The stronger of the two, which the National Hurricane Center says has a 70 percent likelihood of development, is located in the southwestern Gulf of Mexico. That one will probably become a tropical depression or storm and make landfall in Mexico, but its biggest impacts could be stateside — moist flow on the northern side of the circulation could dump excessive rains in Texas, with double-digit totals possible in spots, including Houston. The National Weather Service has already placed large parts of the Texas coast in a Level 3 out of 4 risk area for flash flooding and excessive rainfall.
Then there’s a sneakier disturbance over the northwestern Bahamas. That one could pinch off into a tropical depression or low-end storm and sweep inland between northern Florida and the Carolinas late in the workweek. Squally weather with gusty winds and downpours is possible, but exactly where it might come ashore is still uncertain.
Hurricane season doesn’t peak in the Atlantic until mid-September on average, and experts are calling for a potentially hyperactive season this year. A combination of above-average water temperatures and a burgeoning La Niña — which will make for favorable upper-level winds conducive to tropical development — favors a particularly busy season.
System 1 in Gulf of Mexico
On satellite imagery, a broad counterclockwise swirl is evident over the southwestern Gulf of Mexico, the Caribbean and the Yucatán Peninsula. This is a CAG, or Central American Gyre — in essence a large-scale low pressure system with diffuse spin. Scattered showers and thunderstorms surround its weak circulation.
There is a chance that a more concentrated lobe of vorticity, or spin, consolidates and works toward Mexico. That could lead to the formation of a short-lived tropical storm. If that’s the case, it would earn the name Alberto.
What’s perhaps more impactful, though, is the persistent humid flow that will wrap northwest into Texas around the broader low pressure system. An incredibly moisture-rich air mass will stream into the Lone Star State from Tuesday through Friday. That will lead to heavy downpours and thunderstorms with the potential for localized significant flooding.
Downpours will reach the Texas coastline on Tuesday night or the pre-dawn hours Wednesday morning. Brownsville, Corpus Christi, Rockport and Houston-Galveston will all probably be affected. Downpours will work north and west on Wednesday and into Thursday, probably dissipating Thursday into Friday as showers reach west toward the Permian Basin. In any given area, downpours will probably last 18 to 24 hours.
Widespread totals of 4 to 7 inches are likely across South Texas, including the Texas coastline near and south of Houston. It’s unclear how much moisture works northeast toward the Golden Triangle. This area has been hit repeatedly by rain and storms since the spring and is vulnerable to flooding.
It’s also unclear how far north precipitation will reach. The greatest chances for heavy rain are south of Interstate 20. A few locations in Texas Hill Country or along the coastline could see rain totals in excess of 10 inches.
System 2 — Atlantic Ocean, Bahamas, Florida and Southeast
A broad pocket of spin exists over the northwestern Bahamas. That pocket of spin will continue to be shunted west-northwestward by a broader high pressure force field to the east over the central Atlantic.
Weather models struggle with simulating where, within that zone, a more focused area of spin will develop. On Sunday, for example, weather models hinted at possible formation of a tropical depression that would work toward Florida; on Monday morning, conversely, they painted a picture of a system having more time to organize and making landfall Saturday in the Carolinas as a tropical storm.
As such, it’s impossible to sort out any potential impacts or ascertain the timing of any hazards. For now, the National Hurricane Center estimates a 30 percent chance of eventual tropical development.
