Tropical storm warnings are in effect from Port Aransas, Tex., to Morgan City, La., including the greater Galveston area. Roughly the same area is under a storm-surge warning, where up to 2 to 4 feet of storm-surge flooding is happening.
Storm-surge flooding is even raising coastal water levels in southeastern Louisiana, in part because of the broad wind field with this storm, with tropical storm-force winds extending out to 175 miles from the storm’s center.
The surge threat includes a 1-to-3-foot surge into Calcasieu Lake, south of Lake Charles, La. That same area was threatened by an “unsurvivable” storm surge during Category 4 Hurricane Laura’s landfall in late August, but the system jogged east at the last minute, averting an even greater disaster.
Inland flooding is another threat with this storm, with some places in the greater Houston area having seen 2 to 3 inches of rain by Monday morning. Beta’s sluggish movement means that same area could see another 6 to 10 inches by Wednesday into Thursday.
“Flash, urban, and minor river flooding is likely,” wrote the National Hurricane Center. “Rainfall will also spread north into the ArkLaTex region and east into the Lower Mississippi Valley.”
Beta is only the second storm in 15 years to be assigned a Greek letter for its name, attesting to the rapid-fire generation of storms this season that quickly exhausted 2020′s list of conventional hurricane names.
A record 23 named storms have formed thus far during the season, with two months left to go. This compares to the average storm count of 11 for an entire season.
Beta makes its move
At 11 a.m., the center of Tropical Storm Beta was about 110 miles south-southwest of Galveston, Tex., or about the same distance east of Corpus Christi. Maximum sustained winds were 50 mph, and the storm was moving west-northwest at 7 mph. As it has during much of the past few days, Tropical Storm Beta has been fending off some dry air and disruptive wind shear — a change of wind speed and/or direction with height — which is holding its intensity at bay.
That dry air had already taken a toll on the structure of Beta, leaving it with a lopsided circulation. The National Hurricane Center opened its Monday morning forecast discussion summarizing the situation succinctly: “Beta is struggling this morning.”
A “dry slot” had wrapped almost entirely around the system’s center, cutting off the core of Beta from its main outer band of heavy rains and gusty winds. That meant a 150-mile-wide swirl of showers and embedded thunderstorms was rolling toward the middle of the Texas coastline, while a second wave of heavy rain worked northwestward into the Lake Charles, La., area.
That piecemeal structure may lead to some irregularities in how much rainfall ultimately is realized, with two localized peaks, one associated with each feature.
“Beta is expected to produce rainfall accumulations of 5 to 10 inches with isolated totals of 15 inches from the middle Texas coast to southeast Louisiana,” wrote the National Hurricane Center. The heavy rains in Louisiana are unwelcome, considering that thousands still lack power and access to fresh water after Hurricane Laura’s landfall last month.
The agency notes that Beta’s slow motion will result in a long-duration rainfall event that could last well into midweek. The National Hurricane Center’s forecast calls for Beta to have moved about 100 miles to the north by Wednesday after a slow arc inland and sharp bend to the northeast.
In addition to the rain, strong winds are also accompanying Beta’s circulation as the core of the storm moves ashore. Gusts in the 50 to 60 mph range are likely along the immediate coastline, especially around Matagorda Island, Tex., including Port O’Connor and Port Lavaca. Farther inland in the direction of Victoria, gusts exceeding 40 mph are likely.
A NOAA buoy just east of Galveston, Tex., has reported a sustained wind of 39 mph (61 km/h) and a gust to 43 mph (66 km/h) during the past couple hours, according to the Hurricane Center.
After the storm’s landfall along the Texas coast, computer models show one main area of heavy rain may take shape east of the storm center, drawing upon Gulf moisture to bring heavy downpours ashore that will slowly pivot northeast along the coast with time.
That band, assuming it develops, could prove especially intense late Tuesday into Wednesday in East Texas or parts of southwest Louisiana.
Andrew Freedman contributed to this report.