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fxus61 kgyx 180831 

Area forecast discussion
National Weather Service Gray ME
331 am EST Mon Nov 18 2019

low pressure off the mid Atlantic coast this morning will move
northward today and into the Maritimes tonight. Generally light
precipitation will slowly spread northward across the forecast
area today, and may contain a mix of sleet and freezing rain
before going over to rain. In the mountains and foothills,
freezing or frozen precipitation is expected to continue
through Tuesday morning. The next weather system looks to move
eastward across the forecast area late in the week, possibly
followed by another low pressure system later in the weekend.


Near term /through today/...
a cold, dry air mass remains in place this early Monday morning
with any concentrated areas of drizzle located down in
southeastern Massachusetts. A coastal front - the dividing line
between cold dry Canadian air and warmer more moist air - can
be seen on the early morning radar loop in the Gulf of Maine
where it is nearly stationary.

We're going to keep the winter weather advisories up for
southern and coastal zones for this morning due to the chances
for freezing drizzle. However, probabilities are looking less
that this will be a big issue for the morning commute as the low
level dry air will continue to allow for the evaporation of
drizzle droplets and any light rain before they reach the
ground. Again, we'll keep the advisories up for now since it
only takes a trace of freezing precipitation to allow for very
slippery roadways. We'll do so even in areas near the mass
border and also on the immediate coast where air temperatures
are just above freezing as bridges and overpasses will still be
at or below freezing owing to the last two cold nights we've
had. Will continue to watch trends early this morning to see if
any advisory areas need to be adjusted or even cancelled.

As far as pops go, we taken the slower consensus approach to the
steadier light rain arrival time as the dry air over the
interior eats away at the eventual leading edge. Blended in the
last several runs of the hrrr to achieve a little more
realistic arrival time. All in all, the steadiest precipitation
probably doesn't arrive til mid afternoon or later, especially
in the mountains where it will probably take until late
afternoon or even the evening hours. Have extended the Winter
Weather Advisory for the mountains and foothills into Tuesday
morning as the steadiest mix of precipitation will be tonight
and Tuesday morning. Freezing rain, sleet, and a few inches of
snow will be likely there.


Short term /tonight through 6 PM Tuesday/...
steadiest precipitation will fall overnight tonight as surface low
pressure passes abeam on the Maine coast as a southern stream
trough and associated higher Theta-E air mass moves overhead.
Much of the coastal plain and southern/central New Hampshire zones should
be a cold light rain with some sleet possibly mixed in at times.
However, it would not be surprising to see pockets of freezing
rain continuing in some valleys. Mountains should see light
freezing rain mixed at times with sleet and snow. The northern
stream short wave trough moves on through Tuesday morning with
another quick hit of steady precipitation. Again, mainly rain
for lower elevations, but mixed precipitation changing to snow
in the mountains. Not out of the question that some sleet and
snow mixes in across lower elevations for a couple of hours
Tuesday morning as the column cools with the passage of the
short wave trough.


Long term /Tuesday night through Sunday/...
the extended continues to feature a fairly active pattern. The
first in a series of potential wx makers will be Wed. An
offshore low will be passing well east of the area...but nrn stream
shortwave trof looks to support a bit of an inverted trof across the
region. These are pretty fickle features so I am not going to
get too wild with the forecast at this time...but this could
bring more widespread cloud cover and some light precip during
the day. Forecast soundings are pretty dry there is a
threat for freezing drizzle. But given the uncertainty and signs
of higher level cloud decks providing seeder-feeder for low
level clouds I have stuck to snow or rain shower wording at
this range.

The next system looks to see the brunt of the forcing pass well
to our north. This will drive a frontal boundary thru the area with
showery precip. In addition the timing looks to be late
I have gone with a non-diurnal trend during the Fri overnight

Finally there is some model support for a follow up wave along
the trailing front over the weekend. Since this would be the
third in a parade of events I am going to keep it close to the
multi-model consensus blend and let the first couple of event
begin to play out first.


Aviation /07z Monday through Friday/...
short term /through Tuesday/...borderline MVFR cigs southern
and coastal sections will remain today and slowly spread north
this afternoon as light precipitation gradually moves
northward. Mainly rain expected at lower elevation terminals,
but areas of freezing rain or freezing drizzle will be possible
before temps warm. Further inland, in the mountains and
foothills, mainly mixed precipitation later this afternoon and
tonight. Northeast surface winds may gust around 25 kt at coastal
terminals today. MVFR to IFR conditions tonight into Tuesday
morning before improving midday.

Long term...will have to watch for lingering areas of MVFR as it
looks like an inverted trof may set up overhead Wed. Any precip
from the trof looks most likely it will be cigs to
worry about. Otherwise a return to VFR late in the day thru Thu.
The next system looks to affect the area Fri. At this time that
looks like mainly a cold frontal passage...with showery wx and
no prolonged lower flight categories.


short term.../through Tuesday/...northeasterly winds strengthen
in response to the approaching ocean low, with gales for all
waters today except for the bays where scas have been issued.
Winds decrease below gales tonight as the low pulls away to the

Long term...while seas will be diminishing into Wed as passing
trof may allow winds to gust again to near 25 kt outside of the
bays by afternoon. After a brief break Thu another trof will
cross the area late in the week and bring another round of at
least Small Craft Advisory conditions. Some gusts to near gale force are possible
outside of the bays.


Tides/coastal flooding...
prolonged NE flow up to gale force, along with building seas
ahead of a coastal low may result in splashover and minor
coastal flooding a few hours either side of the 3 PM high tide
today, mainly south of Casco Bay. Will continue with a coastal
flood statement. We expect surge values to be around a foot to
1.2 ft.


Gyx watches/warnings/advisories...
ME...Winter Weather Advisory from 8 am this morning to 1 PM EST
this afternoon for mez018>022.
Winter Weather Advisory from 10 am this morning to 11 am EST
Tuesday for mez007>009-012>014.
Winter Weather Advisory from 6 am this morning to noon EST
today for mez023>028.
New Hampshire...Winter Weather Advisory from 8 am this morning to 1 PM EST
this afternoon for nhz006-008-009.
Winter Weather Advisory from 10 am this morning to 11 am EST
Tuesday for nhz001>005-007.
Winter Weather Advisory from 6 am this morning to 1 PM EST
this afternoon for nhz011-015.
Winter Weather Advisory from 6 am this morning to noon EST
today for nhz010-012-013.
Marine...Small Craft Advisory until 4 am EST Tuesday for anz151-153.
Gale Warning until 4 am EST Tuesday for anz150-152-154.



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