Wednesday, August 29, 2012

Isaac Still Battering Louisiana and Mississippi...


As feared, Hurricane Isaac continues to move at only a snail's pace across extreme southern Louisiana, producing widespread flooding rain, dangerous storm surge and damaging winds across the region.

Wind gusts have exceeded 50 mph for 13 hours straight at the New Orleans Naval Air Station.  Gusts over 60 mph have been recorded for 10 hours straight now, and there have been 5 hours within that time period with wind gusts over 70 mph.  Unfortunately, the winds will not subside for a number of hours more, as Isaac just lumbers along to the West or Northwest.


Dangerous storm surge flooding also continues across southeast Louisiana and southern Mississippi.  The President of Plaquemines Parish is reporting that people are "trapped on rooftops..." due to the 12 foot levee being overflowed there.  He said its "worse than Katrina".  Of course, many of you will remember that it was exactly 7 years ago today that Katrina was battering the same region.  Katrina was moving rather quickly, but Isaac's very slow motion means that additional wind-whipped flooding is likely across the region today and tonight.

Storm Surge Flooding in Braithwaite, LA

AP Photo of Flooded Area Near Lake Pontchartrain

In addition to the storm surge flooding and inundation threat, fresh water flooding will also be a continued hazard across the region.  Over 10 inches of rain will fall through today and tonight across a large portion of southcentral and portions of central Louisiana:


Isolated tornadoes will also be a continued threat, primarily to the East and Northeast of the center of the system.

As I alluded to above, strong, damaging sustained winds and gusts in excess of hurricane force will continue across much of southeast Louisiana and portions of southern Mississippi for much of the day today.  Based on the present location and expected movement of Isaac, hurricane force winds and gusts should end during the late afternoon or early evening hours, but tropical storm force winds and higher gusts will continue well into tonight across much of the region.

Beyond Louisiana, Isaac is forecast to move slowly toward the North, to the West of the Mississippi River, through the end of the week and the remnants will reach the Midwest over the weekend:


Some computer models are forecasting a more Westerly track, however the above National Hurricane Center (NHC) track assumes that the system will be drawn Northward around the Western edge of an area of high pressure in the middle and upper atmosphere, and I agree with that assessment at this time.  

Beneficial though at times heavy rains will spread along and ahead of the track of Isaac into the Midwest over the weekend, with amounts in excess of 3-6 inches possible (see the rainfall graphic 2 images above).

For the latest imagery and updates on Isaac, please refer to this dedicated webpage at our sister site, WeatherGuidance.com.  I will also post various shorter updates with additional images, etc., on both facebook and twitter throughout the day today and tomorrow.  If you would like to receive those updates, please be sure to follow me there if you aren't already:
 

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