FXUS61 KGYX 161633

Area Forecast Discussion
National Weather Service Gray ME
1233 PM EDT Thu Aug 16 2018

A cold front will slide offshore this morning taking any
lingering shower activity with it. In the wake of the front,
high pressure and less humid air will briefly build across the
area later today and tonight. Low pressure will approach from
the Great Lakes Friday and move east through the region Friday
night. A trailing cold front will gradually push offshore on
Saturday. High pressure will build south from Canada Saturday
night through Sunday and will hold over the region through
Monday night. Low pressure will move in from the west Tuesday
and Wednesday.


1234pm...Quick update to remove any mention of precipitation
this afternoon. It is looking pretty dry and cumulus is just not
getting much in the way of vertical development.

905am...Very minor update this morning to adjust to current
temperature trends. Otherwise, forecast package looks like it's
in very good shape.

620 AM...minor ESTF update to reflect the current mesonet and
radar trends in near term grids.

Prev disc...
At 06z...cold front extended from New Brunswick westward through
central Maine and northern New Hampshire. An area of convection
was presently exiting into Penobscot Bay with scattered convection
noted on NWS Doppler Radar mosaic upstream across northern New
York State as well as northern Vermont. For today...shortwave
impulse over Quebec will ride east and finally drive the baroclinic
zone to the south of the forecast area by early afternoon. Until
then...short range models/ensembles hint at potential for some
spot showers with boundary. Otherwise...a partly sunny day
shaping up with dew points gradually dropping off. Highs will
range from the 70s in the mountains to the lower and mid 80s


A mostly clear start tonight as high pressure crests across the
area this evening before retreating into the maritimes. Clouds
will arrive in the predawn hours in advance of the next shortwave
impulse and associated surface system across much of New
Hampshire while Maine remains mostly clear. We'll see some
patchy valley stratus and fog develop as well. Lows will range
from 50s in the mountains to around 60F elsewhere. On
Friday...low pressure tracks across the eastern Great Lakes and
pulls a warm front north across New Hampshire and adjacent
southwest Maine by early evening. Showers and thunderstorms will
spread north and east then taper with passage of the warm front.
Our northern and eastern zones should remain cloudy and damp for
the balance of the day with warm front yet to clear the area and
with the onshore flow. Southern New hampshire may get into the
warm sector early enough for sufficient heating and
destabilization to occur for a few strong afternoon
thunderstorms. Highs Friday will range from lower and mid 80s
over southern New Hampshire with 70s for the remainder of the


S/WV trof axis does not really clear the forecast area until at
least midday Sat...so the threat for showers and storms will
linger thru the day. The ECMWF has trended towards a bit of an
outlier...that does not sufficient push the front far enough
offshore to remove the chance of rain completely. Right now
being an outlier...I have stayed close to the multi-model
consensus...which is dry for the forecast are from Sun into the
middle of next week.

A deeper trof will set up to our W towards midweek and gradually
move E. Even at this range...ensemble guidance is highlighting
a seasonably strong LLJ...and so likely PoP seems fair given the
forcing. There is some uncertainty regarding how phased the trof
is...with the ECMWF favoring a phased single round of
precip...and the GFS favoring a two phase with the main system
being followed by a drier reinforcing cold front. Behind that
trof...surface high pressure will try and build into the region.


Short Term /through Friday/...Areas of IFR through 12z in stratus
and fog...then bcmg VFR throughout. Lcl IFR developing btw 08
and 12z Fri in stratus and fog. MVFR dvlpg from SW to NE Fri aft
13z in shra/tsra with lcl IFR psb ME coast in fog.

Long Term...Some lingering local IFR conditions are possible
early Sat as cold front works across the forecast area. There
may also be some coastal stratus ahead of the front as well with
IFR CIGs. Generally expect that conditions will be improving
into Sat...with VFR conditions into early next week.


Short Term /through Friday/...Winds and seas remain below SCA
levels through Friday.

Long Term...Generally weak flow is expected...and so winds and
seas remain below SCA thresholds. Some lingering marine fog is
possible Sat before a cold front sweeps the deeper moisture out
to sea.





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