ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM Tropical Storm Eugene Discussion Number 5 NWS National Hurricane Center Miami FL EP062023 900 AM MDT Sun Aug 06 2023 Eugene is on the verge of becoming a hurricane this morning. Scatterometer data from overnight indicated that the maximum winds were 55-60 kt, and a GMI microwave pass now shows the development of a partial eyewall. The storm isn't as impressive on conventional satellite imagery, however, with the central dense overcast weakening during the past several hours. Intensity estimates range from 45-60 kt, and 60 kt is chosen as the initial wind speed, based on the improved microwave structure and overnight scatterometer data. The storm has today to strengthen in marginally conducive conditions before it crosses over very cool waters overnight. Eugene should weaken steadily on Monday and Tuesday due to the lack of instability over the cool waters. Most of the guidance shows Eugene losing deep convection in 36-48 hours over sub-23C waters, so post-tropical status is moved up to day 2 in this forecast. No significant changes were made to the intensity forecast, which remains close to the intensity consensus. Microwave data show that Eugene is moving faster to the west- northwest at about 16 kt. This general motion is anticipated with some reduction in forward speed during the next day or two while the storm moves on the southern side of a mid-level ridge. Eugene should reach the western periphery of the ridge on Tuesday, which will cause the weakening system to turn and move more slowly northward. Model guidance has trended westward on this advisory, and the official forecast follows the trend at longer range. The global models degenerate the system into a trough in 3-4 days. Eugene will likely produce areas of heavy rains and gusty winds across southern portions of the Baja California Sur today as it passes to the south of the peninsula. Interests there should monitor the progress of this system. FORECAST POSITIONS AND MAX WINDS INIT 06/1500Z 21.8N 111.5W 60 KT 70 MPH 12H 07/0000Z 22.9N 113.8W 65 KT 75 MPH 24H 07/1200Z 24.2N 117.1W 55 KT 65 MPH 36H 08/0000Z 25.2N 119.7W 45 KT 50 MPH 48H 08/1200Z 26.0N 121.4W 35 KT 40 MPH...POST-TROPICAL 60H 09/0000Z 27.0N 121.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 09/1200Z 28.0N 121.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 10/1200Z...DISSIPATED $$ Forecaster Blake NNNN