Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 290049 AAB
AFDGYX

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
849 PM EDT Sat Mar 28 2020

.SYNOPSIS...
A warm front lifts north overnight, with rain arriving over
southern and coastal sections by dawn and a mix of snow and rain
across northern New Hampshire and interior western Maine. While
a mix of snow, sleet, and some rain continues across the
mountains and foothills on Sunday, the remainder of the area
will see a cold rain. Colder air will begin to drain back south
Sunday night...with precipitation changing to snow and sleet
across much of the area with the exception of the southern third
of New Hampshire and extreme southwest Maine. On Monday...a
light mix of rain and snow will continue with any accumulation
of snow limited to mountain sections. Cool unsettled weather is
then expected for much of the upcoming week.

&&

.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
9 PM Update...
Rain is reaching the ground in portions of Cheshire and perhaps
Hillsborough Counties. Expect a slow increase in echoes across
southern NH and SW ME overnight before better forcing for ascent
arrives and spreads precipitation north and east. Forecast p-types
look good with lower dew points and heavier precipitation
allowing for cooling and resulting in mixed precipitation...
especially sleet...and snow at times. This is especially true
for the foothills and mountains. Adjusted storm total snowfall
amounts to be better in line with current headlines.


630 PM Update...
Radar echoes are moving slowly into southern NH and SW Maine
early this evening. Dew points are quite low, and not expecting
any measurable precipitation for a few more hours. Moisture is
slowly increasing however as the column moistens ahead of low
pressure moving into NY state and Pennsylvania. Still a few more
hours before light precipitation turns into steady rain or snow.
Towards daybreak much of NH as well as SW ME will be seeing
either snow, rain, or a mix.

Made a few changes, especially for the dew point curve
overnight. Temperatures will drop the first half of the night,
hold steady then gradually increase in the early morning hours
as WAA increases.



Previous discussion...
At 18z a 1022 millibar ridge was draped across the area. high
was centered over western New England. A warm front extended
from the upper Midwest to the DELMARVA. Mid and high clouds
continue to spread north and east on GOES imagery and even our
far northern sections should cloud over this evening. NWS
Doppler Radar mosaic continued to show a large area of
precipitation to the north of the warm front over upstate New
York. This activity will spread east into southern and western
New Hampshire by tonight where it should fall mainly as rain.
Some locations mainly from the Lakes Region on north will cool
enough with precipitation onset to mix with or change to snow.
By dawn...the leading edge of the precipitation will extend from
northern New Hampshire through extreme southwest Maine. Both
deterministic and ensemble model solutions have trended slower
with precipitation onset with the GFS an outlier. Lows will
range from around 30 across the mountains with mid and upper 30s
for the remainder.

&&

.SHORT TERM /7 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
On Sunday...precipitation will gradually overspread the
remainder of the area with a cooling column supporting rain and
snow across the mountains and some sleet as a warm layer moves
in aloft. Elsewhere...we should see largely rain with some
pockets of sleet and wet snow possible at times over the
foothills. Given the expected mix...there will be a wide
variation of snow and sleet amounts across the northern
mountains. Given later onset time and uncertainty with amounts
have held on to the winter storm watch at this juncture. By
tomorrow evening...colder air will begin filtering back south
and we should see precipitation transition back to snow and
sleet across the mountains and foothills with a mix of snow
sleet and rain from central New Hampshire through much of
interior southwest Maine. Outside of the mountains and foothills
I expect little more then a coating by dawn on Monday...with
several inches possible across mountain sections. Lows will be
near 30 across the mountains with mid 30s elsewhere.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
The warm air advection regime and the first part of the weather
system exists on Monday while a strong stacked low moves in to
take its place. The mid level low attempts to redevelop just
off the coast late Monday and Monday. Enough moisture should be
available in conjunction with widespread forcing for ascent to
allow for widespread precipitation Monday into Monday night.
Normally with upper lows the precipitation tends to be showery,
but positive advective processes in association with the
redeveloping low will tend toward a more stratiform event. Snow
will continue in the mountains with rain (or even a break in the
precipitation) elsewhere likely transitioning to snow as Monday
afternoon progresses. Low probability for even a 1-4" plowable
snow event pretty far south (away from the immediate coast and
southernmost NH) ending Monday night.

Otherwise, we`ll have to watch for a retrograding low pressure
system possibly moving our way for mid to late week.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Short Term /Through Sunday night/...Cigs lowering to MVFR then IFR
at all but /KAUG/ and /KRKD/ by 12z Sunday in RA and SN...and
at /KAUG/ and /KRKD/ by 16z. SFC wind gusting up to 25 kt at
coastal terminals Sunday night.

Long Term...Mainly IFR conditions expected in the mountains and
foothills Monday and Monday night, transitioning to IFR Monday
afternoon and night elsewhere in rain, and then snow.

&&

.MARINE...
Short Term /Through Sunday Night/...Increasing onshore flow with
building seas Sunday and Sunday night with SCA conditions developing
all waters. Outside the bays...we cloud see a few gusts approach
Gale Sunday night.

Long Term...SCA conditions continue Monday through Tuesday
night, mainly for seas 5-10 feet on the outer waters.

&&

.EQUIPMENT...
No upper air flights due to lifting gas supply interruption. No
current ETA on resuming flights.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Storm Watch from 8 AM EDT Sunday through Monday morning
     for MEZ007>009.
NH...None.
MARINE...Small Craft Advisory from 4 PM Sunday to 6 AM EDT Monday for
     ANZ150>154.

&&

$$

NEAR TERM...Hanes
SHORT TERM...Schwibs
LONG TERM...Ekster


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