-- Discussion containing changed information from previous version are highlighted. --
501
FXUS61 KBTV 101149
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
749 AM EDT Fri May 10 2024

.SYNOPSIS...
Seasonably cool conditions will continue through the weekend
with scattered showers at times. Temperatures will return to
near normal on Monday, but the weather pattern remains
unsettled with some chances for more light showers most days
through the middle of next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
-- Changed Discussion --
As of 749 AM EDT Friday...Forecast is mainly good shape. Had to
adjust sky and add a little more fog to northeastern Vermont
with locally dense fog observed early this morning via webcam
and satellite imagery. Fog should erode pretty quickly with the
strong May sun angle.

Previous Discussion...
We are on the northern fringes of a broad area of low pressure,
while an upper level trough axis gradually shifts southeastward
from the eastern Great Lakes to the mid-Atlantic coast tonight.
As this occurs, differential heating with mid-level moisture
dropping off in our northern areas will help popcorn showers
develop. With weak forcing, CAMs are rather divergent on the
details of where and when showers will occur today. With lower
clouds currently a bit farther north than expected early this
morning, the idea of showers developing a bit farther north as
well is favored; that would suggest showers could start across
the northern half of our region, with slightly greater chances
west of the Greens due to somewhat cooler, marine influenced low
level winds east of the mountains. Between lack of deep
moisture and unimpressive surface heating (temperatures only
warming into the low 60s), instability will be meager at best
with low cloud tops with these showers. Due to their shallow
nature, the steering flow for the showers will be a bit erratic,
but most likely making a southwestward drift.

Precipitation will gradually wind down tonight, although as a more
vigorous shortwave approaches from the west overnight, some chances
of showers are maintained across northern New York. Low level winds
will shift to the south/southeast but remain light as the surface
pressure gradient appears lackluster even as low pressure slides
towards our region. Focus of rain showers through the entire day
appears to be primarily in northern New York, and forcing for ascent
is relatively strong compared to today. As such, some downpours are
possible, with the greatest likelihood at this time being in the St.
Lawrence Valley, based on the HREF joint probability of maximum
reflectivity exceeding 40 dBZ and MUCAPE exceeding 50 J/kg. That
being said, instability still looks meager with similar restrictions
as on Friday to get vertical growth of convective clouds.
High temperatures both today and tomorrow look similar, roughly
five degrees below normal in the upper 50s to low 60s for most
spots.
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 336 AM EDT Friday...Mid/upper lvl trof wl be deepening acrs the
NE CONUS on Sat night into Sunday as potent s/w energy swings acrs
the Great Lakes into the Mid Atlantic States. The best forcing with
this energy remains to our south, but pocket of enhanced 850 to
500mb moisture and cooling 500mb temps to near -25C wl result in
areas of showers Sat night into Sunday. Still some uncertainty on
the areal coverage and timing of showers, as GFS is rather dry,
while NAM/ECWMF and CMC are slightly more aggressive with qpf.
Soundings show very weak instability with CAPE values only in the
50-150 J/kg range with steepening lapse rates only to 850mb, due to
limited sfc heating and deep layer moisture. So not anticipating any
convection/thunder but just scattered light rain showers from time
to time on Sat night into Sunday. Once again the entire period won`t
feature a steady rainfall, but it won`t be dry either. Highest pop
of 50 to 60% wl be located over northern NY on early Sunday morning
and again on Sunday aftn, before tapering off in the evening hours.
Most chance pops in the 40 to 50% range for VT, but this could
increase as confidence improves on coverage of precip on Sunday
aftn. Progged 850mb temps hover near 0C on Sunday, which with clouds
support highs mostly in the 50s to near 60F warmest valleys, while
summits are holding in the upper 30s to lower 40s. Lows with clouds
wl hold in the upper 30s to mid/upper 40s for both Sat and Sun
nights.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 336 AM EDT Friday...An unsettled pattern prevails especially
early in the upcoming week, but no significant or hazardous wx is
anticipated over the next 7 days. Large scale pattern wl feature a
split flow acrs the northern tier with our wx dominated by the
northern stream jet. This results in the warmest temps, best
instability and deepest moisture staying south of our cwa, with just
showers anticipated. Next warm frnt feature lifts sw to ne acrs our
cwa on Monday with chc of showers, along with warming thermal
profiles and slightly deeper moisture as pw values approach 1.0".
This boundary is progged to become stationary acrs the region on
Monday aftn into Tues with some additional showers possible as weak
s/w energy rides along the boundary in the westerly flow aloft. The
northern stream jet position deepens toward mid week, helping to
suppress deeper moisture and associated heat/humidity to our south,
along with instability. This general idea would support a drying
trend toward mid/late next week with temps near normal. The overall
pattern evolution and timing of boundary dropping south of our cwa
is difficult to determine attm, but did trend drier for late week.
Progged 925mb temps in the 8-12C range support highs mostly in the
60s to locally in the lower 70s for next week, while lows are warmer
than normal due to prevailing cloud cover. Lows mostly in the 40s to
near 50F with limited potential for frost, especially wider valleys.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
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Through 00Z Saturday...VFR conditions will continue through the
period under SCT-BKN mid and high clouds, along with areas of
MVFR/IFR in central/northeastern Vermont this morning associated
with light southeasterly flow. The locally dense fog impacting
EFK should dissipate by 14Z. Afternoon popcorn showers remain
possible but with low confidence and minimal impact that VCSH
was left out of the TAFs. Variable winds 6 kts or less will perk
up a bit, especially in northern New York, but remain largely
no greater than 10 kts. Wind direction is becoming mainly
north/northeast, trending light and variable again after 00Z. A
somewhat similar pattern tonight may lead to redevelopment of
fog at EFK, and possibly at MSS, with BR currently indicated at
these sites after 06Z.


Outlook...

Saturday: VFR. Chance SHRA.
Saturday Night: VFR. Chance SHRA.
Sunday: VFR. Chance SHRA.
Sunday Night: VFR. Slight chance SHRA.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night: MVFR/IFR conditions possible. Chance SHRA.
Tuesday: MVFR/IFR conditions possible. Chance SHRA.
-- End Changed Discussion --

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Kutikoff
NEAR TERM...Kutikoff
SHORT TERM...Taber
LONG TERM...Taber
AVIATION...Kutikoff