023
FXUS61 KBTV 162335
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
735 PM EDT Fri Aug 16 2024

.SYNOPSIS...
Hazy conditions will persist through this evening as we continue to
remain under the influence of wildfire smoke. Rain chances will
increase late tonight across the St Lawrence Valley, spreading
eastward into the daylight hours Saturday as an upper level trough
slowly crosses the Great Lakes. Unsettled weather is expected
through early next week as the trough moves eastward, peaking on
Monday. Temperatures will be seasonable through the weekend, though
conditions will be a bit on the muggy side.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 734 PM EDT Friday...Higher terrain showers from earlier
this afternoon have dissipated and quiet yet hazy conditions
will prevail for the rest of this evening through midnight.
Mid/high clouds approaching from the west will slowly move over
the region overnight and this combined with increasing boundary
layer winds should preclude the development of fog outside of
the CT River Valley. In addition, showers associated with an
approaching warm front look to move into portions of northern
New York during the pre-dawn hours, so sped the PoPs up slightly
there from the previous forecast.

Previous Discussion...Showers have popped up over the higher
terrain as expected this afternoon, with a line of convection
stretching down the spine of the central/southern Greens and over
the High Peaks of the Adirondacks. With little in the way of shear,
this activity will remain garden variety, winding down as we lose
daytime heating this afternoon.

Hazy conditions due to Canadian wildfire smoke will also continue
into the evening hours, but do expect some improvement overnight as
flow starts to turn toward the south, helping to lift smoke back
northward. Much of the night will be dry, though precipitation
chances start to increase late across far western portions of the St
Lawrence Valley. Expect another round of valley fog late
tonight/early Saturday, though coverage will be limited in northern
NY as clouds and winds increase. Lows will generally range from the
upper 50s to the upper 60s.

For Saturday...a slow-moving upper trough will trundle eastward
across the Great Lakes, spreading showers/isolated thunderstorms
into northern NY during the morning hours. Brief heavy downpours
will be possible given increasing PWATs to around 1.75 inch and deep
warm cloud depths, but with convection limited by poor lapse rates
aloft, flooding is not anticipated. Forcing will be lacking as one
heads eastward into the Champlain Valley and eastern VT, so showers
will wane as they exit northern NY, though can`t totally rule out a
stray shower making into VT. Increasing clouds will keep
temperatures a littler cooler than today, especially in northern NY
where highs will struggle to hit 80F. Further east, low to mid 80s
should be more common. South/southwest winds will become a little
gusty during the afternoon, with gusts of 25-30 mph possible.
Showers look to become a little more widespread, or at least make it
further east, Saturday night as weak shortwaves rotate around the
eastward-advancing upper trough. A few thunderstorms will be
possible as well, but as mentioned above, instability will be
lacking with warm air aloft. Still, can`t rule out a few heavy
rainers, but with showers to remain scattered in nature, no flooding
is anticipated. Saturday night lows will be similar to tonight, in
the 60s in most spots.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 335 PM EDT Friday...A slow-moving trough moves into the region
for Sunday and Monday, producing widespread showers. The bulk of the
rain on Sunday looks to fall over northern New York before spreading
into the rest of the region for Monday. The steadiest rain will fall
on Monday when a linear feature attempts to develop on a passing
cold-front. Before the frontal passage, the rain will be more
showery, but the ingredients will be in place for heavy rain. PWATs
should be above 1.5 inches, and they will be approaching 2 inches in
some places. There will also be deep warm-cloud depths and the
potential for training storms. The large-scale trough will have very
little forward west to east motion so any north-south oriented
prefrontal trough to focus the shower development will be very slow-
moving. Even though the showers look to move with relatively fast
south to north motion, with a slow moving pre-frontal trough, there
is the potential for areas to see multiple heavy showers or training
showers. Combined with the atmospheric conditions favoring heavy
rainfall, isolated flash flooding is possible. Weak instability
should limit the heavy rain threat a bit though. The cold front that
passes through on Monday will end any threat for heavy rainfall. The
front will also be quite strong, sending temperatures into the upper
40s and 50s Monday night. Before the frontal passage, it will be
warm and humid with temperatures in the 60s-70s and dew points in
the 60s. Winds will be relatively strong on Sunday, particularly in
the Champlain Valley due to channeled flow. Gusts between 20-25 KTs
are possible though some areas could see them locally higher. There
will be a low-level jet between 30-35 Kts down to 2,000 FT and the
scattered nature of the showers should allow dry periods and decent
mixing.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 335 PM EDT Friday...High pressure will build into the region
for mid and late week, leading to mostly dry conditions and a
warming trend. However, temperatures will start off below
climatological normals and will only rise to around seasonable
averages, so it will almost have an early fall-like feel! Some model
guidance, including the operational Euro, try to form a cut-off low
just off the New England Coast on Tuesday-Thursday, and this could
bring showers into eastern areas. However, this is only supported by
a small number of ensembles so this time period still looks to be
mostly dry. Overall, the pattern mid-late week will favor extensive
ridging over the Great Plains in an almost Omega Block type pattern.
This will keep any of the heat and humidity away to our west and
south.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Through 00Z Sunday...VFR conditions will largely prevail
through the period with SKC-FEW250 this evening through midnight
trending to SCT-BKN250 early Saturday morning before lowering to
around 10kft in the afternoon. Showers along a warm front will
affect KMSS and potentially KSLK from 12-18Z, with more limited
coverage eastward, and could reduce vsby to 4-5SM. Otherwise,
winds will generally be light and variable this evening, but
increase from the SSE after midnight, especially at KBTV where
gusts up to 18kts are possible before sunrise. Thereafter, SSE
winds of 4-8kts will prevail through the day with gusts up to
20kts likely at KBTV, and up to 16kts elsewhere.

Outlook...

Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHRA, Slight chance TSRA.
Sunday: Mainly VFR, with local MVFR possible. Chance SHRA, Slight
chance TSRA.
Sunday Night: Mainly MVFR, with local IFR possible. Definite
SHRA, Slight chance TSRA.
Monday: Mainly MVFR, with local IFR possible. Definite SHRA,
Slight chance TSRA.
Monday Night: MVFR/IFR conditions possible. Chance SHRA.
Tuesday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: VFR. NO SIG WX.

&&

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

&&

$$
SYNOPSIS...Hastings
NEAR TERM...Hastings/Lahiff
SHORT TERM...Myskowski
LONG TERM...Myskowski
AVIATION...Lahiff