ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Hurricane Eugene Discussion Number 11 NWS National Hurricane Center Miami FL EP052017 200 AM PDT Mon Jul 10 2017 Eugene's structure has changed during the past 6-12 hours, as the hurricane no longer has an eye in infrared satellite imagery. Microwave data and the derived MIMIC product from UW-CIMSS seem to suggest that dry air penetrated into the southern portion of Eugene's circulation and eroded the eyewall. In addition, center fixes off of ASCAT data indicate that the low-level center is displaced to the south of the mid-level rotation noted in geostationary satellite imagery, indicative of some unforeseen southerly shear. Subjective and objective Dvorak intensity estimates have decreased slightly from six hours ago, and a blend of the various numbers supports an initial intensity of 85 kt. Eugene will remain over water warmer than 26C for another 12 hours or so, and its intensity will either be steady or decrease slowly during that time. More pronounced weakening is anticipated after 12 hours when the circulation moves over much colder water, and Eugene will likely weaken to a tropical storm by tonight and then degenerate to a remnant low by Wednesday night. The updated NHC intensity forecast is fairly close to the ICON intensity consensus and tries to maintain as much continuity as possible with the previous forecast. However, it should be noted that HCCA and the Florida State Superensemble, both of which have performed well with Eugene, indicate a faster weakening rate than that shown by the official forecast. A weakness in the subtropical ridge located off the northern Baja California peninsula coast is causing Eugene to move northwestward with an initial motion of 320/10 kt. Even as Eugene weakens, low-level troughing near the California coast should maintain a northwestward or even north-northwestward track but at a slower forward speed through most of the forecast period. The track guidance remains in good agreement, and the only notable change in the NHC official forecast is a northeastward shift in the track during the remnant low stage compared to the previous forecast. Swells generated by Eugene will propagate northward along the west coast of the Baja California peninsula to southern California during the next few days, causing high surf and dangerous rip current conditions. Please refer to advisories issued by your local weather office for additional information. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 18.1N 116.5W 85 KT 100 MPH 12H 10/1800Z 19.3N 117.6W 75 KT 85 MPH 24H 11/0600Z 20.7N 118.8W 60 KT 70 MPH 36H 11/1800Z 22.1N 119.9W 45 KT 50 MPH 48H 12/0600Z 23.3N 120.8W 35 KT 40 MPH 72H 13/0600Z 25.5N 122.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 14/0600Z 27.5N 124.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 15/0600Z 28.5N 125.5W 15 KT 15 MPH...POST-TROP/REMNT LOW $$ Forecaster Berg NNNN