Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 081906

Area Forecast Discussion
National Weather Service Gray ME
306 PM EDT Sat Aug 8 2020

Weak high pressure keeps the weekend mostly dry but unsettled
conditions loom nearby so can`t rule out isolated to scattered
thunderstorms Sunday into early next week. Otherwise the
forecast period will be highlighted by increasing heat and
humidity into next week with occasional chances for showers and
thunderstorms, especially mid week.


The short wave trough that aided in the shower and thunderstorms
activity this morning has moved offshore and has been replaced
by short wave ridging. This should mean a mostly dry rest of
afternoon and evening period with just isolated airmass showers
and thunderstorms possible.

Dry weather expected tonight with valley fog likely, especially
in the CT River valley and adjacent areas of western NH that saw
rain this morning. The fog could be locally dense.


A short wave trough will approach from the west on Sunday. This
should aid in the development of scattered showers and
thunderstorms during the day. The short wave trough is a slow-
mover so isolated to widely scattered showers and storms may
continue through much of the night. However, widespread heavy
rain is not expected. During peak heating hours on Sunday the
mid level lapse rates will be weak and deep layer shear will be
25 kt or less. While an isolated severe thunderstorm or two is
not out of the question, the above mitigating factors should
keep the threat to a low probability.


The trend for the week will be for increasing heat and humidity
as a ridge of high pressure bringing a surge or warm air
remains over the area. Far to our north, low pressure will track
through Canada, but most of the dynamics and sensible weather
impacts will remain in Quebec with just a few chances for
showers down into our region.

Starting Monday we`ll see increasing heat and humidity. Dewpoint
will return to the mid to upper 60s and with them overnight temps
will also increase correspondingly. Patchy valley fog is
possible although some mid level cloud cover may be enough to
limit widespread fog formation.

By Tuesday H8 soar to near 20C, with surface highs reaching well
into the 90s. With the southwesterly flow, expect that to
squelch any seabreeze, and have pushed the highs to the upper
edge of the guidance to reflect this favored flow. A weak
shortwave passing to the north may result in a few scattered
shower across the moutnains Tuesday afternoon. Some hints of a
remnant EML layer moving in aloft would provide for favorable
conditions for strong storms on Tuesday.

The heat remains in place through Wednesday, with southern NH
likely seeing three days in a row of above 90 degree
temperatures. Once again we see a chance for some thunderstorms
as steepening mid level lapse rates increase the CAPE across the

The heat begins to moderate on Thursday and Friday as a weak
front pushes through the region. Still expect temps to remain in
the 80s, with some isolated showers possible.


Short Term /through Sunday night/...VFR this evening with local
LIFR conditions in valley fog expected later tonight and early
Sunday morning, mainly in the CT River Valley. Otherwise VFR
Sunday with seabreeze developing on the coast. A few showers and
thunderstorms will be possible during the afternoon and evening
hours. Otherwise, winds will be light. IFR conditions will be
possible Sunday night if a stratus deck moves in from off the
ocean, but confidence on that is low at this time.

Long Term... Increasing heat and humidity through midweek. Some
valley fog is possible in the CT river valley Monday and Tuesday
night as humidity increases with IFR conditions possible.
Scattered thunderstorms are possible across the mountains
through midweek.


Short Term /Through Sunday night/...Gradient remains light
across the waters through Sunday night with winds and seas
below SCA.

Long Term... Quiet over the waters as high pressure moves over
the region bringing increasing heat and humidity. Southerly flow
will likely result in fog, especially over the eastern colder
portion of the waters.





NEAR TERM...Ekster
LONG TERM...Curtis is the U.S. government's official web portal to all federal, state and local government web resources and services.