Issued at 400 AM EST Fri Nov 17 2023
000 WTNT42 KNHC 170837 TCDAT2 Potential Tropical Cyclone Twenty-Two Discussion Number 3 NWS National Hurricane Center Miami FL AL222023 400 AM EST Fri Nov 17 2023 The disturbance remains fairly disorganized this morning. Convection continues to burst near the poorly defined center, although the overall pattern remains ragged with convection displaced well to the northeast. Since the system still lacks a well-defined center and organized deep convection, it remains a potential tropical cyclone. The initial intensity is held at 30 kt for this advisory cycle. The system is moving northeastward at about 9 kt. A mid- to upper-level trough over the Gulf of Mexico is steering the system to the northeast, with increasing forward speed. This northeast motion should take the disturbance across Jamaica later today, eastern Cuba tonight, and across the southeastern Bahamas and the Turks and Caicos Islands on Saturday. The system will merge with the trough on Sunday, although the latest model guidance depicts that this could occur sooner than currently forecast. There remains significant speed differences between the global and hurricane regional models. The NHC track leans towards the global models, which is on the faster side of the guidance envelope near the ECMWF and GFS. The NHC track forecast is quite similar to the previous one, just faster. The latest global model guidance depicts that the system may fail to consolidate convection and remaining elongated as southwesterly vertical wind shear begins to increase, stretching the convective structure. Although the model guidance has trended towards a less organized system, there remains a brief window of opportunity for the system to become a tropical cyclone. The official NHC forecast depicts that the disturbance could become short-lived tropical cyclone while it moves into the west-central Caribbean and near the Bahamas. After passing through the Bahamas, the system is forecast merge with the aforementioned trough and become extratropical in about 48 hours, although this could occur sooner. The NHC intensity forecast is the same as the previous one and lies near the middle of the guidance envelope. Regardless of tropical cyclone formation, the most significant hazard from this system is expected to be heavy rainfall, especially in areas of higher terrain, across portions of Jamaica, southeastern Cuba, and Hispaniola. KEY MESSAGES: 1. Potential Tropical Cyclone Twenty-Two is forecast to become a tropical storm later tonight. Tropical storm conditions are possible across Jamaica, southeastern Cuba, Haiti, the southeastern Bahamas, and the Turks and Caicos Islands through Saturday, and tropical storm watches are in effect for these areas. 2. Heavy rains from Potential Tropical Cyclone Twenty-Two will impact portions of Panama, Costa Rica, Jamaica, southeast Cuba, and Hispaniola through Monday morning. This rainfall is likely to produce flash flooding, along with mudslides in areas of higher terrain. FORECAST POSITIONS AND MAX WINDS INIT 17/0900Z 16.3N 80.3W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 17/1800Z 17.7N 78.6W 30 KT 35 MPH 24H 18/0600Z 19.9N 75.9W 35 KT 40 MPH 36H 18/1800Z 23.0N 72.2W 40 KT 45 MPH 48H 19/0600Z 26.4N 68.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 60H 19/1800Z 30.1N 63.8W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 20/0600Z...DISSIPATED $$ Forecaster Kelly/Brown
