000 WTPZ41 KNHC 022035 TCDEP1 Hurricane Orlene Discussion Number 17 NWS National Hurricane Center Miami FL EP162022 300 PM MDT Sun Oct 02 2022 Although the satellite presentation of Orlene is not as impressive as it was overnight, the center is still embedded within an area of cloud top temperatures of -70 to -80 degrees Celsius. The eye is also not as defined in conventional satellite imagery as earlier today, but an Air Force Force Reserve reconnaissance aircraft that made two passes through the center earlier this afternoon reported a closed 22 n-mi-wide eye on its final pass. The aircraft measured a peak 700-mb flight-level wind of 96 kt, and SFMR winds of 92 kt. Since the plane only made a couple passes through the eastern eyewall, the intensity is set at 100 kt, owing to some undersampling. It has been difficult to determine if today's weakening was caused by an eyewall replacement cycle, the increase in southwesterly shear, or a combination of both. Regardless, southwesterly vertical wind shear is forecast to increase during the next 12 to 24 hours, which is expected to cause an additional reduction in wind speed, plus the entrainment of some drier mid-level air to the west of Orlene. Orlene still is forecast to pass near or over the Islas Marias as a strong hurricane tonight, and reach the coast of mainland Mexico as a hurricane by on Monday. After landfall, rapid weakening is expected, and the low-level center should dissipate over the mountainous terrain of southwestern Mexico in 48-60 hours. Satellite imagery and fixes from the aircraft show that Orlene is still moving northward or 005/7 kt. The track forecast philosophy is unchanged from before. Orlene should bend north-northeastward tonight as it is steered between a mid-level ridge to its east and a broad trough over northwestern Mexico. The track guidance is in much better agreement this cycle, and the NHC forecast was only nudged slightly westward to be closer to the various consensus aids. The updated track and wind radii forecast has necessitated the issuance of a Tropical Storm Warning along the coast of mainland Mexico to the northwest of the Hurricane Warning area. No other changes were made to the existing wind warnings. Key Messages: 1. Hurricane conditions are expected in the Islas Marias tonight, with tropical storm conditions beginning within the next few hours. A Hurricane Warning is in effect for a portion of west-central mainland Mexico, where hurricane conditions are expected on Monday with tropical storm conditions beginning late tonight. Preparations to protect life and property should be rushed to completion. 2. A dangerous storm surge is likely to cause coastal flooding in the Islas Marias and along the coast of mainland Mexico in the warning area in regions of onshore winds. 3. Heavy rainfall from Orlene is expected to lead to flash flooding, as well as possible landslides in areas of rugged terrain of southwest Mexico through Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 20.4N 106.9W 100 KT 115 MPH 12H 03/0600Z 21.4N 106.7W 90 KT 105 MPH 24H 03/1800Z 22.4N 106.3W 80 KT 90 MPH 36H 04/0600Z 23.3N 105.8W 45 KT 50 MPH...INLAND 48H 04/1800Z 24.2N 105.3W 25 KT 30 MPH...INLAND 60H 05/0600Z...DISSIPATED $$ Forecaster Brown