National Weather Service Raw Text Product

Displaying AFOS PIL: AFDGYX Received: 2018-03-21 10:50 UTC


593 
FXUS61 KGYX 211050
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
650 AM EDT Wed Mar 21 2018

.SYNOPSIS...
Low pressure will pass offshore south of New England today 
and will slowly move northeast into the maritimes by the end of
the day on Thursday. A trough of low pressure will linger over
the area on Saturday. High pressure will build in from the north
Sunday and Monday and will hold over the area on Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update...
Have updated the morning forecast. Temperatures have dropped
below zero in the north where radiational cooling was maximized.
Winds have relaxed in this region, while northeasterlies
continue to slowly increase over southern areas.

Dew point depressions continue to be signifant indicating very
dry air draining south from northern Maine and New Hampshire.
This dry air will determine how far north the precipitation will
reach tonight, limiting any potential snowfall to southern
areas.

Prev Disc...
There remains significant disagreement with guidance within the
00Z model suite. 

The battle between a complex system passing to our south and
plenty of dry air over interior Maine and New Hampshire will
continue through early Thursday. GYX 00Z sounding continues to
show this very dry air in place. There are significant dew point
depressions across the region as well. 

A double barrel surface low will elongate with time, making for
a northeast to southwest orientation to the precipitation
field later today. The precipitation will attempt to back into
the region towards sunset as it fights the dry air to the north.

A conveyor belt of cold dry air will develop with a north to
northeast wind. This will allow for maximum temperatures today
to be slightly below most available guidance as clouds increase, thicken
and lower during the day.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Euro and the Canadian remain relatively light on the 
precipitation, while the NAM and GFS solutions suggested warning
criteria for portions of the coastline. Played it down the 
middle and will be issuing winter weather advisories for 
southernmost sections. The headlines will match up well with
adjacent offices. Having said that, this remains a low 
confidence forecast. Expect 2 to 4 inches snowfall, mainly 
along the coast tonight.  

Have brought the precipitation into the region early this 
evening for timing purposes. Mesoscale models suggest the
precipitation may enter southern areas later this afternoon.
However, will lean heavily on the sublimation potential with the
dry air in place.

Very light additional accumulations of snow (mainly eastern
areas) are expected Thursday morning as the double barrel surface
low finally organizes into one system and heads towards the
Canadian Maritimes. No significant clearing expected with the
upper level trough remaining in place overhead.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Cyclonic flow will persist over the region Thursday night into the
weekend as secondary upper trough digs into the northeast. Looking 
for partial clearing Thursday night as low pressure pulls off to 
the northeast. Lows will generally range through the 20s.

Any morning sun will give way to clouds Friday as upper trough 
moves in from the west and low level moisture rotates in from the
east. Highs will average out near normal ranging through the 30s to 
near 40.

More of the same for Friday night and Saturday as upper low slowly
shifts east. Looking for mostly cloudy skies through the period 
with a few snow showers possible on Saturday. Lows Friday night 
will range through the 20s and highs Saturday will range from the 
mid 30s to lower 40s.

After variable clouds Saturday night looking for clearing skies on
Sunday as high pressure builds by to the north. Temperatures will 
range through the 30s from north to south.

High pressure will continue to build over the area Sunday night 
into Monday. Looking for clear skies and light winds with 
temperatures near normal. High pressure will remain parked over 
the area monday night and Tuesday with temperatures moderating 
slightly.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Conditions gradually lowering to MVFR this
afternoon, followed by IFR and LIFR, mainly over southern areas.
Higher ceilings over central and northern areas. Gradual lifting
of the ceiling and visibilities Thursday afternoon.

Long Term...
VFR with areas of MVFR ceilings Thursday night through Saturday.
VFR on Sunday.

&&

.MARINE...
Short Term...Have issued gale warnings for Casco Bay as well.
Therefore, all of the waters will be in a gale at some point
during the storm.

Long Term...
SCA's to minimal Gales possible Thursday night. Sca's likely
Friday through Sunday.

&&

.TIDES/COASTAL FLOODING...
A tidal anomaly at close to a half foot and an additional two 
foot storm surge are expected tonight near the time of high 
tide. This will combine with building nearshore waves of 10 to
15 feet to produce generally minor beach erosion and splash-
over flooding near the time of high tide tonight. Pockets of 
moderate impacts are possible, due in part to the damage of sand
dunes and infrastructure from the storms earlier this month.
Astronomical tides peak out as well tonight.

There will also be coastal flooding with up to a foot of water
on the side streets near Portland Harbor and near Marginal Way.
Flooding can also be expected along Granite Point Road in
Biddeford and the Backbay area of Hampton. Some streets in
Portsmouth may have minor flooding. Areas that have splash-over
will have also some flooding due to the pooling of water
landward of the dunes.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory from 7 PM this evening to 11 AM EDT 
     Thursday for MEZ023>028.
     Coastal Flood Advisory from 1 AM to 5 AM EDT Thursday for 
     MEZ023-024.
NH...Winter Weather Advisory from 7 PM this evening to 9 AM EDT 
     Thursday for NHZ012>015.
     Coastal Flood Advisory from 1 AM to 5 AM EDT Thursday for 
     NHZ014.
MARINE...Gale Warning from 6 AM to 5 PM EDT Thursday for ANZ153.
     Gale Warning from 11 AM this morning to 5 PM EDT Thursday for 
     ANZ150-152-154.
     Gale Warning from 6 PM this evening to 5 PM EDT Thursday for 
     ANZ151.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...