Official Discussion issued by the National Hurricane Center
(AL042024) DATA RELEASED: 8/2/2024 9:00:00 PM UTC
Copy of official data Potential Tropical Cyclone Four Discussion Number 2 NWS National Hurricane Center Miami FL AL042024 500 PM EDT Fri Aug 02 2024 Convection and vorticity associated with the tropical wave, now over central Cuba, have both increased a little this afternoon. However, the circulation is still not well-defined, and the convection is not yet well enough organized to consider the system to be a tropical depression. So, the system remains a potential tropical cyclone at this time. A NOAA Hurricane Hunter is currently investigating the northern side of the wave, and a combination of its dropsondes and earlier scatterometer data suggest that the maximum winds remain near 25 kt. The poorly-defined center has moved more westward since the previous advisory. However the overall motion remains about 290/14 kt. A turn toward the northwest and north is expected during the next couple of days as the system moves into a break in the subtropical ridge caused by a mid-latitude trough over the Ohio Valley. This should be followed by recurvature into the westerlies after 48-60 h. On the forecast track, the system is expected to move into the Straits of Florida and the southeastern Gulf of Mexico on Saturday, followed by a motion near the west coast of Florida Saturday night and Sunday. After that time, the system should cross the northern Florida peninsula and move over the Atlantic near or offshore of the southeastern coast of the United States. While the track guidance generally agrees with this scenario, there are a couple of issues. First, the GFS moves the system much faster northeastward, and by 72 h it is forecasting the center to be off of the South Carolina coast. Meanwhile, the ECMWF and UKMET still have the center over the Gulf of Mexico. Second, due to the track being almost parallel to both the west coast of the Florida peninsula and the southeastern U. S. coast, small changes in the track could cause large differences in potential landfalls and which land areas receive the strongest impacts. There is little change in the intensity forecast philosophy from the previous advisory. Slow development is possible while the system is over Cuba, and the system is likely to become a tropical depression soon after it moves offshore on Saturday. The environment over the Gulf of Mexico is quite favorable for strengthening with light shear and very warm sea-surface temperatures, so subsequent steady strengthening is expected. The two biggest uncertainties in the intensity forecast are how long the system will remain offshore of Florida and how long it will take to consolidate. The system is likely to weaken as it crosses Florida, with re-intensification likely over the Atlantic after 72 h. Key Messages: 1. Heavy rainfall may result in flash and urban flooding across portions of Florida and the coastal areas of the Southeast this weekend through Wednesday morning. Isolated river flooding will also be possible. 2. Tropical storm conditions are expected Saturday night within the Tropical Storm Warning area in southwest Florida from East Cape Sable to Boca Grande. Tropical storm conditions are possible in the Florida Keys on Saturday and along the Florida west coast north of Boca Grande to Suwannee River Saturday night and Sunday where a Tropical Storm Watch is in effect. 3. There is a possibility of life-threatening inundation from storm surge along portions of the west coast of Florida from Bonita Beach to Suwannee River, including Tampa Bay and Charlotte Harbor, where a Storm Surge Watch is in effect. 4. Impacts from storm surge, strong winds, and heavy rains are possible elsewhere in Florida and along the southeast coast of the United States from Georgia to North Carolina through the middle of next week, and interests in those areas should continue to monitor the progress of this system. Additional watches and warnings will likely be required later tonight and on Saturday. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 21.4N 78.3W 25 KT 30 MPH...POTENTIAL TROP CYCLONE 12H 03/0600Z 22.4N 80.1W 25 KT 30 MPH...POTENTIAL TROP CYCLONE 24H 03/1800Z 24.2N 82.2W 30 KT 35 MPH...TROPICAL CYCLONE 36H 04/0600Z 26.1N 83.3W 35 KT 40 MPH 48H 04/1800Z 28.1N 83.3W 45 KT 50 MPH 60H 05/0600Z 29.7N 82.9W 55 KT 65 MPH...INLAND 72H 05/1800Z 30.9N 81.9W 40 KT 45 MPH...INLAND 96H 06/1800Z 32.6N 80.0W 45 KT 50 MPH...NEAR COAST 120H 07/1800Z 34.5N 77.0W 55 KT 65 MPH $$ Forecaster Beven |