The slow moving progress of Hurricane Isaac has provided more than 24 hours of intense rainfall on southern Louisiana. This morning’s 10 hour Doppler radar loop showed the eye making landfall and then passing westward along the south show of Louisiana. Since then the storm has made a curve more to the north and as of 7pm local time the center was 60 miles west of New Orleans. This is the closest the storm has been to the city.
The heavy rain continues to wrap around the counter-clockwise circulation and pull in moisture directly off of the Gulf of Mexico as seen here in the latest 10 hour Doppler radar animated loop. This track has been the worst case scenario for New Orleans. It has kept the city on the heaviest side of the storm the entire time. While the winds only reached Category 1 intensity, the onshore flow piled up the storm surge through a few high tides.
Top wind speed is listed at 60 mph, but Gulfport MS recorded a 67 mph gust. Tropical Storm force winds extend out 175 miles from the center.
In New Orleans today:
Top Speed: 52 mph from the northeast.
Top Gusts: 75 mph from the east.
The only benefit now is that the wind is from the south, off of land for the city, but still a problem for the coasts of Mississippi and Alabama.
NEW: Saffir Simspon Scale wind damage animation and storm surge slide show
Record owned by Isaac compared to Katrina
This storm is being compared to Katrina for a few reasons. Besides the first full test since the levees broke in the 2005 event, both storm have hit on the same date: August 29th. Katrina was a stronger storm but it passed to the east of New Orleans, leaving them on the weaker side. Take away the wind and level break, and we are left with the climate data. The final climate report for New Orleans shows they set a new record rainfall for the date. This broke the record set back in 2005 from Katrina.
Note: This is more than an extra inch of rain and it will be adjusted higher when the final climate report is complete after midnight. Also, the storm rainfall includes August 28 with 1.22” and what will most likely continue to fall on Thursday. Then the rain will continue north along the Mississippi River Valley into the drought stricken Midwest.
Other storm information:
STORM SURGE… STRONGEST ON THE RIGHT SIDE OF THE CENTER OF THE STORM!
THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE… THAT IS WHY A PATH TO THE SOUTH OF NEW ORLEANS WOULD BE THE WORST CASE SCENARIO
THE SLOW MOVEMENT MAY ALLOW FOR 2 or 3 HIGH TIDE CYCLES WITH ONSHORE FLOW IN SOME LOCATIONS!
* MISSISSIPPI AND SOUTHEASTERN LOUISIANA…6 TO 12 FT
* SOUTH-CENTRAL LOUISIANA…3 TO 6 FT
* ALABAMA…2 TO 4 FT
* FLORIDA PANHANDLE AND APALACHEE BAY…1 TO 2 FT
Latest stats from The National Hurricane Center
SUMMARY OF 700 PM CDT…0000 UTC…INFORMATION
- LOCATION…30.1N 91.1W
- ABOUT 30 MI…50 KM S OF BATON ROUGE LOUISIANA
- ABOUT 60 MI…95 KM W OF NEW ORLEANS LOUISIANA
- MAXIMUM SUSTAINED WINDS…60 MPH…90 KM/H
- PRESENT MOVEMENT…NW OR 315 DEGREES AT 5 MPH…7 KM/H
- MINIMUM CENTRAL PRESSURE…977 MB…28.85 INCHES
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WATCHES (issued within 48 hours of impact) AND WARNINGS (issued within 36 hours of impact)
CHANGES WITH THIS ADVISORY…
THE TROPICAL STORM WARNING EAST OF THE MISSISSIPPI-ALABAMA BORDER
HAS BEEN DISCONTINUED.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT…
A TROPICAL STORM WARNING IS IN EFFECT FOR…
- CAMERON LOUISIANA TO THE MISSISSIPPI-ALABAMA BORDER
Tropical storm and hurricane history of naming. 2012 Atlantic list
Tropical Storm formation history: Storm origin maps every 10 days of season
Hurricane Preparedness Week: Storm Surge is the most deadly and destructive