widespread as this morning however.

Warm front aloft will be north of the forecast area Sat. At the
surface it may hang up across NH. However the bulk of the
forcing will be along the mid level front...and so showers are
not expected to be widespread. WAA may allow for some
convection...but I will keep PoP to isolated to widely scattered
for now.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
At 500 MB, the weekend will start will a small area of ridging
over New England as we sit between upstream and downstream
trough and Ernesto to our SE. By Monday that trough shifts over
the NE CONUS. And 500 MB flow on the downstream side tightens
up a bit as it runs into ridging and absorbs Ernesto to our E,
which makes Monday the day with the most dynamic forcing and the
best chance for rain. The trough, and likely associated cold
front swings through on Tuesday, with cooler and less humid air
moving in for the middle of the week. However, will have that
500 MB trough lingering, which means a chance for some showers.
By late week, should see some sfc ridging move in beneath NW
flow aloft.

Models seem a little more optimistic about the weekend, given
the relative ridging overhead. Still cannot rule out a few
SHRA/TSRA, especially if a greater amount of sun leads to
increased instability. Highs on Sunday, with better onshore
flow and more clouds, mainly run in the 75-80 range. Itll be
more humid with Tds running in the mid to upper 60s, and
overnight lows in the low to mid 60s.

On Monday,, as that upper level trough starts to deepening a
bit and a wave lifts out of the base of it, will see more in the
way of SHRA/TSRA, and it`ll be more cloudy as well. Also
humidity will be up with tds in the mid 60s N to the upper 60s
and low 70s S. Highs will be closer to the mid 70s than 80 on
Monday as well. SHRA/TSRA continue into Mon evening, but should
start to wane somewhat after midnight, and the cold front may
make into the mtns late so lows range from the upper 50s there
to the low to mid 60s in the S.

Tuesday and Wed will be cooler and drier as 950 temps drop below
+10C, so highs will generally be in the 70s both days. The
cooler air aloft and the 500 MB trough overhead will be enough
for scattered daytime showers to develop, and perhaps a couple
TSRA as well. Overnight lows will be more comfortable and range
from the low 50s in the mtns to the mid to upper 50s in the S.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Short Term...Areas of marine fog and stratus will continue to
lift and move offshore, with VFR conditions are expected thru
this afternoon. SHRA will be much more isolated today...and
even then mostly confined to the mtns. HIE would be most likely
to see any SHRA this afternoon...but even then confidence is too
low to include in the TAF. Fog is possible again tonight...but
low CIGs look likely again as a warm front lifts towards the
forecast area.

Long Term... While VFR is expected to prevail through the
weekend, cannot rule out some brief flight restrictions due to
SHRA/TSRA and then patch fog at night. Late Sunday night into
Monday could some low stratus and numerous SHRA, plus a few
TSRA, and will likely see MVFR with some periods of IFR through
the day, with possibly some LIFR into Monday night. Expecting a
return to mainly VFR Tuesday morning.

&&

.MARINE...
Short Term...Weak flow remains in place as the coastal waters
are sandwiched between two systems. Light southeasterly flow
will result and likely keep some of the marine fog and stratus
lingering over the waters into tonight. Seas will begin to
increase Sat as swell from Hurricane Ernesto reaches the Gulf of
ME. At least for the first half of the weekend seas are
forecast to remain below SCA thresholds.

Long Term... Winds will not be an issue this weekend into early
next week, but seas will increase, especially on Sunday and peak
on Monday in long period swell from Ernesto. Seas away from the
coast could push to almost 10 ft, while near shore waves could
reach to around 6 ft. The seas will begin to subside late Monday
night and Tuesday.

&&

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

&&

$$

NEAR TERM...Legro
SHORT TERM...Legro
AVIATION...Legro/Palmer