Tropical Storm Beta will meander in the western Gulf of Mexico into next week and poses a major threat of rainfall and coastal flooding to the Texas and Louisiana coasts.
New watches have been issued for the entire Texas coast and a portion of the Louisiana coast, including the area of coastal Louisiana hit by Hurricane Laura a few weeks ago.
Beta’s formation is the 10th Atlantic named storm to form so far this month, which is the most on record for any September, according to Dr. Phil Klotzbach. September is typically the most active month of the hurricane season.
A Hurricane Watch has been issued from Port Aransas, Texas to High Island, Texas, including Galveston. Hurricane conditions are possible in this area on Monday, with tropical storm conditions possible by late Sunday.
A storm surge watch has been issued from Port Mansfield, Texas to Cameron, Louisiana, including Baffin Bay, Corpus Christi Bay, Copano Bay, Aransas Bay, San Antonio Bay, Matagorda Bay, Galveston Bay, Sabine Lake and Calcasieu Lake.
A tropical storm watch has been issued from south of Port Aransas to the Mouth of the Rio Grande and east of High Island to Morgan City, Louisiana. Tropical storm conditions are possible in this area by late Saturday.
With plenty of warm ocean water and lessening wind shear, this system is expected to intensify gradually through the weekend. Some dry air and wind shear are hindering Beta’s circulation this morning.
How strong it will become remains uncertain but is currently expected to become a hurricane. Water temperatures are very warm, which supports intensification, and wind shear should remain low to moderate, at most. However, it could be impacted by some dry air and it could eventually churn up enough cooler water below the surface to keep a lid on its intensification.
Beta’s center may hop around over the next few days as it tries to keep up with the thunderstorms that will power Beta over the next week or so. This will likely lead to jumps in the forecast left and right.
Even without the jumps in the forecast, this system has a number of twists and turns in its future.
First, a weak upper-level low over Texas should help nudge this system north over the next day or so.
But then that upper-low will weaken and move away, leaving the system steered by a weak area of high pressure setting up over the south-central U.S. by early next week that should cause Beta to hang a left and bend it slowly westward. This should be the most prevalent motion through the weekend and possibly into Monday.
After that, a dip in the jet stream and some lower pressures over the South may pick up Beta and take it northeastward by the middle part of next week, near or over the Texas or Louisiana coasts.
It certainly won’t be in any hurry for the next several days.
Slow-moving tropical cyclones can be prolific rainfall producers, as we saw along the Gulf Coast and inland with Hurricane Sally.
Given Beta’s slow movement, heavy rainfall and flooding is an increasing danger near the Texas coast and possibly the Louisiana coast through next week.
Given the numerous changes in forward direction and upper-level winds, the zone of heaviest rainfall will likely change from day to day.
Increased surf and rip currents are also expected from northeastern Mexico to the northern Gulf Coast, beginning as soon as this weekend.
The National Weather Service notes that significant coastal flooding is possible on the middle and upper Texas coast beginning Saturday morning and continuing through at least Tuesday morning, and minor coastal flooding might be possible in southwestern Louisiana late this weekend.
Persistent onshore flow and a possible storm surge component in combination with heavy rainfall could only worsen flooding near the coast into next week.
Here’s the current storm surge forecast from the National Hurricane Center:
For now, all interests near the Texas and Louisiana Gulf Coasts should monitor closely the progress of this system and have their hurricane plans ready to go ahead of time in case it’s needed.