Thursday, July 28, 2011

Tropical Storm Don is en route to Texas

Our fourth tropical system this year in the Atlantic Basin is tracking slowly through the Gulf of Mexico early Thursday morning after becoming Tropical Storm Don on Wednesday east of the Yucatan Peninsula. As of this update, here are the details on Don:

Although Don is barely at tropical storm strength with winds just faster than 39 mph, it will be moving into a favorable environment for intensification over the next day. Sea surface temperatures in the entire Gulf of Mexico are warmer than 80 degrees Fahrenheit (anything red or darker on the map below), which is precisely what a tropical system requires as fuel for intensification and storm maintenance.

In addition to the low-level fuel, upper-level wind shear should be minimal over the next few days as Don chugs northwestward toward the Texas Gulf Coast. That low wind shear means Don should be able to better organize Thursday and early Friday, and also intensify. The forecast track certainly indicates an increase in wind speeds associated with Don, as shown here:

It does not appear at this time that Don will be able to intensify to hurricane strength (74mph+ winds) before it makes landfall somewhere along the Texas Gulf Coast. A Texas landfall is the most likely of the forecast scenarios, which are shown here in a "spaghetti plot" along with the official forecast track from the National Hurricane Center:

You can learn more about the Saffir-Simpson Hurricane Wind Scale by clicking here. We are now entering what is typically the most active part of the tropical season, from August through October:

Tropical Storm Don should bring much-needed rainfall to a drought-stricken part of the country. The drought in Texas is historic, and may end up being one of the worst, if not the worst, drought on record for them. Here are the latest drought conditions for the Lone Star State:

And just to give you some comparison, here is Virginia's latest Drought Monitor, where our conditions have been steadily improving through the Summer:

The forecast for the drought through the Southern U.S. is varied, but generally the Southern Plains into parts of Arkansas and Louisiana are not expected to improve over the next few months.

This is why Tropical Storm Don may be a most welcome visitor to Texas, because they could sure use the rain, even if it comes with some strong winds.
--Meteorologist Carrie Rose