000 WTPZ42 KNHC 250248 TCDEP2 Hurricane Rick Discussion Number 11 NWS National Hurricane Center Miami FL EP172021 1000 PM CDT Sun Oct 24 2021 Rick's convective organization and inner-core structure have both continued to improve since the previous advisory. GMI and SSMI/S passive microwave satellite data at 2245Z and 2310Z, respectively, revealed that the hurricane had redeveloped a 20-nmi-wide low- and mid-level closed eye that was surrounded by a solid ring of intense convection. With better center placement now, satellite intensity estimates using an embedded center technique indicate that Rick is just below the T5.0/90-kt intensity classification threshold. Based on these data, the intensity was increased to 80 kt at 0000 UTC and has been held at that value at the advisory time due to no appreciable change in Rick's appearance in infrared satellite imagery. An Air Force Reserve reconnaissance aircraft is currently enroute to provide a better assessment of Rick's intensity and compact wind field structure around 0600 UTC. The aforementioned GMI and SSMI/S microwave satellite data, compared to earlier microwave imagery, indicate that Rick's eye/center has been moving due north over the past 9 hours, or 360/05 kt. The hurricane is currently located to the right or east of the previous forecast track and model guidance, and only the new GFS model run is on the right side of the latest track guidance envelope. The new NHC track forecast has been nudged a little to the right of the previous track, but not quite as far east as the northward-moving GFS model scenario since the bulk of the other track forecasts still show Rick making a turn toward the north-northwest during the next 6 hours. The subtropical ridge steering the hurricane is forecast to remain in place for the next 36 hours, which should result in Rick making landfall in about 12 h, with the cyclone dissipating in 36-48 h over the mountainous interior of south-central or central Mexico. The deep-layer vertical shear across Rick is forecast to increase to 15-18 kt in 12 h. However, the shear direction is going to be from the south, which be along rather across Rick's forward motion, thus lessening the otherwise adverse effects of the increasing shear. As a result, some slight strengthening will be possible until the hurricane makes landfall late Monday morning. The latest NHC intensity forecast is slightly higher than the previous advisory, but a 5-kt increase is easily within NHC's statistical range of intensity forecast skill. After landfall occurs, Rick should rapidly weaken due to the hurricane's relatively slow forward motion over the very rugged terrain of south-central and central Mexico. In fact, it wouldn't be surprising if the hurricane dissipated sooner than indicated in the official intensity forecast. However, very heavy rainfall causing dangerous flash flooding and mudslides will still continue well after Rick dissipates as a tropical cyclone owing to persistent, moist southerly onshore flow being lifted by the mountainous topography. Key Messages: 1. Rick is forecast to reach the coast of southern Mexico by late Monday morning, 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 continue bringing tropical storm conditions to portions of the southern coast of Mexico 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 spread across the Mexican states of Guerrero and Michoacan through tonight, and could persist through Tuesday. This rainfall will likely produce dangerous flash flooding and mudslides. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 16.8N 101.6W 80 KT 90 MPH 12H 25/1200Z 17.7N 101.9W 85 KT 100 MPH 24H 26/0000Z 18.7N 102.3W 45 KT 50 MPH...INLAND 36H 26/1200Z 19.6N 102.9W 20 KT 25 MPH...INLAND 48H 27/0000Z...DISSIPATED $$ Forecaster Stewart