5PM Tropical Weather Update
Gustav came ashore in Louisiana this morning and now that it is over land, will continue to weaken. The hurricane was weakening as it made landfall, and was probably no stronger than a category two at landfall. This is still enough to cause widespread wind damage and a storm surge over 10 feet. Gustav will slow down as it weakens, and will likely be a flooding problem for east Texas and Louisiana for the next several days.
Hanna is now a hurricane. The flare-up of thunderstorms last night allowed the storm to get more organized, and also moved the center of the storm a bit to the southwest. Hanna will still meander slowly for the next couple of days. On Wednesday Hanna will start to move northwestward and pick up speed. The NHC forecast still shows Hanna making landfall near the SC/GA border on Friday.
For the Carolinas, Hanna will be a fast moving storm, and will likely be a hurricane at the time of landfall. We are already seeing waves from Hanna at Grand Strand beaches, and the risk for rip currents is high today, and will stay high all week. Winds will start to pick up on Thursday, with clouds arriving late in the day, and bands of rain moving in at night. Friday looks to be a stormy day with heavy rain, strong winds, the risk for tornadoes, and rough surf and higher than normal tides along the Grand Strand. Highs tides at Springmaid Pier are 11:34pm Thursday, 12:19pm Friday, and 12:24am Saturday. The current forecast of a fast moving hurricane means that the Friday Noon high tide will be the critical one, but any change in the storm’s movement can bring it here sooner, or slow it down. The current forecast is for Hanna to be moving away Friday night, and gone by Saturday, with diminishing wind. Since Hanna will be a relatively fast moving storm, we will probably not see huge rainfall amounts, but 4-8 inches of rain seems possible, which is more than enough to cause flooding.
If the NHC forecast is correct, and landfall is 150 miles away from Myrtle Beach, we could still see significant damage along the beaches. This depends on the size and direction of movement of the storm. A westward moving hurricane with a small diameter can hit the Sea Islands without any impact here. A hurricane with a large diameter moving northward can bring heavy rain, tornadoes and a storm surge along the Grand Strand, even though the strongest winds are 150 miles away. Some past hurricanes that have hit south of Charleston have sent 6 foot storm surges to the Grand Strand. Northward moving hurricanes that hit south of Charleston can also bring stronger winds to the Pee Dee than to the Grand Strand.
As I mentioned above, last night’s thunderstorm flare up repositioned the center to the southwest. The computer models have adjusted their forecasts a bit to the west as well. There is a chance that Hanna hits Florida before turning north or northeast. This would weaken the storm a bit before it heads toward South Carolina. None of the computer models show the storm making a landfall in North Carolina.
The forecast for Hanna will likely change due to the slow and erratic movement today and tomorrow. Once the storm starts it’s trek to the northwest and picks up some speed there will be more confidence as to where the storm is going, and how strong it will be. My thoughts as to the worst case scenario have changed since last night…. it now looks possible for a category two hurricane for Friday.
Newly formed Tropical Storm Ike looks organized in the mid Atlantic. This storm should become a hurricane in the next few days. A large area of high pressure is building from the Atlantic westward. This is one of the features that is steering Hanna northwestward at the end of the week. The forecast is for this high to get stronger. If this is the case, Ike will stay on a westward track and not curve up the East Coast. This is still a week away, and the forecast can change.
There are also several other areas of concern in the Atlantic, so it should keep us busy for the next few weeks:
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on 09/01 at 03:46 PM
