Tropical Storm Isidore is on the brink of being the second hurricane of the season. After a slow start during the weekend and the first half of this week, the center is finally under the coldest part of the CDO, and recent microwave imagery shows very clearly that an eye has formed in the precipitation. It will be just a matter of hours until that is reflected in the VIS and IR imagery. As of 15Z today, Isidore is located at 20.0N 81.2W and moving WNW at 7kts. maximum sustained winds are 60kts and MSLP is 990mb (which coincides nicely with the classic pressure for eye development in the Atlantic). Aircraft recon will investigate the storm later today, and given the trend in organization and the microwave imagery showing an eye/eyewall, they should find 65-70kt winds, making it a hurricane at that time. The outflow is expanding in all directions, showing that the anticyclone aloft is maturing and assisting the "exhaust" process. A Tropical Storm Warning is still in effect for the Cayman Islands, a Hurricane Watch is in effect for some of central Cuba, and a Hurricane Warning is in effect for the western half of Cuba. It is possible that a Tropical Storm Warning will be issued for the Florida Keys this afternoon if the storm's wind field keeps expanding. The forecast is very difficult, and I'd say that the track forecast is more challenging than the intensity this time. Cuba will be the only hinderance to intensification, and western Cuba is fairly flat, but land nonetheless. All other signs point to a major hurricane in a few days... low shear, very deep, warm ocean to travel over, and time. The models are in good agreement about taking it over the western tip of Cuba, but beyond that, the concensus is to stall it in the southeast Gulf (with several outliers). Depending very strongly on what the trough does that's draped over the central US now, Isidore could end up hitting anywhere from Mexico to Florida, so everyone along the Gulf coast needs to be be watchful and prepared. So far, the track is reminiscent of Helene '00 (and she hit the western end of the Florida peninsula), just FYI. TS Josephine was absorbed by the mid-latitude trough this morning and advisories have ceased as of 15Z (11am EDT). The last advisory placed Josephine at 42.5N 42.5W and tracking NE at 27kts, basically with the front. Intensity was 50kts and 1004mb (definite baroclinic enhancement).
Please visit my tropical Atlantic headquarters.