Area Forecast Discussion
Issued by NWS Burlington, VT
FXUS61 KBTV 280740
Area Forecast Discussion
National Weather Service Burlington VT
340 AM EDT Tue Mar 28 2017
Surface low pressure system continues to push eastward across
Quebec. Scattered showers redevelop Tuesday as surface front
moves west to east across our area. Wednesday and Thursday will
be drier with ridge of high pressure building south out of
Canada and over the North country. Another storm system looks to
affect the region on Friday.
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
As of 1107 PM EDT Monday...The North Country is in between mid-
level troughs this evening. The leading shortwave trough - which
brought this morning`s precipitation (0.30" at BTV since
midnight) - is exiting ewd across nrn Maine and New Brunswick.
There is a weaker shortwave and associated surface trough across
sern Ontario and swrn Quebec, with is maintaining a moist S-SE
flow across the North Country overnight. Not anticipating much
change in wx conditions next 6-12hrs...with temps generally
holding above freezing in the 35-40F range with low overcast in
place. Dewpoint depressions are small, and have seen some
developing fog at MSS/Potsdam this evening. With upr 30s
dewpoints over the existing snowpack, could see some additional
patchy dense fog overnight. Deep-layer forcing is limited. In
fact, NAM/RAP soundings show mid-level drying thru the remainder
of the overnight...so any lingering precipitation should
primarily be drizzle or perhaps a light orographically induced
rain shower or two. Only change with this update was to include
patchy fog areawide.
.SHORT TERM /8 AM THIS MORNING 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
dependant 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
.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 /08Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...A mix of MVFR to VLIFR will continue
through the overnight hours and into the 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 06Z Wednesday through Saturday...
06Z 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