Severe Thunderstorm Warning 129, NWS Binghamton, NY

Area Forecast Discussion
National Weather Service Binghamton NY
120 PM EDT Tue Jul 21 2026

.WHAT HAS CHANGED...
Adjustments were made to PoPs to better represent current
precipitation and expected evolution through this afternoon.

&&

.KEY MESSAGES...
1) Several rounds of showers and thunderstorms are expected this
afternoon and evening. Some of the thunderstorms may contain
gusty to damaging winds and heavy rain.

2) Showers will linger into at least the first half of
Wednesday. High pressure returns for the rest of the week, with
very pleasant weather conditions expected.

&&

.DISCUSSION...
KEY MESSAGE 1...

Complicated setup today with many factors playing into
thunderstorm development and severe storm chances.

A strong shortwave trough moving into the western portion of the
area is driving the development of scattered showers and
storms. Cirrus blow off from storms earlier over OH has limited
the instability over this region, allowing for a few weak
storms but mostly just periods of moderate to heavy rain. East
of this area, we have seen more breaks in the clouds which has
allowed stronger CAPE to develop, with values above 1000 j/kg
currently growing from a N/S line bisecting the the Central
Finger Lakes and to the east. 0-6 bulk shear values are
currently in the 35-40kt range and should remain around this
range through the afternoon hours thanks to the strong shortwave
overhead. With the current storms moving into a much more
favorable environment, we expect some of the storms to grow and
become severe, with damaging winds and heavy rain as the main
threats as the afternoon progresses. Hodographs show some weak
tornadic signatures so an isolated weak tornado cannot be ruled
out, but chances are on the low end.

Guidance suggests we may have a brief lull in activity late
this afternoon and early evening. This would bring a potential
for some clearing that could reinforce some early evening
surface instability. At the same time, a 2nd shortwave
currently over eastern MI is progged to track over the region.
This synoptic lift combined with surface instability and
increased 0-6km shear of 40-50kts would allow for more severe
storms to develop. The big question is will we get enough
clearing to introduce sufficient CAPE. If we do not and the CAPE
remains under 1000 j/kg, the amount of severe storms would be
lower but severe chances will remain given the high shear values
and synoptic lift provided by the transiting shortwave.

Heavy rains will also accompany these storms, allowing for a
potential for isolated flash flooding where multiple rounds of
storms impact an area. Currently, NEPA has a heightened chance
for isolated flash flooding with storms currently rolling
through and the expected 2nd round of storms later this
afternoon and evening.

The severe threat looks to end late this evening. Scattered rain
showers are going to linger through the night, especially north
of the Southern Tier as the trough axis moves over the area.

KEY MESSAGE 2...

With the trough lingering overhead into Wednesday, we expect
some scattered light rain showers to remain streaming across the
area.

After the trough axis moves east of the area, cool Canadian air
is expected to move into the region and plant itself through the
rest of the work week as high pressure dominates the weather
pattern. Wednesday will be the coolest, with highs in the upper
60s to mid 70s. We will see a slight warming trend through the
rest of the week, with low to mid 80s by the weekend. Showers
and storms may return Sunday or Monday as a trough tries to work
its way into the region, but it will depend on if the ridge
overhead weakens or flattens enough to allow for precip to move
in.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Mainly VFR conditions are expected through this morning,
with some MVFR ceilings at KAVP and KBGM. While mainly VFR
conditions will be present this afternoon, a round of showers
and thunderstorms is expected to move through the area from west
to east. PROB30 groups for thunder were added to the TAF for
each terminal, with a four hour window where thunderstorms are
most likely (generally from the mid to late afternoon).

After the bulk of the showers and thunderstorms move east of
the area in the mid to late evening, a deck of lower clouds is
expected to move in and result in at least MVFR restrictions
(mainly after 03Z). IFR restrictions will be possible late
tonight/early Wednesday morning.

Winds will generally be south-southwesterly throughout the TAF
period. Winds will be less than 10kts this morning, before
becoming around 10kts and occasional gusts up to 20kts this
afternoon. Locally higher gusts are possible in any
thunderstorms.

Outlook:

Wednesday...Lingering ceiling restrictions possible in the
morning; otherwise becoming VFR.

Thursday through Saturday...Mainly VFR; morning fog at KELM may
result in restrictions.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

DISCUSSION...JTC
AVIATION...BJG

Hazardous Weather Outlook
National Weather Service Binghamton NY
101 AM EDT Tue Jul 21 2026

NYZ009-015>018-022>025-036-037-044>046-055>057-062-220515-
Northern Oneida-Yates-Seneca-Southern Cayuga-Onondaga-Steuben-
Schuyler-Chemung-Tompkins-Madison-Southern Oneida-Cortland-Chenango-
Otsego-Tioga-Broome-Delaware-Sullivan-
101 AM EDT Tue Jul 21 2026

This Hazardous Weather Outlook is for central New York.

.DAY ONE...Today and tonight.

Several rounds of showers and thunderstorms will move through the
region. Thunderstorms have the potential to produce to gusty to
locally damaging winds and heavy rainfall.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed. Please relay any
information about severe weather to the NWS.

PAZ038>040-043-044-047-048-072-220515-
Bradford-Susquehanna-Northern Wayne-Wyoming-Lackawanna-Luzerne-Pike-
Southern Wayne-
101 AM EDT Tue Jul 21 2026

This Hazardous Weather Outlook is for northeast Pennsylvania.

.DAY ONE...Today and tonight.

Several rounds of showers and thunderstorms will move through the
region. Some of thunderstorms will become severe with damaging winds,
hail and heavy rainfall as the main threats.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed. Please relay any
information about severe weather to the NWS.

Preliminary Local Storm Report
National Weather Service Binghamton NY
1242 PM EDT Tue Jul 21 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1222 PM     Tstm Wnd Dmg     1 N Southport           42.08N 76.81W
07/21/2026                   Chemung            NY   911 Call Center

            Large tree reported down on a car. Wires
            down. Time estimated by radar.

&&

MJM