000 WTPZ42 KNHC 061446 TCDEP2 Hurricane Kay Discussion Number 9 NWS National Hurricane Center Miami FL EP122022 900 AM MDT Tue Sep 06 2022 Satellite data indicate that Kay has been relatively steady in strength during the past several hours. A ragged eye feature has occasionally been apparent, and microwave data show that the eyewall and rainbands are most organized on the south side. The latest satellite intensity estimates range from 65 to 77 kt, and based on that data, the initial intensity is held at 75 kt. An Air Force Hurricane Hunter aircraft is scheduled to investigate Kay later today. It should be noted that Kay is a fairly large hurricane with its tropical-storm-force winds estimated to extend outward up to 175 miles from the center. Kay is also producing a large area of high seas, with swells currently affecting portions of southwestern Mexico and the southern Baja California peninsula. Kay is moving northwestward at 13 kt and it appears to be moving along the previous forecast track. The track models have barely changed this cycle and continue to show a northwest to north-northwest motion continuing for the next few days as the hurricane moves in the flow on the western periphery of a ridge over Mexico. This should take the core of Kay very near the west-central Baja California peninsula on Thursday and Friday. After that time, a turn to the left is predicted as the system is steered by a low- to mid-level ridge over the western United States. The NHC track forecast is basically the same as the previous one and lies closest to the HCCA consensus model. The hurricane is still feeling some effects from moderate northerly vertical wind shear, but the models suggest that the shear should decrease during the next day or so. The anticipated more conducive upper-level wind pattern combined with warm SSTs and a moist environment should allow Kay to strengthen during the next 36 hours, and it could become a major hurricane during that time. Thereafter, sharply cooler SSTs and drier air should end the opportunity for strengthening and induce steady weakening. Kay is expected to become a post-tropical cyclone in 4 to 5 days when it is forecast to be over quite cool SSTs of 21-22 C. The NHC intensity forecast lies near the high end of the guidance, especially during the first 48 hours. Although Kay is likely to weaken before it makes its closest approach to the west-central coast of the Baja peninsula, it is forecast to remain a large and strong hurricane at that time. In addition, winds, surf, and rainfall impacts will extend far from the center so users should not focus on the exact forecast track. KEY MESSAGES: 1. Heavy rainfall from Kay could lead to flash flooding, including landslides, across portions of western Mexico, including the Baja California peninsula, through Thursday night. 2. Tropical storm conditions are expected over portions of the southern Baja California peninsula beginning Wednesday morning, where a Tropical Storm Warning is now in effect. 3. While the details of the long-range track and intensity forecasts remain uncertain, there is increasing risk of significant wind, surf, and rainfall impacts across the central portion of the Baja California peninsula later this week. A tropical storm or hurricane watch could be issued for that region later today. FORECAST POSITIONS AND MAX WINDS INIT 06/1500Z 18.0N 110.0W 75 KT 85 MPH 12H 07/0000Z 19.1N 111.4W 85 KT 100 MPH 24H 07/1200Z 20.7N 112.6W 95 KT 110 MPH 36H 08/0000Z 22.5N 113.5W 100 KT 115 MPH 48H 08/1200Z 24.6N 114.3W 90 KT 105 MPH 60H 09/0000Z 26.4N 115.2W 75 KT 85 MPH 72H 09/1200Z 28.0N 116.0W 60 KT 70 MPH 96H 10/1200Z 30.2N 118.6W 45 KT 50 MPH 120H 11/1200Z 30.5N 120.9W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Cangialosi