000 WTPZ41 KNHC 012033 TCDEP1 Hurricane Orlene Discussion Number 12 NWS National Hurricane Center Miami FL EP162022 300 PM MDT Sat Oct 01 2022 Orlene has strengthened some since the last advisory. An Air Force Reserve Hurricane Hunter aircraft reported 700-mb flight-level winds of 80 kt in the the northeastern eyewall, and reliable- looking surface wind estimates of 69-72 kt from the SFMR. The central pressure inside the 16-n mi wide eye was 979 mb. Based on these data, the initial intensity is increased to a possibly conservative 70 kt. Data from the aircraft and a recent scatterometer overpass show that Orlene remains a small tropical cyclone. Orlene should remain in a generally moist and light-shear environment for about the next 18-24 h, and continued steady intensification is expected during that time. The new intensity forecast now calls for a peak intensity of 85 kt in about 24 h, a slightly higher intensity than the previous forecast. After that, strong southwesterly shear should cause steady to rapid weakening until landfall in Mexico. This should be followed by dissipation over the mountains of northwestern Mexico between 72-96 h. As mentioned previously, while it cannot be ruled out that Orlene could reach mainland Mexico as a hurricane, the chances of that are decreasing based on the guidance and the forecast shear. The new intensity forecast again lies near or at the upper edge of the intensity guidance. Orlene is generally moving slowly northward, 360/4 kt, to the west of a mid-level ridge. After about 12 h, the cyclone should turn north-northeastward in the flow between this ridge and an upper- level trough seen in water vapor imagery over northwestern Mexico and the northern Baja California peninsula. This motion is forecast to continue until Orlene dissipates over mainland Mexico. The track guidance is fairly tightly clustered together, although the GFS remains a bit to the right of the other models after 24 h. The guidance envelope has shifted a little westward since the previous advisory, and based on this the new forecast track is again nudged a little to the west. However, the new track lies a little east of the various consensus models, between them and the GFS. Key Messages: 1. Hurricane conditions are expected in the Islas Marias Sunday night, with tropical storm conditions beginning late Sunday. Hurricane conditions are possible over portions of west-central mainland Mexico starting on Monday. Tropical storm conditions are expected within the tropical storm warning area along the west-central coast of Mexico on Sunday. Tropical storm conditions are possible over other portions of southwestern and west-central Mexico in the tropical storm watch area tonight or Sunday. 2. Heavy rainfall from Orlene is expected to lead to flash flooding, as well as possible landslides in areas of rugged terrain of southwest Mexico into Monday evening. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 17.9N 107.1W 70 KT 80 MPH 12H 02/0600Z 18.6N 107.0W 80 KT 90 MPH 24H 02/1800Z 19.7N 106.8W 85 KT 100 MPH 36H 03/0600Z 20.9N 106.6W 75 KT 85 MPH 48H 03/1800Z 22.1N 106.2W 65 KT 75 MPH 60H 04/0600Z 23.1N 105.8W 45 KT 50 MPH...INLAND 72H 04/1800Z 24.1N 105.2W 25 KT 30 MPH...INLAND 96H 05/1800Z...DISSIPATED $$ Forecaster Beven