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| #1153679 (Received by flhurricane at: 4:57 PM 20.Sep.2023) TCDAT5 Hurricane Nigel Discussion Number 22 NWS National Hurricane Center Miami FL AL152023 500 PM AST Wed Sep 20 2023 Nigel has changed little in organization on satellite images since earlier today. The ragged-looking eye remains quite large, reported to be 60 n mi in diameter by the NOAA Hurricane Hunter aircraft. There are still bands of deep convection with cloud tops to near -70 deg C, primarily over the northwestern and western portions of the circulation, and the overall cloud pattern continues to have a symmetrical appearance. The central pressure measured by the aircraft has not changed much since earlier today and wind data from the plane suggest that the intensity remains near 80 kt. Center fixes from the Hurricane Hunters and satellite images show that the hurricane`s motion is beginning to bend to the right and is now north-northeastward, or around 030/16 kt. Nigel should move along the northwestern periphery of a subtropical high pressure cell tonight. In 12 to about 60 hours, the flow on the southeastern side of a strong mid-latitude 500 mb trough should carry the system northeastward at a fast pace toward, and over, the northern Atlantic. According to the global models, in 72 to 96 hours, Nigel should undergo a binary interaction with a large extratropical low over the North Atlantic. By 120 hours or sooner, the system is forecast to merge with this low. Over the next few days, Nigel will be moving over progressively cooler ocean waters and into an environment of stronger southwesterly vertical wind shear. Gradual weakening is forecast, and the system is expected to become embedded in a baroclinic zone on Friday. Therefore, extratropical transition is indicated in the 48 hour forecast. Since Nigel is expected to merge with the aforementioned North Atlantic low in about 5 days, dissipation is shown at the end of the forecast period. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 37.4N 53.0W 80 KT 90 MPH 12H 21/0600Z 39.8N 49.6W 80 KT 90 MPH 24H 21/1800Z 42.8N 43.2W 75 KT 85 MPH 36H 22/0600Z 45.7N 35.2W 60 KT 70 MPH 48H 22/1800Z 49.0N 27.6W 55 KT 65 MPH...POST-TROP/EXTRATROP 60H 23/0600Z 53.0N 23.4W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 23/1800Z 56.0N 23.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 24/1800Z 57.0N 23.5W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 25/1800Z...DISSIPATED $$ Forecaster Pasch |
