Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 261911
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
311 PM EDT Fri May 26 2017

.SYNOPSIS...
Low pressure in the Gulf of Maine will continue northeast into the
maritimes tonight. Weak high pressure will build over the
area on Saturday and will shift offshore on Sunday...allowing a window
of dry weather. The next system over the eastern Great Lakes
will lift north into Quebec Sunday night and will drag a front
toward the region on Monday bringing rain showers. That front
will slowly cross the area late Monday night and Tuesday with
unsettled weather.

&&

.NEAR TERM /THROUGH TONIGHT/...
A cool, damp cyclonic flow continues through tonight as the
center of low pressure in the Gulf of Maine exits into the
Maritimes. Clouds and a few random lingering showers expected
through the evening. With lower levels near saturation some
patchy drizzle and fog may occur in areas along and near the
coast. Temps will only drop a few degs into the mid-upper 40s
overnight. Used a blend of models for overnight lows.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
A lack of ventilation Saturday with weak high pressure over the
area will make for slow clearing to occur since there will be
lingering low level moisture. At least it will be a dry day!
Temps will recover into the 60s in the afternoon as partly sunny
conditions eventually develop in the afternoon.

Saturday night the weak high pres remains over the area with dry
conditions.  Overnight lows once again in the 40s.
&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
The 500 mb pattern continues to remain dominated by moderate to
strong blocking across the nrn hemisphere, especially poleward
of about 50N. The trend for for NE CONUS will be sit at the
equatorward end of a trough, although some weak ridging will be
possible at times as well, especially mid to late week. What
this means for sensible weather is that temps will trend toward
around normal, but there will be some threats for showers at
times as weak waves move around the base of the trough to our
north. So, maybe not great weather, but better than we have had
for a large part of May.

It continue to look like we will squeeze a decent day out of
Sunday as weak 500mb ridging moves over the region and helps
support sfc high. May see more clouds clip the NE zones, but
overall partly to mostly sunny skies and highs coming close to
normal. 70-75 inland, and in the 60s along the coast, as sea
breeze develops.

Closed 500mb low begins shift SE from Ontario Sun night into
Monday, with decent wave rotation around the base, and this will
bring in good threat for showers late Sunday night into Monday.
Monday, therefore is not expected to be a great day withe
numerous showers and a cool onshore flow, producing highs only
in the mid-upper 50s on the coast and 60-65 inland.

The upper level low begins to wobble NE out of the gReat Lakes
Mon night and Tue, and should see a decrease in precip Mon
night into early Tue, but another wave will rotate around the
system by later Tue, and the htreat for showers will increase.
Overall, the system aloft will be filling and flow aloft will be
shifting W-SW which should at least allow some warmer air and
some sunny breaks by Tue way from the coast, at least. Still
showers will hold in the forecast on Tue with highs ranging from
the low 60s in the eastern zones to near 70 in southern NH. As
we move into Wed and the latter part of the week, the 500 mb low
shifts slowly NNE, and although there will still be some wave
rotating around it, and a threat of showers, the best chc chance
of showers will begin northward, with more breaks of sun, and
temps running close to normal, upper 60s in the mountains to mid
70s in southern NH.


&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Short Term...MVFR to IFR conditions at times in areas of low
clouds and patchy precipitation and fog. During Saturday
conditions improve to VFR and continue into Saturday night.

Long Term...VFR Sunday into Sun evening, then MVFR to IFR
possible Sun night into Mon night, with the best chance for the
worst conditions along the coast. VFR, with tempo MVFR in
showers Tuesday into Wed.



&&

.MARINE...
Short Term...Winds have diminished and have backed to the north
and northwest. Not enough of an offshore flow to knock down the seas
until later tonight so expect they will remain high through
the night over the outer waters and will issue a SCA for
hazardous seas into Saturday morning. During Saturday and
Saturday night winds and seas will be light as we enter into a
col zone.

Long Term...For the most part winds/seas will remain below SCA
conditions Sunday through Wed.



&&

.TIDES/COASTAL FLOODING...
The astronomical high tide in Portland is 12.0 feet mllw in
Portland at 12:22 am Saturday. Winds will be offshore by that
time. However, due to this being the highest tide of the year
and still a lingering minor storm surge expected of up to a 1/2
foot, minor flooding can be expected in the usually prone
areas. A coastal flood statement has been issued for the time
near high tide tonight.


&&

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

&&

$$
NEAR TERM...Marine
SHORT TERM...Marine
LONG TERM...Cempa



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