FXUS61 KBTV 220535
Area Forecast Discussion
National Weather Service Burlington VT
135 AM EDT Wed Mar 22 2023
A mid level warm front is approaching from the southwest
tonight, drawing more clouds into the region. High pressure over
the western Atlantic will promote mild air ahead of our next
weather system on Thursday. Well above freezing temperatures
even in higher terrain will support a rainy period on Thursday.
Below normal temperatures will settle back into the region on
Friday ahead of an elevationally dependent snowstorm anticipated
for the weekend.
.NEAR TERM /THROUGH THURSDAY/...
As of 124 AM EDT Wednesday...No big changes for the 130 AM
update. Previous discussion follows below.
Previous Discussion: The best forcing for snow showers across
our northern zones is currently occurring just behind a decaying
surface cold front. Throughout the day, model guidance tended
to have too much low level moisture which allowed for
precipitation to be more widespread than reality. For much of
the afternoon, snow showers were isolated to high elevations,
but finally is beginning to expand across the northern tier of
Vermont counties looking at glaciation of clouds in the Day
Cloud Phase GOES-16 satellite product. With the weak lift and
limited moisture, precipitation amounts will be very light.
Otherwise, increasing moisture associated with a mid-level warm
front will bring cloud cover from central New York into the
region tonight. This scenario will limit low temperatures
tonight in an otherwise favorable environment for radiational
cooling. As such, lows look to be mainly in the 20s. However,
have continued the idea of northeastern Vermont being colder,
where skies will clear overnight with light winds nearer to
Canadian high pressure nosing southward.
No precipitation chances areawide from roughly midnight to
midnight as ridging aloft occurs with surface ridging building
in the western Atlantic. As such, temperatures should trend
warmer in the higher terrain and remain mild at lower
elevations. Highs again will be well into the 40s at lower
elevations with some 50 degree readings favored across the lower
Connecticut River, Champlain, and Winooski River valleys. Cloud
cover will tend to lower late in the day as cyclonic flow
slides into our region, but forcing for precipitation looks
meager. Light winds will trend southerly from east to west as
the Atlantic high pressure area drifts farther east. At the same
time, by late tomorrow night, precipitation chances will
increase from west to east. Expect scattered rain showers to
race eastward associated with a frontal wave advancing out of
the Midwest. Steadier rain may arrive by daybreak but most of it
will occur on Thursday.
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
As of 328 PM EDT Tuesday...Low pressure tracking well north of
the region near James Bay will lift a warm front through the
region Thursday morning and a cold front Thursday evening. This
combined with shortwave energy travailing eastward along the
boundary originating from a decaying upper trough over the
northern plains will provide enough dynamical support to produce
light to moderate rain through the day with snow levels rising
above the mountain tops. Showers taper off Thursday night as the
cold front moves south of the forecast area, and could end as a
brief period of snow, especially across the higher terrain
where a dusting to an inch is possible. The more moderate rains
look to be along the international border where storm total QPF
will range from 0.5-0.75", with 0.25-0.33" across
central/southern zones. Post frontal passage, high pressure will
build into the region for Friday, but skies will be slow to
clear. Temperatures will cool back below seasonal norms for
Thursday night and Friday with lows in the mid 20s to low 30s,
and highs in the mid 30s north to lower 40s south.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 328 PM EDT Tuesday...Heading into weekend confidence is
increasing that we`ll see a strong low pressure system impact
the region with models coming into better agreement and pointing
towards an elevationally dependent snow storm. The overall
synoptic setup remains unchanged with low pressure developing
over the lower Mississippi River Valley Friday night, then
tracking into Ohio Valley by Saturday morning, and northward
through the Great Lakes Saturday/Saturday night. Secondary
cyclogenesis looks to occur after sunset Saturday evening along
the mid-Atlantic coast which while weak, around 1000mb, will aid
in keeping colder air in place across the Adirondacks and
eastern Vermont, cold enough for snow to be the dominant ptype,
while the broader valleys below 1000 feet will be warm enough
for mainly rain. Given the recent trends in the guidance towards
a weaker coastal low, the best dynamics will remain northwest
of the region, with the heaviest QPF more closely tied to the
primary low. Nevertheless, Saturday through Sunday a blend of
model guidance supports widespread QPF amounts around a half
inch, with upwards of 0.75" across the higher peaks, which where
the pytpe is all snow could translate to a plowable snowfall
(>4") with several more inches possible in the higher
elevations. Based on marginal boundary layer temps in the 30s
though, the expected snow- to-liquid ratios are low (8-10:1),
and could present some power outage issues with heavy snow laden
As the aforementioned system moves out Sunday night
precipitation will taper off as a brief ridge of high pressure
builds in for Monday. But the pattern looks to remain active
heading into the middle part of next week with a potential rinse
and repeat mixed rain/snow storm during the Tue/Wed timeframe.
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Through 06z Thursday...VFR conditions are expected at all
terminals for the entirety of the forecast period. Some higher
clouds are moving in as a front moves into the area, but cigs
remain VFR. Winds will become light and variable to calm
overnight, and stay that way for most of the TAF period as high
pressure builds in. Overall, fairly quiet and calm weather
expected. Have a tempo group with some BR at EFK.
Thursday: Mainly MVFR, with areas IFR possible. Definite RA.
Thursday Night: Mainly VFR, with areas MVFR possible. Chance
SHRA, Slight chance SHSN.
Friday: Mainly VFR, with local MVFR possible. NO SIG WX.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. Definite RA, Definite SN, Chance SHSN.
Saturday Night: Mainly MVFR, with local IFR possible. Definite
RA, Definite SN.
Sunday: MVFR and IFR. Likely RA, Likely SN, Chance SHRA.