Issued at 1100 PM EDT Sat Oct 19 2024
000 WTNT41 KNHC 200254 TCDAT1 Hurricane Oscar Discussion Number 4 NWS National Hurricane Center Miami FL AL162024 1100 PM EDT Sat Oct 19 2024 Satellite images indicate the center of Oscar passed very near Grand Turk Island earlier this evening. Passive microwave data show the tiny hurricane has a compact inner core with a small curved band that wraps around much of its circulation. In the past several hours, the cloud pattern has become a little less symmetric, with a sharp edge to the cloud pattern on the northwest side. The conventional satellite intensity estimates remain too low relative to what the aircraft found this afternoon, and without any new observations, the initial intensity is held at 75 kt. The Air Force Hurricane Hunters are scheduled to investigate Oscar on Sunday. Oscar continues moving westward at about 10 kt, but it is forecast to turn slightly south of due west during the next day or so while moving on the southeastern side of a mid-level ridge centered over the eastern Gulf of Mexico. This should bring the center of Oscar very near or over Great Inagua in the southeastern Bahamas early Sunday, then toward the northeastern coast of Cuba through Sunday night. There has been a southward shift in the latest track guidance, with more models indicating Oscar could make landfall and move inland over eastern Cuba in 24-36 h. The latest NHC prediction has been adjusted to reflect this and lies closest to the simple consensus TVCN and GFEX aids. Thereafter, the track forecast becomes more uncertain, as the extent and duration of land interaction will dictate the depth of the vortex and how it is steered. For now, the longer-range forecast still follows the ECMWF, which shows Oscar turning northward and accelerating northeastward through midweek ahead of an amplifying upper trough. The intensity forecast for Oscar remains challenging, since its compact size makes it susceptible to more rapid intensity fluctuations. While some near-term intensification cannot be ruled out, satellite trends indicate the hurricane could be starting to feel the effects of northwesterly shear, which the global models insist will increase during the next 12-24 h. The NHC forecast still shows Oscar reaching the coast of Cuba as a hurricane on Sunday night, and the government of Cuba has issued a Hurricane Warning for a portion of the northern coast. Afterwards, land interaction and stronger shear should induce weakening, which could occur even faster than forecast if the center of the small cyclone remains inland as long as some of the guidance suggests. Key Messages: 1. A Hurricane Warning remains in effect for the Turks and Caicos and southeastern Bahamas, and a Hurricane Warning has been issued for a portion of the northern coast of Cuba. 2. Oscar is expected to produce a dangerous storm surge on portions of the Turks and Caicos Islands and the southeastern Bahamas tonight and along the north shore of Cuba later on Sunday. 3. Heavy rainfall from Oscar will lead to areas of flash flooding along with the potential of mudslides across portions of eastern Cuba, especially within the Sierra Maestra. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 21.3N 72.2W 75 KT 85 MPH 12H 20/1200Z 21.0N 73.5W 75 KT 85 MPH 24H 21/0000Z 20.6N 74.8W 70 KT 80 MPH...NEAR THE COAST 36H 21/1200Z 20.6N 75.8W 60 KT 70 MPH...INLAND 48H 22/0000Z 21.4N 76.0W 50 KT 60 MPH...OVER WATER 60H 22/1200Z 22.2N 75.5W 45 KT 50 MPH 72H 23/0000Z 23.8N 74.2W 40 KT 45 MPH 96H 24/0000Z 27.0N 71.5W 35 KT 40 MPH 120H 25/0000Z...DISSIPATED $$ Forecaster Reinhart