303
FXUS61 KBTV 022306
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
706 PM EDT Sat May 2 2026
.WHAT HAS CHANGED...
As of 234 PM EDT Saturday...
Frost Advisory has been issued from 2 AM to 8 AM tonight for eastern
Essex and eastern Clinton County in New York, and western
Addison County in Vermont.
&&
.KEY MESSAGES...
As of 234 PM EDT Saturday...
1. Below normal temperatures will remain into tomorrow with the
potential for Frost tonight as showers taper off this evening.
2. Temperatures will quickly rebound to at or above normal for
the start of next week as our pattern turns more active.
3. Generally unsettled weather is expected mid next week into
the weekend.
&&
.DISCUSSION...
As of 234 PM EDT Saturday...
KEY MESSAGE 1: Diurnally enhanced cold advection showers will continue
into the mid afternoon, before tapering off this evening as diurnal
heating wanes. Some of these showers may contain some small
graupel with cooling temperatures aloft that will support some
small graupel/hail growth. A few hundreths of precipitation is
expected within any showers today. Subtle ridging will begin to
build in tonight which will provide a reprieve from shower
activity into tomorrow, but will also allow for the potential
for patchy fog tonight. With the Climatological growing season
in the Champlain Valley underway, given the potential for
temperatures to drop below the Frost threshold of 36F, a Frost
Advisory has been issued for western Addison County in Vermont,
and eastern Clinton and eastern Essex County in New York form 2
AM to 8 AM tonight.
There is still some uncertainty in the overall cloud coverage based
on the HREF and observed broken to overcast skies across eastern
Ontario. However, as already evident, some downsloping off the
eastern Adirondacks has allowed for some daytime breaks in the
clouds across the eastern Adirondacks. This clearing, albeit
conditional, bodes some confidence in at least some patchy fog in
the sheltered locations of the western Champlain Valley. Moreover,
some weak radiative cooling in western Addison County from blocking
by the Adirondacks will also lead to some potential patchy Frost.
Confidence outside the aforementioned areas in the Champlain Valley
is much lower for frost development due to some waa from Lake
Champlain under northwest flow, in addition to some confidence in
more cloud coverage from a developing coastal off the New England
Coast. While temperatures will also be conducive for Frost outside
the Champlain Valley, we will not issue headlines as the
climatological growing season outside the CPV has not begun yet.
Sunday will remain chilly with highs 5-10 degrees below normal into
the upper 40s to low 50s. Moisture should clear out with a much
drier day as relative humidities fall into the 30-40% range.
Wester/northwest winds will become breezy into the afternoon as
subtle ridging crests over northern New York. Temperature Sunday
night will be in the upper 30s to low 40s, with little concern for
any Frost.
KEY MESSAGE 2: Our pattern will turn more active beginning early next
week. Mid/upper troughing will become dominant across northern New
York as our flow becomes oriented southwest to northeast along a
stretched long wave trough across the western US. This troughing
will advect both warmer temperatures and continued moisture into the
entire region for early next week. Temperatures will climb into the
60s on Monday and to near 70 Tuesday. Consequently with the sudden
rise in temperatures, both precipitation chances and windy
conditions will increase. The first of several shortwaves will ride
along this elongated trough Monday morning into Monday afternoon. A
few hundreths of rainfall is expected, mainly in the Adirondacks and
locations near the International Border. Weekend dryness, in
addition to an approaching 40-50 knot low level jet likely will lead
to some virga initially with any precipitation associated with this
shortwave. Furthermore, virga may also allow some gusty winds up to
25 to 30 MPH, particularly across the northern fringes of the
Adirondacks, to mix to the surface.
The better setup, with overall better forcing, and dynamics will be
Tuesday into Tuesday night. A frontal system will draw upon strong
upper level flow from a 250mb jet streak advecting Pacific moisture
well into the interior of the country and even perhaps into our
region. This streak will also be the cause of continued gusty winds
into Tuesday ahead of widespread wetting rain into Tuesday night.
DESI NBM probabilistic guidance shows around a 50% of reaching a
quarter inch or more, with 40% of half an inch or more of rain
across the St. Lawrence Valley. The winners from these early week
systems will likely be the St. Lawrence Valley where the axis of the
trough is expected to setup. The GFS does show a narrow ribbon of
instability associated with the showers Tuesday night, but the
rainfall appears to be more post frontal, so not anticipating much
in the way of thunder, but will lead mention of thunder in the
grids. These early week showers will set the stage for more active
and wet conditions into mid to late next week.
KEY MESSAGE 3: A large-scale trough gradually builds into the region
during Tuesday through the end of the week. It will be slow enough
that a few different shortwaves will pass through and surface lows
will develop along those. The first one passes well to the northwest
on Tuesday. An associated cold front will move into the region
Tuesday and bring a round of rain, particularly to northern New
York. The next low passes through Wednesday with the center looking
to track over or slightly west of the region. A rumble of thunder is
possible as the cold front pushes through in the afternoon. The
final low looks to track through Thursday into Friday, with the
center passing to the east of the region. There will be enough cold
air on the backside of it that it could end as a few snow showers in
the mountains. Through Friday, GEFS/EPS/CMCE combined ensemble
probabilities of receiving 1 or more inches of rain are 85-100
percent, 2 or more inches are 35-55 percent, and 3 or more are 0-20
percent. Most of the precipitation will be stratiform and limit
flooding concerns, but the effects of potentially three storm
systems in a row will still be watched.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Showers taper off this evening, resulting
in widespread VFR conditions across all TAF sites. As
atmospheric mixing comes to an end tonight, high pressure nosing
in from the Plains will assist with some subsidence and sinking
air as an inversion makes to trap moisture at the surface. This
will likely mean slightly lowering ceilings (2000-3000 feet
above ground level) throughout the night, though any clearer
spots could see temperatures fall below threshold levels and
produce some patchy fog and near-surface clouds. Timing for this
will be sometime between 05Z and 13Z Sunday, with highest
potential for MVFR or lower conditions occurring at SLK, MPV,
EFK, and RUT. While not out of the question at BTV, PBG, and
MSS, the St. Lawrence Valley should keep a west-southwesterly
wind 5-10 knots overnight, and the Champlain Valley will likely
be influenced by the lake and keep conditions VFR throughout the
night. Sunday morning, we`ll see winds pick up out of the west
and northwest, quickly scouring out any low clouds and/or fog,
likely gusting 15-25 knots by the afternoon.
Outlook...
Sunday Night: VFR. Chance SHRA.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Likely SHRA, Slight chance TSRA.
Tuesday Night: Mainly VFR, with local IFR possible. Likely SHRA.
Wednesday: MVFR/IFR conditions possible. Definite SHRA.
Wednesday Night: Mainly VFR, with local IFR possible. Likely
SHRA.
Thursday: Mainly MVFR, with areas IFR possible. Likely SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Frost Advisory from 2 AM to 8 AM EDT Sunday for VTZ009.
NY...Frost Advisory from 2 AM to 8 AM EDT Sunday for NYZ028-035.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Danzig/Myskowski
AVIATION...Storm
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