Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 191243

Area Forecast Discussion
National Weather Service Gray ME
843 AM EDT Wed Oct 19 2016

Expect a warm day today with clearing skies as high pressure
builds in from the west. This area of high pressure moves into the
maritimes on Thursday as low pressure developing over the Ohio
Valley tracks northeast toward northern New England by Friday.
This will bring a period of wet weather from late Thursday into
Saturday. A cold front pushes through from the west on Saturday
bringing colder weather but a return to dry conditions for the
latter part of the weekend into early next week.


845AM UPDATE... Morning upper air observation shows a steep
inversion with a very warm layer just above the surface. This
should allow temperatures to pop up quickly this morning, likely
hitting the mid 70s fairly quickly before slowing their upward
trajectory. Have updated the forecast to show a quick warming and
increase high temperatures a few degrees, now showing a few
locations hitting 80. Also zeroed out the precipitation chances as
no more rain is expected. No other changes were made.

545AM UPDATE... Cold front along with any surface convergence
along the boundary was almost offshore around 6 am this morning.
QPF amounts have been very light. There is still some light rain
mainly over the Augusta/Wiscasset/Rockland environs. Adjusted PoPs
based on radar and current timing. Also adjusted temperatures and
dew point temperatures based on latest mesoanalysis.

A cold front was moving through central New England this morning,
albeit slowly. A warm front snaked through portions of Maine and
New Hampshire with readings in the 70s noted over northern MA.
This warmth will continue to spread this morning and have kept the
non-nocturnal curve in place. To the northeast a cooler wedge of
air including dense fog and drizzle was eroding from the southwest
as mixing increases ahead of the warm front. Underneath the
inversion temperatures are in the 50s and 60s and will continue to
slowly tick upwards overnight.

Rain showers will come to an end this morning as the frontal
boundaries are swept offshore. The coastal plain will clear out
quickly with sunny skies expected. Over the higher terrain some
upslope clouds will linger. Temperatures will vary from the lower
60s north to near 80s near Nashua and Manchester where the
downslope component of the winds will be enhanced.


Despite clear skies tonight we will not fully realize our
radiational cooling potential everywhere. Where winds do decrease
enough, temperatures will drop into the 30s. The mid to upper 40s
will be much more likely across the forecast area however.

Cloud cover returns Thursday as another warm front lifts into the
northeastern states. This will spread rain cross the region and
will likely bring some measurable precipitation to many areas.
Highs will be slightly cooler due with readings generally in the
upper 50s to lower 60s.


A progressive digging upper trough will move across the Ohio
Valley and Great Lakes region will allow showers to become
widespread Thursday night. The upper trough will continue to
develop over the eastern Great Lakes Friday becoming vertically
stacked and spawning surface cyclogenesis across the St Lawrence
and then a redevelopment along the New England coast late Friday.
A broad area of rain is expected for Friday. The upper trough
will continue to develop as it becomes negatively tilted and then
becomes a closed low by Friday night. As the system develops,
models are indicating a strong southeast flow will develop to its
east and will likely pick up some tropical moisture from a system
off the southeast coast of the U.S. This may bring some soaking
rains to the area late Friday into early Saturday. Modes in some
disagreement with the EURO being the wettest model.

Models indicate the closed upper low is expected to move slowly north
and east into the maritimes Saturday and Sunday allowing some
lingering showers mainly in the mountains due to the unstable
cyclonic flow. In southern areas generally dry conditions expected
for the weekend.  Much cooler temperatures will arrive behind the
system Saturday into early next week.


Short Term...A mixed bag of VFR to LIFR conditions are prevailing
this morning- mainly in ceilings that will last a few more hours
until a cold front pushes offshore taking much of the moisture
with it. All terminals will see VFR shortly after sunrise today,
which will persist through Wed night. Somewhat gusty westerly
winds are om tap for this afternoon.

Long Term...Conditions become IFR Thursday night as an onshore
flow persists in bringing in low level moisture. More substantial
rainfall is possible on Friday and Friday night as low pressure
moves through the area, likely keeping conditions IFR to lifr. A
cold front pushes east through the area Saturday morning, allowing
clearing conditions to VFR over southern areas while in the
mountains and foothills MVFR conditions in scattered showers will
persist through much of the weekend.


Short Term...SCA has been extended through noon for a few gusts
to 25 kts as well as seas around 5-6 ft. After daybreak the higher
seas will be confined from Cape Elizabeth eastward. We will near
SCA conditions again on Thursday.

Long Term...East to southeasterly wind flow ahead of low pressure
moving through northern New England should stay near or below
advisory levels, but the onshore nature of the wind will allow
wave heights to build to over 5 FT. A cold front pushes east
across the waters Saturday morning, with a west to northwesterly
flow behind it which will likely gust above 25 KT at times.





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