Area Forecast Discussion
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FXUS61 KGYX 231718
Area Forecast Discussion
National Weather Service Gray ME
118 PM EDT Sun Apr 23 2017
High pressure and drier air will finally build into the region
today. A cold front will drop south into northern New England
tonight into Monday and stall. Low pressure will slowly move up
the Eastern Seaboard Tuesday and Wednesday with drizzle and
periods of rain. A cold front will slowly approach from the
west Thursday into Friday, before finally crossing the region on
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
120 PM Update...Fine day underway across ME and NH with
temperatures into the 50s and 60s with little in the way of
clouds. Seabreeze should continue to push inland this afternoon.
945 AM Update...Have updated the forecast for minor adjustments
to temperatures and sky cover based on latest trends in
observational and mesoscale model data. Raised max temps a
little bit, mainly inland. Have also increased cloud cover for
eastern zones for the next several hours based on latest
6am update... some `sunrise surprise` dense fog will quickly
burn off over the next hour.
prev disc...Overall look for a clearing trend today
as high pressure builds in from the west. At 3 AM, clouds
remained in place over much of Maine with a few pockets of
clearing in New Hampshire. These clouds will move east and as
they do areas which are able to clear before sunrise may see fog
form. Augusta is the usual culprit here with visibilities
already decreasing. Any fog will be patchy and brief as the sun
rises and quickly burns off the moisture. The sun will allow for
temperatures to climb to the mid to upper 50s by mid morning.
High pressure crests over the region this afternoon, which will
allow a sea breeze to develop. With a weak pressure gradient the
sea breeze should be able to push inland as far as Sebago lake.
This south flow will keep high temperatures cooler along the
coast, especially from Portland east through Penobscot bay.
South of Portland, highs will still approach 60 along the water
and be in the low 60s inland.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
The evening will start off with clear skies across the region. A
cold front will approach from Quebec, but the high pressure to
our south will push it off to the north. The result is just a
slight chance of showers along the northern border and
increasing clouds through the mountains. Monday the same high
pressure will be in control for much of the day with high
temperatures once again getting into the 60s. Clouds will
increase from the south ahead of an approaching low pressure
system on Monday night.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Models continue to slowly lift an upper level low pressure
system to the northeast. By Monday night, models in good
agreement with surface low pressure near the North Carolina and
South Carolina border. As the system moves northeast,
precipitation will spread northward through our forecast area.
Patchy drizzle may form along the coast as onshore winds begin
By Tuesday night, models remain in relatively good agreement
with the 00Z suite, bringing low pressure to the New Jersey
coastline. Latest ensemble information supports this track as
Thereafter, the system begins to fill as it reaches New
England on Wednesday, however there will be plenty of moisture
in place for areas of rain and drizzle to continue especially
along the coast.
QPF: Best estimates show about an inch to 1.5 inches along the
coast. Lessor amounts will occur inland near the headwaters.
Therefore, river flooding is not expected at this time.
The system moves east Thursday as a cold front remains well to
our west. Lots of low level moisture will remain in place with
a developing southerly flow, so not much clearing expected.
Latest models suggest that the long awaited cold front will
cross the region Friday. Thunder will be possible with these
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
Short Term...The region will remain VFR through this afternoon
and into Monday.
Long Term...An onshore flow will lead to lowering ceilings into
the MVFR or IFR category during the day Tuesday as rain and
drizzle begins. Conditions continue to lower Tuesday night
through Wednesday night possibly locally to LIFR. Conditions
slowly begin to improve Thursday as a light southerly flow
Short Term...Expect waves to continue to diminish as high
pressure builds in for the day. Low chance of SCA conditions
tonight on the ocean waters.
Long Term...Onshore flow increases Monday night into Tuesday as
low pressure slowly moves up the Eastern Seaboard. Winds will
increase Tuesday night and waves will gradually build into early
Wednesday as the persistent onshore flow continues. Wave
forecasts may be underdone by the current model solutions with
such a persistent onshore flow.
High pressure builds in for Sunday as sunny skies help to dry
out conditions. RH will drop to near 30 percent across much of
New hampshire. The drier air will linger through Monday before
another system approaches tuesday spreading rain into the
High astronomical tides will continue for the week, increasing
during the midweek period. At Portland the astronomical tide is
forecast at 11 FT Tuesday night and 11.5 FT Wednesday night.
With a prolonged period of onshore flow expected, the ESTOFS
prediction for minor storm surge values of about a foot appears
to be reasonable. Winds decrease Wednesday night, however high
water anomaly`s will likely continue.
Nearshore waves will not be overly large during this period,
mainly ranging in the 5 to 9 foot range. However, with such high
astronomical tides, NART wave runup matrices and in-house
matrices suggest erosion and minor splash-over may occur
beginning as early as Tuesday night.
Very high astronomical tides will continue for the rest of the
week, with tides peaking out at 11.7 feet on Thursday and Friday
night in Portland Harbor.