It’s that time of year. The tropics are showing signs of activity and we could be just over a week away from a possible hurricane strike from what’s now being called Tropical Depression 4. Actually, it looks like it may have achieved tropical storm status as I’m posting. That would make it Tropical Storm Dean. Keep an eye on it.
If you live on the Gulf or East Coasts you can’t put this off much longer. Make sure that you have a family plan. Everyone should have a disaster supply kit year round but if you don’t now is the time to put one together. It’s also a good idea to plan your escape route well in advance. Know where you’re going to go. You’ll also save yourself time, frustration, and money if you buy the supplies you’ll need to secure your home now – before the rush and price gouging. Oh, don’t forget about your pets either. If you’re fleeing inland to safety there’s no reason to assume that they’ll be safe when left behind.
Update:
More from Dr. Jeff Masters on TD4-TS Dean:
Track forecast
Two major models–the ECMWF and NOGAPS–stubbornly refuse to develop TD 4 at all. These models are in great likelihood wrong. The GFS, UKMET, and new HWRF model all develop TD 4 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.Intensity forecast
The 06Z run of new HWRF model indicates that TD 4 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 TD 4 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 TD 4 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.
