Alert archive / New York / Mesoscale Discussions in 2026

Mesoscale Discussion 710

May 13, 202613 counties in New York; 13 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at May 13, 2026, 11:56 AM EDT for 13 counties in New York; 13 counties in Pennsylvania. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
May 13, 2026, 11:56 AM EDT (15:56 UTC)
Expired
May 13, 2026, 2:30 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 26 counties

Allegany County, NY, Cayuga County, NY, Chemung County, NY, Cortland County, NY, Madison County, NY, Onondaga County, NY, Ontario County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Yates County, NY, Cameron County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Elk County, PA, Forest County, PA, Jefferson County, PA, McKean County, PA, Mercer County, PA, Potter County, PA, Tioga County, PA, Venango County, PA, Warren County, PA

The radar

The State College radar (KCCX), 118 km from the middle of the area, began a volume at 15:58 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 3.9 hours before the alert went out and 122 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Buffalo Intl Airport, NY at 12:00Z on 2026-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 12:00Z on 2026-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 250 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
2 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
619 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
250 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

716 
ACUS11 KWNS 131557
SWOMCD
SPC MCD 131556 
NYZ000-PAZ000-131830-

Mesoscale Discussion 0710
NWS Storm Prediction Center Norman OK
1056 AM CDT Wed May 13 2026

Areas affected...portions of western/central NY into
northern/western PA

Concerning...Severe potential...Watch unlikely 

Valid 131556Z - 131830Z

Probability of Watch Issuance...5 percent

SUMMARY...A band of thunderstorms may bring locally gusty winds and
small hail to portions of western/central New York into western and
northern Pennsylvania this afternoon. A severe thunderstorm watch is
not expected.

DISCUSSION...Thunderstorms are beginning to develop just ahead of a
surface cold front from far western NY into northeast OH. While 12z
regional RAOBs and current regional VWPs indicate 30-40 kt
west/southwesterly flow in the 1-3 km range, instability remains
scant. Lingering cloudiness will limit stronger heating and
boundary-layer moisture is expected to remain modest this afternoon.
However, cold temperatures aloft will support modestly steep
midlevel lapse rates. As a result, a narrow band of weak MLCAPE
(less than 500 J/kg) is forecast just ahead of the cold front. This,
along with sufficient deep layer flow, should allow for an organized
band of thunderstorms developing eastward across the region this
afternoon. Given cool surface temperatures, poor low-level lapse
rates, and limited instability, overall severe potential appears
low. However, given the strength of deep layer flow and cold
temperatures aloft, the strongest cells could produce locally gusty
winds and perhaps small hail through the afternoon.

..Leitman/Mosier.. 05/13/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BGM...BUF...CTP...PBZ...CLE...

LAT...LON   43007727 43367625 43357573 43227550 42347587 41557688
            41277735 40927833 40907971 41048023 41178028 41288029
            41418016 43007727 

MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 5:54 PM EDTMesoscale DiscussionSPCBroome, Chemung, Chenango, Cortland, Madison, Oneida and 4 more2 hr
May 13, 12:41 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Cambria, Fayette and 6 more3 hr

Nearby

Mesoscale Discussions in New York, 2026Mesoscale Discussions in Pennsylvania, 2026Every mesoscale discussion in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.