ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM HURRICANE MARIE DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132014 800 PM PDT MON AUG 25 2014 Satellite data indicate that Marie has gradually been weakening. Inner-core deep convection has been slowly warming, with coldest tops now south of center. Additionally, the eye has become less defined and has cooled significantly since the last advisory. A 2210 UTC TRMM overpass shows that the hurricane has also been maintaining a classic concentric eyewall structure - a double eyewall within 60 n mi of the center, with the inner eyewall possibly in the process of collapsing. A third, less-defined eyewall was noted at around 110 n mi radius, separated by a prominent dry slot. The initial intensity for this advisory is reduced to 100 kt, based on the latest Dvorak CI numbers from SAB and the UW-CIMSS ADT. Continued slow weakening is expected in the short term due to gradually decreasing sea surface temperatures and the possibility of the current eyewall replacement evolving further. Even though the vertical shear is forecast to be light, Marie will be crossing the 26 deg C isotherm in 12-18 hours and should reach sub-24 deg C waters by 48 hours. With the thermodynamic environment worsening so quickly, near-rapid weakening is likely after about 24 hours until the cyclone becomes post-tropical by day 3. The cyclone will then continue to spin down over even cooler waters, but the remnant circulation could linger beyond the end of the forecast period. The intensity forecast has been lowered a bit relative to the previous one due mostly to the greater rate of weakening observed since the last advisory. Marie is continuing on a steady northwestward course of 305/11. Mid-level ridging extending west-southwestward from the eastern United States in the subtropical eastern Pacific should continue to steer Marie on a west-northwestward to northwestward path during the next few days. After losing its deep convection by day 3 or so, the cyclone's track should bend north-northwestward or even northward and slow down. There continues to be little change with regard to the track guidance and little in the way of modifications was made to the previous track. The new NHC track is in the center of guidance envelope and close to the multi-model consensus TVCE. Although Marie is expected to remain well offshore, very large swells will continue to affect southwestern Mexico through tonight and much of the Pacific coast of the Baja California peninsula during the next few days. Southerly swells will also reach the coast of southern California by Tuesday, producing life-threatening surf and rip currents, as well as minor coastal flooding. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 19.2N 116.7W 100 KT 115 MPH 12H 26/1200Z 20.2N 118.3W 90 KT 105 MPH 24H 27/0000Z 21.3N 120.6W 75 KT 85 MPH 36H 27/1200Z 22.4N 123.0W 60 KT 70 MPH 48H 28/0000Z 23.5N 125.5W 45 KT 50 MPH 72H 29/0000Z 26.5N 130.0W 35 KT 40 MPH...POST-TROPICAL 96H 30/0000Z 29.4N 132.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 31/0000Z 30.8N 133.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Kimberlain NNNN