281
FXUS61 KBTV 191744
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
144 PM EDT Wed Jun 19 2024

.SYNOPSIS...
Dangerous heat and humidity across the region today into
Thursday. Highs in the 90s will combine with humid conditions to
create heat index values up to 105. Please be sure to take
appropriate precautions to avoid heat stress through the
remainder of this week. Isolated to scattered thunderstorms are
possible again today, but greater chances for showers and
thunderstorms, a few possibly severe, arrive Thursday.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 130 PM EDT Wednesday...Minor updates to the forecast,
mainly to tweak chances of precipitation, as showers and
thunderstorms are slightly more widespread and intense than
initially expected. Previous discussion below:

Previous discussion...Morning temperatures around the
Burlington Airport only dropped to right around 80 degrees
(warmer than our average daily maximum temperature), which could
be a daily record warmest minimum temperature if BTV doesn`t
drop further this evening. As such, we are starting quite warm
with some mid clouds. Once the clouds break, heating will
rapidly increase with dangerously hot conditions returning.
Showers and thunderstorms are already forming this morning being
kicked off by a mid level disturbance left over from
yesterday`s thunderstorms. With the heat, instability, and a
triggering mechanism, we could see isolated severe
thunderstorms; have a plan for thunderstorms today.

Elevated instability is evident across portions of southern
Canada and could kick off an isolated shower or thunderstorm
this morning across the North Country. Best chances will be
9am-2pm across central Vermont and the Adirondacks. Thunderstorm
chances will be 10-20% in this time frame with ridging aloft
potentially being the foil for sustained convective activity.
Should something get going, damaging winds will be possible as
well as localized heavy rainfall.

Heat remains the main focus through Thursday with dangerously
hot conditions continuing. Some locations could possibly not dip
below 77 this morning resulting in an incredibly warm start. A
rapid heat-up is expected again with potential for slightly
higher humidity. Dew points in the mid 70s are expected and
could briefly push portions of Addison/Rutland/Chittenden
County to a 105 heat index; today will be the hottest day.
Clouds and showers could be the foil if convection gets going
however. Another warm night is ahead with continued heat for
Thursday.

For Thursday, conditions will warm early, but shear aloft from
an approaching front will likely begin some marginal cooling for
northern locations towards the Canadian border. The front poses
another concern with shower chances increasing north to south.
With additional forcing, increasing wind shear, and oppressive
heat, marginal to slight (5-15%) chances of severe thunderstorms
are expected. Unlike yesterday and today, this will be a
stronger trigger for convection supported by height falls and
cooling aloft. Damaging winds will be the primary threat from
any storms.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
As of 308 AM EDT Wednesday...The cold front will still be over
southern Vermont on Friday and it looks to take long enough to drop
to the south that some instability will be able to develop. With
forcing from the front and more shear, some isolated severe storms
are still possible. However, they look less widespread than
Thursday. There is still some model disagreement on the timing of
the frontal passage so if it passes earlier in the day, that will
keep the severe threat to the south. There should be a break in the
precipitation Friday night as high pressure is briefly able to build
into the region from Canada. It should also be able drop dew points
into the 50s in northern areas though they will be stuck in the 60s
in southern areas. Lows Friday night will be in the 50s and low 60s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
As of 308 AM EDT Wednesday...The front looks to push back north
into the region on Saturday, and it will bring some showers and
possible thunderstorms. However enough colder air will be able
to drain down from the north at the surface that it will keep
the lower atmosphere stable and any instability will be
elevated. This will prevent a severe threat. The front looks to
stall over the region and showers are possible into Sunday. A
low pressure system moves through Sunday into Sunday night and
it will cause more widespread rainfall. PWATs will increase back
close to 2 inches for Sunday so areas of moderate to heavy
rainfall will be possible. After the low moves out, a warming
trend will occur, though temperatures will not approach the
levels of this week. Dew points look to stay in the 60s for much
of the period so while it will not be as humid as this week, it
won`t feel very refreshing either.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...Thunderstorms are becoming more
widespread than initially anticipated across the forecast area
this afternoon, impacting several TAF sites with rain, including
visibilities less than 3 miles at times, gusty winds, and
lightning. We will be monitoring this an issuing amendments as
needed. For now, most sites have VCTS or a TEMPO group detailing
gusty south/southwesterly winds up to around 30 knots and IFR
visibilities. Showers and thunderstorms will dissipate
overnight tonight as winds decrease and calm, turning focus to
the potential for some fog or mist at select sites, particularly
SLK, MPV, and EFK. While temperatures aren`t expected to drop
dramatically overnight, an appreciable amount of moisture is
present in the lower atmosphere that could cause lowered
visibilities and even potentially low ceilings.

Outlook...

Thursday Night: VFR. Chance SHRA, Chance TSRA.
Friday: VFR. Slight chance SHRA.
Friday Night: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
Saturday: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Saturday Night: Mainly MVFR, with local IFR possible. Likely
SHRA, Slight chance TSRA.
Sunday: MVFR/IFR conditions possible. Likely SHRA, Slight chance
TSRA.
Sunday Night: MVFR/IFR conditions possible. Likely SHRA, Slight
chance TSRA.
Monday: Mainly MVFR, with areas VFR possible. Chance SHRA.

&&

.CLIMATE...
Hot temperatures will result in values near records by the
middle of next week. Below are some of the records under threat
of being broken.

Record High Temperatures:

June 19:
KBTV: 100/1995 Forecast 94
KMPV: 95/1995 Forecast 91
KPBG: 93/2001 Forecast 90
KMSS: 94/1955 Forecast 91
KSLK: 93/1994 Forecast 88

June 20:
KBTV: 95/2012 Forecast 92
KMPV: 90/2020 Forecast 90
KPBG: 94/1964 Forecast 87
KMSS: 92/2012 Forecast 85
KSLK: 92/1995 Forecast 83


Record High Minimum Temperatures:

June 19:
KBTV: 78/1923 Forecast 77
KPBG: 70/1949 Forecast 74

June 20:
KPBG: 70/1953 Forecast 71
KSLK: 68/2012 Forecast 65

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Heat Advisory until 8 PM EDT Thursday for VTZ001>011-016>021.
NY...Heat Advisory until 8 PM EDT Thursday for NYZ026>031-034-035-
     087.

&&

$$
SYNOPSIS...Boyd
NEAR TERM...Boyd/Storm
SHORT TERM...Myskowski
LONG TERM...Myskowski
AVIATION...Storm
CLIMATE...Team BTV