St. Albans, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

428
FXUS61 KBTV 030207
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1007 PM EDT Wed Apr 2 2025

.SYNOPSIS...
A dynamic low pressure system to our west will spread
widespread, and occasionally heavy, precipitation along with areas
of strong winds tonight into Thursday. As temperatures climb,
snow will quickly become a wintry mix and then all rain by the
daytime hours for most locations. Much warmer conditions during
the afternoon will give way to a cold front, bringing
temperatures back down to more seasonable values to end the
week ahead of another wet period over the weekend.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 1001 PM EDT Wednesday...Winter weather and wind headlines
are unchanged as a potent warm air advection scenario unfolds
tonight through tomorrow morning.

Things continue to play out as expected. Snow and a wintry mix
continue to lift northeast. Both Massena and Potsdam are
currently reporting freezing rain suggesting the SPS was a good
call. CCs on KTYX don`t appear to indicate much in the way of
varying precipitation types and the RAP mesoanalysis suggests
mid-level temperatures have yet to warm above freezing. Perhaps
some of this is less saturation in the DGZ than forecast
soundings suggested, and there is some embedded freezing
drizzle within the batch of lighter reflectivities. Other than
that, forecast soundings do highlight modest mid-level
instability with the latest RAP suggesting elevated CAPE
potentially in excess of 300 J/kg. Given the vertical forcing
and observed lightning near Lake Huron, there is now thunder
expressly in the forecast overnight into early tomorrow morning.
All else is in good shape. Previous discussion below...

All winter weather types are expected across the region tonight
before temperatures warm well above freezing tomorrow amidst
impressive dramatic warming aloft; 850 millibar temperatures
will surge from roughly -5 Celsius to 10 Celsius within 6 hours
in much of the area (about 25 degrees Fahrenheit of warming up
to a few thousand feet above the ground). Generally as the cold
air erodes, precipitation type should trend from snow to sleet
to freezing rain and plain rain. Unusually high probabilities of
sleet as the primary weather type amongst model guidance exists
for a substantial period of time tonight. This precipitation
type is consistent with how high aloft the strong warm nose is
expected to be and the resulting large refreeze layer with our
antecedent cold air. That being said, as that refreeze layer
shrinks with continuing low level south winds, precipitation
will go over to freezing rain and rain overnight.

Given how strong the southwest jet is, even the more vulnerable
eastern mid-slope locations in the Greens should warm above
freezing within a few hours of that wintry mix period. Before
that happens though, the precipitation rates associated with
convection, and pre-dawn timing, are looking significant in
terms of frozen precipitation. Higher elevations will have a
shallower cold layer such that ice will accumulate in some of
the same areas that saw significant ice last weekend. With this
forecast, we did bump up ice accretions a bit in these areas for
this forecast although confidence in sub-warning levels is high
(under 0.5" flat ice). So while the duration of freezing rain
looks brief, potential for icy conditions is high in much of the
Winter Weather Advisory area through daybreak.

In addition to winter weather, we also have an unusually high
probability of thunderstorms through the overnight period associated
with rich moisture at the top of an elevated mixed layer several
thousand feet above the ground. The timeframe continues to look
largely in the early morning hours, roughly between 2 AM and 8
AM, and this could be overlapping with precipitation in the form
of snow, sleet, and/or freezing rain as surface temperatures
remain marginally cold. Given the strong inversion, don`t be
surprised to be woken up to loud thunder as convection may be
rather widespread overnight.

After the winter weather, we will move into a period of strong
winds. Peak south winds still look to be coincident with rain
showers early in the morning, which will limit the spatial
extent of the gusts outside of the northern Champlain Valley and
northern slopes of the Adirondacks. Winds will be unusually
strong for this time of year on Lake Champlain with sustained 40
40 MPH winds possible, especially around or a bit before
daybreak. Then the potential for strong wind southwesterly wind
gusts throughout northern New York through the afternoon hours
remains high as cooler and drier air aloft moves into the
region. Mean mixed layer winds will easily be in excess of 45
MPH and upwards of 55 MPH in northwestern portions of northern
New York, especially in the late afternoon, given 60 to 65 knots
at 850 millibars and steepening lapse rates.

Afternoon deep convection remains very unlikely due to warm and
dry air aloft. So despite some steep lapse rates and warm and
humid air at the surface ahead of the cold front, any showers
that develop and shift south and east should not grow
sufficiently tall to produce lightning. Post frontal west winds
have trended a bit stronger with the latest data. However, even
in eastern slopes winds do largely taper off after 8 PM so the
end time of the wind advisory looks reasonable.

