LRandyB's Tropical Weather Discussion

Good morning! I'm headed out to fly Tropical Storm Hanna shortly and I'll try to bring back some good pictures but here's a quick morning update before I go.

Hanna.....

From the looks of satellite, we might be able to fly Hanna this morning without actually flying through any clouds! The IR loop this morning shows nearly all the convection with Hanna being sheared off to the north off the center of circulation. The RGB loop already clearly shows the low level circulation nearly free of convection and I suspect you'll see it in the open by the time we get our first visible image this morning. Despite that, the models call for Hanna to at least maintain it's current strength just short of hurricane force through the forecast as the storm makes landfall in the Carolinas this weekend. NHC, in the interest of safety and caution (and the fact that it almost already is a hurricane), makes the storm a minimal hurricane before landfall.

Ike.....

"We Don't Like Ike". That'll be the slogan for this storm. Ike is a rather impressive looking category 4 hurricane at this time. By the time a hurricane becomes as powerful as this one is, it begins to develop it's own environment. As we saw with Gustav in the Caribbean, the eyewall can shield the storm from all but the most intense shear and the combination of the strong low level circulation and large upper level anticyclone that develops over the hurricane basically allows the hurricane to take it's own environment with it. Eyewall replacement cycles often seen in intense storms are impossible to predict and can cause fluctuations in storm intensity and during these cycles, shear can have a greater impact. This morning IR loops clearly show the eye of Ike embedded in a very nicely symmetrical eyewall and outflow pattern. There is evidence of some northwesterly shear as the outflow is disrupted somewhat on the NW side of the storm. The models forecast an increase in this shear to as much as 30 knots. We're seeing less shear than that tear the convection completely away from Hanna but Ike's eyewall and much more powerful circulation should help protect the storm from losing too much to the shear. The SHIPS intensity model drops the storm to a category 1 storm by the 3-4 day point before the shear relaxes and the model begins to increase intensity again. But given it's current strength, none of the other models call for that much weakening. The official forecast calls for Ike to drop to a still dangerous category 3 storm before intensifying again to category 4 late in the forecast period. The forecast track is highly dependent on the strength of the high pressure ridge to the north and northwest of Ike as well as the evolution of a weakness forecasted in the ridge toward the end of the forecast period. It's too early at this point to know for sure in the long term where this storm will end up making landfall, if at all, in the US. Model guidance varies wildly from complete recurvature to a hurricane in the Gulf of Mexico.

Josephine......

Or Jo as I have affectionately come to know her. I labeled Jo the hurricane that couldn't yesterday but I may have been a bit premature. Jo is still holding on to some convective bands on the north side of the system and the models, as well as the official NHC forecast, maintains Jo as a TS through the 5 day forecast, which is an improvement from yesterday when it was expected that she would drop to a depression by the end of the forecast. If Jo manages to maintain her identity through the shear that will inhibit her strengthening over the next 3 or 4 days, she may have a chance at further development further west in the Atlantic. We'll see.

I'll see you guys tonight after my 13 hour flight into Hanna. Maybe I can get some shots of the low level circulation for myself!