473
FXUS61 KBTV 041818
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
218 PM EDT Sat Apr 4 2026
.WHAT HAS CHANGED...
As of 217 PM EDT Saturday...
The forecast wind gusts have increased for some areas, and Wind
Advisories have been expanded to now include all of Essex County in
NY as well as adding Lamoille and Orleans County in Vermont.
Otherwise, the forecast remains on track.
&&
.KEY MESSAGES...
As of 217 PM EDT Saturday...
1. An impactful system will move through tonight, bringing
strong winds and widespread rainfall.
2. Showery weather is expected to start the week, with
unseasonably cold temperatures expected for Tuesday and minor snow
accumulations possible.
3. High pressure will build into the region and bring a
stretch of dry weather for mid week. Precipitation chances will
increase towards the weekend, with temperatures remaining seasonable
for the latter half of the week.
&&
.DISCUSSION...
As of 217 PM EDT Saturday...
KEY MESSAGE 1: A dynamic system will move through tonight and bring a
period of strong winds and rain. The most impactful aspect of the
system will be the strong winds, and Wind Advisories have been
expanded across northern portions of the CWA to account for the
winds. The core of a very strong jet (65-75 knots at the 850 to 900
mb layer) will move over our forecast area tonight. Just how strong
winds will get at the surface is always tricky in these situations,
due to the development of a strong inversion near and just below the
core of the strongest winds aloft. In addition, spotty
precipitation ahead of the main front also would locally stabilize
the lowest levels, limiting mixing potential. All these factors
taken into account, forecast soundings suggesting the strongest
winds will be observed over the northern slopes of the Adirondacks,
over the northern Champlain Valley, and over portions of the
northern Green Mountains.
Looking closer at each of these areas, more specific details follow.
For the northern slopes of the northern Adirondacks, the strongest
winds of the event are expected in this area. Winds will peak along
the NY-Route 11B corridor between 11 PM this evening and 3 AM Sunday
morning with localized gusts 55+ MPH. Wouldn`t be surprised if the
Malone to Altona area sees some briefly higher gusts, though these
would be localized. For the Champlain Valley, the slight
southeasterly component of the winds will result in strongest gusts
over the northwestern part of the valley, where portions of eastern
Clinton County along with Grand Isle County will see gusts peak in
the 50 to 55 mph range around 2 AM Sunday morning. A third area of
peak winds will be focused over the western slopes of the northern
Green Mountains, especially over eastern Franklin and eastern
Chittenden Counties in Vermont. The overall southeasterly
trajectory of the winds favors these areas for localized stronger
winds due to downsloping off the spine of the Greens. Higher
elevations in these areas (especially furthest north, near the
International Border) can expect wind gusts peaking in the 50 to 55
mph range as well. Mountain summits both in the Adirondacks and the
northern Greens will see gusts to 70 mph. Elsewhere in the
advisory, including the Saint Lawrence Valley, the northern
Adirondacks (outside of the northern slopes and highest peaks, where
locally stronger winds are expected), the eastern Champlain Valley,
and Orleans County VT, wind gusts will peak around 45 to 50 mph in
the overnight hours.
We have continued mention of Slight Chance for thunderstorms in
areas of northern NY this evening into early tonight based on
marginal instability, but thunderstorm potential is limited to the
early part of the event. Any thunderstorms that form would result
in locally heavier rainfall rates, and the more convective aspect of
the rain earlier in the event over the western portions of our
northern NY zones translates to a slightly higher QPF forecast for
those areas. No severe weather is expected.
While a slight chance of thunderstorms is possible in northern NY,
higher elevations of eastern and southern Vermont will be looking at
a brief window for the development of patchy freezing rain early
tonight. However, this window is brief and temperatures will only
lower to freezing in very localized areas. Temperatures will quickly
warm back above freezing by 3 or 4 AM, so impacts will be minimal.
Even in areas where air temperatures fall below zero, most surfaces
won`t be cold enough to accumulate any ice. There may be some patchy
slick spots on elevated surfaces or bridges however, so use caution
if travelling overnight in these areas.
