Dangerous Thunderstorms Predicted for East Today

(June 6) -- The same storm system that produced 48 tornado reports -- including a deadly Ohio tornado -- on Saturday will result in the threat of dangerous thunderstorms along the Eastern Seaboard today into tonight, including the highly populated cities from New York City to Baltimore and Washington.

On Saturday, the bulk of tornado reports spanned the Midwest through the Ohio Valley, from Iowa to eastern Ohio. At least seven people were killed and at least 50 homes were destroyed when a tornado moved through Millbury, Ohio, on Saturday night. Many of Saturday's tornado reports occurred overnight, which is the most dangerous time for tornadoes. Not only are the tornadoes not visible as they are in daylight, but many residents are asleep and not aware of any National Weather Service tornado warnings.

Weather Resources:
- Get Your Forecast
- National Doppler Radar

The thunderstorms will move through New England, the Middle Atlantic region, and the Carolinas on Sunday and Sunday evening, and the greatest risk for dangerous thunderstorms -- capable of producing large hail, flash flooding and isolated tornadoes -- will be from southern New England to New Jersey and eastern Pennsylvania. This includes the cities of Boston, New York, and Philadelphia. Dangerous thunderstorms are also a threat farther to the south, including in Baltimore, Washington, D.C. and perhaps the Carolinas even though these areas are not included in the area of greatest risk.

(Risk of severe weather through Sunday night. (SLGT stands for slight, MDT for moderate) Image courtesy of Storm Prediction Center)

Also: 5 Killed as Powerful Storms Sweep Through Midwest

The dangerous thunderstorms are being fueled by the contrast between warm, humid air riding a southwesterly wind flow as and much cooler, drier air following the system. In addition to this standard atmospheric contrast, the risk of the thunderstorms producing isolated tornadoes is being heightened by atmospheric wind shear, which is a shift strength and speed of the wind and direction with height.

When the wind is blowing at a different speed and direction in the lower part of the atmosphere than it is a couple of thousand feet higher, this produces the spin necessary for potential tornado development.

Drier air following the storms will result in a tranquil start to the week in the Northeast and Mid-Atlantic regions. Both Monday and Tuesday will be dry and comfortable.