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Area forecast discussion 
National Weather Service Gray ME
646 am EDT Tuesday Sep 2 2014

Synopsis...
a cold front will approach from the west tonight and Tuesday and
will cross the area Tuesday night. High pressure will build in
from the west Wednesday through Thursday and will shift offshore
Thursday night. High pressure will hold off the East Coast on
Friday as a cold front approaches from the west. The front will
stall near the coast Saturday.

&&

Near term /through tonight/...
update...
have updated the grids based on current conditions. Dense fog
continues to develop over the midcoast region westward through
central New Hampshire with visibilities below a half mile over the
region. Have issued a dense fog advisory for this region...with
good collaboration with weather forecast office car. Visibilities have just turned lower as
well in the Portland area. This fog is in a very shallow layer and
should mix out within the next hour.

No other changes with this update.

Previous disc...
patchy dense fog will continue through early this
morning. Otherwise...mesoscale models continue to suggest a short
wave will cross the forecast area early this morning. Any impact
will be minimal as the system weakens as it approaches and crosses
the region.

Complex weather day today. Mesoscale models continue to show
significant instability over western portions of the forecast area
as leading short wave enters New Hampshire. Will keep the mention
of strong gusty winds. Plenty of juice remains in the atmosphere
so some storms may produce locally heavy rainfall as well.

&&

Short term /Wednesday/...
main front with trailing short wave enters the region late this
afternoon and early this evening. This will produce more showers
and scattered storms. A few of these storms may produce locally
heavy rainfall as well as a mesolow crosses the Portland area. Any
training storms could produce local flooding. Will mention in the
severe weather potential statement for now.

&&

Long term /Wednesday night through Monday/...
high pressure builds in Wednesday night with some less humid air
in place. Should see good cooling conditions which will likely
lead to fog in the valleys.

High pressure moves offshore on Thursday with southwest flow
bringing in warm/humid air again. Should see plenty of 80s on
Thursday and again on Friday along with increasing humidity. Cold
front moves into the area from the northwest Friday night into
Saturday... with showers and thunderstorms possible along it.
GFS/European model (ecmwf) are in better agreement on the timing of this front than
previous runs... though the European model (ecmwf) is a little slower moving it out
of the area.

Canadian high pressure moves in behind this front... so expect
cooler and drier air to be in place by Sunday. The cool/dry
weather will persist into early next week with temperatures more
fall like... highs in the 60s to near 70 and lows in the 40s and
50s.

&&

Aviation /12z Tuesday through Saturday/...
short term...IFR and LIFR ceilings and visibilities continuing through
early this morning in patchy dense fog. Thunderstorms this afternoon over
New Hampshire will lower ceilings/visibilities once again...before making
its way to the coastline this evening.

Long term...should see mostly VFR conditions but will continue to
have a threat for valley fog each night. September is the month
with the most frequent dense fog at our valley terminals.

&&

Marine...
short term...winds and seas will remain below Small Craft Advisory levels.

Long term...high pressure moves over the area Wednesday into
Thursday with light winds. Southwest winds may increase on Friday
but should stay below advisory levels. A cold front arrives on
Saturday with a northwest flow behind it.

&&

Gyx watches/warnings/advisories...
ME...dense fog advisory until 9 am EDT this morning for mez012>014-
019>022-024>028.
New Hampshire...dense fog advisory until 9 am EDT this morning for nhz003>006-
009.
Marine...none.

&&

$$
Jc

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