896
FXUS61 KBTV 120627
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
227 AM EDT Sun Jul 12 2026
.WHAT HAS CHANGED...
As of 215 AM EDT Sunday...
No significant changes to the forecast.
&&
.KEY MESSAGES...
As of 215 AM EDT Sunday...
1. Seasonable conditions today will trend more uncomfortable to
start next week with increasing temperatures and humidity.
2. Precipitation chances increase early week. A sharp cold
front will pass through the region late Tuesday into Wednesday
bringing a chance for thunderstorms, some of which could be
strong.
3. Forecast trends suggest seasonable conditions, but the
pattern predictability appears relatively low.
&&
.DISCUSSION...
As of 215 AM EDT Sunday...
KEY MESSAGE 1: Beautiful summer weather will continue today with
temperatures similar to yesterday, but a degree or two warmer, but
remaining dry. Some localized valley fog in central Vermont and the
Adirondacks may be possible through sunrise, but should dissipate by
early to mid morning. Ridging centered over the Great Lakes will
continue to slide east towards the region with strong subsidence
aloft keeping winds light and variable today. Additionally, drying
low levels will promote good mixing through the day today keeping
the humidity low. Overnight lows will dip towards the 50s, with
perhaps some 40s in the usual cold hollows with good radiational
cooling tonight. In the Champlain Valley, warm Lake Champlain water
temperatures will likely keep the surrounding locations to near 60
tonight through Sunday night.
Temperatures and the humidity will begin to rebound back up to start
off next week as high pressure crests over the region by Tuesday.
This warm up will be relatively short as compared to a few weeks
ago, and only last a day. Temperatures begin the climb on Monday
with winds shifting to the south and west with highs in the mid to
upper 80s. Models still continue to have high agreement in anomalous
warmth by Tuesday as ridging crests overhead. Thankfully, the
humidity will not be as high as our last heatwave due to a
displacement from good moisture advection off the Gulf or Pacific.
However, some dewpoint advection is still anticipated with southwest
flow Tuesday, keeping uncomfortable heat past sunset Tuesday.
Contrary to the current NBM which is running hot compared to
consensus, GEFS 850mb temperatures are only 20-23C which would
suggest highs on Tuesday around the low to mid 90s. With any
moisture advection, heat index values would be highest in the
Champlain Valley, eastern Windsor County, and perhaps the St.
Lawrence Valley, though uncertainty is highest there. The latest
thinking is that Heat Advisory criteria will be reached in the
Champlain Valley; maximum heat index values could be in the mid to
upper 90s in the Champlain Valley and the Upper Valley of Vermont
with lower 90s in most other valley locations. Heat risk maps show
widespread moderate heat risk for most valleys across the area, with
isolated major heat risk in the Champlain Valley, focused over the
central Champlain Valley of western Addison County. Since this is
expected to be a single hot day, heat-health impacts aren`t
anticipated to be as significant as a longer duration event but will
be meaningful for vulnerable populations. Following a sharp cold
front Tuesday night into Wednesday temperatures and subsequently
heat index values will lower into the low to mid 80s on Wednesday,
giving us a quick end to the one off high heat day.
KEY MESSAGE 2: While the current forecast looks to remain dry through
at least Monday, there are some ensembles denoting a few chances for
rain. Some ensembles denote a weak shortwave passage Monday
afternoon, which could bring a brief light rain shower or sprinkle
to the northern Champlain Valley. Though confidence is relatively
low with only a 10-20% chance of precipitation with dry low levels.
More likely than not, any radar returns on Monday afternoon will
fall as virga with stout dryness in the low levels.
The more concerning forecast aspect is the potential for stronger
thunderstorms late Tuesday into Wednesday with a sharp cold front.
Given how hot and humid Tuesday will be, some instability cannot be
ruled out, particularly over the terrain and across the Northeast
Kingdom. GFS and NAM soundings show up to 2000J/kg of elevated
MUCAPE instability late Tuesday into Tuesday night. Shear profiles
are equally as impressive with soundings denoting a strong low level
jet associated with the front. NAM soundings show nearly 80kts of
surface to 500mb shear, focused over the Northeast Kingdom and
sliding south into central Vermont with the front by early Wednesday
morning. Thankfully, most of this instability and stronger dynamics
look to be "wasted" Tuesday night due to the presence of a strong
EML, or warm nose in the low to mid levels. Convection will struggle
to get going due to a lack of buoyancy in the low levels in part
also due to some lingering dry air at the surface. However, the
pattern ahead does bode some slight confidence that there will be
thunderstorms of some sort with a quasi-ridge running pattern from
Canada. SPC still has all of northern Vermont and the northern
Champlain Valley in a Day 4 15% chance for severe weather Tuesday.
Should the EML weaken in time, or should any earlier convection help
prime the evening convection, there could be some locally strong
storms near the Vermont International Border and the Northeast
Kingdom. With the high shear profiles, storms could become organized
into bowing segments leading to a wind threat. While our current
confidence remains low at this time due to competing forces, model
evolution of these patterns, even from our recent events, has shown
low predictability. Those with outdoor activities and/or camping
plans Tuesday into Wednesday should keep a close eye to the forecast
as it evolves over the next couple of days. Regardless of storm
potential, winds Tuesday will increase to between 25-35 mph in the
St. Lawrence Valley from channeling and the presence of the low
level jet and corresponding good mixing. Tuesday will be breezy to
gusty for most areas as the front passes through.
KEY MESSAGE 3: Thursday is likely to be another day on the list of
beautiful summer days in 2026 across Vermont and northern New York.
Dry mid-level air and incoming cool air will produce pleasant
weather conditions. A strong vort will angle southeast at the base
of a broad upper low taking shape in far eastern Canada. With such
dry air, it may be hard to produce much, but cannot completely rule
out a shower or two across northern Vermont as that embedded upper
trough approaches.
Then the pattern becomes increasingly uncertain. Model spread
between the 25th and 75th percentile 500mb heights are maximized
across the Pacific Northwest and New England. Some forecast
scenarios depict precipitation Friday, while others are dry, and
then some suggest a modest frontal boundary on Sunday, while others
are dry. Personally, inclined to pose drier conditions considering
PWATs will be running around 60-90% of normal, and probabilities of
total QPF > 1" in the extended range has a relative minimum in our
region. Given the large spread in model depictions on the underlying
weather pattern, we`ll hold off on making stronger assertions at
this point. At the very least, we`ll be outside the breadth of deep
high pressure in the central US, and so we`ll likely be relatively
seasonable to perhaps below normal in terms of temperatures.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Through 06Z Monday...Quiet aviation conditions are expected the next
24 hours. Some river valley fog is expected, but with conditions
being drier today, the span of time will be shorter, and only placed
fog at KMPV and KSLK from 08z-12z. After 12z, mostly clear skies
will give way to fair weather cumulus with bases around 5000-7000 ft
agl. Light northwest winds around 5 knots will prevail, with light
and terrain driven flows returning after 00z.
Outlook...
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. Chance TSRA, Slight chance SHRA.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
&&
.CLIMATE...
High temperatures on Tuesday will be hot, but we are at the
climatological warmest part of the year. Therefore, it is far
from a certainty that any records will occur. At this time, PBG,
MPV, and MSS are the more likely long-term climate sites to
set a record. See below for current records:
Max Temp Records
Date BTV MPV MSS PBG SLK
07-14 100|1995 94|1952 92|2012 95|1952 95|1934
High Min Temp Records
DatePBG
07-14 70|1974
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Danzig/Haynes
AVIATION...Haynes
CLIMATE...NWS BTV
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