Communities from Lake Charles, La., to Mobile, Ala., are feeling the effects of Isaac with conditions deteriorating into Tuesday night.
Isaac showed signs of strengthening Tuesday morning with an eye forming and flight-level winds from aircraft increasing.
Isaac finally became a hurricane Tuesday midday after traveling thousands of miles since emerging off the coast of Africa.
Landfall along the southern coast of Louisiana is forecast by AccuWeather.com Tuesday night, considering that the center may brush the coast for a time while moving west-northwest.
A larger version of the latest forecast track map for Isaac (with times in EDT) can be found on the AccuWeather Hurricane Center.
Ironically, Isaac is expected to threaten lives and property along the northern Gulf Coast almost seven years to the date of Hurricane Katrina's devastating landfall.
As the AccuWeather.com Hurricane Center has been calling for since last Thursday, Isaac is expected to slam into the northern Gulf Coast Tuesday afternoon or evening as strong as a category 1 hurricane (with maximum sustained winds between 96 and 110 mph).
A developing split between high pressure over the interior United States is directing Isaac toward the Louisiana Coast Tuesday and Tuesday night.
Isaac will pound those in its path with destructive winds, widespread flooding rain and perhaps isolated tornadoes.
A track into southeastern Louisiana would spell trouble for New Orleans, Biloxi and Mobile in terms of storm surge.
Such a track will still cause water from Lake Pontchartrain to put stress on the city's levee system.
Winds circulating around Isaac would still funnel some water from the Gulf of Mexico directly into Mobile, via Mobile Bay.
With Isaac's path will drive significant storm surge around Houma and Morgan City, La. Tuesday night.
Those at risk of taking a direct hit by Isaac should closely monitor the progress of the storm, heed all evacuation orders and avoid flood-prone areas.
The dangers of Isaac will not end when the storm makes its final landfall. Flooding rain and the potential for isolated tornadoes will accompany Isaac inland through the South.
Snow will linger across parts of the northern Plains to the Upper Midwest as December begins.
December will begin with a roar across the Northwest as rounds of rain, mountain snow and even ice are in store this week.
Downpours will continue the threat for flooding across parts of southern India this week.
Tens of thousands will gather in rainy and mild conditions at 30 Rockefeller Plaza in New York City on Wednesday, Dec. 2, 2015, for the 83rd annual Christmas tree lighting.
As the Northern Hemisphere plunges into winter, the night sky will come to life with several notable astronomical events throughout the season.
Rain will return across much of the eastern U.S. to begin the last month of 2015.
Ohio, Ontario (1996)
A line of severe thunder storms moved across the state. In Cleveland, OH there was a 60 mph wind gust. An 18-foot tractor trailer was blown over on I-77 in Richfield, OH. In Guelph, ON a wind gust lifted the roof of a gym, where a church group was playing basketball. Residents of one neighborhood saw a car spinning on its grill like a top.
Erie Canal (1831)
Coldest December ever closed Erie Canal.
Snow fell for 5 minutes in South Florida in the Ft. Myers area.