921 WTNT41 KNHC 100849 TCDAT1 Tropical Storm Francine Discussion Number 7 NWS National Hurricane Center Miami FL AL062024 400 AM CDT Tue Sep 10 2024 Francine has not become appreciably better organized overnight. There is a large cluster of cold-topped convection located well to the northeast of the center, but the central deep convection is still not very strong. Some banding features appear to be developing over the northeastern portion of the circulation. The advisory intensity is held at 55 kt for now, in agreement with earlier data from an Air Force Hurricane Hunter aircraft, and a subjective Dvorak Current Intensity number from TAFB. Objective Dvorak intensity estimates from UW-CIMSS are a little lower. Air Force and NOAA Hurricane Hunter aircraft are scheduled to investigate the storm in a few hours and should provide a good estimate of Francine's intensity. Center fixes from an Air Force Hurricane Hunter aircraft and ASCAT data showed little motion a few hours ago, but recent satellite imagery suggest a slow north-northwestward motion at around 340/4 kt. The general steering scenario for the next couple of days remains about the same as in the previous advisory. Francine should move mostly northward today along the western periphery of a mid level high over the southeastern Gulf of Mexico. By late tonight, a shortwave trough over Texas is expected to cause a turn toward the northeast with an increase in forward speed. This motion should bring the center of the system to the Louisiana coast tomorrow afternoon or evening. The model tracks are in fairly good agreement on this scenario, although there is still some cross- and along-track spread. The official track forecast in the 36- to 48-hour time frame has been nudged just a few tenths to the east of the previous one, and lies between the ECMWF solution and the multi-model consensus prediction. The tropical cyclone should be over very warm waters before landfall, although west-southwesterly vertical wind shear over the system is likely to increase. The latter environmental influence will probably limit Francine's strengthening. Nonetheless, the SHIPS-RI Index shows a significant probability of at least a 25-kt increase in maximum winds during the next 24 hours. The official intensity forecast is now at the high end of the model guidance. An experimental cone graphic that includes inland Hurricane and Tropical Storm Watches and Warnings in the U.S. is now available on the NHC website. Due to the time needed to compile the inland watch and warning information, the experimental cone graphic will not be available as quickly as the operational cone. Once it is available, the experimental cone graphic can be found from a red weblink above the operational cone graphic at www.nhc.noaa.gov/graphics_at1.shtml?cone#contents. Users are encouraged to take the experimental product survey found below the experimental cone. KEY MESSAGES: 1. There is a danger of life-threatening storm surge for portions of the Upper Texas and Louisiana coastlines where a Storm Surge Warning is in effect. Residents in the warning area should follow advice, including evacuation orders, given by local officials. 2. Damaging and life-threatening hurricane-force winds are expected in portions of southern Louisiana Wednesday, where a Hurricane Warning is in effect. Preparations to protect life and property should be complete by tonight, since tropical storm conditions are expected to begin within this area early Wednesday. 3. Francine is expected to bring heavy rainfall and the risk of considerable flash flooding for much of Louisiana and Mississippi through Thursday. Flash and urban flooding is probable across portions of northeast Mexico and far southern Texas into early Wednesday, and the Mid-South Wednesday night into Friday morning. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 24.4N 96.2W 55 KT 65 MPH 12H 10/1800Z 25.4N 95.6W 70 KT 80 MPH 24H 11/0600Z 27.1N 94.2W 80 KT 90 MPH 36H 11/1800Z 29.0N 92.5W 85 KT 100 MPH 48H 12/0600Z 31.4N 91.1W 50 KT 60 MPH...INLAND 60H 12/1800Z 33.8N 90.5W 30 KT 35 MPH...INLAND 72H 13/0600Z 35.7N 90.2W 25 KT 30 MPH...POST-TROPICAL 96H 14/0600Z 37.0N 90.0W 20 KT 25 MPH...POST-TROPICAL 120H 15/0600Z...DISSIPATED $$ Forecaster Pasch
Tropical Storm Francine Forecast Discussion
10
Sep