424
FXUS61 KBUF 181733
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
133 PM EDT Fri Jul 18 2025

.SYNOPSIS...
Cool and calm weather will continue tonight. A wavy cold front will
bring another round of scattered to numerous showers and
thunderstorms Saturday evening, with these potentially lingering
into a portion of Sunday. Another area of high pressure will then
build across our region while bringing dry weather for Monday and
Tuesday.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
Canadian high pressure will move overhead tonight and temperatures
will fall into the 50s. Patchy fog is possible, especially in valley
locations across the western Southern Tier, western Finger Lakes,
and Black River Valley.

The surface high will move off the east coast through Saturday
morning. A dull shortwave trough will approach from the Mid-West
with moisture slowly increasing across the eastern Great Lakes
region. Forecast soundings show subsidence and dry low levels
through most of the afternoon which should result in dry weather
across the region. Warm air advection will result in warmer weather
with highs in the low to mid 80s, upper 80s across the lake plains.

An area of low pressure along a cold front will be on our doorstep
Saturday evening. A corridor of moisture with PWATS near 2" (>90th
percentile for July 19) will enter western NY. The chance for
showers and thunderstorms will increase from west to east Saturday
night. Upstream convection will approach the region, however there
is uncertainty how much will hold together. Hi-res guidance
including the 12z HRRR brings a line segment across Lake Erie into
the western Southern Tier. The warm lake (78F at Buffalo) may help
fuel storms through the evening hours. The Day 2 SPC outlook
includes a Slight Risk for Chautauqua, Cattaraugus, and southern
Erie counties, with a Marginal risk to about the Genesee River.
Coverage and severity is expected to trend down the second half of
the night. The cold front is expected to move through Lake Erie and
the Niagara Frontier by 8am Sunday, with showers and a few
thunderstorms possible across the region.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
A few showers with embedded rumbles of thunder will start the day
Sunday along a cold front before improvements will be found with
surface high pressure bringing afternoon and evening
clearing...along with lower humidity.

Fair weather can then be expected through the end of this period
with overnight fog filling the valleys of the Southern Tier.

Could see temperatures a bit lower than forecasted east of Lake
Ontario Monday night into Tuesday, where an overhead Canadian
surface high pressure (and cooler airmass at 850 hPa than tonight)
could allow for the mercury to drop into the mid 40s inland.

&&

.LONG TERM /WEDNESDAY THROUGH THURSDAY/...
A warm front will lift northward across our region Wednesday,
sending summers heat and humidity back into our region...along with
chances for showers and thunderstorms through the forecast period,
highlighting Wednesday night through Thursday night with the
passage of several shortwave troughs.

NBM with a modest spread in afternoon temperatures (25th to 75th
percentile) Wednesday, becomes even greater in spread Thursday and
Friday, especially inland where higher temperatures than forecasted
are possible...which would bring heat index values possibly into the
advisory range for the traditionally warmer inland areas.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
High pressure will be overhead through tonight. Light winds and calm
skies may result in patchy fog across the western Southern Tier into
the Finger Lakes region. Due to rainfall yesterday at KART, patchy
fog may occur this evening. Fog will erode through daybreak
Saturday. VFR conditions will persist through Saturday afternoon.

Outlook...

Saturday night...VFR/MVFR with showers likely along with a chance of
thunderstorms.

Sunday...VFR/MVFR with a chance of showers and thunderstorms, mainly
early.

Monday and Tuesday...VFR.

Wednesday...VFR/MVFR with a slight chance of showers and
thunderstorms.

&&

.MARINE...
Quiet conditions are expected across the Lower Lakes region through
Saturday...with continued weakening of the large-scale flow allowing
local lake breezes to develop each afternoon.

The next chance for disturbed weather will then arrive late Saturday
and Saturday night...when a wavy cold frontal boundary will make its
way across the Lower Lakes. This feature will bring a renewed
potential for showers and scattered thunderstorms...particularly
during Saturday night. The front is then forecast to slip south of
Lakes Erie and Ontario during Sunday...with Canadian high pressure
then providing dry and uneventful weather through Monday and Tuesday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...Hitchcock/JJR
NEAR TERM...HSK
SHORT TERM...Thomas
LONG TERM...Thomas
AVIATION...HSK
MARINE...JJR