--Isaac's Storm Surge Overpowered the River's Drought-Shriveled Flow
Hurricane Isaac's storm surge triggered a powerful upstream flow on North America's greatest river, the Mississippi.
US Geological Survey gages on the Mississippi at Belle Chase, La., registered the backward-flowing tide on Tuesday, as Category 1 Hurricane Isaac landed in southern Louisiana, the BBC News website said.
Upstream flow at Belle Chase was 182,000 cubic feet per second (cusesc). Normal downstream flow at this gage is 125,000 cusses.
The storm surge hiked the gage height nearly 10 feet above average.
Another 100 miles up stream, at Baton Rouge, an 8-foot rise in gage height was registered, the BBC said.
The Aug. 28-29 spike in gage height marks the storm surge of Hurricane Isaac at Belle Chase, below New Orleans, La. As the river gage height rose from 1 to 11 feet, the river actually flowed backwards (USGS Image).
Reversal of flow on the "Big Muddy," as the Mississippi is sometimes known, is not at all unprecedented. After all, the lower river has a very low gradient, the river being only about 60 feet above sea level where the Mississippi crosses the Arkansas-Louisiana line.
Hurricane Katrina caused backup on the river that boosted gages by 13 feet back in 2005.
Nor are hurricanes the only natural phenomenon known to reverse the Mississippi's flow. Great earthquakes on the New Madrid Fault Zone, Mo., are known to have caused backwards flow and even "waterfalls," back in 1812.
Tropical Cyclone Mahasen has necessarily had some say in the onset timing of the Monsoon.
Warmth will wax June-like in some capitals. Many others will experience the feel of mid summer for at least one day.
The Huntsville Mayor, Claude Doughty, said that it would take months and millions of dollars to repair road damage.
Localized severe wind gusts near 60 mph (about 95 km/h) will whip Ireland, Wales, northern England and southern Scotland.
Among the highest observed winds as of Tuesday were gusts of 60 mph at Lechars and 56 mph at Dundee, both in eastern Scotland. In Edinburgh, gusts hit 53 mph.
Much of England, France, the Low Countries and even Germany warmed 5 to as many as 10 degrees C (9-18 degrees F) above normal Sunday. Put another way, daytime warmth was more fitting of early to midsummer than mid-April over a wide area.