Drenching and gusty thunderstorms threaten to ruin weekend plans up and down the East Coast into this evening.
Today started with heavy thunderstorms rattling the central Gulf Coast, leading to flooded and impassible streets in North Slidell, La., early this morning.
Other streets and highways could face a similar fate into this evening as additional drenching thunderstorms rumble along the corridor from Savannah, Ga., to Norfolk, Va., to New York City to Boston, Mass., to Lebanon, N.H., and Portland, Maine.
Rainfall rates of an inch or more an hour in some of the thunderstorms through this evening will easily overwhelm storm drains, causing water to flood streets and basements.
Water could pond on roadways, significantly heightening the risk of vehicles hydroplaning when traveling at highway speeds.
In any downpour, it is better to seek shelter than use your umbrella if lightning is also present.
Even where flooding does not ensue, motorists should use caution as the downpours will dramatically reduce visibility.
Heavy bursts of rain could also lead to flooding of low-lying, poor drainage and urban areas.
"Small streams can rapidly rise and overflow their banks," warned AccuWeather.com Expert Senior Meteorologist Alex Sosnowski.
It is not just blinding and flooding downpours AccuWeather.com meteorologists are concerned about. A handful of the thunderstorms have and will become severe with damaging winds and frequent lightning.
Violent thunderstorms will even expand northwestward to the southern St. Lawrence Valley, home to Montreal, into this evening. An isolated tornado cannot be ruled out here, while waterspouts remain a concern along the shores of lakes Erie and Ontario.
Residents and visitors along the East Coast will find that Sunday will actually be a better day for outdoor plans than this afternoon.
A shower or thunderstorm will continue to dot the region to close out the weekend, but this activity will be spotty and there will be less of a severe weather and flooding downpour threat.
The exception will be across eastern New England, including Boston. Additional thunderstorms triggering localized flash flooding are expected.
While lulls in tropical activity in the Atlantic will continue, a rapid end to the hurricane season in September does not always occur during an El Nino.
After heat has dominated headlines this summer, cool air has finally taken control of the northern half of Europe with no signs of departing anytime soon.
Steering winds could take Ignacio, as a remnant storm, into the southeastern arm of Alaska or British Columbia during the middle days of next week.
While Tropical Storm Kevin will stay well away from Mexico, its moisture will still lead to an increase in showers and thunderstorms from Baja California to the Four Corners region of the United States.
A stormy weather pattern will prevail through September across much of southern South America.
Downpours will spread from Italy to Ukraine to start the weekend before cooler air works southward and eventually sweeps the heat wave away from the Balkan Peninsula.
Los Angeles, CA (1988)
110 degrees -- all-time September record.
Washington, DC (1939)
"Once in a hundred-year rainstorm" 4.40 inches in 2 hours at the Washington Zoo.
Minneapolis, MN (1941)
Tornado - 5 dead - $450,000 damage.