814 WTPZ43 KNHC 041449 TCDEP3 Tropical Depression Eighteen-E Discussion Number 1 NWS National Hurricane Center Miami FL EP182021 1000 AM CDT Thu Nov 04 2021 The area of low pressure we have been tracking since it formed several days ago over the southwestern Caribbean Sea has moved over the far eastern Pacific and gradually become better-defined over the past couple of days. In addition, the convective organization has steadily increased. An ASCAT-C overpass earlier this morning showed that the surface low was slightly elongated. However, the deep convection has persisted near, or just east of that low for several hours since that time. First light visible satellite imagery also indicates that the circulation is well-defined. Therefore, advisories are being initiated for Tropical Depression Eighteen-E. The ASCAT pass also showed peak winds of 28 kt associated with the system, and a blend of the latest Dvorak intensity estimates from TAFB and SAB suggest an initial advisory intensity of 30 kt. The initial motion of the depression is 280/7 kt. The cyclone is located to the south of a broad mid-tropospheric ridge extending across southern Mexico and much of the eastern Pacific basin. This feature should steer the depression generally westward for most of the forecast period, along with a gradual increase in forward speed. By day 5, a turn to the west-northwest may occur, as the cyclone becomes situated along the southwestern portion of the ridge. The track model guidance is in good agreement on this scenario, and the NHC track forecast is near the various multi-model consensus solutions. The environment surrounding and ahead of the depression appears generally favorable for strengthening with ample atmospheric moisture and SSTs of 27 to 28 degrees C. The only inhibiting factor to strengthening may be the westerly shear vector, which although should remain under 10 kt, when combined with the cyclone's increasing westerly forward motion may cause convection to periodically get stripped to its east of its center. Based on these conditions, the model guidance indicates a slow and steady pace of strengthening over the next several days, and NHC follows suit with an intensity forecast near the IVCN and NOAA-HCCA consensus. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 9.4N 90.0W 30 KT 35 MPH 12H 05/0000Z 9.6N 90.9W 30 KT 35 MPH 24H 05/1200Z 9.4N 92.0W 35 KT 40 MPH 36H 06/0000Z 9.2N 93.4W 35 KT 40 MPH 48H 06/1200Z 9.0N 95.2W 40 KT 45 MPH 60H 07/0000Z 9.0N 97.3W 40 KT 45 MPH 72H 07/1200Z 9.0N 99.6W 45 KT 50 MPH 96H 08/1200Z 9.7N 104.1W 50 KT 60 MPH 120H 09/1200Z 11.1N 108.5W 55 KT 65 MPH $$ Forecaster Latto