000 WTPZ42 KNHC 182038 TCDEP2 TROPICAL STORM POLO DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP172014 200 PM PDT THU SEP 18 2014 An Air Force reconnaissance plane just traversed the core of Polo, and although a dropsonde measured a pressure of 983 mb with 25 kt winds in the center, neither the flight-level nor SFMR-winds in any quadrant support keeping Polo at hurricane intensity. The maximum winds have been lowered to 60 kt in this advisory. This is also reflected in the cloud pattern, which has become a little bit disrupted in the past few hours. Polo had the opportunity to strengthen, but it appears that the northeasterly shear increased earlier than anticipated, halting the intensification. Little change in strength is expected for the next 12 hours or so, but a gradual weakening trend is forecast to begin in 24 hours, as indicated by most of the guidance. There is no change in the forecast track, and as in previous runs, most of the guidance maintains Polo moving toward the northwest or west-northwest around the periphery of an amplifying mid-level ridge centered over Mexico. On the forecast track, the cyclone will pass well south of the southwestern coast of Mexico and well south of the southern Baja California peninsula. The confidence in the track forecast is relatively high since both the multi-model consensus TVCN and the average of the GFS and the ECMWF models, GFEX, are keeping Polo well removed from land. However, any unexpected deviation to the right of the track could require the issuance of a tropical storm watch for the southern portion of the Baja California peninsula. FORECAST POSITIONS AND MAX WINDS INIT 18/2100Z 17.8N 105.9W 60 KT 70 MPH 12H 19/0600Z 18.5N 106.7W 60 KT 70 MPH 24H 19/1800Z 19.2N 107.6W 55 KT 65 MPH 36H 20/0600Z 20.0N 108.5W 50 KT 60 MPH 48H 20/1800Z 20.8N 110.0W 45 KT 50 MPH 72H 21/1800Z 21.5N 112.5W 40 KT 45 MPH 96H 22/1800Z 22.0N 115.0W 30 KT 35 MPH 120H 23/1800Z 22.0N 117.0W 25 KT 30 MPH...POST-TROP/EXTRATROP $$ Forecaster Avila