937
FXUS61 KBTV 071728
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
128 PM EDT Mon Oct 7 2024
.SYNOPSIS...
Intervals of isolated to scattered showers will be possible while an
upper low shifts close to our region. Higher elevations may see a
few snowflakes mixing in with rain, especially Wednesday night into
Thursday morning, when a light dusting will be possible above 2500
foot elevations. Dry weather conditions are likely on Friday, and
then the next larger scale weather system will approach next
Monday.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 925 AM EDT Monday...A few light showers have developed
across the Adirondacks this morning as expected but have been
weaker and have had less areal extent than the high-res CAMs
have suggested. The latest mesoanalysis by the SPC shows a
highly capped environment given cool temperatures and a thick
layer of clouds across the North Country. Even with steepening
mid-level lapse rates, elevated instability is meager at best.
Isolated to scattered showers will remain possible today but
will likely be less than previously expected.
Previous Discussion...Things are relatively quiet this
morning across the region. After briefly popping a thunderstorm
west of Gouverneur, the main axis of the cold frontal has
largely failed to produce additional precipitation. This should
reverse course at some point with showers developing beneath a
strong upper vort with some weak diurnal destabilization.
Temperatures today will be a bit cooler, with high temperatures
ranging from the upper 50s to mid 60s. For tonight, there is the
narrowest of ridges between the departing front and the
incoming upper low. Winds should trend lighter overnight with a
brief interval for some fog or frost with cool conditions in the
30s the region, except lower 40s in the Champlain Valley and
Connecticut River Valley. Another upper vort max shifts east on
Tuesday. With a little moisture from Lake Huron and Lake
Ontario, a few showers could pop up across the region during the
day on Tuesday. It will be cooler still with highs in the 50s,
but perhaps a few spot 60 readings still in the Connecticut
River Valley. Summit levels are likely to be in the 30s, and a
few snowflakes should try mixing in at the highest peaks.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
As of 409 AM EDT Monday...We continue to be under the influence of a
large gyre centered near Hudson Bay, Canada. On Tuesday night,
deterministic model guidance suggests our region will be between
vorticity lobes which reduces the chances of precipitation. Winds
will probably be light enough that the boundary layer will decouple
such that temperatures can drop to near freezing by daybreak in much
of the region aside from near Lake Champlain. There may be some
passing low to mid level clouds that would impact the development of
frost, but conditions look favorable for frost especially in many
locations near and east of the Green Mountains and Adirondacks.
During the day Wednesday, light low level flow will transition from
southerly to westerly. That will induce transport from Lake Ontario
such that low level moisture will increase from west to east.
Combined with modest heating and surface destabilization, scattered
showers will develop. Activity will probably spread across portions
of northern New York during the late morning hours and into Vermont
as the day progresses. Most likely rainfall amounts during the day
are up to a few hundreths of an inch with most of this accumulation
in the Adirondacks and western slopes of the central Greens. With
dry air near the surface, eastern slopes of the high terrain will
struggle to see measurable precipitation with these short lived
showers. With uniform westerly flow, good mixing will help
temperatures warm through the 50s and touch 60 in a few lower
valleys; these temperatures are just a touch below normal.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
As of 409 AM EDT Monday...The most noteworthy part of the forecast
remains the potential for mountain snow showers Wednesday night into
Thursday. Have continued the idea of light snow accumulations above
about 2500 feet associated with good model agreement on a lobe of
colder air aloft digging into northern New York from the northwest.
The resulting cold air advection and northwesterly flow will squeeze
out showers with the freezing level lowering from northwest to
southeast during the overnight hours. Minimum snow levels have been
trending a bit lower for this period, which increases the confidence
in at least a mix of snow and rain at lower elevations at times,
especially in the Adirondacks and towns in the vicinity of the
northern Greens/Northeast Kingdom through Thursday daybreak before
snow levels rise a bit. With 850 millibar temperature during the day
Thursday settling into the -4 to 0 Celsius range, it will be the
coldest day of the week. Highs for most spots will probably reach
the upper 40s to mid 50s, while our highest summits remain near or
below freezing during the day. As ridging builds in overnight,
Friday morning remains a time to watch with regards to an early
freeze in many locations that have not yet seen one. Otherwise quiet
weather is likely for Friday with milder temperatures.
Over the weekend, there will be northwest flow aloft and a frontal
system that approaches our region. There is uncertainty in
temperatures and precipitation chances on Saturday with differences
in timing and amplitude of this system. If it arrives on the later
side, Saturday will be a warm and mainly dry day, but if it comes in
earlier, showers and clouds will arrive to dampen an otherwise
pleasant weather day. Behind this system, the air mass will probably
become seasonable again on Sunday with lower precipitation chances.
However, a stronger system may approach from the west-southwest
during the day, which will bear watching with regards to heavier
rain and gusty winds; the model guidance cluster that does depict
such a low pressure area would be tied to a more dynamic upper air
pattern than anything we see this week.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Through 18Z Tuesday...IFR conditions remain locked in east of
the Green Mountains as the frontal boundary slowly moves across
Vermont. These IFR conditions are expected to lift by 20Z with a
quick improvement to VFR conditions expected. Further west, VFR
conditions prevail with W/NW winds increasing to 10-12 knots at
times. Additional spotty rain showers are expected this
afternoon but should be light enough to not pose any reduced
ceilings or visibilities at area terminals. Showers will taper
off tonight with decreasing cloud cover expected through Tuesday
morning. There is a slight chance (less than 20%) that we could
see a brief period of IFR stratus between 9Z and 13Z but have
omitted it in the current TAF package given the lack of
confidence at this time.
Outlook...
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: VFR. Chance SHRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Thursday: Mainly VFR, with areas MVFR possible. Slight chance
SHRA.
Thursday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Friday: VFR. NO SIG WX.
Friday Night: VFR. Slight chance SHRA.
Saturday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Haynes
NEAR TERM...Clay/Haynes
SHORT TERM...Kutikoff
LONG TERM...Kutikoff
AVIATION...Clay
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