Area Forecast Discussion
Issued by NWS Burlington, VT

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FXUS61 KBTV 281109
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
709 AM EDT Tue Mar 28 2017

.SYNOPSIS...
Low pressure tracking eastward across central Quebec this
morning will push a cold front through the North Country this
afternoon with scattered showers developing from mid-day through
this evening. Behind the front, some scattered snow showers are
expected tonight into Wednesday, with drier conditions on
Thursday as a ridge of high pressure builds over the region.
Unsettled weather returns for the end of the week and into the
weekend though, as another storm system will bring valley rain
and mountain snow to the area Friday into Saturday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 708 AM EDT Tuesday...A few minor changes to the forecast
mainly to adjust PoPs up for the day based on current radar and
hi-res model trends. Otherwise remainder of the forecast is in
good shape.

Previous Discussion...Little overall change from previous
forecast thinking as the North Country will be in between mid-
level troughs today, one to our south and another to our north.
Northern trough and associated surface low will sag southward
through the day dragging a cold front into the forecast area
this afternoon and tonight. Abundant low level moisture
currently over the area combined with some additional moisture
from the southern stream system and frontal lift will aid in
developing scattered rain showers across the region today.
Precip will come in 2 waves with the first round shifting from
the St. Lawrence Valley this morning into northern portions of
New York and the northern Champlain Valley before additional
showers develop across more of the forecast area this afternoon
and evening. Based on current upstream radar and modeled
reflectivity expect showers to be scattered in nature and hit or
miss in any one single location. Temps will continue to run
mild with highs ranging through the 40s with a couple of spot
50s possible.

For tonight, aforementioned cold front slips through the region
with and lingering precipitation transitioning from rain to snow
showers, especially across the higher terrain. Modeled Froude
numbers show increasing blocked flow overnight with winds
shifting to the northwest and this combined with the parent
upper trough and weak shortwave energy passing through supports
some locally enhanced precipitation across the western slopes of
the Greens backing up all the way into the northern Champlain
Valley late tonight into early Wednesday, before becoming
unblocked by Wednesday afternoon. Ptype will be all snow by this
time with low temps tonight around freezing, so some light
accumulations are possible, perhaps up to an inch in the lower
elevations and a couple inches over the high peaks. Temps rise
Wednesday afternoon into the mid 30s to low 40s so any precip
leftover by that time will transition back to a rain/snow mix.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
As of 340 AM EDT Tuesday....The upper trough and attendant
backside energy then depart east on Wednesday night with broad,
albeit short-lived ridging at lower and mid levels building
across the area later at night into Thursday. As such, any
northern mountain snow showers/flurries will gradually end
Wednesday night setting the stage for a partly to mostly sunny
day on Thursday. Low temperatures a bit tricky and will be
dependent on amount of clearing or lack thereof, but generally
stuck with blended guidance showing values in the 20s to locally
near 30 in the Champlain Valley and slightly cooler in northern
NY where clearing probabilities are higher. Thursday highs from
the upper 30s to mid 40s still look on track as advertised by
prior forecast.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 340 AM EDT Tuesday...By Thursday night mainly clear skies
gradually give way to increasing mid and higher level clouds as
first signs of next system arrive on warm thermal advection
rippling in aloft. There will be increasing chances of light
snows across our far southwestern counties toward morning, but
uncertainty on arrival time of precipitation puts low confidence
on any potential minor accumulations in these areas through
sunrise Friday. Lows mainly in the 20s.

By Friday into Friday night, deeper moisture will ride northeast
into our area on increasing warm thermal advection and a fairly
robust southwesterly 850 mb jet as low pressure tracks northeast
from the Ohio Valley. Thus will continue the idea of widespread
precipitation arriving southwest to northeast over time into Friday
evening as highs top out from the upper 30s to lower 40s. Depending
on arrival time, some of the morning precipitation may fall in the
form of wet snow across the southwestern half of the forecast area
before a transition to all rain below 1500 feet by late
morning/early afternoon. Any accumulations should be minor to
negligible. Higher up, precipitation may fall as a mix of rain/snow
or even all snow for elevations above 2500 feet given wet bulbing
processes and 850 mb temperatures hovering around the 0C mark give
or take a degree or two. Several inches of wet snow will be possible
in these higher elevation areas, especially by Friday night as
thermal profiles cool slightly and snow levels lower accordingly. A
mix with wet snow may even occur to the Champlain/St. Lawrence
Valley floors for a brief while Friday night, but little if any
accumulation is expected.

Looking further out, a general trend toward quiet weather is
expected on Saturday as scattered rain/snow shower activity
gradually tapers off and sets the stage for a mainly dry
Sunday/Monday. Temperatures will remain close to seasonal early
April norms with highs ranging through the 40s and overnight lows in
the 20s to lower 30s.

&&

.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
Through 12Z Wednesday...A mix of MVFR to VLIFR will continue
through into the mid-morning hours before a slight lift to
MVFR/IFR through the remainder of the period. Some scattered
rain showers are likely from mid-morning through the evening as
a cold front shifts into the region with brief reductions in
vsby. Light winds shift to the northwest at 5-10 knots behind
the front after 18Z across northern New York and after 21Z
across Vermont.

Outlook 12Z Wednesday through Saturday...

12Z Wednesday through 00Z Thursday...MVFR/IFR in scattered
scattered rain/snow showers, mainly across central/northern
Vermont.

00Z Thursday through 12Z Thursday...Mainly VFR. Isolated snow
showers over higher terrain.

12Z Thursday through 12Z Friday...VFR under high pressure.

12Z Friday through 00Z Sunday...Areas of MVFR/IFR in rain and
snow.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Lahiff
NEAR TERM...Lahiff
SHORT TERM...JMG
LONG TERM...JMG
AVIATION...Lahiff



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