&&

.SHORT TERM /FRIDAY NIGHT/...
As of 313 PM EDT Wednesday...The short term begins rather seasonable
with dry conditions between weather systems this week. Friday will
feature sunny skies with highs in the mid to upper 40s, with low 50s
in the valleys. Winds will generally be light with some breezy
conditions across the Northeast Kingdom. By Friday night,
temperatures will fall into the upper 20s/low-to-mid 30s, with
clouds increasing ahead of our next weather system tracking out of
the Ohio Valley.

Sandwiched between a sub-tropical high off the Carolinas, and
another high centered over the northern Plains, a stationary front
will set up from the Gulf into our region. Rounds of precipitation
over the weekend look likely as moisture and repeated lows track
northeastward. Precipitation will move in by Saturday morning as
mainly rain for most locations. Higher elevations in the Adirondacks
and along the spine of the Greens could start off as a wintry mix of
freezing rain and sleet before changing over to all rain. Little to
no snow is currently expected, but the Adirondacks and the spine of
the Greens could see a glaze of ice from freezing rain Saturday
morning. Temperatures on Saturday will rise into the mid to upper
40s which will see precipitation change completely over to rain
areawide. The Northeast Kingdom could see wintry mix conditions
return by late Saturday afternoon from potential wet-bulbing and
normal diurnal cooling towards the evening. A low-level jet looks to
accompany the moisture which could mix down to the surface gusty
winds with 30 to 40 knots winds at the top of the boundary layer.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 313 PM EDT Wednesday...A pair of blocking highs looks to keep
the remainder of the weekend and start of next week on the wet side.
Rain will continue Saturday night with some locations still holding
on to a wintry mix, especially in the Northeast Kingdom. Rain will
continue throughout the day Sunday becoming more showery by Sunday
afternoon. The uncertainty in precipitation amounts lies in the
location of where the boundary sets up. The GFS, which is running
cooler than consensus firstly, is more progressive with the system,
becoming more showery with less overall QPF. Whereas the ECMWF is
slower in its progression yielding more precipitation, and given the
typical slowing trend for these large-scale systems, this solution
looks more favorable. Temperatures on Sunday will be fairly
persistent from Saturday with highs in the upper 40s to low 50s, and
lows overnight in the upper 20s to mid 30s in the valleys.

By Monday, the main weekend storm finally is able to move eastward
as steering flow aloft increases. The upper-level trough associated
with this unsettled weather will slowly begin to traverse across
Canada with high pressure building in behind across the northern
Plains. A cold front will pass through the region Monday morning
with some back-end snow showers possible as temperatures Monday
morning hover near freezing. Behind the front, temperatures look to
remain below average for the start of the work week as a broad area
of high pressure builds in across the eastern third of the country
Tuesday.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...Precipitation is beginning to overspread
the area this evening as SLK, MSS, and PTD report snow.
Precipitation in the form of snow, rain, and/or freezing rain
will start at all terminals over the next few hours, reducing
visibilities to 1-4 miles for most, and conditions may be up
and down for a while. Most likely sites to have IFR visibilities
in the next 6 hours will be SLK, PBG, and MSS. Lowering
ceilings are also associated with this incoming precip, with all
sites expected to reach ceilings 2000-3000 feet above ground
level by about 02Z-06Z Thursday. Southerly winds (except at MSS
where typical northwesterly winds prevail) will continue for
most over the next 24 hours, gusting on and off as high as 35-40
knots. LLWS will continue to be a concern starting 02Z-07Z and
continuing throughout the next 24 hours. Ceilings will remain as
low as 3000 feet or lower for most sites through about 20Z-22Z,
and there is the potential for some transient 900 feet or lower
cigs for several sites between 12Z and 20Z.

Outlook...

Thursday Night: VFR. Windy with gusts to 35 kt. NO SIG WX.
Friday: VFR. NO SIG WX.
Friday Night: VFR. Slight chance FZRA.
Saturday: MVFR. Definite RA, Slight chance FZRA.
Saturday Night: Mainly MVFR, with areas IFR possible. Definite
RA.
Sunday: Mainly IFR, with areas MVFR possible. Chance SHRA.
Sunday Night: MVFR/IFR conditions possible. Chance SHRA.
Monday: Mainly VFR, with local MVFR possible. Slight chance SHRA,
Slight chance SHSN.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Wind Advisory from 2 AM to 8 PM EDT Thursday for VTZ001-002-
     005.
     Winter Weather Advisory until 11 AM EDT Thursday for VTZ003-
     004-006>008-010-018>021.
NY...Wind Advisory from 2 AM to 8 PM EDT Thursday for NYZ026>031-
     034-035-087.
     Winter Weather Advisory until 11 AM EDT Thursday for
     NYZ029>031-034.

&&

$$
SYNOPSIS...Kutikoff
NEAR TERM...Haynes/Kutikoff
SHORT TERM...Danzig
LONG TERM...Danzig
AVIATION...Storm