198
FXUS61 KBUF 191750
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
150 PM 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 /THROUGH THURSDAY NIGHT/...
Hot and humid weather will continue, with a Heat Advisory still
in effect for the entire area through Thursday. An upper level
high across the Mid-Atlantic will move very slowly southward
Thursday and Thursday night.

For the rest of today, 850 mb temperatures of +20C on the 12Z
Buffalo sounding will result in afternoon high temperatures in
the upper 80s to lower 90s. Fairly extensive mid/high cloud
cover will keep highs couple degrees lower than if it were
clear. But even so, dew points in the lower to mid 70s will
combine with the high temperatures to push heat index values
into the lower 100s at many locations.

Thunderstorms have not developed in our forecast area yet early
this afternoon, but with surface temperatures approaching the
sounding convective temp it`s only a matter of time before
storms develop. Timing is similar to yesterday...in the 4 - 9
p.m. timeframe. Precipitable water values around 1.75 inches,
and with a weak flow aloft the slow storm motion may result in
localized heavy rainfall and the potential for flash flooding.
DCAPE similar to yesterday, so there`s also a potential for
pulse storms to develop and collapse producing downbursts with
damaging wind gusts. Convection should mainly be along and
inland of lake breeze boundaries. This includes the Western
Southern Tier, Genesee Valley, and Western Finger Lakes.

Any storms that do develop should weaken/taper off late this
evening. However, there will remain a small risk for showers or
thunderstorms if any upstream convective waves move through
since will still be instability overnight. Lows will range from
the upper 60s to lower 70s, with patchy fog in the Southern
Tier river valleys.

Heat index values on Thursday may be slightly lower since 850mb
temps will drop to +18C, but values will still be within
advisory criteria, reaching 100 again at some locations. High
temperatures will be 2-3 degrees lower than today at most
locations.

The southward progression of the upper level ridge should allow
for earlier and more widespread convective initiation on
Thursday. This is reflected in model guidance also, with storms
developing along and inland of lake breeze boundaries early
afternoon. There will again be a risk for slow moving storms and
flash flooding. Winds aloft and shear will be slightly more, so
there will again be a risk for severe weather with damaging
winds and hail possible. SPC has most of the area in a marginal
risk for severe weather, with greater slight risk near Central
NY. Showers and storms will gradually diminish late Thursday
night. A partial clearing may allow for areas of fog to develop
Thursday night, especially in the Southern Tier.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
A frontal boundary will stall out over the forecast area on
Friday, 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 WEDNESDAY/...
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 /17Z WEDNESDAY THROUGH SUNDAY/...
Mainly VFR flight conditions through this evening. Showers and
storms 3 - 10 p.m. will produce localized MVFR or lower
conditions at times. Storms will mainly develop along and inland
of lake breeze circulations, with a lower risk at KBUF/KIAG/KART
than at KROC and KART.

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

On Thursday, mainly VFR again outside of showers and
thunderstorms. These will develop early afternoon and last
through the evening hours. Areal coverage a bit more than today,
with a risk of heavy rain and gusty winds.

Outlook...

Thursday night...VFR except areas of IFR or lower in areas of
fog. Also a chance of thunderstorms.

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

Sunday...VFR/MVFR. Showers and thunderstorms likely.

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

&&

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