7pm tropical update

As we close in to 30 hours before landfall, the forecast is falling into line. The hurricane hunter plane has just left the storm, and has discovered some interesting things. Surface pressure has lowered slowly this afternoon, but nothing that indicates the storm is strengthening. Dry air has wrapped around the whole storm, and is really keeping thunderstorms from forming near the center, and finally, the center of the storm at the airplane’s flight level was displaced about 20 miles northwest of the center at the surface. This is a critical observation, because unless the storm is stacked vertically, it will not properly use heat from the ocean to get stronger.

Although Hanna is not very organized, it does have a large circulation and still has strong winds. I am not expecting the storm to get much stronger, but I also do not expect it to get much weaker either. Hanna is currently a 65 mph tropical storm, and I will give it a 10 mph leeway on either side…. Meaning I can see it as weak as a 55 mph tropical storm, or as strong as a 75 mph hurricane. Keep in mind that there is not too much difference between a strong tropical storm and a weak hurricane, so even though this may not strike as a hurricane, we still need to prepare.

The track takes the center of the storm just east of the Grand Strand around the 12:30 am high tide tomorrow night. This will enhance the threat for coastal flooding

Since Hanna has such a large wind field, much of our area will experience tropical storm force winds. The strongest winds will be within 15 miles of the coast, where the 55-75 mph winds can occur. Beyond 15 miles of the coast, winds will be in the 45-65 mph range.

The dry air that has wrapped around the storm has really killed off a lot of the thunderstorms. While 4-8 inches of rain may still occur in a few areas, I think most rain amounts will be lower, more like 2-4 inches, and west of I-95 will get less than an inch.

Finally, the track of the storm is critical, and a 10 mile jog back to the west will bring a much higher storm surge and a longer period of high winds to the Grand Strand.

Timeline:

Rain arriving after lunch tomorrow along the coast, late afternoon inland. Winds will steadily pick up all day long. The worst part of the storm will be from 9pm Friday to 3am Saturday. The center of the storm will be just offshore around the time of high tide (about 12:30am), so although the worst storm surge will be in North Carolina, there will likely still be some coastal flooding. The storm will quickly subside Saturday morning with the rain ending early, and winds diminishing throughout the day.



Hurricane Ike is a cat 4 hurricane and should continue to move in a general westerly direction. Ike will not impact the US until Tuesday, so there is still uncertainty in the forecast. I think Ike will continue west and threaten Florida or even Cuba. There are some computer models that curve Ike northward toward North Carolina or out to sea. This is due to a strong cold front, and if it happens, I think it will be an abrupt enough of a turn to the northeast that Ike will not impact South Carolina. We will continue to watch Ike.



Josephine is a tropical storm and will likely not affect land.

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