United States

Severe weather apparently didn't get the memo that today is a national holiday, because it won't be taking a day off in observance of the fourth.

Severe storms are already ongoing across northern Minnesota and parts of Wisconsin and they may impact multiple additional regions of the country into tonight, including the D.C. Metro area, already hard hit by severe weather the past couple of weeks.

No matter where or how you decide to spend your Fourth of July, keep an eye on the sky and be smart around thunderstorms, especially if you live in any of the severe weather hot spots into this evening.

Mid-Atlantic Threat
With warm air surging into the mid-Atlantic, increasing levels of heat and humidity will prime the air for thunderstorms across the Northeast. Scattered showers and thunderstorms will fire through this evening over much of the mid-Atlantic region.

However, western Pennsylvania and eastern Ohio southeastward into the Chesapeake and Delaware bay areas have the right conditions to brew storms of the stronger variety. A very unstable air mass will be in place, and storms that fire in the juicy air could bring damaging winds and hail, along with the usual heavy downpours and dangerous cloud-to-ground lightning.

The overall severe weather threat will diminish after sunset as daytime heating goes away, but not before potentially interfering with some local fireworks displays.

Quebec and New England Threat
While the air mass in northern Maine and eastern Quebec does not look as juicy as the one in the mid-Atlantic, a cold front pushing across the region will provide atmospheric lift, forcing to initiate an area of storms that will still have plenty of fuel to work with.

The region will be a battleground between the sticky conditions across the Northeast and cooler more comfortable air attempting to move into the region from Canada. When the two regions clash, thunderstorms of the severe variety are always a possibility.

Strong thunderstorms have already developed over far northern New England and additional storms will affect the remainder of New England and the St. Lawrence Valley into this evening. Wind damage will be the chief concern, however hail and torrential downpours along with the always dangerous cloud-to-ground lightning can be expected.

Wisconsin, Minnesota and the southern Canadian Prairies
A similar situation will persist into this evening across the border with the United States and Canada. This will occur as a low pressure system will pull warm, moist air across the region, while a cold front attempts to cut through it.

This storm system brought severe weather to the northern Plains yesterday and is expected to produce additional severe weather into this evening.

Ongoing storms over northern Minnesota and parts of Wisconsin will continue to track from northwest to southeast across the region into this evening. Wind gusts of 60-70 mph have already occurred over eastern North Dakota this morning in associated with these storms.

The main threats from these storms will once again be damaging winds and large hail across the region, along with heavy downpours and cloud-to-ground lightning. Although unlikely, an isolated tornado cannot be ruled out.