Don nears the south Texas coast at 2:30 p.m. Latest loop. (NOAA/Colorado State)

Packing maximum winds of 50 mph, tropical storm Don is closing in on the south Texas coast. As of 2 p.m. eastern, it was 145 southeast of Corpus Christi, Texas headed west northwest at 15 mph. Landfall is projected to occur tonight between Corpus Christi and Brownsville. Tropical storm warnings extend from the mouth of the Rio Grande to Matagorda (which is southwest of Galveston).

A low-end tropical storm, Don is unlikely to produce extensive wind damage. Its rains are sure to benefit the water-deprived state but almost certainly not enough.

Given Don’s path and it’s relatively small size, the rain may only soak south Texas and largely miss the drought-afflicted regions of the vast central and northern portions of the state. The National Hurricane Center predicts a general 3-5 inch rainfall from south Texas into extreme northeastern Mexico, with some isolated amounts to 7 inches.

Of all areas of Texas, the extreme south probably is least desperate for rain. Whereas 75 percent of the state is experiencing exceptional drought, a small area of extreme south Texas is just abnormally dry or in moderate drought. Tropical storm Arlene, which came ashore northeast Mexico on June 30, produced upwards of 3” of rain in that part of the state.

And even if Don took a jog to the north, the 3-5 inches of rain would only make a minor difference.

“The lucky areas, if they receive 2″ to 5″ of rainfall, will be picking up one or two months’ worth of precipitation,” said John Nielsen-Gammon, state climatologist for Texas. “That’s not enough to end the drought, but it will help reduce irrigation demands and perhaps let struggling ranchers produce another cutting of hay.”

In sum, Don does not look to deliver either quantity or coverage of rain needed to substantially reduce the massive rainfall deficit throughout the Lonestar state.

“It’s been so dry in Texas for so long, this one storm will be a drop in an empty bucket,” Nielsen-Gammon said.