936
AWUS01 KWNH 291544
FFGMPD
NYZ000-292140-

Mesoscale Precipitation Discussion 0888
NWS Weather Prediction Center College Park MD
1143 AM EDT Wed Jul 29 2026

Areas affected...Parts of New York State from the St. Lawrence
River Valley to the Southern Tier

Concerning...Heavy rainfall...Flash flooding possible

Valid 291540Z - 292140Z

Summary...Scattered thunderstorms with pockets of 2-4" rainfall
totals are possible through this afternoon across parts of New
York State, centered over the eastern shores of Lake Ontario,
which may lead to isolated instances of flash flooding.

Discussion...Latest regional radar and MRMS estimates show
developing efficient rain-producing showers across far northern
New York State near the St. Lawrence River Valley along a frontal
boundary wrapping southward to the east of Lake Ontario and into
the Southern Tier of New York. MRMS hourly rates have been
estimated up to 2" across far northwest parts of the state so far.
This is all occurring to the west of a strong and stacked low-mid
level low over southern New England, with high PWs being directed
to the north and west into this frontal zone. PWs of 1.5-1.75" via
SPC`s mesoanalysis are found across this region and actually
higher from Oswego, NY on northward.

With ample moisture and an axis of convergence in place,
instability is not overly impressive, but is highest over the
highlighted area where compared to the remainder of the Northeast
and New England. SBCAPE values remain around 1000 J/kg and should
keep showers from growing upscale, but the slow forward
propagation and uniform northerly flow could allow for some
repeating of showers. Should this occur, rainfall amounts could
add up to around 2-4" and is supported by recent HRRR and RRFS
runs. 12Z REFS neighborhood probabilities for at least 2" per
3-hrs are between 20-40% and match recent radar trends, with the
expectation that these totals are isolated in nature.

Snell

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...ALY...BGM...BTV...BUF...

ATTN...RFC...RHA...TAR...NWC...

LAT...LON   45027499 44627474 43737517 43027532 42527545
            42407602 42727661 43577670 44477621 44897560