219
FXUS61 KBTV 140630
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
230 AM EDT Tue Jul 14 2026
.WHAT HAS CHANGED...
As of 228 AM EDT Tuesday...
Smoke has been added to parts of northern New York and Vermont based
on wildfire smoke developing across Canada. The potential for
high heat and widespread strong to severe thunderstorms,
especially along the international border, remains on track.
&&
.KEY MESSAGES...
As of 228 AM EDT Tuesday...
1. A Heat Advisory is in effect for Vermont and much of
northern New York today, along with some wildfire smoke moving into
the region. Some localized fire weather concerns are possible
2. An Enhanced risk of severe thunderstorms remains for
northeastern New York and northern Vermont tonight when significant
severe weather and isolated flash flooding is possible. A more
typical potential for showers and perhaps some thunderstorms returns
for Thursday.
3. Relatively seasonable weekend and start to next week with
shower chances.
&&
.DISCUSSION...
As of 228 AM EDT Tuesday...
KEY MESSAGE 1: Hot weather is expected today as a brief surge of heat
breaking out of the expansive upper high in the Central US will
bring 90s across the region. A humid air mass will build, but not
reaching the heights of the heat at the end of June into early July.
Heat indices of 93-103 will be common through the region. There are
a few caveats to make note of. One will be gusty winds. That can be
a double-edged sword, allowing downslope regions to warm, but also
resulting in turbulent mixing that can allow some of the cooler air
aloft to filter to the ground not completely washed out by adiabatic
compression. There`s also cloud cover associated with the convective
mass in northern Quebec Province, and some of the wildfire smoke due
to fires initiated as a result of thunderstorms rounding the ring of
fire across central Canada. HRRR and Canadian smoke forecasts depict
increasing smoke aloft, and even some near the surface as well
propagating east this morning and afternoon. On one hand, this might
slightly reduce temperatures at the surface, but wildfire smoke can
exacerbate heat-health hazards. Regardless if this causes us to come
up short on the heat index forecast, the impacts will be the same.
Avoid prolonged exposure outdoors and drink plenty of water. Seek
shade often and take frequent breaks. Finally, the combination of
breezy conditions with gusts 20-35 mph and relative humidity values
of 35-45 percent in south-central Vermont could produce localized
fire weather concerns where less precipitation has been observed.
KEY MESSAGE 2: There has been little change regarding the severe threat
along the international border. Some variations in the coverage of
storms remains, but the intensity will not be in question as 2000-
3000 J/kg of CAPE will be present along northern Vermont and
northern New York as a sharp frontal boundary initiates
thunderstorms north of the international border. Ample shear will
provide the potential for organization of storms into bowing
segments and significant downburst winds. One potential
consideration will be the smoke aloft and how that will effect the
removal of the capping inversion in place. Mid-level smoke can
absorb solar radiation that can stabilize conditions in the low-
level, but on the other hand, this could maintain mid-level
lapse rates until the height falls and precipitation begin to
erode the cap. Based on soundings, it still seems to be about
6PM or 7PM that the cap erodes, and then the convection already
ongoing across Canada, and the sharp boundary they are
associated with allows the development of strong updrafts in our
region. Storms will be in a bit of a race against the clock.
Decreasing CAPE, storm-relative helicity, and
eroding/translating EML are expected after 8-9 PM. So storms
have a 2-3 hour window to become intense, and then gradually
weaken as they pass south. If initial convection heads east
early, this could also stabilize our area, and smoke is always a
wild card with these features. Some isolated flash flooding
will be possible if thunderstorms redevelop on the western
periphery of any bowing segments, with the greatest chances for
such a feature across the northern half of Vermont. Guidance
remains more stayed with the hydro potential, but we will
monitor closely.
Thus, risk timing is greatest between 7 PM and midnight. All hazards
are possible, including low probabilities of wind gusts greater than
70 MPH and a tornado risk, although we emphasize straight line winds
are much more likely to be the hazard in this environment given
fairly straight hodographs in the low levels. The risk dwindles
heading south and west due; however, a long tracked, well-developed
line or supercell poses some risk across our region, consistent with
the Slight (Level 2 of 5) risk of severe thunderstorms south of the
Enhanced area (Level 3 of 5).
Following any additional showers ahead of the cold front early
Wednesday morning, the next chance for showers and thunderstorms
comes on Thursday ahead of a weaker variety cold front. Gradual
cooling will take place as an upper low spirals to our
northeast. The Thursday evening/Thursday night front will also
come from the north, but with much less heat and humidity to
work with and more limited wind shear, expect much less impact
with perhaps a couple of afternoon/evening thunderstorms
depending on the timing of convection.
KEY MESSAGE 3: A somewhat strong area of low pressure for the time of
year will make a run at the region for the latter part of the
weekend and the beginning of next week, and it will likely bring
multiple rounds of showers. Ensemble consensus brings the pressure
just under 1000 MB. GEFS/EPS/CMCE combined ensemble probabilities of
the region receiving more than 0.5 inches of rain are between 30-60
percent and they fall to below 15 percent for receiving more than an
inch. Temperatures will stay around seasonable normals, with highs
generally in the 70s to mid 80s, and lows generally in the 50s and
low 60s. Depending on the storm track and timing of any associated
frontal passages, the threat of strong to severe storms will be
watched, but the threat should remain on the lower side due to a
cooler and less humid airmass.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...Conditions are currently all VFR and that
will be the case through the afternoon. A broken line of showers and
storms will move down from the north this evening and overnight. It
will cause frequent lightning, a period of MVFR to IFR visibility
and gusty/erratic winds at any terminal it reaches. The storms
should exit northern areas by 6Z. Winds will be relatively light and
variable for the rest of the night, except at PBG and MSS where
gusts out of the west to southwest up to 15 KT are possible. Winds
become stronger and southwesterly at the rest of the terminal today,
with gusts in the 15-25 KT range. Winds slowly diminish this
evening. A round of LLWS is possible this evening at all terminals.
Outlook...
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Slight chance SHRA, Slight chance TSRA.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. Chance SHRA, Chance TSRA.
&&
.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.
MSS looks most likely to set a new record. PBG also is
currently forecast to set a new record. MPV, and especially BTV
and SLK, are unlikely to do so. 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...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
for VTZ001>011-016>021.
NY...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
for NYZ026>029-031-035-087.
&&
$$
WHAT HAS CHANGED...Haynes
DISCUSSION...Haynes/Myskowski
AVIATION...Myskowski
CLIMATE...NWS BTV
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