FXUS61 KBTV 150804
Area Forecast Discussion
National Weather Service Burlington VT
404 AM EDT Sun Oct 15 2017
Low pressure across the northern Great Lakes region early this
morning will track across southeastern Ontario and southern
Quebec later today. An associated warm front, bringing light
rain to the St. Lawrence Valley early this morning, will lift
north of the international border resulting in breezy and very
warm conditions for the balance of the day. High temperatures in
the 70s...15 to 20 degrees above normal for mid-October... are
expected this afternoon. Late this afternoon into this evening,
a trailing cold front will bring a line of showers with a few
embedded thunderstorms possible, especially across northern New
York. The showers and possible thunderstorms may locally enhance
wind gusts for a brief period this evening, with wind gusts in
excess of 40 to 45 mph possible. Cooler and drier weather is
expected for Monday, and dry conditions with moderating
temperatures for the mid-week period.
.NEAR TERM /THROUGH TONIGHT/...
As of 333 AM EDT Sunday...Little overall change in expected
conditions today and tonight with the 00Z NWP suite. Warm front
along the St. Lawrence Valley continues to bring light rain
across far nrn NY at 0730Z, and have seen about 0.10" at KMSS
early this AM. As parent low pressure system across Lake
Michigan continues enewd, the warm front will lift northward and
associated shower activity will shift into srn Quebec, leaving
dry conditions in the warm sector across the North Country for
the balance of the daylight hrs today.
Despite this, appears sunshine will be rather limited today with
widespread low stratus in place across NJ/ern PA/srn NY, which
will lift nwd with increasing southerly gradient flow. Air mass
is still quite warm (+13 to +14C) at 850mb, and starting in the
upr 50s to low 60s early this AM. Thinking mainly mid-70s for
highs across the area. A few breaks in the overcast could result
in upper 70s in spots, but not optimistic given upstream cloud
Continued the Wind Advisory for the Saint Lawrence Valley from
5pm Sunday to 2am Monday and for most of the Northern
Adirondacks from 8pm Sunday to 2am Monday morning. Greater cloud
cover may lessen low-level downward mixing potl a bit, but
still looking at gusts 40-45 mph as a general rule across the
advisory area, with a few higher gusts. Also close to 40 mph
across the Champlain Islands and surrounding nrn Champlain
Valley late this afternoon and evening. Included mention of
these gusts in the morning HWO issuance. Also, a Lake Wind
Advisory has been posted for winds 25-35kts sustained on Lake
Champlain by this afternoon.
In terms of precipitation, good consistency with low-topped
convective line developing along pre-frontal trough across nrn
NY between 21-23Z, through the Champlain Valley 23-01Z, and then
exiting east of VT quickly by 03Z. SBCAPE up to 250 J/kg, mainly
across nrn NY, so kept the slight chance of an embedded tstm.
The convection may induce better sfc wind gusts, and peak winds
may occur in vicinity of this convective line this evening, and
will need to be monitored as it tracks from west to east across
Westerly wind shift expected overnight, with secondary frontal
passage around 06Z. May see a few lingering orographic induced
showers thru the pre-dawn hrs, with temps falling back to the
low-mid 40s by daybreak Monday.
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 341 PM EDT Saturday...Well, as summer-like as it`s going
to feel on Sunday is equally as fall-like Monday will feel. The
aforementioned cold front will be east of the forecast area come
Monday morning, with the parent upper trough swinging through
during the day and mean 925mb temps around 0C to start the day
only warming about a degree or two C in the afternoon. Combine
this with a stiff northwest wind at 10-15mph with gusts up to
30mph, and yeah, it`s going to be brisk to say the least with
highs only in the 40s to perhaps 50 in the deeper valleys. In
addition, though subsidence will be building in aloft as high
pressure begins to build in, latest hi-res guidance indicates
abundant low level moisture trapped below a weak mid-level
inversion. This, combined with northwest upslope flow will keep
skies mostly cloudy across much of the region through most of
the day, with some clearing in the downslope regions towards
sunset. Also can`t rule out some patchy drizzle in these same
upslope regions, with possibly some freezing drizzle and/or
riming across the high peaks.
For Monday night, skies continue to slowly clear through the night
as surface high pressure builds into the region and subsidence
aloft finally erodes the low level moisture. With such a cold
airmass aloft, clearing skies and abating winds will lead to the
coldest night yet of this young 2017 fall season, with lows
areawide in the upper 20s to low 30s. Frost/freeze headlines
will most certainly be in our future where the program
continues, which will just be the Champlain Valley.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 341 PM EDT Saturday...Not much to say about the long term
forecast as the North Country will be dominated by high
pressure the entire week. An upper low ejecting out of the lee
of the Rockies will attempt to break into the ridge aloft
Wednesday, but with strong subsidence in place feel that only an
increase in cloud cover and perhaps some virga will be
realized. Otherwise, a good deal of sunshine is expected every
day with temps gradually warming from the low/mid 50s on
Tuesday, to mid/upper 60s by Saturday. Lows most nights will
range through the 40s.
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Through 12Z Monday...Mainly MVFR/VFR ceilings through much of
the period. Wind gusts 25-35kts from the south expected this
afternoon into early this evening, and locally SW 40kt gusts at
KMSS possible around 21Z today. Will see a gusty line of rain
showers track W-E across the North Country from 21Z Sunday to
03Z Monday. An embedded tstm is possible, mainly across nrn NY
21-00Z. A westerly wind shift is expected in the wake of these
showers and possible tstms this evening.
Sunday Night: VFR with lcl MFVR cigs. Strong winds with westerly gusts
35 to 40 kts possible esp at MSS. Chance SHRA.
Monday: VFR. Breezy. Slight Chance DZ.
Monday Night: VFR. Areas FROST.
Tuesday: VFR. Breezy. NO SIG WX.
Tuesday Night: VFR. Slight Chance SHRA.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Lake Wind Advisory posted for today into tonight. Will see south
winds ramp up quickly this morning, reaching 15-25 kts by late
morning, and then 25-35kt range for the afternoon and early
evening hrs. Waves will build to 3-5ft, highest across the
northern end of the broad lake and south of the Route 2 causeway
near Grand Isle/South Hero.
NY...Wind Advisory from 5 PM this afternoon to 2 AM EDT Monday for
Wind Advisory from 8 PM this evening to 2 AM EDT Monday for