FXUS61 KBTV 242327
Area Forecast Discussion
National Weather Service Burlington VT
727 PM EDT Fri Jun 24 2022
A clear and comfortable night is anticipated with some patchy valley
fog developing after midnight. Saturday will feature mostly sunny
skies and warm temperatures with just an isolated shower or
thunderstorm possible across the Adirondacks. Heat and humidity
return for Sunday, as temperatures warm into the mid 80s to lower
90s with chances for showers and thunderstorms increasing toward
evening. A cold front produces showers with embedded storms
overnight Sunday with cooler and drier weather to start the new
.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 727 PM EDT Friday...No major changes need to the evening
and overnight forecast as fair weather cumulus continue to
dissipate with some scattered cirrus moving through St.
Lawrence County and the Adirondacks. Skies will be mainly clear
tonight with just some passing cirrus and winds will be calm
setting the stage for some river valley fog to develop in the
early morning hours of Saturday.
Previous Discussion from 401 PM...Near term challenge wl be
potential for patchy fog tonight in climo favored valleys,
followed by isolated shower chances on Sat aftn. Big picture
shows weak building height fields acrs the NE CONUS with pocket
of strong subsidence directly overhead, while some high cirrus
angles acrs northern NY. A quiet night anticipated with mostly
clear skies and light winds, allowing temps to drop into the
upper 40s to mid/upper 50s. Given recent rainfall acrs northern
NY into parts of central/northern VT, expect as cross over
values are reached some patchy fog to develop. Soundings support
llvl inversion developing with light winds and near boundary
layer saturation, helping in the development of fog/br, mainly
For Saturday, high resolution guidance such as the NAM 3KM, HRRR,
RAP, and BTV 4KM indicate a weak boundary slides south along the
international border during the aftn hours. In addition, weak
convergence wl be enhanced by lake breezy boundary acrs the eastern
Dacks, supporting enough forcing for a few isolated showers. Have
noted embedded 5h vort in water vapor north of Great Lakes, helping
to promote synoptic scale lift which crosses near the border on Sat
aftn. General coverage wl be limited with large dry layer btwn 850-
500mb, but given very weak flow showers/embedded rumbles wl just
drift at 5 knots or so. Sounding show 10 knots or less of flow thru
500mb midday Saturday. Did note some weak instability in soundings
as temps climb into the mid/upper 80s locally and dwpts in the upper
50s/lower 60s, creating CAPE values in the 500 to 1000 j/kg range.
So a rumble or two of thunder is possible, but no shear convective
wl stay below svr limits. Main threat would be locally heavy
rainfall in very small foot prints acrs the eastern Dacks.
Saturday night, southerly flow continues with dwpt values climbing
into the mid 50s to mid 60s depending upon location. Slightly more
humid airmass is anticipated, with lows upper 50s to mid 60s.
Warmest values wl be in the SLV/CPV where better mixing wl occur and
keep values in the mid/upper 60s most of the night. Fog/BR potential
is tricky, with guidance showing LLJ of 15 to 22 knots 500 to 800
feet AGL, but a few deeper valleys could see some patchy
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 401 PM EDT Friday...Sunday is set to be a scorcher with a ridge
building in over the North Country at the upper levels and veering
winds with height, indicating some warm advection. A south-
southwesterly breeze with slightly packed isobars is expected to
funnel some heat through the valleys as steep lapse rates allow
toasty 925 mb temperatures (21-23 C) to mix toward the surface. We
ended up topping out temperatures in the upper 80s for most and the
lower 90s in valleys.
It`s important to note that the forecast highs continue to climb for
Sunday, a trend that many models (ECMWF has highest temps) are
enforcing, showing temps in the mid-90s. Dew point temperatures are
anticipated to be in the lower to middle 60s, keeping us below heat
advisory levels (heat indices of 95+ for 2 or more hours) but still
humid enough to be uncomfortable. The worst conditions are expected
to exist in the Champlain and Connecticut River Valleys.
Especially with this occurring not long after snow fell on various
mountaintops, North Country residents with outdoor plans are
recommended to take all the proper precautions for this muggy heat,
including knowing the signs of heat illness, taking frequent breaks
and staying hydrated.
Clouds will begin to fill in from the west late Sunday ahead of
precipitation pushed onward from a cold front. We have PoPs nearing
20% across the St. Lawrence Valley Sunday afternoon into the
evening, increasing to 50-70% overnight.
This precipitation could take the form of light to moderate showers
and thunderstorms with the GFS and NAM putting out pwats over 2
inches along with some instability, though the highest values are to
the south of the CWA. Since the precipitation is expected to sweep
through during the night and the system is overall not vertically
stacked, this will limit severe concerns. The front will also be
moving fairly swiftly through, lowering chances of flooding despite
potentially heavy rain.
Thanks to the showers and thunderstorms continuing through the night
along with some continued warming southerly winds through the north-
south-oriented valleys, overnight lows are expected to be mild in
the 60s, with near 70s in the Champlain Valley.
.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 401 PM EDT Friday...Rain will continue across the North Country
on Monday before departing eastward late Monday afternoon. A slight
chance of thunder exists during this time, though at this time, the
primary concern remains moderate to heavy rain. Total rainfall by
Monday night is expected to range from 0.25 to 0.75 inches, though
locally higher amounts are possible. Flooding is not a concern at
this time given the progressive nature of the system. A cooler, more
seasonal airmass will advect into the North Country behind the
departing front with high temperatures on Monday only in the upper
60s to mid 70s. A secondary cold front is expected to pass through
late Monday afternoon, causing lingering chances for rain showers
across the Adirondacks Monday evening. Otherwise, dry conditions
will ensue late Monday night through Tuesday as high pressure
settles across the North Country. Overnight lows Monday into Tuesday
will be in the mid 40s to mid 50s with daytime highs on Tuesday
again in the 70s. A mainly dry day is then expected on Wednesday,
though there is a slight chance of showers near the Canadian border
as a decaying front lifts well to the north. Once again dry weather
is expected on Thursday as high pressure settles across the
Northeast. A warming trend will take place for the end of the week
as west to southwest flow resumes aloft, with highs warming into the
mid to upper 80s by Friday. Additional chances for showers return
for the weekend.
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Through 00Z Sunday...VFR conditions will generally prevail
through the period with mainly clear skies overnight and FEW-SCT
cumulus developing along the higher terrain Saturday afternoon.
Only exception will be from 08-12Z where dense river valley fog
will bring VLIFR conditions to KMPV and perhaps KSLK and KEFK.
Winds will be light and variable through the period except
locally SE at 5-7kts overnight at KRUT and from late morning
through Saturday at KPBG.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: Mainly VFR, with local MVFR possible. Likely SHRA,
Slight chance TSRA.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.