735 WTPZ42 KNHC 240839 CCA TCDEP2 Hurricane Rick Discussion Number 8...Corrected NWS National Hurricane Center Miami FL EP172021 400 AM CDT Sun Oct 24 2021 Corrected typo in the first Key Message The overall satellite presentation of the hurricane has not changed much overnight. Rick's center is embedded within a small central dense overcast, and an earlier SSMIS microwave overpass suggests that the small eye was slightly better defined. An Air Force Reserve Hurricane Hunter aircraft investigating Rick overnight has found that the hurricane has not strengthened since the mission yesterday afternoon. Although the aircraft did not measure flight-level winds as strong as during the previous mission, a dropsonde released in the southwestern eyewall measure mean winds in the lowest 150 m that still support an intensity of 75 kt. The aircraft reported that the minimum pressure is around 980 mb, which is close to the pressure reported yesterday afternoon. It is surprising that Rick has not intensified over the past 6-12 hours as the hurricane remains in a low shear environment and the outflow is well established. Given the expected favorable upper-level wind pattern and warm sea surface temperatures along the track of Rick, strengthening is forecast to resume today. Since Rick has not strengthened as much as expected and it only has about 12-18 hours before southwesterly shear is forecast to increase over the storm, the updated intensity forecast calls for a lower peak intensity than before and is at the high end of the guidance envelope. As Rick approaches the coast of southern Mexico tonight, the aforementioned increase in southwesterly shear and land interaction could case some weakening. After landfall, rapid weakening will occur as the cyclone moves over the mountainous terrain of Mexico, and Rick is expected to dissipate Monday night or Tuesday. The overnight aircraft fixes were a little east of the earlier satellite-based position estimates, yielding a more northward long-term motion estimate of 355/3 kt. Rick is forecast to move northward or north-northwestward at a slightly faster forward speed toward a weakness in the subtropical ridge over Mexico. This motion should bring the center of the hurricane to the coast of southern Mexico within the hurricane warning area tonight or early Monday, and inland over southern or southwestern Mexico on Monday. The dynamical models are in relatively good agreement on this scenario, and the official forecast lies near the various consensus aids. The new track forecast is a little right of the previous advisory due to the more eastward initial position. Key Messages: 1. Rick is forecast to strengthen today and reach the coast of southern Mexico tonight or early Monday, bringing life-threatening storm surge and dangerous hurricane-force winds within a portion of the Hurricane Warning area from Tecpan de Galeana to Punta San Telmo. Residents in this area should follow any advice given by local officials. 2. Rick is expected to bring tropical storm conditions to portions of the southern and southwestern coasts of Mexico beginning today from east of Tecpan de Galeana to Acapulco, and by Monday morning from west of Punta San Telmo to Manzanillo, where a Tropical Storm Warning is in effect. 3. Heavy rains associated with Rick are expected to move into the Mexican states of Guerrero and Michoacan today, and could persist through Monday night. This rainfall will likely produce flash flooding and mudslides. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 15.6N 101.7W 75 KT 85 MPH 12H 24/1800Z 16.2N 101.8W 90 KT 105 MPH 24H 25/0600Z 17.2N 102.0W 85 KT 100 MPH 36H 25/1800Z 18.4N 102.6W 60 KT 70 MPH...INLAND 48H 26/0600Z 20.2N 103.7W 30 KT 35 MPH...POST-TROP/INLAND 60H 26/1800Z...DISSIPATED $$ Forecaster Brown