Issued at 1000 AM CDT Wed Jun 17 2026
000 WTNT41 KNHC 171454 TCDAT1 Tropical Storm Arthur Discussion Number 5 NWS National Hurricane Center Miami FL AL012026 1000 AM CDT Wed Jun 17 2026 The low pressure area near the Middle Texas coast has produced sustained convection well to the east of its center this morning. A 1200 UTC TAFB Dvorak classification indicated enough convective organization to designate the system as a sheared tropical cyclone. Within the past hour or two, buoy observations and a ship report have indicated tropical-storm-force winds occurring within this convection. Additionally, Air Force Reserve Hurricane Hunters investigating the storm found peak 850-mb flight-level winds up to 52 kt, which also suggest this system has reached tropical storm intensity. Based on these findings, the system is designated as Tropical Storm Arthur with an intensity of 35 kt. Arthur is starting to accelerate northeastward (045/8 kt) within strengthening southwesterly flow associated with a low- to mid-level trough. There are no significant changes to the track forecast reasoning, with a faster northeastward motion expected today that will move the center of the system along or over the Texas coast today and then farther inland over southeastern Texas and southwestern Louisiana by tonight. With no major changes to the track guidance this cycle, the updated NHC forecast is very similar to the previous one. Given the unrelenting westerly shear and Arthur's close proximity to land, it seems unlikely that much additional strengthening will occur. The tropical-storm-force winds are confined to the eastern semicircle and mainly occurring over the offshore waters. Arthur will likely maintain its intensity while it remains over water, and then weaken by tonight once it moves inland. Global model fields indicate it will open into a trough soon thereafter, and although a 24-h forecast point is included mainly for continuity purposes, Arthur should dissipate before that time. There is still a signal in the global models for low pressure development over the western Atlantic late this week or this weekend as remnant vorticity from Arthur emerge off the Southeast U.S. coast. The exact nature of this low remains unclear, so we will continue to monitor model trends to evaluate the potential for tropical cyclone formation. Heavy rainfall and life-threatening flash flooding remain the primary hazard with this system. Based on recent observations, the Tropical Storm Warning has been extended westward along the Upper Texas coast to High Island. KEY MESSAGES: 1. Potentially life-threatening flash flooding and urban flooding are likely through Friday across southern Louisiana, southern Mississippi, southern Alabama, southwestern Georgia, and the Florida Panhandle, with possible flooding near the Upper Texas coast. Ongoing heavy rainfall could prolong the flood threat into the weekend. 2. Tropical-storm-force winds are expected along the Upper Texas and Louisiana coasts today from High Island to Morgan City where a Tropical Storm Warning is in effect. 3. Minor to moderate coastal flooding is expected along portions of the Upper Texas and Louisiana coastlines today. FORECAST POSITIONS AND MAX WINDS INIT 17/1500Z 28.6N 95.8W 35 KT 40 MPH 12H 18/0000Z 30.0N 94.2W 30 KT 35 MPH...INLAND 24H 18/1200Z 31.9N 91.6W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 19/0000Z...DISSIPATED $$ Forecaster Reinhart