The system`s cold front will sweep through as a period of rain that
will translate from west to east during the early to late morning
hours Sunday. All said and done, storm total QPF amounts will range
from 0.1 to 0.6 inches for most areas, which will result in a
marginal rise in area rivers but no hydro concerns are expected.
Behind the system, some gusty west winds are expected Sunday,
especially over northern NY, though these wont be near as strong as
the overnight winds. Temperatures will lower to below normal to
start the work week.
KEY MESSAGE 2: A stretch of more winter-like weather is expected to
start the week, as much colder air works its way into the region.
Upslope snow showers will be possible throughout the day Monday as
northwesterly flow develops across the region, although any
accumulations would be minor and limited to the higher terrain.
Another shortwave looks to move through the region on Tuesday,
bringing more widespread chances for snow showers and minor
accumulations. Model soundings show steep low level lapse rates,
plenty of cold air, and decent moisture in the snow growth zone
which will help with any snowfall accumulations. The current
forecast continues to show about an inch of accumulation throughout
the Adirondacks and in portions of the Green Mountains. Temperatures
on Tuesday will be unseasonably cold for early April, with high
temperatures only climbing into the upper 20s and 30s for most
locations, although some portions of southern Vermont may be able to
warm into the 40s. Overnight lows will also be quite cold, dropping
into the teens and 20s, nearly 10 degrees below normal.
KEY MESSAGE 3: After a cold and showery start to the week, high
pressure looks to build into the region towards the middle of next
week, bringing a stretch of drier weather. Temperatures on Wednesday
will be more seasonable, with high temperatures warming into 40s to
near 50 and overnight lows in the mid 20s and 30s. A gradual warming
trend is expected through the end of the week, with temperatures on
Thursday and Friday climbing into the 50s and 60s. Chances for
precipitation look to increase late in the week towards the weekend
as low pressure passes well to our north and a frontal boundary
drags across the region. There`s still a lot of uncertainty
regarding the front and how much precipitation to expect across our
region, with a wide range of solutions supported by ensemble and
deterministic guidance, so trends will need to be monitored as we
get closer.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Through 18Z Sunday...After the lingering cloud cover this morning,
most terminals have improved to VFR conditions, which will continue
for a few more hours this afternoon. Conditions are expected to
lower to MVFR once again later this evening as showers move across
the region. In general ceilings are expected to drop to 1500 to 2500
ft AGL, with some localized IFR ceilings possible, especially at
KMPV. Some reductions in visibility will also be possible within any
rain showers, generally between 4-6SM. The main threat to aviators
during this time period will be gusty winds and widespread LLWS at
all terminals. Winds this afternoon are generally northerly, but
will become more variable as they become more south/southeasterly
this evening. Wind gusts will increase to 25 to 35 knots towards 00Z
or so, continuing through the overnight hours before gradually
lessening towards the end of the forecast period. LLWS is expected
at all terminals for a period overnight as the strong low level jets
moves across the region.
Outlook...
Sunday Night: Mainly VFR, with local MVFR possible. Slight chance
SHSN.
Monday: Mainly VFR, with local MVFR possible. NO SIG WX.
Monday Night: Mainly VFR, with local MVFR possible. Slight chance
SHSN.
Tuesday: Mainly VFR, with local MVFR possible. Chance SHSN.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Chance SHRA.
&&
.EQUIPMENT...
The Colchester Reef meteorological station is out of service.
This site is not serviced by the NWS. An estimated return to
service is May 1st. Please contact us if you observe winds
significantly deviating from the recreational forecast.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Wind Advisory from 8 PM this evening to 8 AM EDT Sunday for
VTZ001>003-005-006-016-017.
NY...Wind Advisory from 8 PM this evening to 8 AM EDT Sunday for
NYZ026>031-034-035-087.
&&
$$
WHAT HAS CHANGED...Duell
DISCUSSION...Duell/Kremer
AVIATION...Kremer
EQUIPMENT...NWS BTV
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