FXUS61 KBTV 092338
Area Forecast Discussion
National Weather Service Burlington VT
738 PM EDT Sun May 9 2021
Low pressure will pass south of the area tonight into early
Monday with a few showers north and a period of steadier light
rain south. Unsettled, showery conditions continue Monday
afternoon into Tuesday before a trend toward drier weather
occurs by Wednesday, and especially on Thursday and Friday.
Temperatures remain seasonably cool through Tuesday, then trend
milder toward the back half of the work week and into next
.NEAR TERM /THROUGH MONDAY NIGHT/...
As of 730 PM EDT Sunday...No significant changes with this
update as precipitation is tracking well with current forecast.
Best chances of precip remain mainly south of a SLK-MPV line as
low pressure near PIT approaches. Can`t quite rule out a shower
north of that however. Did note a couple of lightning pulses
and cloud flash north of the international border about 50 miles
north of KEFK this evening, but not expecting any of that here.
Tonight low pressure tracking east from the Ohio Valley region
will pass to our south, generally through the NYC area and into
the southern New England offshore waters. As such, thickening
clouds will overspread the area from south to north this evening
and trend cloudy overnight. The best forcing with this system
will largely remain south of our area however, and I`ve leaned
heavily toward hourly blended PoPs which is capturing current
rainfall distribution across the eastern Ohio Valley/northern
Mid- Atlantic region quite well. This supports the idea of
steadier light rains mainly affecting Rutland/Windsor counties
overnight with only a few/scattered light showers through
central counties and little if anything along the international
border. Low temperatures to generally run in the upper 30s to
Any early morning showers to taper off central/south before 900 am
leaving a mainly dry remainder of the morning despite variable
cloudiness. However, steepening boundary layer lapse rates combined
with some evidence of mid-level instability should be enough to
spark a few/scattered showers across the area once again by mid to
late afternoon. Coverage should be scattered however, so not all
areas will see additional rainfall. Highs remain seasonably cool
from the mid 50s to lower 60s.
Variable cloudiness then continues Monday night in advance of a more
potent upper trough approaching from the northwest across southern
ON/QE. Still can`t rule out stray shower here or there given
improving upper dynamics, but loss of insolation should allow
overall coverage to wane significantly. Low temperatures a tad
cooler - mid 30s to lower 40s.
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
As of 342 PM EDT Sunday.... General idea for scattered to
numerous showers developing Tuesday afternoon still looks good
as instability increases with an upper- level low moving
overhead. Have added isolated thunderstorm chances across the
corridor corresponding to the best combination of daytime
heating and cold air aloft. The highlighted area at this time is
the large majority of the North Country excluding southern
portions of the Adirondacks and Greens and far northeastern
Vermont. Most locations could see sufficient surface heating to
generate strong updrafts that allow substantial growth of
initially shallow cumulus, resulting in some cloud tops cold
enough (about -20 celsius) to support small hail, especially
with low freezing levels only 2 to 4 thousand feet above the
ground. Not expecting any strong storms with unimpressive
winds/wind shear aloft (cloud layer shear of under 20 knots),
and meager atmospheric moisture supports small cells with
limited rainfall efficiency that would preclude any flood
threat. Otherwise, skies will be variably cloudy trending
overcast. Cooler than normal temperatures will be felt even with
sunshine, peaking in the low to mid 50s in lower valleys, upper
40s most other locations. Moderate gradient flow and well-mixed
air will support west winds mostly in the 12 to 18 mph range,
and slightly stronger gusts are possible with any thunderstorms.
The progression of the upper-level low Tuesday night should lead to
additional showers as instability aloft increases again. Current
model guidance supports better chances of these showers across the
St. Lawrence Valley and Northeast Kingdom areas during the first
part of the nighttime hours, with a more general chance of showers
over the area beyond that timeframe. With a lot of cloud cover in
place and continued gradient winds in most locations, think
temperatures will not fall off too much, with lows generally 36 to
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 342 PM EDT Sunday...Unsettled weather lingers for one
more day as cyclonic flow still will be in place, with best
chances of showers of northeastern Vermont, and chances of wet
weather trending less as you go west of Lake Champlain.
Temperatures will remain below normal but should be a few to
several degrees warmer than on Tuesday.
Wednesday night/Thursday morning we will monitor temperatures
and winds as better radiational cooling conditions will support
areas of frost. In particular, over central Vermont the median
last frost date will have passed, so a frost advisory may be
needed in some areas. Otherwise, still anticipating return of
fair and warmer conditions - highs in the 60s - as high pressure
builds northeastward into the region on Thursday.
The weather pattern late week shows a split flow with
relatively weak steering over our area, so no stormy weather is
expected and temperatures should be near normal, or 65 to 70 for
highs and lows 40 to 45 in most locations. Once we get to
Sunday, better chances of showers exists as a northern stream
trough may move through the region.
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Through 18Z Monday...VFR through 05Z under light flow less than
10 kts. A few light showers may pop up across mainly elevated
terrain of Adirondacks/southern Greens in the 00-05Z time frame,
but scattered nature of potential coverage only warrants mention
at KSLK at this point. After 05Z scattered showers at
KSLK/KBTV/KMPV possible with a steady light rain likely at KRUT.
Winds remain light though cigs lower to MVFR at KSLK/KRUT and
possibly at KMPV. BKN/OVC VFR expected elsewhere. After 11Z
light rains and/or scattered light showers end as cigs trend
SCT/BKN VFR under light west/southwesterly flow from 4-8 kts.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Chance SHRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Chance SHRA.
Wednesday: VFR. Chance SHRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. Slight chance SHRA.