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000
FXUS61 KGYX 251959
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
359 PM EDT Wed Apr 25 2018

.SYNOPSIS...
Low pressure over the mid Atlantic coast will move north through
the area tonight and early Thursday with a good soaking rain.
This system will slowly exit the region late Thursday allowing
clearing Thursday night into early Friday. Another area of low
pressure will move into the region late Fri and Friday night.
Some instability showers are possibly mainly in the afternoon
and evening Saturday. A cold front with cooler drier air arrives
on Sunday. A warming trend is expected to begin early next
week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Most of the precip with this even will fall through this evening
as decent slug of rain, currently congealing over SE MA, will
move NNE across areas along and just inland of the coast. This
is in response to tightening WAA at mid-lvls, which is also
developing a low level jet in the region. Models are in some
agreement that some places near the coast could see close to an
inch of rain or so between 22-06Z or so. So, the +RA wording was
put into the forecast for the evening. Could see some localized
areas of urban and poor drainage flooding, but overall not
anticipating anything significant. The surge of decent SE
upslope flow overnight, will also produce enhanced amounts in
these areas of the mtns, and this will drain into some rivers
and tributaries that are already running high due to snowmelt,
so, the flood watch will be held as it is. The rain will lighten
up some after midnight, but should continue thru most of the
night before it tapers off to showers anywhere but maybe srn NH.
Temps will fall off a little bit tonight, but lows will mostly
be in the mid to upper 40s.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Could see another surge of steady rain move across ern zones Thu
morning, but other areas will be more showery, although clouds
and fog will linger through at least the first part of the
morning, until winds shift to the west. Should see showers end
around midday in srn NH and far SW ME, but clouds  will linger
through a good part of the day, with some breaks of sun late.
Most everywhere else will see a chance of showers thru the
afternoon, with mainly cloudy skies. Highs will generally be in
the mid to upper 50s in the mtns and eastern zones, where
clouds and rain will hang around longer, to 60-65 in SW ME and
srn NH, where it will be drier, with a greater chance of some
sun, and downslope W flow.

Should see showers ending early Thu evening everywhere with clearing
overnight. Winds will diminish a bit and allow temps to cool,
with lows upper 30s to mid 40s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Models indicate another short wave trof moving across the
southern jet stream will lift northeast to the mid Atlantic
region Fri forming another area of low pres along the mid
Atlantic coast that will move north into the area with a similar
track as its predecessor. This will mean another round of rain
or showers will overspread the area late Fri through Fri night.
QPF amounts may be in the 1/2-1 inch range. The system will be a
fast mover and move into the maritimes by Sat with a dry slot
of air to arrive for Sat with a cyclonic flow aloft remaining.
The combination of some heating on Sat with the cyclonic flow
aloft may allow some scattered afternoon showers to develop. On
Sunday the cold trof aloft over the Great Lakes progresses east
and allows a cooler northwest flow to develop Sunday with more
instability showers expected due to steepening lapse rates with
any daytime surface heating. Winds may become gusty due to the
strong northwest winds aloft mixing down to the surface. Temps
will be cool through Sunday.

Early next week a progressive large upper ridge will build east
and become further amplified by Wed with a much warmer southwest
flow to develop with dry conditions. Bottom line is a major
warm up is looking like a reality beginning early next week and
continuing through at least mid week. With a broad west to
southwest flow expected Tue-Wed, guidance temps will likely be
forecast too low for days 6-7. For now stayed close to guidance
temps to match surrounding forecast areas.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
Short Term...Conds will drop to IFR or lower everywhere this
evening and stay there into early Thu. Some improvement to VFR
possible by afternoon at KCON/KMHT/KPSM/KPWM, with MVFR
lingering thru the afternoon elsewhere. VFR expected everywhere
Thu night.

Long Term...VFR early Fri with conditions lowering to MVFR/IFR
late Fri into Sat in rain showers. VFR conditions return Sunday
with gusty NW winds in the afternoon.

&&

.MARINE...
Short Term...SCA up for both winds and seas tonight, as SE winds
gust to 30 kts or so. Seas stay up Thu into Thu night, although
winds will shift to W and diminish, so will likely need to
convert SCA to haz seas versions during the day Thu, and extend
it thru at least Thu night.

Long Term...Seas over the outer waters will remain aoa 5 ft F
Fri into Sat so SCA`s for seas will likely be needed even
though winds will remain light for that time frame. On Sun winds
shift to westerly and continue into early next week and should
remain generally below SCA conditions.

&&

.HYDROLOGY...
Expect continued snow melt to combine with about
an inch or so of rainfall to bring further rises to all rivers,
but especially the headwaters that drain eastward out of the
mountains toward the Atlantic. These are the areas most likely
to see minor flooding, and some locations are currently forecast
by the RFC to reach minor flooding. Because of this, we have
issued a Flood Watch covering the most likely impacted areas,
including the upper Saco River as well as tributaries of the
Androscoggin River. Flooding cannot be ruled out on the upper
Pemigewasset River as well as along the Kennebec.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch from 8 PM EDT this evening through Thursday
     afternoon for MEZ007>009-012>014-021.
NH...Flood Watch from 8 PM EDT this evening through Thursday
     afternoon for NHZ001>006.
MARINE...Small Craft Advisory until 8 PM EDT Thursday for ANZ150-152-
     154.

&&

$$