-- Discussion containing changed information from previous version are highlighted. --
941
FXUS61 KBTV 182347
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
747 PM EDT Tue Jun 18 2024

.SYNOPSIS...
A period of dangerous heat and humidity will continue across the
region into Thursday. Highs will reach well into the 90s each day,
and overnight temperatures will remain muggy and uncomfortable.
Please be sure to take appropriate precautions to avoid heat stress
through the remainder of this week. Although an isolated
thunderstorm can`t be ruled out Tuesday or Wednesday, greater
chances for showers and thunderstorms arrive late Thursday.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
As of 706 PM EDT Tuesday...High temps today ranged from the
upper 80s to mid 90s acrs the region with heat index values in
the mid 90s to lower 100s. Temps have only dropped a few degrees
from daily highs, while boundary layer moisture has increased
with dwpts in the upper 60s to mid 70s acrs the region. A very
warm and muggy night is anticipated with lows only in the mid
60s to mid 70s. Did tweak lows up by several degrees locally in
the Burlington Urban Heat Island area, along with increasing sfc
dwpts by several degrees for several hours this evening.
Convection has been very very isolated this evening with just a
spot shower or two, so have continued with limited mention of
precip. Fog potential is tricky, especially with such warm
dwpts, but winds around 500 ft agl are expected to increase at
10 to 15 knots again tonight and given the lack of rain today,
thinking some areas of 3-5SM in haze with maybe a few intervals
of patchy fog possible near sunrise. Areal coverage is <5% and
probability of sfc vis at any particular station below 1/2sm is
in the 5-10% range. For now have not mention in fcst, given the
low confidence and probability of occurring.

Previous discussion below:
Dangerous heat is expected to continue across the region
through Thursday with a strong upper level ridge continue to
amplify as it shifts towards the region. Despite the showers and
cloud cover early in the day, temperatures this afternoon have
warmed into the upper 80s and 90s, with heat indices in the
upper 90s to low 100s. This period of prolonged heat will
continue the next couple of days, with a Heat Advisory in effect
until 8PM Thursday. Some isolated showers and thunderstorms may
pop up throughout the afternoon into the evening due with
plenty of available CAPE given the moist airmass and warm
temperatures, although lack of forcing and shear will limit any
development. Overnight lows will continue to be quite warm amd
humid, with temperatures struggling to drop below 70 in several
locations, which will add to the cumulative impacts of the heat.
Some patchy fog may develop overnight, especially across
northern New York where rain had fallen this morning.

Tomorrow looks to be a few degrees hotter than today, with highs
climbing into the 90s and heat indices once again near or exceeding
100F. Experimental NWS HeatRisk highlights the threat well, showing
major to extreme risk of heat related impacts for the middle of this
week. Be sure to practice heat safety by staying hydrated, avoiding
strenuous outdoor activity and checking up on your family, friends,
neighbors, and those most vulnerable to heat. Several CAMs are
showing the development of some isolated to scattered thunderstorms
and showers across the forecast area, particularly along the
periphery of the upper level ridge and across the Adirondacks.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 404 PM EDT Tuesday...Thursday will be the final day of this
early summer heat have with temperatures forecast to range from the
upper 80s along the Canadian border to low/mid 90s across
south/central VT. Relief is in sight though as a weak cold front
remains progged to drop southward through the region during the mid-
day to evening hours. Timing of the front will play a large role in
the forecast temps, as well as the convective potential, which right
now coincides with peak heating. Forecast soundings indicate
1500-2500J/kg of SBCAPE likely, but 0-6km shear isn`t very
impressive. Thoughts are pulse storms will be likely, with heavy
rain and downbursts the greatest threat with DCAPES > 1000 J/kg and
PWATs still up around 2". As the front shifts south of the region
Thursday evening, and with the loss of surface heating, showers and
storms will dissipate but mild and muggy conditions will continue
Thursday night with lows only in the mid/upper 60s for most areas.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 404 PM EDT Tuesday...Brief high pressure looks to build across
southern Ontario and Quebec on Friday, filtering in across northern
zones, but the aforementioned cold front will stall across southern
New England and may provide the focus for additional showers and
isolated thunderstorms to develop across Rutland/Windsor counties in
the afternoon. Thereafter for the weekend, several shortwave troughs
will renew chances for showers and isolated storms, with moderate to
heavy rain a possibility as PWATs surge again to near 2".
Temperatures won`t be quite as warm as they currently are, but will
remain above normal in the 80s with dewpoints likely in the 60s so
it will continue to feel quite humid.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Through 00Z Thursday...VFR conditions will largely continue
throughout the forecast period with a low chance of an isolated
shower or thunderstorm during the day Wednesday at any given
location. Following a rain shower earlier today and muggy
conditions, KSLK may see some fog development overnight. With
low probability and being beyond the first six hours of the
period, have continued to show VCFG at SLK as well as MPV, given
similar conditions as last night when fog briefly was observed.
Generally terrain driven winds should become southerly/southwesterly
after sunrise, with wind speeds most likely to exceed 10 knots
at MSS with modest channeled flow up the St. Lawrence Valley.


Outlook...

Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Likely SHRA, Chance TSRA.
Thursday Night: VFR. Chance SHRA, Slight chance TSRA.
Friday: VFR. Slight chance SHRA.
Friday Night: VFR. Slight chance SHRA.
Saturday: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday Night: MVFR/IFR conditions possible. Chance SHRA.
Sunday: MVFR/IFR conditions possible. Chance SHRA, Slight chance
TSRA.
-- End Changed Discussion --

&&

.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 95
KMPV: 95/1995 Forecast 93
KPBG: 93/2001 Forecast 92
KMSS: 94/1955 Forecast 92
KSLK: 93/1994 Forecast 89

June 20:
KBTV: 95/2012 Forecast 93
KMPV: 90/2020 Forecast 92
KPBG: 94/1964 Forecast 90
KMSS: 92/2012 Forecast 89
KSLK: 92/1995 Forecast 87


Record High Minimum Temperatures:
June 18:
KBTV: 73/1994 Forecast 74

June 19:
KPBG: 70/1949 Forecast 74

June 20:
KPBG: 70/1953 Forecast 74
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...Kremer
NEAR TERM...Kremer/Taber
SHORT TERM...Lahiff
LONG TERM...Lahiff
AVIATION...Kremer/Kutikoff
CLIMATE...Team BTV