Tropical Storm Dean appears to be headed for the gulf, but you never know, he may change his mind .
In the meantime, a healthy storm off the coast of Africa last week might have had enough musturd to deliver some small southern hemi lines by the weekend, somewhere in the 1-3′ range @ 14-17 second intervals, which could translate to some fun punchy little waves if we’re lucky, plus small windswell cleanup possible for friday am…so stay tuned.

JEFF MASTERS WUNDERGROUND BLOG

Two major models–the ECMWF and NOGAPS–stubbornly refuse to develop Dean at all. These models are in great likelihood wrong. The GFS, UKMET, and new HWRF model all develop Dean into a hurricane that threatens the central and northern Lesser Antilles Islands Friday or Saturday. The big question is how strong the trough of low pressure predicted to pass north of TD 4 on Saturday will be. If the trough is strong enough, it may be able to pull TD 4 far enough north so that it misses the Lesser Antilles. Another big question is, will the trough spawn a cut-off upper-level low pressure system off the Southeast coast of the U.S.? If so, this feature could act to steer TD 4 on a more northerly track early next week, increasing the threat to New England and the mid-Atlantic coast. If not, a high pressure ridge is expected to build in, forcing TD 4 westward into Florida. It’s far too early to know which of these scenarios might occur. In any case, there is a significant possibility that TD 4 will hit the U.S. as a hurricane, and possibly a major hurricane. This could happen as early as Tuesday August 21. Of course, Dean could also stay farther south in the Caribbean, as forecast by the UKMET model, and eventually track into the Gulf of Mexico.

Intensity forecast

The 06Z run of new HWRF model indicates that Dean will not start intensifying until Wednesday afternoon. HWRF is then very aggressive intensifying the storm, bringing it to 956 mb (Category 3) on Saturday morning as it passes through the Lesser Antilles, then 920 mb (Category 4 or 5) Sunday morning near Puerto Rico. I’d be surprised to see Dean get that strong that fast, and HWRF is likely overdoing the intensification. The 06Z run of the GFDL model also shows a slow intensification starting Wednesday morning, followed by a steady increase to a Category 3 storm (956 mb) Sunday night as it passes through the northern Lesser Antilles. Given the upper-level high pressure system forecast to develop over Dean beginning Wednesday, combined with steadily increasing Sea Surface Temperatures and total oceanic heat content under the storm (Figure 1), intensification to a major Category 3 hurricane by Sunday is a reasonable forecast. -Jeff Masters @ Wunderground.com

JEFF MASTERS WUNDERGROUND BLOG