Tropical Depression Ten

Invest 99L in the eastern Atlantic continues to develop steadily. At 5am EDT, the NHC began advisories on Tropical Depression 10. Its satellite presentation is very good this morning. Conditions appear favorable to continued intensification. Vertical shear should remain low for the next 36 hours, and an upper low to the northwest will provide a good outflow channel. However, thermodynamics are not as favorable, with relatively low ocean heat content and some dry air. In addition, by day three, it will begin to feel the effects of the upper low, and some southerly shear will likely develop. The intensity forecast relies strongly on the exact track: further north will result in higher shear and lower SSTs. Right now it looks like an mid level high will build in by day 5 and direct the storm more to the west. The model guidance is fairly widespread but the consensus is toward a recurvature. I am confident that this will not enter the Caribbean. If it threatens the east coast, it wouldnt be until day 8 or 9. If and when it becomes a tropical storm, its name would be Josephine.

In the mean time, the tropics are far from void of activity. Hanna was looking good again this morning, however it has been drifting south and recently took shore leave over Haiti. While a landfall did not take place, much of the broad circulation has been disrupted by the mountains and at 8am, Hanna was downgraded back to a tropical storm. As some stronger steering currents reach Hanna, it will begin to move towards the northwest. As it moves away from Haiti, and shear diminishes (with the deterioration of Gustav) Hanna will be in a good environment for intensification. At this time, model guidance indicates a Georgia to South Carolina strike around day 4. Landfall intensity will be at least hurricane status, and even a chance at a category 3 major hurricane strike. Regardless of the exact track, the remnants, or an actual storm will likely affect the northeast by day 6 with some showery weather and gusty winds.

Moving back east, Tropical Storm Ike is holding its own over the eastern Atlantic. Satellite imagery continues to show a very symmetric storm. Convection is a little scant especially on the west side, however that should fill in with the increase in ocean heat content as it moves toward the west. The subtropical ridge to its north will force it on a general westward motion for the next 6 days, and model guidance shows this with good consensus. The main intensification inhibitor could be a potential proximity to Hispanoila by day 5. While most models keep it north of the island, tropical cyclones this year do seem to like visiting there, so I wouldnt rule out a stop over "Shredspanoila". Otherwise, conditions appear favorable for steady strengthening to hurricane status, and possible major hurricane strength. In the long term, watch out again Gulf coast as ridging could push it through the Florida straits or over Cuba by day 7.