TL;DR

The NOAA Storm Prediction Center (SPC) has issued an Enhanced Risk for severe thunderstorms across portions of the Northeast, Mid-Atlantic, and Lower Great Lakes today. Damaging wind gusts of 50-70 mph will be the primary threat this afternoon and evening, with the strongest winds expected along the I-95 corridor from the Chesapeake Bay into southern New England. A few tornadoes are possible, including perhaps a strong tornado. Peak severe weather is expected between 2 PM and 10 PM EDT.

Where is the highest risk today?

The Enhanced Risk area covers portions of the Ohio Valley, Lower Great Lakes, Mid-Atlantic, and Northeast. Major metropolitan areas in the Enhanced Risk zone include:

The I-95 corridor from the Chesapeake Bay northward into southern New England faces the highest probability of widespread damaging winds, with locally stronger gusts of 55-70 mph possible.

According to the SPC Day 1 Convective Outlook, "severe thunderstorms are expected across portions of the Ohio Valley and Lower Great Lakes into the Mid-Atlantic and Northeast this afternoon and evening."

What's driving today's severe weather?

A potent mid-level shortwave trough is moving southeast over the Upper Great Lakes toward the Northeast. Surface analysis this morning shows a 1004-mb low pressure system north of Georgian Bay with a cold front extending west-southwestward into northern Iowa. An attendant warm front arching southeastward through the Lower Great Lakes and draped over the Mid-Atlantic states will advance northward through the day.

South of the boundary, a very moist air mass is in place, with dewpoints in the upper 60s to lower 70s F. Early morning cloud cover will gradually dissipate, allowing strong heating to combine with the northeastward advancement of the warm sector. This will promote a broad area of moderate to strong instability later today, with mixed-layer CAPE (Convective Available Potential Energy) values reaching 1000-3000 J/kg from the Ohio Valley eastward into the Mid-Atlantic and parts of the Northeast.

A belt of westerly 30-45 kt winds at 700 mb (around 10,000 feet) from northern Virginia into the Northeast will aid in storm organization and enhance the severe potential this afternoon and evening.

When will the storms hit?

Timing varies by region:

  • Ohio Valley and southern Great Lakes: Storms will develop during peak heating this afternoon, roughly 2-6 PM EDT, and continue into early evening.
  • Mid-Atlantic and I-95 corridor: Peak severe weather expected between 4 PM and 10 PM EDT as multicellular bands of storms move eastward.
  • Northeast: Severe weather will spread into the region during the late afternoon and evening hours, continuing into tonight.

The SPC notes that "a few thunderstorm clusters this morning have developed near the warm frontal zone from the Lower Great Lakes into the Mid-Atlantic states," but early-day storm activity will likely be limited due to widespread cloud cover initially inhibiting strong heating.

What are the primary threats?

Damaging winds (primary threat)

Widespread damaging wind gusts of 50-60 mph are expected, with locally stronger gusts of 55-70 mph possible, particularly along the I-95 corridor from the Chesapeake Bay into southern New England. The SPC emphasizes that damaging gusts will be the primary hazard across the entire Enhanced Risk area.

Several multicellular bands of storms are expected to develop during peak heating and organize as they move east. Some of the more intense cells may become supercellular, posing an all-hazards severe risk.

Tornadoes (secondary threat)

A few tornadoes are possible both from linear and cellular storm structures. The SPC specifically notes that "a few tornadoes are possible, including perhaps a strong tornado." Low-level hodograph enlargement and moist low levels will support tornado development in some storms.

Farther west across the southern Great Lakes into the Ohio Valley, veered low-level flow ahead of the cold front will promote upscale growth into a few bands of cells and line segments. A localized risk for a couple of tornadoes may accompany this activity.

Hail

Large hail is a secondary concern with any supercells that develop, particularly with isolated cells ahead of the main line of storms.

Recent severe weather activity

Over the past 24 hours, 39 wind reports and 5 hail reports were recorded across multiple states, though no tornadoes were reported. The wind reports were concentrated in Florida, Wisconsin, Minnesota, and Kentucky, with several instances of trees downed and power outages. In Ashland, Wisconsin, a personal weather station recorded a 66 mph wind gust, and roof damage was reported with roof and truss supports torn off a building and thrown onto Highway 2.

Quarter-size hail was reported in multiple locations across Montana, Wisconsin, and Florida.

What should you do today?

If you live in or will be traveling through the Enhanced Risk area today:

  1. Monitor weather conditions closely. Conditions can deteriorate rapidly once storms develop. The SPC outlook and local National Weather Service forecasts should be checked frequently this afternoon.
  1. Have multiple ways to receive warnings. Tornado and severe thunderstorm warnings may be issued with limited lead time, especially for tornadoes embedded in squall lines. Third-party weather apps are silenced by Do Not Disturb, though Wireless Emergency Alerts for tornado warnings still break through on most phones by default.
  1. Avoid outdoor activities during peak storm hours. If you're outdoors this afternoon or evening, have a plan to get indoors quickly. Lightning is a threat with all thunderstorms.
  1. Secure outdoor objects. Wind gusts of 50-70 mph can turn patio furniture, trampolines, and other loose items into projectiles.
  1. Know your safe place. For tornado warnings, move to the lowest floor of a sturdy building, away from windows. Interior rooms, hallways, or closets offer the best protection.
  1. Stay off the roads if possible during severe weather. Downed trees and power lines may block roadways. If you must drive, be prepared to pull over and wait out intense storms.

The combination of strong winds, possible tornadoes, and large hail makes this a significant severe weather event for the Northeast and Mid-Atlantic. The threat is not limited to rural areas—major cities are all within the Enhanced Risk zone.

Looking ahead

The SPC has issued a Slight Risk for portions of the Northern Plains, Minnesota, and parts of Virginia and North Carolina for Sunday (Day 2), and another Slight Risk for portions of the Northern Plains, Midwest, Great Lakes, Southeast, and Northeast for Monday (Day 3). While neither day features the same level of organized severe weather potential as today, scattered severe storms remain possible across multiple regions through early next week.

Today's Enhanced Risk represents the most significant severe weather threat to the Northeast and Mid-Atlantic in several weeks. Stay weather-aware and be prepared to act quickly if warnings are issued for your area.

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.