Tropical Storm Alberto came ashore around daybreak Thursday near the border of Tamaulipas and Veracruz in northeastern Mexico.
The sprawling tropical storm continued to bring tropical storm conditions and moderate coastal flooding to parts of South Texas hundreds of miles north of where the center made landfall. Coastal flood advisories were issued all the way to lower Alabama as the strong onshore winds from Alberto’s expansive circulation filled up nearly the entire western half of the Gulf of Mexico.
As Alberto approached the coast on Wednesday, its tropical storm winds – winds of 39 mph or stronger – were estimated as far as 414 miles from its center. By this estimate, Alberto was the largest tropical or subtropical storm system recorded in the Gulf of Mexico in at least 20 years and the largest observed this far south in the Atlantic since 2004, when official wind radii records began.
Despite its maximum winds never having exceeded 50 mph, Alberto was a stark reminder of the problems big storms can pose, particularly at the coast. Several coastal towns were inundated with major flooding from the persistently strong onshore winds from Alberto. Just south of Galveston Island, the town of Surfside, Texas, almost 500 miles northwest of Alberto’s center, saw extensive flooding from the runup of high surf and storm surge. A nearby tide gauge at San Luis Pass measured over 4 feet of storm surge flooding, the third highest water level observed in the 27 years since the station was established.
The heavy rains also materialized on Wednesday, with the highest totals just north of Corpus Christi where radar estimates double-digit rainfall since early yesterday.
Officially, the highest totals were around 6 to 8 inches just north of Corpus Christi, according to the National Weather Service.
Conditions should begin to slowly improve today, though coastal flooding will likely persist, especially around the times of high tide, into Friday.
Small disturbance swirling toward north Florida and southeast Georgia
The area of low pressure that caught our attention over the weekend has shown slow but steady organization since yesterday despite less-than-ideal upper-level conditions.
On Sunday, we discussed how small systems can sometimes get overlooked by lower-resolution forecast models and often find ways of overcoming marginal environments due to their size. We’re seeing a little of that with the compact swirl now located just east of the northern Bahamas.
Despite moderate wind shear nearby, the system – now designated Invest 92L by NHC – is small enough to duck the worst of it. That said, the shear and dry air surrounding it are making it tough for a fledgling system to thrive.
Because the small low-pressure center is already well-defined, it would only take a persistent batch of thunderstorms to classify it a tropical depression, which is why NHC bumped their odds on Thursday morning.
Regardless, the system isn’t expected to have much of an impact other than increasing rain chances and worsening the already rough beach and surf conditions from east-central Florida through the Carolinas. The full moon tomorrow could create some minor flood issues into the South Carolina Lowcountry with 92L’s approach. For now, the threat of rainfall flooding appears low as the system washes inland over the southeast this weekend.
Alberto déjà vu?
Forecast models continue to insist on another tropical system developing from the larger Central American Gyre this weekend. This was a credible scenario we discussed almost a week ago in this newsletter and it now appears increasingly likely.
While the system is poised to follow in Alberto’s footsteps – moving into northern Mexico by Monday – it should stay broad and weak. Rainfall forecasts don’t look nearly as threatening as the forecasts ahead of Alberto. Of course, it’s worth following the trends as additional rainfall could compound any lingering flood issues in the wake of Alberto.