— Strong to severe thunderstorms moved across parts of the U.S. Northeast on Saturday, prompting a severe thunderstorm watch from Maryland to Maine until 8 p.m. ET and placing more than 25 million people along the I-95 corridor on alert for damaging winds, hail, lightning and localized flash flooding.
Key Takeaways
- More than 25 million people placed under a severe thunderstorm watch across the Northeast on Sept. 6, 2025.
- Watch area runs from Maryland through Maine and covers major I-95 cities, including Baltimore, Philadelphia, New York City and Boston.
- Primary hazards: damaging wind gusts, frequent lightning and isolated large hail; a few brief tornadoes remain possible.
- Localized flash flooding is a concern where storms train or move slowly; highest flash-flood risk (Level 2 of 4) from Philadelphia to Bridgeport, Connecticut.
- Multiple heavy-rain rounds may produce urban and poor-drainage flooding; storms could continue into the overnight hours.
- Behind the front, cooler, fall-like air is expected for the latter half of the weekend before a gradual warming trend next week.
Verified Facts
A severe thunderstorm watch was issued Saturday covering portions of the Mid-Atlantic and New England states and was in effect until 8 p.m. Eastern Time. The watch included large population centers along Interstate 95, placing metropolitan areas from Baltimore to Boston under heightened alert.
The most likely immediate hazard from storms in the watch area is strong, potentially damaging straight-line wind gusts. Forecasters also warned of frequent cloud-to-ground lightning and the possibility of isolated large hail. Northern New England locations inside the watch were noted as having a slightly elevated chance of a brief tornado.
Forecasters highlighted the flood threat tied to slow-moving or training thunderstorms. When storms repeatedly pass over the same area, urban neighborhoods and zones with poor drainage can experience rapid rises in water levels. The highest flash-flood concern, assessed as Level 2 out of 4, extended along a corridor roughly from Philadelphia eastward to Bridgeport, Connecticut.
Heavy downpours and multiple storm rounds were expected to continue into the overnight period in some locations. Emergency managers and local weather offices urged residents to monitor watches and warnings and to avoid driving through flooded roadways.
Context & Impact
Timing and placement of these storms affected outdoor activities and events across the region; large-venue events saw interruptions from rain and lightning. Transportation could be disrupted by standing water and downed branches, and utility outages were possible where strong gusts or lightning struck infrastructure.
Urban areas are especially vulnerable to flash flooding during intense, short-duration downpours because storm drains can be overwhelmed. In addition to immediate safety risks, localized flooding can impede emergency response and recovery in the hours after heavy rainfall.
Public-safety officials typically recommend simple precautions: secure outdoor items, bring pets and people indoors during lightning, and avoid flooded streets. Motorists should remember the guideline: turn around, don’t drown.
Severe thunderstorm watch in effect until 8 p.m. ET; stay alert for warnings and take shelter if threatened.
National Weather Service
Unconfirmed
- Exact storm tracks and the specific neighborhoods that will see the worst flooding remain uncertain until storms develop and move.
- Forecasts allow for isolated brief tornadoes, but a widespread tornado outbreak was not expected; individual occurrences remain possible.
Bottom Line
On Sept. 6, 2025, a severe thunderstorm watch covered parts of the Northeast and put over 25 million residents at risk from damaging winds, hail, lightning and localized flash flooding. Residents in the watch area should monitor local forecasts and heed warnings; cooler air is expected behind the system, but warming will return gradually next week.