Isaac left some very impressive rain totals in its wake, and we are still seeing rainbands in a few areas this afternoon. The system will track up into the mid-Mississippi River Valley by tomorrow and Saturday. This should provide some drought relief for folks up that way. We are now running a rain surplus of well over a foot in our area thanks to the additional rain from Isaac.
Tropical Storm Isaac is moving very slowly and the outer rainbands continue to soak the area. Winds are still gusting to tropical storm force along the coast. We are seeing a storm tide of 5′ in Mobile Bay, and those levels are gradually dropping. Rain totals are close to 7″ at Mobile Regional Airport. As the circulation gradually moves west, our conditions will slowly improve. We still expect to see soaking rains over the area on Thursday. We will continue to see the threat of isolated tornadoes in these rainbands into tonight.
At the time i’m typing this discussion, Isaac is still a Category One Hurricane with Max Sustained Winds of 80mph. As he pushes farther inland we’ll see Isaac weaken back into a Tropical Storm before the day is over. Here’s a look at the track.
As you can see, he should become a Tropical Storm later today and then weaken farther into a Depression by tomorrow. But let’s focus on what we can see later today and that is the risk for more spin up tornadoes.
Isaac will continue to create the risk of tornadoes in the feeder bands but these will be short lived and VERY weak. Jackson and Mobile counties has the highest risk of seeing more warnings issued throughout the day today. But conditions will improve greatly as we hit late tomorrow.
The center Hurricane Isaac is moving very slowly over the s’east Louisiana coast. The National Hurricane Center says the system is moving west-northwest at 7 mph. The motion has pulled the center slightly further away from our area. Our primary threat will continue to be isolated tornadoes, heavy rain, and above normal tides. A tornado watch is in effect for the entire area until 7am this morning. As of 12:30 am we are still seeing very heavy rain bands over the western third of our forecast area: Jackson, George, Greene, Mobile, Washington, and Baldwin counties. Tides are still running 3-4 feet above normal in Mobile Bay, with a peak tide of 6 feet expected at high tide. We will see the highest coastal flooding values around 10am. We have seen nearly four inches of rain so far at Mobile Regional Airport and at Brookley Field. The center of Isaac will slowly weaken and pull away from our area by the late afternoon. We may continue to see gusty winds, heavy rain bands, and higher tides through the evening.
…ISAAC MAKES LANDFALL IN EXTREME SOUTHEASTERN LOUISIANA…
…STRONG WINDS AND A DANGEROUS STORM SURGE OCCURRING ALONG THE
NORTHERN GULF COAST…
NOAA DOPPLER RADAR INDICATES THAT HURRICANE ISAAC MADE LANDFALL
ALONG THE COAST OF SOUTHEAST LOUISIANA IN PLAQUEMINES PARISH JUST
SOUTHWEST OF THE MOUTH OF THE MISSISSIPPI RIVER AT 645 PM CDT…
2345 UTC…WITH MAXIMUM SUSTAINED WINDS OF 80 MPH…130 KM/H.
AT 700 PM CDT…0000 UTC…THE CENTER OF HURRICANE ISAAC WAS
ESTIMATED BY NOAA DOPPLER WEATHER RADAR NEAR LATITUDE 29.0
NORTH…LONGITUDE 89.4 WEST…OR ABOUT 10 MILES SOUTHWEST OF THE
MOUTH OF THE MISSISSIPPI RIVER…AND ABOUT 90 MILES SOUTHEAST OF
NEW ORLEANS LOUISIANA.
A SUSTAINED WIND OF 45 MPH WITH A GUST TO 62 MPH WAS OBSERVED WITHIN
THE PAST HOUR AT LAKEFRONT AIRPORT IN NEW ORLEANS. A WIND GUST TO
56 MPH WAS RECENTLY REPORTED AT GALLIANO LOUISIANA.
A STORM SURGE OF 8.8 FEET WAS RECENTLY REPORTED AT A NATIONAL
OCEAN SERVICE TIDE GAUGE AT SHELL BEACH LOUISIANA. A STORM SURGE
OF 5.5 FEET WAS OBSERVED AT A NATIONAL OCEAN SERVICE TIDE GAUGE IN
From Rod Huff, Ft. Morgan as Isaac nears.
Tides are currently running four feet above normal around Mobile Bay and Dauphin Island. We expect tides 6-8 feet above normal near high tide Wednesday morning. Stronger feeder bands and squalls are now moving across the area. Tropical Storm force winds are being reported at Dauphin Island and along the beaches.
TORNADO WATCH is in effect until 7PM tonight for the following counties: Mobile, Baldwin, Escambia FL, Santa Rosa, Okaloosa, Escambia AL, George, and Jackson. Isaac is a Category One Hurricane. This system has a large wind field with tropical storm force winds extending out over 200 miles from the center. Hurricane Isaac has maximum sustained winds of 75 mph and tracking NW at 10 mph. The forecast fan focused on southeastern Louisiana. The system could make landfall late this afternoon or Wednesday. This is a large system. We will still see Tropical Storm force winds in our area, especially along the beaches, bays, and over the western third of the forecast area: Jackson, Mobile, and Baldwin counties. Isolated tornadoes are possible later today and tonight in the heavier squalls. A Tornado Watch is in effect. Heavy rain is possible into Wednesday and possibly Thursday. Rainfall totals will be in the 5”-10” range for our viewing area, especially Jackson and Mobile counties. We will also see storm tides running 5-8 feet above normal.
Isaac is still a Tropical Storm as of 6:30 this morning, but is still projected to become a Category One Hurricane later today. This will be the intensity at the time of landfall which is projected to be tonight and into tomorrow with the likely destination around New Orleans. Since we are on the eastern side of the system, we will still feel the impacts from Isaac without a doubt.
This graphic shows that the cone of uncertainty doesn’t exist for our area which leads us to believe that New Orleans will in fact be his final destination. Our biggest hazards will end up being storm surge of around 6′, flash flooding, and isolated tornadoes in the feeder bands. Conditions will improve once we move in towards Thursday and Friday and as always, we’ll be watching very closely.
Isaac is still a tropical storm with 70 mph winds and a forward movement of 12 mph to the NW. The storm is currently about 150 miles from the mouth of the Mississippi river.
With Isaac’s slow forward speed we will have to deal with this storm for quite awhile. Heavy rain bands will start sometime this morning and likely continue through Wednesday evening. So it’s possible we could have 36 hours of tropical storm conditions that will give us huge rainfall totals topping more than a foot.
Another threat from the storm is the surge we expect to come with it. For our viewing area the forecast is for a 6-8 ft rise. For coastal Mississippi it will be even worse, 9-13 ft. This will be the first major test for many structures rebuilt after they were flooded and/or destroyed by Katrina in 2005.
Lastly, the right-front quadrant of a landfalling tropical system can produce tornadoes within the squalls. We will have that threat as well throughout the day.