Tropical Storm Bertha Forecast Discussion
|
U.S. Watch/Warning Local Products Español: Aviso Publico Discusión |
321 WTNT42 KNHC 222048 TCDAT2 Tropical Storm Bertha Discussion Number 14 NWS National Hurricane Center Miami FL AL022026 400 PM CDT Wed Jul 22 2026 Bertha's center made landfall on the eastern side of St. Bernard Parish, Louisiana, around 2 pm CDT. The main part of the circulation remains devoid of deep convection, although there is a large and persistent convective complex ongoing south of the Louisiana coast. Based on flight-level data from an earlier Air Force Reserve Hurricane Hunter flight and scatterometer data, the maximum winds are estimated to be 40 kt, primarily in a band well to the south and southeast of the center over the Gulf waters. These winds are likely to begin spreading onshore over parts of extreme southeastern Louisiana later this evening as Bertha continues moving westward. After moving west-northwestward since last night, Bertha's center appears to have resumed a westward motion over the past few hours. The short-term track forecast is intriguing, with just about every global model suggesting that the center will take a dip or re-form to the southwest along the southern Louisiana coast as early as this evening or tonight. Thereafter, the storm is expected to track westward, moving very near the southwestern coast of Louisiana to the upper Texas coast by Thursday afternoon. Despite this morning's northward jog, the updated NHC track forecast is very close to the previous prediction and is near the middle of the guidance envelope. In this particular case, the forecast is a bit south of the HCCA and GDMI guidance, which probably wouldn't handle a center re-formation as well as the global models. Model fields suggest that the prominent band of tropical-storm-force winds to the east and south of the center will persist through Thursday, and therefore only minimal weakening is expected over the next 24 hours. The NHC forecast maintains Bertha as a tropical storm for about the next 24 hours until the center reaches the upper Texas coast. Global model fields suggest the surface circulation will disintegrate shortly after the center moves onshore the Texas coast. A remnant low forecast position is provided inland over Texas at 36 hours, but it's possible the system will have dissipated by then. Key Messages: 1. Tropical storm conditions are expected to spread westward along the northern Gulf Coast from Alabama to southwestern Louisiana, including the Metro New Orleans area, tonight and on Thursday. Tropical storm conditions are possible for the extreme southwestern coast of Louisiana and upper Texas coast on Thursday. 2. A Coastal Flood Warning is in effect for the Mississippi and Louisiana coastlines, where moderate coastal flooding is expected. 3. A risk for isolated flash flooding shifts west along the Gulf Coast from Northwest Florida to southern Texas through Thursday night. FORECAST POSITIONS AND MAX WINDS INIT 22/2100Z 29.8N 89.8W 40 KT 45 MPH...INLAND 12H 23/0600Z 29.6N 91.3W 40 KT 45 MPH...NEAR THE COAST 24H 23/1800Z 29.5N 93.9W 35 KT 40 MPH...OVER WATER 36H 24/0600Z 29.4N 96.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 24/1800Z...DISSIPATED $$ Forecaster Berg