572
FXUS61 KBTV 170633
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
233 AM EDT Fri Apr 17 2026
.WHAT HAS CHANGED...
As of 233 AM EDT Friday...
Have added some patchy valley fog tonight as surface winds become
light and variable, surface pressure increases, and skies become
clear. Uncertainty remains on the extent and density of this fog, as
southerly winds aloft will be a limiting factor. Have lowered dew
points both today and Sunday due to drier air masses arriving to the
region.
&&
.KEY MESSAGES...
As of 233 AM EDT Friday...
1. Quieter and mild weather for today and tonight with perhaps
some patchy valley fog tonight.
2. Warm and breezy weather on Saturday will give way to much
cooler, blustery, and rainy conditions on Sunday. Brief mountain
snow will be possible as temperatures drop well below normal.
3. Much colder but mainly dry to start next week, trending
warmer with chances of rain by mid week.
&&
.DISCUSSION...
As of 233 AM EDT Friday...
KEY MESSAGE 1: The frontal boundary that helped produce the showers and
thunderstorms yesterday is drifting southward early this morning and
will clear the region by this afternoon, replaced by high pressure
nosing in from Hudson Bay and upper ridging building. A few
lingering showers are expected early this morning, mostly before
sunrise, then today looks like a fairly dry day overall, save the
odd shower in the Connecticut River Valley. Northerly winds will
increase throughout the day as cloud cover decreases. Gusts 10-20
knots are likely by the late morning and early afternoon, keeping
temperatures cooler than yesterday with highs in the mid 60s to
lower 70s, but still above seasonal normals under increasing
sunshine. Tonight we`ll see a return of overall southerly flow ahead
of our next frontal system, which should keep temperatures
relatively mild in the upper 30s and 40s despite partly to mostly
clear skies. As we do typically see temperatures fall quickly in
high pressure and clear skies, there is the potential for it to be a
touch cooler than anticipated, and this may result in some patchy
valley fog, but not nearly as dense and widespread as previous
nights` fog and low cloud have been.
KEY MESSAGE 2: Surface low pressure over the Hudson Bay and associated
upper level closed low in Ontario on Saturday will drag a cold front
through northern New York and Vermont Saturday night as it moves
northeastward. Ahead of this frontal passage, Saturday will feature
increasing southerly to southeasterly winds, drawing warmer air into
the region. Highs Saturday will reach into the 60s and lower 70s,
with warmest temps across the St. Lawrence Valley where the low
level jet will peak overhead winds will be more southwesterly and
channel through the valley, while coolest temps will linger east of
the Greens in Vermont. Widespread wind gusts are expected to reach
around 15-35 knots, highest in the St. Lawrence and Champlain
valleys. The cold front approaches from the west late in the day and
then crosses the forecast area Saturday night into early Sunday. As
such, expect we`ll have a period of non-diurnal temperatures, with
temperatures rising or holding steady overnight, then falling or
holding steady on Sunday under strong cold air advection. Widespread
showers will likewise spread from west to east along/ahead of the
front, with the bulk occurring overnight Saturday night through
Sunday morning. Moisture will be ample ahead of the front with PWATs
approaching 1.50 inch, or near/above the 99th percentile. There
could be some briefly heavy rain as the front moves through. Much
drier air will follow the front, ending the bulk of the showers by
early Sunday afternoon. However, some isolated to scattered activity
may linger into the Sunday evening hours as a secondary front
crosses the region. As mentioned above, expect temperatures to be
much colder Sunday than Saturday (topping out in the 40s and lower
50s, below seasonal normals), and likely dropping in the afternoon,
especially on the higher summits. Therefore, any lingering showers
could mix with and/or change over to snow by late in the day, though
any daytime accumulation would be limited to 2500 ft or higher.
Total rainfall will range from around 0.45 inch to around 1.10 inch
in most areas, with highest amounts along the spine of the Green
Mountains. Winds Sunday will become blustery out of the W/NW, only
adding to the chilly, raw feel of the day.
KEY MESSAGE 3: Following a cold front on Sunday, a cooler and drier air
mass will filter into the region for the start of next week with
perhaps some snow shower chances early on Monday. Brisk northwest
flow will draw cooler and drier Canadian air as high pressure begins
to shift east out of the Great Lakes. A trailing shortwave on the
backside of the departing Sunday trough will shift south on the
leading edge of the high with a few chances for snow showers in the
higher terrain. With 925mb temperatures Monday to -5C to -9C, sfc
highs will struggle to reach 40 areawide, with the higher terrain
hugging the freezing mark. The GFS model progs the 520dam line to
sag south into the Mohawk Valley of New York and southern Vermont
further supporting cold surface temperatures and cool enough mid
level atmospheric profiles to support a saturated thin DGZ. Snow
growth will be limited, however, due to a low equilibrium level to
700mb and a significantly dry low level. Any snow showers that do
form will likely fall as virga for most of the region, outside of
the higher summits. Strong radiational cooling looks likely Monday
night with cresting high pressure. Overnight lows will plummet
across the region with lows in the low to mid 20s, with perhaps some
isolated upper teens in the colder hollows of the Adirondacks,
Northeast Kingdom, and Lamoille Valley.
Towards mid week, temperatures will moderate back to near
climatological normals in the upper 40s to 50s. Model agreement has
generally trended towards a weak frontal system traversing the
region Tuesday night/Wednesday. Temperatures aloft may be conducive
for some mountain snow, but most of the region should see a cold
rain from this system as surface temperatures will be seasonably cool
in the upper 40s to low 50s.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Through 06Z Saturday...Changeable conditions will return similar to
previous nights with a stationary boundary remaining overhead.
Intermittent IFR ceilings are likely across the area at all
terminals with ceilings trending down behind precipitation from
earlier tonight. Persistence forecasts highlight better confidence
in prevailing IFR after 09Z tonight, with some MVFR visibility
reductions due to patchy fog. Terminals will likely bounce between
these low IFR clouds and a steadier stratus deck to 2500-3500ft agl
through 12Z. Beyond sunrise, ceilings will begin to improve, but
with low level moisture lingering, terminals likely will remain
IFR/MVFR until 14-15Z, as drier air pushes south eroding our low
level moisture. As moisture decreases, already dry mid to upper
levels will allow for widespread VFR today with clear skies at times
between high scattered clouds. Skies will remain VFR through the end
of this TAF package. Winds are beginning to turn to the
north/northwest as the stationary boundary slowly drifts south
reaching RUT by 08-09Z. Wind speeds will remain light and variable
(< 10 knots) outside of BTV, where an occasional gust to 15-20 knots
is possible through 12Z.
Outlook...
Saturday: VFR. NO SIG WX.
Saturday Night: Mainly MVFR, with local IFR possible. Likely
SHRA.
Sunday: Mainly MVFR, with local IFR possible. Definite SHRA.
Sunday Night: VFR. Chance SHRA, Slight chance SHSN.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. Chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Storm
DISCUSSION...Danzig/Storm
AVIATION...Danzig
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