Tropical Storm Rafael Forecast Discussion Number 23
Issued at 900 PM CST Fri Nov 08 2024 893 WTNT43 KNHC 090234 TCDAT3 Tropical Storm Rafael Discussion Number 23 NWS National Hurricane Center Miami FL AL182024 900 PM CST Fri Nov 08 2024 Rafael has become significantly less organized since the last advisory due to the effects of shear and dry air entrainment. An Air Force Reserve Hurricane Hunter aircraft that investigated the cyclone a few hours ago reported maximum 700-mb flight-level winds of 69 kt in the northwest quadrant and that the central pressure had risen to the 985-990 mb range. The aircraft also reported that the eyewall structure had disintegrated and that the 700-mb center was located northeast of the surface center. Microwave satellite imagery also suggests that the low-level center is now southwest of the main convective mass. Based on these data and the likely continued weakening since the aircraft mission, Rafael is downgraded to a tropical storm with the initial intensity of 60 kt. This value is a little below the latest CIMSS Satellite Consensus estimate. Even though Rafael remains over the warm waters of the Gulf of Mexico, increasing westerly vertical wind shear and intrusions of dry air should cause steady to rapid weakening for at least the next couple of days. While the shear may decrease some after 48 h, the airmass is expected to be too dry for the system to make a comeback. The new intensity guidance follows the trend of the global models and the regional hurricane models in showing Rafael weakening to a depression by 60 h and degenerating to a remnant low pressure area soon after that. The initial motion is now west-northwest or 285/4 kt. A low- to mid-level ridge to the north of the storm should steer it lowly west-northwestward for the next 36 h or so. After that, the track guidance has come into better, although not unanimous, agreement that the cyclone will make a small loop or hairpin turn and wind up moving south-southwestward as a ridge builds to its west. The new forecast follows the general direction of the somewhat-spread consensus models and lies a little to the east of the previous forecast after 36 h. Based on the current track and intensity forecasts, Rafael is expected to have little direct impact on land areas. However, swells generated by the storm should cause high surf along the coast of the Gulf of Mexico. Key Messages: 1. Swells generated by Rafael are likely to cause life-threatening surf and rip current conditions along the Gulf Coast for the next few days. 2. Rafael is forecast to move slowly over the central Gulf of Mexico this weekend and early next week. Interests in the southern and southwestern Gulf of Mexico should monitor the progress of this system. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 24.8N 89.9W 60 KT 70 MPH 12H 09/1200Z 25.0N 90.7W 50 KT 60 MPH 24H 10/0000Z 25.3N 91.5W 40 KT 45 MPH 36H 10/1200Z 25.6N 91.8W 35 KT 40 MPH 48H 11/0000Z 25.1N 91.8W 35 KT 40 MPH 60H 11/1200Z 24.4N 91.9W 30 KT 35 MPH 72H 12/0000Z 23.4N 92.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 13/0000Z 22.0N 92.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 14/0000Z 20.5N 94.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven
Issued at 900 PM CST Fri Nov 08 2024
893 WTNT43 KNHC 090234 TCDAT3 Tropical Storm Rafael Discussion Number 23 NWS National Hurricane Center Miami FL AL182024 900 PM CST Fri Nov 08 2024 Rafael has become significantly less organized since the last advisory due to the effects of shear and dry air entrainment. An Air Force Reserve Hurricane Hunter aircraft that investigated the cyclone a few hours ago reported maximum 700-mb flight-level winds of 69 kt in the northwest quadrant and that the central pressure had risen to the 985-990 mb range. The aircraft also reported that the eyewall structure had disintegrated and that the 700-mb center was located northeast of the surface center. Microwave satellite imagery also suggests that the low-level center is now southwest of the main convective mass. Based on these data and the likely continued weakening since the aircraft mission, Rafael is downgraded to a tropical storm with the initial intensity of 60 kt. This value is a little below the latest CIMSS Satellite Consensus estimate. Even though Rafael remains over the warm waters of the Gulf of Mexico, increasing westerly vertical wind shear and intrusions of dry air should cause steady to rapid weakening for at least the next couple of days. While the shear may decrease some after 48 h, the airmass is expected to be too dry for the system to make a comeback. The new intensity guidance follows the trend of the global models and the regional hurricane models in showing Rafael weakening to a depression by 60 h and degenerating to a remnant low pressure area soon after that. The initial motion is now west-northwest or 285/4 kt. A low- to mid-level ridge to the north of the storm should steer it lowly west-northwestward for the next 36 h or so. After that, the track guidance has come into better, although not unanimous, agreement that the cyclone will make a small loop or hairpin turn and wind up moving south-southwestward as a ridge builds to its west. The new forecast follows the general direction of the somewhat-spread consensus models and lies a little to the east of the previous forecast after 36 h. Based on the current track and intensity forecasts, Rafael is expected to have little direct impact on land areas. However, swells generated by the storm should cause high surf along the coast of the Gulf of Mexico. Key Messages: 1. Swells generated by Rafael are likely to cause life-threatening surf and rip current conditions along the Gulf Coast for the next few days. 2. Rafael is forecast to move slowly over the central Gulf of Mexico this weekend and early next week. Interests in the southern and southwestern Gulf of Mexico should monitor the progress of this system. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 24.8N 89.9W 60 KT 70 MPH 12H 09/1200Z 25.0N 90.7W 50 KT 60 MPH 24H 10/0000Z 25.3N 91.5W 40 KT 45 MPH 36H 10/1200Z 25.6N 91.8W 35 KT 40 MPH 48H 11/0000Z 25.1N 91.8W 35 KT 40 MPH 60H 11/1200Z 24.4N 91.9W 30 KT 35 MPH 72H 12/0000Z 23.4N 92.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 13/0000Z 22.0N 92.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 14/0000Z 20.5N 94.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven
