Hurricane Kristy Forecast Discussion Number 8
Issued at 800 AM MST Wed Oct 23 2024 000 WTPZ42 KNHC 231442 TCDEP2 Hurricane Kristy Discussion Number 8 NWS National Hurricane Center Miami FL EP122024 800 AM MST Wed Oct 23 2024 The impressive rapid intensification of Kristy has continued this morning. The gradually warming eye of the hurricane is surrounded by a ring of very deep convection, with infrared cloud tops as cold as -75 to -80 deg C. GOES-West derived motion winds indicate good upper-level outflow, particularly over the southern and western portions of the circulation. Subjective Dvorak classifications were a consensus T5.5/102-kt from TAFB and SAB at 12 UTC. Satellite trends suggest Kristy has kept strengthening since that time, and the initial intensity is set at 110 kt, following the rising objective estimates from UW-CIMSS. The hurricane is moving quickly westward (265/17 kt) while being steered by a strong subtropical ridge to its north. This quick westward motion should continue for the next 24-36 h. Then, an upper-level trough between the Hawaiian Islands and the west coast of the United States is forecast to erode the western extent of the ridge. As a result, Kristy is expected to move toward the west-northwest and northwest late this week and into the weekend. A westward motion is shown by day 5, as it is anticipated that Kristy will become highly sheared and decoupled, with the vertically shallow vortex steered by the low-level ridge. No significant changes were made to the latest NHC track forecast. Kristy is a relatively small hurricane that remains susceptible to rapid intensity fluctuations in a weak shear environment over warm SSTs. The latest GFS and ECMWF SHIPS output shows a 50 to 60 percent chance of a 20-kt increase during the next 12 h, and the satellite trends suggest continued near-term strengthening is likely. The updated NHC forecast reflects these signals and lies above the intensity guidance in the near term, showing Kristy peaking as a category 4 hurricane on Thursday. By Friday, the aforementioned trough is expected to impart increased shear on the hurricane, which should induce weakening through the rest of the 5-day forecast period. With SHIPS-diagnosed shear values of 40-50 kt by the weekend, Kristy is forecast to quickly weaken over the weekend and degenerate to a post-tropical remnant low by 120 h. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 14.3N 113.9W 110 KT 125 MPH 12H 24/0000Z 14.2N 116.4W 125 KT 145 MPH 24H 24/1200Z 14.1N 119.7W 130 KT 150 MPH 36H 25/0000Z 14.3N 122.5W 125 KT 145 MPH 48H 25/1200Z 15.1N 125.1W 115 KT 130 MPH 60H 26/0000Z 16.5N 127.3W 105 KT 120 MPH 72H 26/1200Z 18.0N 129.3W 90 KT 105 MPH 96H 27/1200Z 20.5N 132.5W 55 KT 65 MPH 120H 28/1200Z 21.0N 136.5W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Reinhart
Issued at 800 AM MST Wed Oct 23 2024
000 WTPZ42 KNHC 231442 TCDEP2 Hurricane Kristy Discussion Number 8 NWS National Hurricane Center Miami FL EP122024 800 AM MST Wed Oct 23 2024 The impressive rapid intensification of Kristy has continued this morning. The gradually warming eye of the hurricane is surrounded by a ring of very deep convection, with infrared cloud tops as cold as -75 to -80 deg C. GOES-West derived motion winds indicate good upper-level outflow, particularly over the southern and western portions of the circulation. Subjective Dvorak classifications were a consensus T5.5/102-kt from TAFB and SAB at 12 UTC. Satellite trends suggest Kristy has kept strengthening since that time, and the initial intensity is set at 110 kt, following the rising objective estimates from UW-CIMSS. The hurricane is moving quickly westward (265/17 kt) while being steered by a strong subtropical ridge to its north. This quick westward motion should continue for the next 24-36 h. Then, an upper-level trough between the Hawaiian Islands and the west coast of the United States is forecast to erode the western extent of the ridge. As a result, Kristy is expected to move toward the west-northwest and northwest late this week and into the weekend. A westward motion is shown by day 5, as it is anticipated that Kristy will become highly sheared and decoupled, with the vertically shallow vortex steered by the low-level ridge. No significant changes were made to the latest NHC track forecast. Kristy is a relatively small hurricane that remains susceptible to rapid intensity fluctuations in a weak shear environment over warm SSTs. The latest GFS and ECMWF SHIPS output shows a 50 to 60 percent chance of a 20-kt increase during the next 12 h, and the satellite trends suggest continued near-term strengthening is likely. The updated NHC forecast reflects these signals and lies above the intensity guidance in the near term, showing Kristy peaking as a category 4 hurricane on Thursday. By Friday, the aforementioned trough is expected to impart increased shear on the hurricane, which should induce weakening through the rest of the 5-day forecast period. With SHIPS-diagnosed shear values of 40-50 kt by the weekend, Kristy is forecast to quickly weaken over the weekend and degenerate to a post-tropical remnant low by 120 h. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 14.3N 113.9W 110 KT 125 MPH 12H 24/0000Z 14.2N 116.4W 125 KT 145 MPH 24H 24/1200Z 14.1N 119.7W 130 KT 150 MPH 36H 25/0000Z 14.3N 122.5W 125 KT 145 MPH 48H 25/1200Z 15.1N 125.1W 115 KT 130 MPH 60H 26/0000Z 16.5N 127.3W 105 KT 120 MPH 72H 26/1200Z 18.0N 129.3W 90 KT 105 MPH 96H 27/1200Z 20.5N 132.5W 55 KT 65 MPH 120H 28/1200Z 21.0N 136.5W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Reinhart
