571
FXUS61 KBTV 191129
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
729 AM EDT Tue May 19 2026
.WHAT HAS CHANGED...
As of 722 AM EDT Tuesday...
Updated shower and thunderstorm potential for the morning hours
across northern New York and northern Vermont. Chances have
increased with a trough moving through.
&&
.KEY MESSAGES...
As of 727 AM EDT Tuesday...
1. Unusually warm temperatures continue today into Wednesday
before a cold front moves through the region bringing much cooler
conditions by Thursday and Friday.
2. Strong to locally severe thunderstorms possible this
afternoon and evening with more widespread showers possible
overnight into Wednesday.
3. Breezy to gusty winds are expected today through Wednesday.
4. Seasonable temperatures and increasing chances of
precipitation expected for the weekend into early next week.
&&
.DISCUSSION...
As of 727 AM EDT Tuesday...
KEY MESSAGE 1: Heat will continue today with 925mb temperatures
favored to warm into the 20-24C range. This is down from
yesterday, but the warmer start this morning will continue to
promote hot conditions. Maximum temperatures are favored back
into the mid and upper 80s with 90 within reach for a few select
locations. Flow will be swinging southwesterly, so Burlington
may get a marginal reprieve as air moves across the colder
surface of Lake Champlain; upper 80s are favored here.
Conversely, eastern slopes will have an increase in temperatures
from this wind direction that will promote increased
compressional warming off the terrain of the Adirondacks and
Greens. 90-93 degrees is more probable for eastern Essex County,
NY and for the Springfield, VT area. Around 90 is possible for
portions of Rutland/Addison Counties as well. Temperatures are
expected to drop by 10-15 degrees for Wednesday, but remain 5-10
degrees above seasonal averages. Warmest spots will be in
southern Vermont where there will be potential for more heating
ahead of the boundary. Highs in the 70s are forecast with low
80s for southern Vermont locations. Northwest flow will dominate
behind the front bringing sharply cooler temperatures for
Thursday and Friday with highs likely in the mid/upper 50s, then
60s respectively. This will be around 10 degrees below seasonal
averages and around a 30 degree departure from yesterday and
today`s high.
KEY MESSAGE 2: A conditional threat for strong to severe
thunderstorms remains as heat continues while dew points rise.
Highs in the mid/upper 80s to 90s coupled with dew points in
the upper 50s to mid 60s would support a few stronger variety
storms. Should any storms fire off, it`s probable that outflows
would be sufficient to ignite other cells, especially if they
interact with lake breeze or move into convent flow around
terrain. The biggest issue will be a trigger. Models are showing
a subtle 500mb trough moving through late this morning and
early afternoon which is what some of the CAMs are highlighting
as a trigger. There should be ample cloud breaks to allow for
heating which will put the focus on shower/cell initiation over
higher terrain. Have increased chances of showers over the
Adirondacks coincident with trough timing and as temps on the
slopes rise to near 80 degrees which aligns with about noon. The
biggest concern will be winds (15%) with a stout low level jet
and deep layer of 40+kts extending from 2500-15000ft. There will
be about a 5% chance of any storm developing hail this
afternoon. The continued absence of strong low level shear means
the tornadic threat is very low. Finally, can`t rule heavy rain
completely out with PWATs in excess of 1.5". If storms fire and
a persistent boundary can set up, training cells could occur
resulting in localized heavy rainfall. The threat for stronger
storms will end around sunset with loss of heating and decrease
further behind the prefrontal trough overnight Tuesday.
More synoptically induced precipitation is expected as the front
begins to moves through tonight along a prefrontal trough and
Wednesday as the surface front moves through.
KEY MESSAGE 3: Winds will be breezy through Wednesday given
periods of low level jet passages and a moderately strong
thermal/pressure gradient along and behind Wednesday`s front.
Gusts 20-35 mph are likely with highest gusts in the northern
Champlain Valley and along the Highway 11 corridor in the
vicinity of Malone/Ellenburg, NY. Gusts to 40 mph are possible
should mixing be more pronounced; model soundings show robust
southwest flow aloft with a deep 35-45kt layer 2500-15000+ft.
Some model guidance is suggesting a narrow potential at gusts to
40 mph for portions of northern New York tonight, but this will
be highly dependent on convection which is less certain. These
winds will result in rough lake conditions on Lake Champlain.
Lighter winds return Thursday as high pressure moves across the
region.
KEY MESSAGE 4: There continues to be considerable differences in
both ensembles and deterministic models in how shower chances
play out for the upcoming holiday weekend. Ensemble members of
both the GEFS and ECMWF are roughly split equally on whether
waves of precipitation will cross the area Saturday into Sunday.
The deterministic ECMWF also favors a wetter solution.
Meanwhile, the remaining ensemble members along with the GFS and
CMC keep ridging more firmly in place, with the axis running
just to our east. This would keep rain shunted to our south and
west through the day Saturday and most of Sunday, then trending
rainy for Memorial Day. With this much uncertainty, have stayed
with the NBM solution for now. Either way, temperatures will be
seasonable with highs mainly in the 60s and lows in the 40s.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Through 12Z Wednesday...This morning, some showers are moving
into northern New York with a focus on MSS and SLK through 16Z.
More nebulous are chances as the area of showers track into the
Champlain Valley - have about 30% chance of showers 15-21Z.
After 18Z, isolated to scattered showers/thunderstorms are
possible, some of which may be strong to perhaps severe.
Coverage/timing is too uncertain at this point to include any
mention in the TAF, but MVFR/IFR conditions will be possible in
any thunderstorms. Surface winds become light and variable
around 5 kt this evening. However, a LLJ moving overhead will
allow for periods of LLWS at all terminals overnight. Surface
winds increase out of the S/SW after 14z Tue, gradually shifting
toward the W/SW with gusts of 18-25 kt expected. LLWS will
become pervasive overnight as LLjet spread across northern New
York and much of Vermont ahead of an approaching cold front.
Showers will begin at MSS after 09Z.
Outlook...
Wednesday: VFR. Chance SHRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.
Friday Night: VFR. Chance SHRA.
Saturday: VFR. Chance SHRA.
&&
.MARINE...
As of 236 AM EDT Tuesday...
A Lake Wind Advisory remains in effect for the Broad Waters of
Lake Champlain. Winds are expected to increase this morning out
of the south with sustained speeds 15 to 20kts and gusts around
25kts. These stronger winds will continue through 8 AM and will
diminish to 15 knots or less until the early afternoon; winds
then increase again as faster winds aloft mix to the surface.
Gusts in excess of 20kts are probable before flow turns more
southwesterly. South winds return tonight with stronger gusts
possible. A front will pass through the region Wednesday
resulting in a wind shift out of the north with gusts up to
30kts.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Boyd
DISCUSSION...Boyd/Hastings
AVIATION...Boyd/Hastings
MARINE...Clay
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