962
FXUS61 KBTV 221836
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
236 PM EDT Sun Sep 22 2024

.SYNOPSIS...
Stationary high pressure across New England will remain in
place through Tuesday. An approaching frontal system from the
Great Lakes region will spread mid and upper level clouds across
the North Country tonight into Monday. While there is a chance
for light rain showers on Monday across the St. Lawrence Valley,
the frontal system will generally weaken as it encounters the
area of high pressure across our region. A stronger upper level
low will finally bring a wetting rain to the region Wednesday
into Thursday. Temperatures will slowly trend downward over the
next several days, but generally remain above average for late
September.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
As of 235 PM EDT Sunday...Stagnant sfc ridging remains in place this
afternoon, with the ridge axis extending from the Gulf of St.
Lawrence swwd across Maine and New Hampshire. Over the past 24-36
hours, maritime moisture from the Gulf of Maine has become entrained
into the clockwise low-level circulation around the system, yielding
stratus and mostly cloudy skies across central/ern VT throughout
much of this afternoon. Skies are mainly clear across nrn NY
unaffected by this maritime air mass. Aloft, winds are very light in
the 850mb to 500mb layer, and this has resulted in little overall
movement of broken cloud layer, with just modest changes with
daytime heating/mixing.

As we head through tonight, will see p-gradient tighten up a bit
west of the ridge axis across our forecast area. Winds in the 950-
900mb layer reach 25kts at times per NAM3/HRRR soundings, and this
combined with some upper level cloudiness spreading in from the
Great Lakes should limit fog potential overnight. Only included
patchy fog mention for 06-12Z tonight across the deeper CT River
valley. Should see stratus clouds begin to scour out across VT
after 00Z as 950-900 mb winds increase. Overnight lows
generally 45-50F, except low-mid 50s in the Champlain and St.
Lawrence Valleys. Should see winds mixing down to the surface
near lake Champlain, with gusts locally 20-25kts across Grand
Isle county overnight into Monday morning and generally near the
lake shore.

On Monday, the shortwave trough across the nrn Great Lakes generally
shears out as it encounters the persistent ridge over New England.
Will see increasing mid-upper level clouds, and did include a 30
percent chance of a rain shower during the day on Monday across St.
Lawrence county (especially far western areas). Precipitation should
diminish/dry up further east, so have limited shower mention to far
wrn CWA. Temperatures trend downward a few degrees on Monday, with
highs generally in the upper 60s to lower 70s areawide.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
As of 312 AM EDT Sunday...Dry weather will continue to prevail
through much of the short term period with high pressure keeping
hold over the region. The ridge axis finally starts to shift
eastward Tuesday night, allowing precipitation to make some headway
into northern NY late. With rain to arrive later than previously
anticipated, we`re now expecting fewer clouds Monday night and
Tuesday, which will impact temperatures. More optimal radiational
cooling Monday night will make for another cool night with lows in
the mid 40s to low 50s. Meanwhile, have been bumped up Tuesday`s
highs a few degrees since we`re expecting more sunshine. Highs will
remain seasonable, in the mid 60s to around 70F. Tuesday night`s
lows will be similar to Monday night, though this will depend on how
quickly clouds arrive ahead of our next system.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 312 AM EDT Sunday...In general, the second half of the week is
looking unsettled, though there are still a lot of differences in
model solutions. Precipitation chances will increase on Wednesday
into Thursday as a northern stream upper trough digs into the Great
Lakes and pivots eastward. The uncertainty comes thereafter with how
this interacts and/or phases with a southern stream system over the
Southern Plains/Lower Mississippi Valley. And a potential tropical
system lifting toward the Gulf Coast by the end of the week only
further complicates matters. Note that the latest GFS phases the
northern and southern stream troughs, tapping into the tropical
moisture from the Gulf system, resulting in widespread rainfall
across our region with multiple inches of rain. This is an outlier,
however, and given the persistent pattern we`ve been in, favor
something more like the ECMWF and CMC which keep northern and
southern systems separate and shunts any tropical moisture well to
our south. Given the range of solutions, stayed close to the NBM for
this period.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Through 18Z Monday...Generally VFR conditions expected through
the period. Prevailing BKN stratus deck across VT generally
3-5kft, so may see occasional MVFR conditions at MPV/EFK through
early this evening. The stratus will generally dissipate
thereafter, with a trend toward SCT-BKN150-250 from west to east
late tonight and into the daylight hours on Monday. Locally at
KMSS, may see BKN-OVC070-080 Monday morning with 20-30% chance
for some light -RW activity. Winds generally S-SE through the
period, except locally NE 5-9kts at KMSS through 04Z Monday. Locally
gusty winds to 20kts at KPBG this afternoon and possibly again
15-18Z Monday. Not expecting much in the way of nocturnal fog
at the TAF locations tonight. In addition to increasing mid-
upper clouds overnight, winds in the 700-1500 ft agl layer
should increase to 20 knots after 00z, and occasional mixing
should help limit fog formation except for the deeper river
valleys of far ern VT.

Outlook...

Monday: VFR. Slight chance SHRA.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Slight chance SHRA.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: Mainly VFR, with areas MVFR possible. Chance SHRA.
Wednesday Night: Mainly MVFR, with local IFR possible. Likely
SHRA.
Thursday: Mainly MVFR, with areas IFR possible. Chance SHRA.

&&

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

&&

$$
SYNOPSIS...Banacos
NEAR TERM...Banacos
SHORT TERM...Hastings
LONG TERM...Hastings
AVIATION...Banacos