137
FXUS61 KBTV 021908
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
308 PM EDT Wed Sep 2 2026
.WHAT HAS CHANGED...
As of 148 PM EDT Wednesday...
There`s some uncertainty with coverage of showers and storms
tonight as some higher resolution models show we could miss out
on rain as bulk of precipitation may pass to our north and
south.
&&
.KEY MESSAGES...
As of 308 PM EDT Wednesday...
1. Gusty south winds continue today. Widespread rainfall will
move in this evening and overnight, with periods of moderate to
locally heavy rain expected along with some embedded
thunderstorms.
2. Some scattered afternoon showers are possible each day
Thursday through Saturday.
3. No significant weather Sunday through Wednesday. Moderating
temperatures and dry weather expected early next week, then likely
trending cooler with a low chance for showers.
&&
.DISCUSSION...
As of 308 PM EDT Wednesday...
KEY MESSAGE 1: Continue to expect some active weather this
evening and overnight across the north country. A low pressure
system passing north of our region will bring surface fronts
across our area. Rain will move in from the west during the
afternoon hours as a warm front approaches. Increasing southerly
flow is evident and will continue, especially over Lake
Champlain where gusts over 30 kts have occurred and will
continue into this evening. Lake Wind Advisory is in effect.
Outside of Lake Champlain, highest gusts this afternoon will
mainly be observed over the northern Champlain Valley, higher
elevations of the Greens and Adirondacks, and over the northern
slopes of the Adirondacks. Gusts will be strongest ahead of the
steady rain, then will diminish as rain becomes widespread due
to low-level stabilization. The increased southerly flow has
bumped PWATS up to 1.5 to 2.0 inches, which is around 150 to
200% of climatological normal for our area this time of year.
This anomalously moist air mass will support some periods of
moderate to heavy rain this evening into tonight. Models are
indicating rates will mainly remain under a tenth of an inch an
hour, but some heavier showers and thunderstorms could produce
brief rainfall rates up to a quarter to a half inch an hour.
Overall, the flood risk this evening into tonight is low (WPC`s
Excessive Rainfall Outlook has our entire area in a marginal
risk of rainfall exceeding flash flood guidance). However, if
any heavier storms track over the same area, those areas will
need to be watched closely. In addition to moderate to briefly
heavy rainfall, some thunderstorms are anticipated this evening
into early tonight. The surface based instability and overall
severe threat will be limited by a maintained low level
inversion over most areas. However, the environment is slightly
more favorable over the southern Saint Lawrence Valley, where
the development of some marginal SBCAPE is progged. The amount
of surface based instability is still somewhat in question, but
latest SPC Convective Outlook maintains the Marginal Risk for
most of Saint Lawrence County, with the Slight Risk just
clipping our area and extending to the southwest. The main
threat from thunderstorms in northern New York will be gusty
winds and locally heavy rainfall. The remainder of our forecast
area remains within the General Thunder contour, and risk of
severe weather outside of the Saint Lawrence Valley is low
tonight. There are some indications from higher resolution
models that coverage of showers could be lower than anticipated
with our region becoming split between an area of showers
passing to our north while another passes to our south where the
better instability exists.
KEY MESSAGE 2: An upper level low in the area will keep chances
for showers each afternoon continuing from Thursday through
Saturday. Temperatures will be a bit cooler than seasonal
normals with periods of instability-driven afternoon showers.
Coverage of showers will be greatest over higher terrain.
Meanwhile, the Champlain Valley and Saint Lawrence Valley will
remain mainly dry during this timeframe.
KEY MESSAGE 3: As the big upper level low continues to depart
slowly to the east Sunday in an Omega block pattern, the storm
track behind it is favored to remain to our north with the upper
level ridge suppressed to our south. As a result, we will be in
a fairly dry northwest flow pattern through the middle of next
week. There is very good clustering of temperatures and lack of
precipitation on Sunday and Monday. Temperatures should warm
from slightly below normal to near normal.
Much larger spread in temperatures and dew points is noted after
that time, associated with the possibility of a surface cold
front passing through from the north on Tuesday, which could
bring substantially cooler and drier air into the region along
with some lighter variety showers. A similar degree of
uncertainty exists Wednesday but with temperatures shifted a
bit warmer with more guidance showing a return to southerly low
level flow. No huge swings in temperature are expected in this
pattern, but fluctuations are possible.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...Scattered to overcast clouds with bases
in the 2500 to 4000 feet range are generally expected over the
next six hours. Aside from a shower in the vicinity of MSS at
issuance time, no precipitation is expected until about 22-00Z.
Showers will increase in coverage from the west towards 00Z and
especially 02-06Z. These showers will be moderate to heavy at
times, which will result in intervals of IFR visibility. While
unlikely, some embedded thunderstorms are possible especially in
the vicinity of MSS. Ceilings will tend to lower to low
MVFR/IFR levels after 06Z as moisture is trapped below a
strengthening low level inversion following the exit of these
showers, but a shift in winds towards the west during the 12Z to
18Z period will help improve conditions.
Winds currently are 10 to 15 knots with gusts 20 to 25 knots
out of the south or southeast at most terminals, except under
10 knots at MSS. Some LLWS is likely when surface winds weaken
as the aforementioned jet strengthens, primarily outside of the
Champlain Valley and from 03Z to 08Z.
Outlook...
Thursday Night: VFR. Slight chance SHRA.
Friday: VFR. Chance SHRA.
Friday Night: Mainly VFR, with local IFR possible. Slight chance
SHRA.
Saturday: Mainly MVFR, with local IFR possible. Chance SHRA,
Slight chance TSRA.
Saturday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Labor Day: VFR. NO SIG WX.
&&
.MARINE...
As of 219 PM EDT Wednesday...South winds 20 to 30 knots
continue into this evening. Waves will build to 2 to 4+ feet by
late tonight. Winds will be strongest this evening into the
early overnight hours, then will decrease once steady rain
develops. Winds on Thursday will be 15 to 20 knots in the
morning, then become light and variable later in the day.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Neiles
DISCUSSION...Neiles/Kutikoff
AVIATION...Kutikoff
MARINE...Neiles
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