Forecast Discussion

093
FXUS61 KBUF 190513
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
113 AM EDT Sat Sep 19 2026

.WHAT HAS CHANGED...
Minor changes to the forecast with this update.

&&

.KEY MESSAGES...
1) Rain showers and isolated thunderstorms arrives tonight and
through Sunday.

&&

.DISCUSSION...
KEY MESSAGE 1...Rain showers and isolated thunderstorms arrives
tonight and through Sunday.

A plume of subtropical moisture has reached the western Great lakes
this morning, and will spread eastward across our region tonight
bringing the next round of rainshowers. This plume of moisture will
increase PWats over our region to around 1.5 to 1.75 inches, or
greater than the 90th percentile for Buffalo sounding climatology
for mid September.

Broad scale lift ahead of a few shortwave troughs aloft combined
with lower level isentropic lift will generate a period of rain
showers tonight through Sunday. Activity will advance northeastward
across the CWA with light stratiform rain possible across the North
Country by daybreak Sunday morning.

The axis of deeper instability will remain south of a frontal
boundary that will remain draped across the midwest, leaving the
thunder threat low. However the deepening warm cloud depth to over
12K feet on Sunday combined with the anomalously high moisture
content of the airmass will lend to heavy rain as the primary
hazard. Basin average QPF will range from around an inch near the
state line, to a third/half an inch across the North Country. With
the rain showers rather stratiform, falling over a greater duration
of time the flood threat will remain low. If any convection were to
develop across our southern zones, localized heavier amounts of
rainfall would be possible.

These rain showers will shift to the east Sunday afternoon and
evening, though a moisture rich lower atmosphere will remain Sunday
and into the evening hours with higher terrain low stratus and fog
possible.

A broad area of surface high pressure over the province of Ontario
will advect a cooler and drier airmass southward later Sunday night
and into Monday, possibly bringing a brief period of fair weather
before another impulse returns the chances for showers and possible
thunderstorms for Tuesday and Wednesday.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Aloft, W`erly to WNW`erly flow and embedded disturbances affect
Western and Central NY through 06Z/Sun. At the surface, a ridge
exits slowly from our area as the embedded high pressure center
wobbles ESE`ward from west-central QC toward the Canadian Maritimes.
Simultaneously, a trough overspreads our region slowly from the
southwest as a front approaches from near the Lower and Mid OH
Valley. Our regional surface winds trend light and variable before
12Z/Sat. From 12Z through 06Z/Sun, our regional surface winds should
trend NE`erly to SE`erly around 5 to 10 knots.

Mainly VFR and dry weather are expected through the TAF period.
Scattered to widespread cloudiness, especially in the mid/upper-
levels, will accompany the disturbances aloft and stream generally
E`ward to ESE`ward over Western and Central NY. In North-Central NY,
steam mist or fog resulting in MVFR to LIFR is possible along and
near the Black River between ~07Z/Sat and ~13Z/Sat, including
at/near KART. Between ~03Z/Sun and 06Z/Sun, scattered showers and
associated ceilings near 2kft to 5kft AGL should overspread the
Western Southern Tier generally from the west as moist ascent occurs
along the upper-reaches of the aforementioned front.

Outlook...

Sunday through Sunday night...Periodic showers with MVFR or worse
expected. Isolated thunderstorms possible in/near the Western
Southern Tier Sunday morning.

Monday...Dry weather and VFR likely.

Monday night through Wednesday...Periodic showers with MVFR or worse
possible. Isolated thunderstorms possible Tuesday night and
Wednesday.

&&

.MARINE...
Easterly flow around a surface high pressure that is centered near
the Ontario/Quebec province line will elevated waves on the waters
west of Hilton, with waves around 3 feet at times this morning,
before winds and waves slowly decrease through the afternoon hours.

Winds will then veer to southeast and southerly tonight, with
lingering higher wave action forced to the northern waters of the
Lower Great Lakes.

A wave of low pressure riding along a frontal boundary late tonight
and Sunday will increase winds...first as they back around to
northeasterly Sunday and then strengthen further Sunday night as the
pressure gradient increases between a Canadian surface high and this
frontal boundary. This will likely bring the next round of small
craft advisories to our region beginning Sunday night, with these
SCA then continuing into the middle portion of next week.

&&

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

&&

$$

DISCUSSION...Thomas
AVIATION...Jaszka
MARINE...Thomas

NWS BUF Office Area Forecast Discussion