000 WTPZ42 KNHC 201432 TCDEP2 TROPICAL STORM POLO DISCUSSION NUMBER 18 NWS NATIONAL HURRICANE CENTER MIAMI FL EP172014 800 AM PDT SAT SEP 20 2014 Although the convection has increased a little in the past couple of hours, Polo is still a sheared cyclone. The cloud pattern consists of a tight swirl of low clouds located on the northeastern edge of an area of intermittent deep convection. Based on the trend of satellite estimates, the initial intensity has been lowered to 40 kt, and these winds are probably occurring in the convection in the southwest quadrant. The shear is forecast to increase even further, and the cyclone is heading toward cooler waters. The combination of these two factors should result in additional weakening, and Polo is expected to become a tropical depression in about 24 hours. In fact, the SHIPS and LGEM models dissipate the cyclone by 36 hours. Polo has been moving between the northwest and west-northwest since yesterday at about 5 to 7 kt. The cyclone is trapped south of an amplifying mid-level ridge over Mexico, and this pattern should force Polo to move on a west-northwest to west track until dissipation in a few days. The NHC forecast has not changed, and continues to be very close to the multi-model consensus. Based on the forecast track and wind radii, tropical storm force winds are anticipated to remain south of the Baja California peninsula. Since any unexpected deviation to the north of the forecast track could bring tropical storm force winds to the coast, the government of Mexico has wisely opted to maintain the tropical storm watch until Polo moves away from Baja California. FORECAST POSITIONS AND MAX WINDS INIT 20/1500Z 20.9N 109.0W 40 KT 45 MPH 12H 21/0000Z 21.3N 109.8W 35 KT 40 MPH 24H 21/1200Z 21.9N 111.2W 30 KT 35 MPH 36H 22/0000Z 22.3N 112.5W 25 KT 30 MPH 48H 22/1200Z 22.5N 113.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 23/1200Z 22.0N 115.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 24/1200Z 21.5N 115.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 25/1200Z 20.5N 116.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Avila