ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION EIGHTEEN-E DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP182015 800 AM PDT FRI OCT 09 2015 Satellite images indicate that the area of low pressure in the far southwestern portion of the eastern Pacific has become better organized. Curved banding features have increased, along with a growing area of deep convection near the center. Thus the system is declared a tropical depression, the 18th of the season. The initial wind speed is set to 30 kt using the Dvorak estimate from TAFB. The minimum pressure is 1008 mb on the basis of buoy 43535 near the depression, which reported 1009 mb a couple of hours ago. The cyclone is expected to be in a favorable environment for strengthening for the next few days, with low wind shear, very warm waters and high mid-level moisture. Thus steady intensification is forecast until early next week. Thereafter, an increase in southwesterly shear and some cooler waters should cause the cyclone to weaken some by day 5. The official intensity prediction is on the high side of the intensity guidance, a reflection of both the conducive environment and the low bias of the guidance during this season. It would not be surprising if the cyclone intensified more than shown here given the large-scale environment, but timing this is not possible at this time. The depression is moving westward at about 12 kt. This general motion is expected for the next 2-3 days while it remains under the influence of the subtropical ridge located over the eastern and central Pacific. This pattern is expected to change quickly after day 3 when a mid-latitude trough erodes the ridge, causing the cyclone to recurve well east of the Hawaiian Islands. For a first forecast, the guidance is in rather good agreement, and the official forecast is close to the overall consensus, with a bit more weight on the ECMWF model. FORECAST POSITIONS AND MAX WINDS INIT 09/1500Z 11.1N 132.0W 30 KT 35 MPH 12H 10/0000Z 11.3N 133.8W 35 KT 40 MPH 24H 10/1200Z 11.7N 136.2W 45 KT 50 MPH 36H 11/0000Z 12.0N 138.8W 55 KT 65 MPH 48H 11/1200Z 12.2N 140.9W 65 KT 75 MPH 72H 12/1200Z 12.8N 143.5W 85 KT 100 MPH 96H 13/1200Z 14.5N 145.0W 85 KT 100 MPH 120H 14/1200Z 17.0N 144.0W 75 KT 85 MPH $$ Forecaster Blake NNNN