The National Hurricane Center confirmed Wednesday afternoon that Tropical Storm Arthur came ashore over Matagorda County, Texas, earlier in the day, based on satellite imagery and ground-level weather observations.
Despite making landfall, Arthur’s circulation center has become increasingly disorganized and harder to pinpoint over the past several hours. A broad area of heavy thunderstorm activity continues over the northwestern Gulf of America, but powerful westerly wind shear has pushed that storm activity far away from the actual center of circulation.
Data gathered by NOAA Hurricane Hunter aircraft and marine weather stations show that tropical-storm-force winds — including strong gusts — are still occurring within that convection, located well to the east and southeast of the storm’s center. Based on a combination of aircraft data and surface observations, the storm’s current maximum sustained winds are estimated at 40 knots, or about 45 miles per hour.
The storm’s center tracked farther north than forecasters initially anticipated, moving north-northeastward at roughly 6 knots. Most computer forecast models indicate the circulation will fall apart within the next 6 to 12 hours. Wednesday’s updated track forecast shifted the projected path farther inland compared to earlier predictions, though forecasters note that has little practical impact since the most dangerous conditions are occurring well east of the center.
With Arthur now over land and battling strong wind shear along with drier air moving in from the west, further weakening is expected. Forecast models suggest the storm’s associated thunderstorm activity will largely collapse overnight Wednesday. The 12-hour forecast designates Arthur as a remnant low, though forecasters say it could dissipate even sooner than that.
Some weather models — specifically the European and Canadian models — hint at the possibility of a new area of low pressure developing over the western Atlantic later this week or into the weekend, as leftover energy from Arthur moves off the southeastern U.S. coastline. Forecasters say it is unclear how tropical that system might become, and they will continue watching model data closely.
Forecasters are stressing that heavy rainfall and life-threatening flash flooding remain the top hazard from this storm — and that this danger extends far beyond the storm’s center, even after Arthur fully dissipates.
The National Hurricane Center issued three key messages with this forecast discussion:
First, potentially life-threatening flash flooding and urban flooding are expected to continue through Friday across southern Louisiana, southern Mississippi, southern Alabama, southwestern Georgia, and the Florida Panhandle. Some rivers could see isolated moderate to major flooding, and ongoing heavy rain could keep the flood threat going through the weekend.
Second, tropical-storm-force winds, particularly in gusts, are expected along the Upper Texas and Louisiana coastlines over the next several hours, where a Tropical Storm Warning remains in effect.
Third, minor to moderate coastal flooding is anticipated along portions of the Upper Texas and Louisiana shorelines through Wednesday.
Arthur is forecast to be fully dissipated by Thursday evening. This discussion was prepared by Forecaster Reinhart at the National Hurricane Center.
