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-- Discussion containing changed information from previous version are highlighted. --
566
FXUS61 KGYX 211622
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1222 PM EDT Fri Jul 21 2017

.SYNOPSIS...
A weak front crosses the region today with a trend toward cooler
weather expected this weekend. Several areas of low pressure
will track through southern New England late this weekend and
into early next week, providing a chance of rain while keeping
temperatures cool.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...

1220 PM...Minor ESTF update to ingest the current mesonet into
near term grids.

Prev disc...
912 AM...Modified BUFKIT soundings support afternoon CAPES of
1000 to 1500 j/kg across our northern Maine zones and coupled
with strong wind field expect any storms that develop there to
have the potential for strong winds gusts and to a lesser extent
hail. Have added enhanced wording there for gusty winds and
small hail with this ESTF update. some haze and fog was
introduced to our far eastern offshore marine zone per GOES
imagery trend.

Prev disc...
Light westerly flow expected today with continued warm but
slightly less humid conditions. A cold front will drop in from
the north late in the day and could trigger a few showers and
thunderstorms in the far north. Expect temperatures in the upper
80s to low 90s for most areas, with only some minor cooling
right along the Maine coastline.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Front drops south across the area tonight. Any lingering showers
should dissipate as the night goes on. While winds will be out
of the northwest on Saturday with cool advection ongoing, we
should still see temperatures warm into the mid to upper 80s
with downsloping conditions on the coastal plain.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
We head into a rather cool period for Sunday through the start
of next week.The long wave pattern will transition to a trough
over the eastern United states as a short wave digs south out of
Saskatchewan on Saturday. By Sunday night a trough is
entrenched over the Northeast and will hold there through the
start of the week. This will lead to below normal temperatures
with highs struggling to reach 70 /about 10 degrees below
normal/ by Tuesday.

A series of short waves will move through this broad upper
trough leading to several rounds of showers.

On Sunday a quick moving wave will rotate through the trough.
Consensus seems to be to keep most precipitation south of our
area but southern New Hampshire may still see some shower
activity.

A stronger wave approaches on Monday as the trough digs further
south. This will spin up a surface low south of Long Island.
This low will then pass over the Cape Cod canal and cross the
Gulf of Maine during the day on Monday. With northeasterly flow
ahead of the low we set up a surface pattern more familiar for
the cold season. The northeasterly surface flow will keep colder
air dammed at the surface while aloft 850mb winds will remain
easterly at around 30kts. Expect this set up to result in a
region of heavy rain within Maine as the saturated easterly flow
runs into the mountains. Still quite a bit of spread in the
timing and location within various guidance but overall have
kept likely pops in the mountains overnight Monday into
Tuesday.

The showers will continue as the low moves off to the east on
Tuesday with temperatures again remaining below normal. Brief
ridging will move in for Wednesday returning temperatures to
more seasonable values under clearing skies.

&&

.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
Short Term...VFR conditions are expected outside some early
morning fog in valley locations.

Long Term... Cool and unsettled weather returns with showers and
MVFR ceilings being the norm for the daytime and IFR in fog
returning into the overnight from Sunday night right through
Wednesday.

&&

.MARINE...
Short Term...Light winds expected over the waters with wave
heights remaining generally less than 2 feet.

Long Term...A low will cross the waters on Monday into Tuesday.
Ahead of it we may approach SCA on the outer waters as
northeasterly flow develops.

&&

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

&&

$$

ES