181
FXUS61 KBTV 172353
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
753 PM EDT Sun May 17 2026
.WHAT HAS CHANGED...
As of 224 PM EDT Sunday...
Have increased PoPs Monday morning as confidence grows in some
scattered showers ahead of a warm front. Unseasonably hot
temperatures are on track for the first half of the week while
lake and river water temperatures remain dangerously cold.
&&
.KEY MESSAGES...
As of 224 PM EDT Sunday...
1. Unseasonably warm temperatures continue this afternoon and
trend well above seasonal averages with highs in the mid 70s to near
90 F through Wednesday. Meanwhile, lake and river water temperatures
remain dangerously cold across the region, and breezes on Lake
Champlain may result in rough lake conditions.
2. Shower and thunderstorm chances increase Tuesday through
Wednesday ahead of and along a cold front.
3. Major shift to below normal temperatures on Thursday and
continuing through the weekend. Rain to return next weekend.
&&
.DISCUSSION...
As of 224 PM EDT Sunday...
KEY MESSAGE 1: A cold front is crossing the forecast area this
afternoon, triggering a few showers in northern New York and
southern Vermont. Otherwise, the afternoon is shaping up to be quite
warm and quiet weather-wise, with widespread temperatures in the
70s. Winds are a touch breezy out of the northwest with gusts 15-30
knots, highest on mountaintops. With wind direction out of the
north/northwest, we could see some additional channeling of winds in
the Champlain Valley into the evening, producing rougher conditions
on Lake Champlain. Water temperatures in bodies of water across the
region, including Lake Champlain, remain in the 40s, so we urge
anyone looking to recreate on waterways to use extreme caution and
always wear a life jacket.
Multi-level high pressure and ridging will build into the forecast
area from the Atlantic Ocean tonight through the mid week, resulting
in southerly to southwesterly flow and 925 mb temperatures around 20
to 26 C each day. The upper ridge crests over northern New York and
Vermont Monday as a surface warm front crosses with highs in the
upper 70s to mid 80s. There is the potential for some clouds and
showers Monday morning (20-50% chance of measurable precip) on the
leading edge of the warm front, which could locally limit
temperatures from reaching their full potential, but conditions are
expected to largely clear by peak heating in the afternoon. Gusty
winds once again look to channel through the Champlain Valley on
Monday afternoon, resulting in potentially rough conditions on Lake
Champlain in 25-30 knot winds. Though it will be a weekday, due to
hot air temperatures, gusty winds, and local graduations drawing out
of state travelers, we continue to draw attention to how cold the
water temperatures remain this week and urge any recreators to use
extreme caution on bodies of water.
On Tuesday, flow turns more southwesterly as a low level jet
strengthens overhead, with highs forecast in the 80s to near 90 F,
making this the likely hottest day of the week. Warmest locations
may be east of terrain as flow aloft turns more southwesterly
resulting in some compressional warming downslope off of terrain.
Thunderstorms and rain showers Tuesday afternoon ahead of a cold
front may blunt highs for locations that receive showers. Dew points
also look highest on Tuesday afternoon in the lower 60s for most,
making the heat feel a bit more sticky this day. These conditions
will be the warmest of the year so far. It is important to remember
to stay safe in warmer temperatures by staying hydrated and take
frequent breaks if working outside, especially after we had such a
cool start to the month. A cold front is expected to cross the
region on Wednesday, which will impact how warm we can get that
day. At the moment, highs in the upper 60s to mid 80s look
likely, with central and southern Vermont getting the warmest
before the cold front and associated precipitation arrive. In
addition to warmth during the days, our lows likely won`t fall
below the upper 50s and 60s until the cold front arrives,
providing only some relief from heat overnight.
KEY MESSAGE 2: All of the heat and humidity discussed in Key Message 1
will aid in destabilizing the atmosphere over the region on Tuesday,
with high resolution models suggesting surface CAPE values around
400-1200 J/kg, highest in southern and central Vermont, even
reaching into the Champlain Valley with widespread dew points in the
lower 60s forecast and high temperatures in the 80s to near 90 F.
Effective Bulk Wind Shear values range around 35-45 knots Tuesday
evening, indicating that strong to severe storms are not out of the
question. Forcing will be mainly from an upper level weak wave and
its potential interactions with topography, while surface forcing
looks minimal Tuesday afternoon into the overnight period, and mid
level lapse rates don`t look overly impressive. Most likely
precipitation will be in the mountains and Northeast Kingdom on
Tuesday. As things look now, we could see a series of weaker fronts
early Wednesday morning before the main cold front drops through
during the day Wednesday, which would allow some of Vermont to
destabilize again before surface forcing arrives, resulting in
highest chances of precipitation in Vermont on Wednesday. As we get
closer to the event, the timing of the cold front or fronts should
become more set. Should the front be delayed, the potential for
stronger storms would increase during the day on Wednesday with more
time to destabilize.
KEY MESSAGE 3: Following the frontal passage on Wednesday afternoon, a
major pattern shift is expected to unfold across the region. High
temperatures on Thursday will struggle to warm into the mid 50s to
lower 60s in response to significant cold air advection in the wake
of the cold front. The good news, however, is that we are expecting
plentiful sunshine on both Thursday and Friday as high pressure
becomes well entrenched across the region with subsidence keeping
moisture noticeably lacking. Next weekend isn`t looking as nice as
it appears moisture along the northern edge of the subtropical high
will advect northward and bring the return of cloud cover. A series
of shortwaves associated with a trough to our west will likely be
the focus for showers through the weekend. Model soundings show the
potential for some heavier rain showers with PWATs hovering around
1.5" so it`ll be something to keep an eye on. The timing of these
showers will take a few days to resolve as these low amplitude
features are not well forecast by low-resolution global guidance.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Through 00Z Tuesday...VFR conditions will prevail through the
entire TAF period. Clouds will thicken and lower late tonight
into Sunday morning ahead of an approaching warm front, and
scattered showers are expected to quickly move from west to east
across the region roughly 08z-16z Mon. Showers should be
relatively light, so would anticipate little in the way of
visibility reduction as they move through. Ceilings will lower
to 3500-5000 ft; there are some indications that MVFR ceilings
are possible, but certainty is too low at this time to include
in the TAF. Showers and clouds will exit after 18z, with FEW-SCT
clouds AOA 4000 ft expected. Winds will turn to the south
overnight, remaining generally 4-8 kt into Monday morning. Gusts
of 15-20 kt are likely during peak heating hours, especially at
KMSS and KBTV. A period of LLWS is expected overnight as well as
a low-level jet of 30-40 kt moves overhead. Best chances for
LLWS will be at KSLK, KEFK, and KMSS.
Outlook...
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Chance SHRA, Chance TSRA.
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Storm
DISCUSSION...Kremer/Storm/Clay
AVIATION...Hastings
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