Very little has changed with Isidore since he exited the Yucatan Peninsula. Without question, the most notable feature of the storm is its size. It has lost all central convection, but the low and mid-level swirl (including an area of tropical-storm-force winds 800km in diameter) is now perhaps 2000km across in the E-W direction and 3000km across in the N-S direction. The outflow, assisted by a mid-latitude trough to the north and the ITCZ to the south extends from just west of Costa Rica and up to central NY. See http://www.nrlmry.navy.mil/archdat/atlantic/tropics/vis/20020925.1445.goes-8.vis.x.trop.x.jpg for an impressive basin-wide VIS shot. At 15Z TS Isidore was located at 26.0N 90.2W (430km south of New Orleans) and tracking N at 11kts. Intensity is 50kts and 990mb, indicating that the Low is filling (pressure is rising). However, a Tropical Storm Warning is in effect from approximately Galveston, TX to Apalachicola, FL and a Hurricane Watch is in effect for all of the LA and MS coasts. Landall is expected to be during the early morning hours on Thursday in eastern LA. The forecast is for gradual strengthening before landfall (perhaps not to a hurricane though), then to track over the southeast U.S. and up to the northeast, passing over TN, PA, and ME as landmarks along the way. This journey will be part of his merging with a mid-latitude trough... forcing him to become extratropical. By the time the remnants are over Pennsylvania, New York, and New England on Friday, there could potentially be a very big rain event, not to mention wind. The convective patterns and wind structure already indicate that Isidore may be losing tropical characteristics... however, this does certainty not mean he is no longer a threat. TS Lili has been having problems dealing with vertical shear (only 10kts SW-erly, but the convection is displaced from the low-level center nevertheless). The storm is poorly organized and even aircraft flying through the system had difficulty finding the center. But conditions are expected to improve (depending on track), allowing her to once again approach hurricane strength during the weekend. The 15Z position was 14.1N 69.3W and movement was WNW at 10kts. She is a weak TS with 40kt sustained winds and a 1008mb MSLP. A Tropical Storm Watch is in effect for most of the southern coast of Hispaniola and I suspect that southeast Cuba will also soon issue a watch. The official forecast is an outlyer in terms of track... NHC is going north of most of the model tracks, which agree on taking her between Jamaica and Cuba and eventually into the Gulf. That version of the track forecast would be less favorable for her development, but as I said, the models are in pretty good agreement on that, so we'll see. TS Kyle is just now moving over 28C+ SSTs, and the convective pattern indicates that he's taking advantage of the increased fuel source. Since this morning, an eyewall has formed; for the first time, convection has wrapped all the way around the center. As of 15Z, Kyle was located at 29.2N 54.8W and heading WSW at 7kts. Intensity is 60kts and 990mb, very much on course to maintain the eye and reach hurricane status later today... the third of the season. The forecast is for continued strengthening in the low shear and warming SST environment, then weakening as a trough approaches and shears him apart (tough world out there!). The tropical wave I'd been mentioning the past couple days in the central Atlantic has dissipated.
Please visit my tropical Atlantic headquarters.
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