019
FXUS61 KBTV 281717
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
117 PM EDT Sun Jun 28 2026
.WHAT HAS CHANGED...
As of 242 AM EDT Sunday...
No significant changes have been made.
&&
.KEY MESSAGES...
As of 242 AM EDT Sunday...
1. Pleasant weather conditions will continue through Monday
with comfortable humidity, light winds, and seasonable warmth.
A transition towards hot and humid weather will occur on Tuesday,
with potentially dangerous heat and/or thunderstorms following
on Wednesday.
2. Hot and humid weather expected for late week, with multiple
rounds of showers/thunderstorms possible right through the
holiday weekend.
&&
.DISCUSSION...
As of 242 AM EDT Sunday...
KEY MESSAGE 1: Today looks pretty similar to yesterday across our
region. Looking at the upper air analysis over the past 24 hours,
the air mass aloft has become a touch more moist while near surface
conditions have trended a touch warmer and drier. So while high
temperatures will almost certainly be a few degrees higher than
recent days, dew points will slip a little bit. Have noted greater
CAPE in excess of 500 J/kg will be in southern Quebec and our
northernmost areas, where slightly more moisture and steeper mid-
level lapse rates will be present. A few thunderstorms will likely
push southward late in the day, so can`t rule out an evening shower
or thunderstorm in northern portions of Vermont. Following this
activity, high pressure will be in charge through Monday with
the next chance of rain beginning Tuesday, when the forecast
details become quite challenging.
On Tuesday, a warm front will lift northeastward towards New England
associated with a pronounced thermal ridge, which will have built
northward early this week over the Midwest and then amble towards
the east. The air mass under the ridge is quite humid with dew
points in the 70s already as far north as central Ohio as of this
hour. There will be a sharp instability and humidity gradient near
the warm front, with thunderstorms more likely across western
portions of New York Tuesday morning and relatively low chances
of showers as one heads eastward during the day. As such,
Tuesday may be mainly dry and we have continued to back off
PoPs from the six hour Precipitation Potential Index.
Increasingly humid air will advect in from the west such that
uncomfortable heat and humidity is possible as early as Tuesday
afternoon, especially in northern New York. However, the greater
potential for significant heat and humidity appears to start on
Wednesday for our region when current maximum heat index values
are forecast to top out in the mid 90s or higher nearly areawide
below 2000 feet elevation. Note these values are unusually
uncertain, as they will be sensitive to the footprint of a
possible mesoscale convective system that will arrive from the
northwest.
Overlap of very high instability (CAPE values in the 2000-3000
J/kg range) and at least moderate deep layer shear (30 knots)
will be possible during the day Wednesday, which would fuel
thunderstorms capable of damaging winds and hail. A volatile
situation could unfold, but this is dependent on the position of
the upper level ridge on Wednesday. The latest guidance remains
somewhat split, with one camp of models farther south and west
than the consensus idea such that we stay out of both the
extreme heat and instability. Please keep abreast of the
forecast for midweek, as impactful thunderstorms and/or heat is
likely.
KEY MESSAGE 2: Summery conditions expected late this week
onward into the holiday weekend as high pressure builds eastward
from the Ohio River Valley. The overall trend will be toward
hot and humid weather as this high moves in; however, we also
look to be active as models indicate the potential for ridge
roller-type systems to ride up over the top of the ridge and
across our region. Daytime temperatures will rise well into the
mid 80s to mid 90s on Thursday, with a few locations in the
wider valleys perhaps warming into the upper 90s. Dewpoints will
be in the 60s and 70s, so quite uncomfortable, and serving to
keep nighttime conditions mild and muggy. As mentioned above,
periods of showers/thunderstorms are expected, especially in the
afternoons as the heat and humidity will provide ample CAPE for
storm development. Any precipitation could keep daytime highs a
cooler than currently indicated, but it`s hard to pinpoint
timing of these systems with any skill this far out. Regardless,
it will be dangerously hot and humid, especially Thursday and
perhaps Friday, when heat index values could approach 100F. We
see a bit of a reprieve heading into the weekend, but still
expect daytime temperatures in the 80s to around 90F and muggy
overnights. Anyone with outdoor plans next week should stay
aware of future forecasts and include both hot weather and
thunderstorm safety steps in your plans.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Through 18Z Monday...High pressure continues to build across our
taf sites this afternoon with VFR conditions and light terrain
driven winds under 6 knots. Given surface dewpoints are already
4 to 8 degrees lower this afternoon and another day removed from
precipitation, the probability of fog at MPV/SLK and EFK is <
20% at this time. Maybe a brief window of 20 to 40 minutes near
sunrise of IFR cigs/vis, but otherwise VFR conditions prevail
thru 18z Monday. Winds eventually turn to the south by Monday at
4 to 8 knots.
Outlook...
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. Chance SHRA, Slight chance TSRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Chance SHRA,
Chance TSRA.
Wednesday: Mainly VFR, with local MVFR possible. Slight chance
SHRA, Slight chance TSRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA, Slight chance TSRA.
Thursday: Mainly VFR, with local MVFR possible. Slight chance
SHRA, Slight chance TSRA.
Thursday Night: VFR. Chance SHRA, Slight chance TSRA.
Friday: VFR. Chance SHRA, Chance TSRA.
&&
.CLIMATE...
Extreme heat and humidity is possible later this week,
especially on Wednesday and Thursday, which could lead to some
daily records. Below are the current daily high and low
temperature records in jeopardy at our area climate sites.
Record High Temperatures:
June 30:
KBTV: 93/2018
July 1:
KBTV: 96/2018
KMPV: 92/2018
KPBG: 94/1968
KMSS: 94/2018
July 2:
KBTV: 97/2018
KMPV: 90/2018
KMSS: 94/2018
July 3:
KMPV: 91/2002
Record High Minimum Temperatures:
July 1:
KBTV: 76/2018
KPBG: 73/1971
KSLK: 69/2018
July 2:
KPBG: 77/2002
KSLK: 68/2002
July 3:
KBTV: 76/1911
KPBG: 73/2002
July 4:
KPBG: 71/1973
KSLK: 67/1952
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Kutikoff
DISCUSSION...Kutikoff/Hastings
AVIATION...Taber
CLIMATE...NWS BTV
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