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.
Tropical Depression Two has formed in the Atlantic and could become the next tropical storm of the season by midweek.
Warm and humid air in place over much of the Midwest and Northeast at midweek will contribute to the risk of drenching, gusty and locally severe thunderstorms on Wednesday.
After temperatures briefly climb to typical midsummer levels, another cooldown will roll into the Midwest and expand to the East for the last part of July.
Severe storms will fire up Tuesday afternoon and evening, threatening outdoor activities and travel for many.
Powerful winds, heavy rainfall and dangerous mudslides will threaten Taiwan on Wednesday as Matmo moves across the island.
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Spokane, WA (1980)
Mt. St. Helen's erupted again; flash flood watch issued for 20 mile radius due to mud slides.
Heat wave continues; Ft. Worth, Waco and Wichita Falls all over 100 degrees for the 30th consecutive day. El Paso had its 40th consecutive day of 100 degree plus heat.
Barrow, Alaska (1989)
Thunder reported for the first time since July 1982 (no rain fell with this so-called storm) July 1989 did go on to become the wettest July on record with more than 3 inches of rain.