624
FXUS61 KBUF 191403
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1003 AM EDT Wed Jun 19 2024

.SYNOPSIS...
Hot and humid weather through at least Thursday with apparent
temperatures likely to reach 100F at many locations during the
afternoon hours. There will also be showers and thunderstorms at
times, especially during the afternoon and early evening hours. A
modest respite from the heat will come in time for the weekend as a
cold front approaches the region on Friday, although temperatures
will still remain very warm.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
The upper level high will remain in place today, centered over the
Mid-Atlantic, with the 850 mb temps hovering around +20C as
shown by the 12Z Buffalo sounding. This will support another
hot day with high temperatures in the upper 80s to mid 90s.
There`s a lot of mid and high clouds which will help keep
temperatures a degree or two lower than they would otherwise be
with full sunshine. Dewpoints do not really back off that much
with lower to mid 70s at most locations, leading to maximum heat
index values in the lower 100s. The lower Genesee Valley and
city of Rochester will be close to heat warning criteria (105).

The region will continue on the western periphery of the upper high
keeping much of the area dry, but scattered thunderstorm will once
again be possible mainly during the peak of the diurnal cycle
late this afternoon into this evening. Convection mostly
focusing on or inland of lake breeze boundaries or associated
with disturbances working around the high. This includes the
Western Southern Tier, Genesee Valley, and Western Finger Lakes.

Strong gusty winds are the main concern with this weakly
sheared convection. Precipitable water values will remain high
(around 1.75 inches), with slow storm motion again presenting a
risk for localized very heavy rainfall bringing the potential
for flash flooding.

Any afternoon and evening convection will diminish overnight
tonight, other than perhaps a stray shower or storm. There will be
little reprieve from the muggy conditions with low temperatures in
the lower to mid 70s, with some upper 60s across the Southern tier
and North Country.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
...Heat Advisory in Effect for the Entire Area as Dangerous Heat
Continues Through Thursday...

The broad ridge the has built itself across New England this week,
will settle south across the Mid-Atlantic, while a northern stream
trough slides across eastern Canada (Quebec and the Canadian
Maritimes). At the surface, low pressure well to the north of New
York State, will drag its surface cold front sag south across the
region Thursday before stalling across the southern portions of the
state. This being said, chances for showers and thunderstorms will
start Thursday morning and become more organized in the afternoon.
The Storm Prediction Center has placed the majority of the forecast
area under a Marginal Risk for severe thunderstorms, along with a
Slight Risk across the eastern Southern Tier due to the increase in
instability. In addition to the thunderstorm risk, Thursday will
remain HOT, though it will be on the tail end of the heat. Highs
Thursday will topple off in the upper 80s to lot 90s across much of
the area.

Thursday night through Friday, the aforementioned frontal boundary
will stall out over the forecast area, continuing the opportunity
for showers and thunderstorms. The best chance for showers and
thunderstorms will lie across the southern portion of NY State
towards the state line. While it will still be warm on Friday,
temperatures will have `cooled` off some with highs in the mid to
upper 80s.

The stalled front from earlier in the day Friday, will then advance
north now as a warm front late Friday night into Saturday. This
being said, with the lack of diurnal heating Friday night, the area
should remain mainly on the dry side. Showers and thunderstorms will
then increase in coverage starting Saturday morning and mainly
impact the North Country, however certainly can`t rule out a stray
shower or thunderstorm across the remainder of the area as the warm
sector of the next surface low moves north of the region.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
The warm sector of a surface low crossing the Great Lakes will be in
place for Saturday night and Sunday continuing the potential for
showers/storms across the entire area. Temperatures will be a few
degrees warmer than Friday, but not as warm as the current mid-week
temperatures.

The cold front associated with the surface low passing to the north
will cross the area on Sunday evening and into the night, causing
more organized showers/storms to move through the area. A potent
shortwave trough tracking across the area behind the passing front
will continue the shower potential for Monday.

Increased ridging and an incoming surface high will result in drier
conditions for Monday night through the rest of the period.

Temperatures will be well above normal for the weekend with highs in
the mid 80s to low 90s. Temperatures cool behind the passing cold
front to the mid 70s to low 80s for Monday before warming again for
Tuesday back to the low to upper 80s.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...

Mainly VFR flight conditions through the day today. Showers and
storms will develop during the afternoon hours and last into
this evening. Localized MVFR or lower possible.

Mainly VFR tonight outside of convection, but there is a risk of
fog in the Southern Tier river valleys.

Outlook...

Thursday through Saturday...Mainly VFR, but a chance for
afternoon and evening thunderstorms inland from the lakes.

Sunday...VFR/MVFR. A chance of thunderstorms.

&&

.MARINE...
A generally quiet period is expected for the lower Great Lakes
through the rest of the week and into the weekend as a large
upper-level ridge remains across the eastern CONUS, resulting
in a lighter surface flow. Only concern will be in the
afternoon and early evening hours this week as daily isolated to
scattered thunderstorms could produce higher wind gusts and
waves.

&&

.CLIMATE...
The heat will continue through Thursday. Below are record high
temperatures for our three main climate sites:

...Buffalo...

...Date.....Record Maximum (F)...Record warm Minimum (F)...

...June 19........90/2001............73/1919
...June 20........92/1995............73/2012


...Rochester...

...Date.....Record Maximum (F)...Record warm Minimum (F)...

...June 19........95/2001............72/1919
...June 20........95/1953............72/1923


...Watertown...

...Date.....Record Maximum (F)...Record warm Minimum (F)...

...June 19........91/2007............70/1949
...June 20........90/1971............71/2012

Temperature records for Buffalo and Rochester date back to 1871.
Temperature records for Watertown date back to 1949.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Heat Advisory until 8 PM EDT Thursday for NYZ001>008-010>014-
     019>021-085.
MARINE...None.

&&

$$

SYNOPSIS...Apffel/TMA
NEAR TERM...Apffel/TMA
SHORT TERM...EAJ
LONG TERM...SW
AVIATION...RSH/TMA
MARINE...TMA
CLIMATE...Thomas/TMA