TL;DR
The NOAA Storm Prediction Center (SPC) has issued a Slight Risk for severe thunderstorms across parts of Pennsylvania and New York for Tuesday, September 1, 2026. Damaging winds are the primary threat, with large hail and isolated tornadoes also possible. Northeast storms develop this afternoon and move southeast through evening.
Where is the highest risk today?
A Slight Risk area is in effect for September 1:
Northeast: Parts of Pennsylvania and New York face scattered strong to severe thunderstorms this afternoon and evening. The SPC outlook highlights a zone of strong instability—mixed-layer CAPE values exceeding 2500 J/kg—developing as temperatures climb through the 80s and interact with dewpoints in the mid to upper 60s along a baroclinic boundary from central New York into southern New England.
Both regions share similar threats: damaging winds as the primary hazard, with large hail and a tornado or two possible in the most favorable environments.
What's driving today's severe weather?
The synoptic setup features a broad upper ridge over the Mid-Mississippi and Tennessee Valleys, with northwest flow aloft affecting the Northeast and Mid-Atlantic states. This pattern is steering a baroclinic zone across the Northeast.
In the Northeast, ongoing morning convection may delay daytime heating, but the SPC expects strong storms to eventually form as the atmosphere destabilizes through the afternoon. The lack of a more obvious upper-level feature to provide large-scale forcing may limit overall storm coverage, but individual cells that do develop will tap into significant instability.
When will the storms hit?
Northeast (PA/NY): Storm development is expected through the late afternoon, with activity spreading southeastward through the evening hours. Peak severe weather timing falls roughly between 4 PM and 10 PM local time.
Cities in or near the Slight Risk areas include:
- Northeast: Scranton, Binghamton, Syracuse, Albany
What hazards should you prepare for?
Damaging winds
Damaging winds are the primary concern in the risk area. The SPC outlook emphasizes the potential for strong instability and adequate wind shear to support isolated damaging wind gusts with the strongest cells.
Large hail
Large hail is possible with strong thunderstorms. The combination of strong instability will support hail production during the afternoon and evening.
Isolated tornadoes
A tornado or two cannot be ruled out, according to the SPC. While tornado probabilities remain low, the atmospheric ingredients—instability, shear, and lift—are sufficient to support brief tornadoes, particularly with any supercells that develop.
Yesterday's severe weather
The past 24 hours brought 14 wind reports, primarily across the Southwest and central Rockies, with no tornado activity. One hail report came from Kershaw-Ryan State Park near Caliente, Nevada, where one-inch hail was observed at 1810 UTC.
Wind gusts reached 77 mph near Lamar, Colorado, and multiple reports of 60+ mph winds were recorded across Utah, Colorado, Kansas, and New Mexico as thunderstorms tracked across the region Monday evening. The activity was typical of late-summer monsoon and High Plains convection, with no organized severe weather outbreak.
Looking ahead
The SPC Day 2 outlook (valid September 2) maintains a Slight Risk for parts of Michigan and the Great Lakes as the system continues eastward. Day 3 (valid September 3) shows another Slight Risk emerging over the Ohio Valley and Midwest as additional shortwave energy moves through the region.
If you're in today's Slight Risk areas, now is the time to review your severe weather plan. Ensure you have multiple ways to receive warnings—NOAA Weather Radio, a smartphone weather app, and local media. If severe storms develop this afternoon or evening, move to an interior room on the lowest floor of a sturdy building, away from windows.
Nighttime severe weather presents unique challenges. Third-party weather apps are silenced by Do Not Disturb, though Wireless Emergency Alerts for tornado warnings still break through on most phones. Outdoor warning sirens are designed for people outside and may not be audible indoors, especially in newer, well-insulated homes.
VORTEX is a free web app at vortexintel.app that monitors severe weather nationwide. Pro ($4.99/month) places phone calls to your phone when a tornado or flash flood warning is issued for a location you care about — calls can ring through Do Not Disturb once you enable Emergency Bypass for the number, unlike most third-party app notifications.