295
FXUS61 KGYX 182029
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
429 PM EDT Fri Apr 18 2025

.SYNOPSIS...
A warm front will lift through the Northeast tonight. Some areas
of showers will ride along that front through Saturday but that
may still result in large portions of the forecast area
remaining dry. Those areas that are lucky enough to remain dry
and relatively cloud free will see temperatures soar into the
70s to near 80 on Saturday. That will be short lived warmth
though as a strong cold front drives through the region
overnight. Sunday will be cool with northwest winds gusting to
35 or 40 mph at times. It will remain dry until the next system
moves through the area Monday night or Tuesday.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
First area of showers will move through this afternoon and early
evening, but dry air in the low levels will result in virga and
some sprinkles through sunset across the north and interior.
Isolated to scattered showers continue tonight, with low
confidence in coverage. This is both due to remaining low level
dry air and the chaotic nature of the convective systems moving
east of the Great Lakes. Overnight temps lower, but will remain
mild in the 40s and lower 50s.

Model fields have been advecting elevated instability into the
forecast area tonight, and keep mention of thunder across the
mountains and western ME. Some of the MUCAPE values are robust
above a stout low level inversion. This is supported by mid
level lapse rates of 6 to 7 c/km. Given the chance at more
substantial lift, storms may contain small hail. Not enough
confidence to put enhanced wording in the forecast at this
moment, but lightning and dbz trends should be tracked
overnight.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Isolated to scattered showers continue Saturday with
temperatures soaring into the mid 70s for much of the interior.
Readings close to 80 will be possible in southern NH. With the
passage of a warm front overnight, the forecast area will reside
in the warm sector of the parent low crossing southern Quebec.

Model profiles contain enough dry layers to expect a couple
breaks of sun during the day tomorrow, which will help attain
these above normal temperatures. However, thicker cloud cast
could prevent some of these forecast highs being met, especially
around areas of more continuous shower activity.

Surface based instability remains low to marginal tomorrow
afternoon, but embedded waves will attempt to initiate one or
two rounds of showers and storms through the early evening. Mid
level lapse rates will have weakened, thus CAPE values will
struggle unless low level moisture feed improves. Broad LLJ
draped across New England may bring gusty winds to stronger
showers or storms through the afternoon. MPAS CAMs do indicate
some broken lines or multicellular development into western and
southern NH. Will monitor trends ahead of the expected cold
front that passes Saturday night.

Breeze that picks up midday continues into the evening and
overnight hours keeping the surface mixed. Temps are slow to
fall until cold front makes its way overhead. This will result
in temps finally falling across the mountains and then interior
overnight. Showers, some snow, continue in the mountains into
early Sunday morning.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Key Message: The steady march of spring continues with temps
alternating between cool and warm. Two solid signals for precip
around Tue and again at the end of the week...although timing
remains low confidence in the second system.

Impacts: The most significant weather impact will be fire
weather on Sun. Min RH may fall into the low to mid teens along
with gusty winds.

Forecast Details: Right out of the gate on Sun I had to make
some adjustments to the guidance. The main concern is dewpoints.
Bufkit soundings indicate that mixing to at least 875 mb is
probable. Using this as a starting point for mixing down
dewpoints would yield min readings in the single digits. Both
NBM and MOS guidance are more in the mid teens. So I have
heavily blended the mixed down dewpoints into the forecast. The
result is min RH values around 15 percent which will combine
with northwest wind gusts of 35 mph. IF we do not get rain on
Sat...the fact that temps are on the cool side may not matter so
much for fire starts.

Otherwise there was little change to the NBM consensus blend.
There is a solid signal for precip Tue. Like the Sat
event...there is broad consensus across model suites for a
similarly light event. Additionally the best chances for rain
will across the northern areas where the fire threat is already
lowest. So that will have to be monitored thru midweek.

By late in the week a western CONUS trof combined with a
flattish ridge over eastern CONUS will result in a fast flowing
pattern locally. The timing differences between waves have PoP
generally spread out over several periods...but chance wording
sounds appropriate given that uncertainty.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Short Term...VFR this evening with LLWS after midnight across
all terminals ahead of a warm front. Some low stratus may
develop towards RKD overnight with MVFR/IFR ceilings until
midday Sat. MVFR ceilings settle near HIE late Saturday.
Scattered SHRA expected through much of the area tonight and
Saturday. Some TS can`t be ruled out tonight across the
mountains and again Saturday afternoon for western and southern
NH. A cold front passes Saturday night with winds becoming gusty
and from the NW.


Long Term...VFR conditions prevail until Tue. Northwest surface
gusts near 30 to 35kt possible Sun. Warm front arrives early
Tue and CIGs will lower and areas of IFR are possible. A return
to VFR conditions is anticipated behind the cold front...as
early as Tue night or Wed morning.

&&

.MARINE...
Short Term...SCA continues this evening through Saturday as a
warm front lifts over the waters. Expect building waves until a
cold front crosses Saturday night with winds shifting offshore.

Long Term...SCA conditions expected Sun in offshore winds. Winds
and seas will diminish thru Mon morning as high pressure builds
over the region. Warm front will lift into the Gulf of ME
Tue...and bring the potential for some marine fog.

&&

.FIRE WEATHER...
Despite cool temps Sun...RH values will be very dry and winds
will be gusty. Dewpoints may fall into the single digits and
result in min RH around 15 percent for a large portion of the
forecast area. Northwest winds may be sustained in excess of 20
mph and gusting over 35 mph at times during the day. If showers
don`t produce much wetting rain Sat...that could leave fuels
dry for Sun.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 PM EDT Saturday for ANZ150>154.

&&

$$

NEAR TERM...Cornwell
SHORT TERM...Cornwell
LONG TERM...Legro
AVIATION...Cornwell/Legro
MARINE...Cornwell/Legro