951
FXUS61 KBTV 201802
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
202 PM EDT Sat Jul 20 2024

.SYNOPSIS...
Surface high pressure will bring another pleasant summer day
today with warm temperatures and modest humidity levels
expected. A weakening cold front approaching from southeastern
Ontario and southern Quebec will bring increasing clouds and
just a low chance of a brief shower for tonight. Dry and
slightly cooler conditions are expected with north winds on
Sunday behind the cold front. Rain chances increase Tuesday into
Wednesday as a quasi-stationary front sets up across New York
and New England. Some embedded heavier showers and thunderstorms
are possible.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 202 PM EDT Saturday...No changes needed on this very
pleasant weather day. Looking upstream at the approaching cold
front in southern Canada, there are no surprises. MRMS radar
reflectivity shows a broken line of light rain showers causing
clouds to lower but without much fanfare, with some areas
getting a just a couple brief bouts of rain. On the cold side of
the front, dew points in west central Ontario have fallen into
the mid and upper 40s. The front is still on track to pass
through our region from north to south gradually between about 9
PM and 7 AM.

Previous Discussion...
A narrow zone of surface high pressure extending from the
southern Great Lakes ewd across New York and New England will
remain our controlling weather feature throughout today. Other
than some patchy early AM fog in the favored valley locations of
central/ern VT and within the Adirondack region of NY, looking
for mostly sunny conditions and just passing high clouds,
especially across s-central VT. Valley high temperatures will
once again reach the low-mid 80s with dewpoints in the mid-upper
50s. All in all, modest humidity levels across the North
COuntry compared to much of the past 2-3 weeks. Gradient winds
become SW 5-10 mph during the daylight hrs. Winds may locally
gust 20-25 mph in the St. Lawrence Valley with valley channeled
flow.

A cold front across northern Quebec and Ontario early Saturday
AM will translate southward, bringing increasing clouds across
our region from NW-SE for the overnight period into early Sunday
morning. The front and associated low-level convergence is
generally weakening with time, but may see a few rain
showers/sprinkles across northern areas, mainly after midnight
tonight consistent with NAM-3km and HRRR/RAP forecasts. Have
indicated 30-40 PoPs across the far north, and a few spots may
see up to 0.05-0.10" rainfall during the pre-dawn hours Sunday.
Winds shift into the N-NW toward daybreak with a several hour
period of post-frontal stratus likely, especially across the
northern half of the region. While a few isold showers may
persist in the Adirondacks and central/nern VT after daybreak,
the general trend Sunday morning will be for gradual clearing
and mostly sunny conditions developing by noon or so. Modest
low- level CAA will result in slightly cooler high temperatures
on Sunday, especially across the northern zones (roughly 5F
cooler than the expected highs on Saturday). Highs on Sunday
generally in the mid-upper 70s across the northern valleys, but
still reaching the lower 80s in the upper CT Valley Sunday
afternoon.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 314 AM EDT Saturday...A period of dry weather is expected
Sunday night through much of Monday in the wake of the cold front
pushing through the region earlier in the day on Sunday. Model
soundings show a plethora of mid- level moisture descending across
the region Sunday night which should yield clear skies through much
of this period before we start to see the cold front lift back north
as a warm front Monday night. Increasing low-level and mid-level
moisture is expected to bring the return of clouds and some
scattered showers to southern Vermont Monday night while the
northern half of the state is expected to remain dry with just an
increase in cloud cover.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 314 AM EDT Saturday...An active period of weather is expected
to unfold beginning on Tuesday. The Bermuda High, located over the
western Atlantic Ocean, is expected to shift westward and intensify
which will help push the aforementioned warm front into interior New
England. A high PWAT airmass (1.75" to 2.0") is expected to
overspread portions of New England with moisture-rich Atlantic air
spreading inland. The question remains how far inland this front is
able to make it with the latest guidance suggesting it will lift
into Vermont and New York on Tuesday. This is expected to allow
increasing shower activity across the region, especially during the
afternoon hours, to the region. Thunderstorms will also be possible
but given tall and skinny CAPE profiles on model soundings, it seems
like heavy rain will be the only concern with any storms that
develop. The front is expected to be somewhat transient but slow
moving meaning the axis of any heavy rain that develops will lift
north on Tuesday and then begin sinking southward on Wednesday and
Thursday. It won`t be raining all of Tuesday, Wednesday, and
Thursday at any one location but several rounds of showers and
thunderstorms are expected at many locations across the region. The
latest probabilistic guidance from the LREF and NBM show decent
probabilities of exceeding one inch of rainfall next week with less
than a half of an inch on any given day. However, with thunderstorm
potential, localized heavy rainfall is likely and will be tied to
the placement of the warm front given localized enhanced surface
convergence. We remain under a marginal (5-15%) risk for flash
flooding on Tuesday and Wednesday given antecedent wet conditions
and the possibility of heavy rain. It`s worth monitoring next week
closely, especially if you live in areas that experienced heavy rain
on July 10th and 11th. More details will be provided in coming days
as more information becomes available.

Strong surface high pressure and increasing mid-level heights are
expected to move overhead Friday into Saturday which should finally
push the front out of the region and allow for rainfall come to an
end. This pattern change from wet to dry conditions will be
highlighted by increasing temperatures next weekend as it`s feasible
to think we could see a few locations in southern Vermont approach
90 degrees.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Through 18Z Sunday...VFR conditions are in place, with some MVFR
ceilings expected for up to several hours between 06Z and 14Z,
most likely at higher elevation sites of EFK, MPV, and SLK. At
SLK, high-resolution ensemble forecast data suggests SLK in
particular may see ceilings lower, such that chances of IFR
conditions peak at 60% around 11Z.

A cold front approaching from southern Quebec and southeast
Ontario will bring increasing clouds tonight into tomorrow
morning, pushing through MSS around 04Z, PBG, BTV, and EFK
around 06Z, between 07Z and 08Z at SLK, and 09Z at MPV and RUT.
Ceilings associated with these clouds will be mainly BKN-OVC
060-080, although embedded light showers will cause ceilings to
dip close to 030 on the cool side of the front. Shower chances
generally peak from 06Z to 11Z (in the 25 to 35% range) and are
much lower at MPV and RUT compared to other sites. Winds will
be light and variable behind the front, then increasingly N-NW
around 5 knots by 12Z.


Outlook...

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

&&

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

&&

$$
SYNOPSIS...Banacos
NEAR TERM...Banacos/Kutikoff
SHORT TERM...Clay
LONG TERM...Clay
AVIATION...Banacos/Kutikoff