000 WTPZ43 KNHC 191457 TCDEP3 Tropical Depression Twenty-Three-E Discussion Number 1 NWS National Hurricane Center Miami FL EP232018 1000 AM CDT Fri Oct 19 2018 Two distinct areas of low pressure formed late yesterday within a sprawling area of disturbed weather that stretched from Central America westward over the eastern Pacific waters south of Mexico. The easternmost low south of Guatemala is small and has spun up quickly, with deep convection continuing to burst near the center of circulation. Microwave data, first-light visible images, and valuable radar data from Guatemala also show a tight core and increasing convective bands. Maximum winds are set at 30 kt, slightly above last evening's ASCAT pass and a T1.5 Dvorak classification from TAFB, given the system's well-developed structure. The depression is located over warm waters (28-29 degrees Celsius) and in a light-shear environment. These conditions should support further strengthening, and the depression's small size may allow for intensification higher than what is indicated by the intensity models. For this first advisory, the NHC intensity forecast is near the top end of the guidance envelope and levels off the maximum winds in 3-5 days when there could be an increase in shear. Since the low formed recently, the depression's current motion is uncertain. However, microwave fixes indicate that it hasn't moved much since last evening, and the initial motion estimate is slowly west-northwestward, or 300/2 kt. A strong mid-level ridge spanning across the Gulf of Mexico and northern Mexico should steer the cyclone generally westward for the next 3 days or so. After day 3, the ridge is expected to retreat eastward a bit, and the cyclone should begin to turn northwestward between the ridge and another low pressure system to the west. The track models are in good agreement on this general scenario, but there is not agreement on how close the system could get to the coast of Mexico during the forecast period. Therefore, interests along the southern and southwestern coast of Mexico should monitor the progress of this system during the next few days. Regardless of how close it gets to the coast, heavy rainfall, with possible life-threatening flash flooding, is expected over portions of El Salvador, Guatemala, and southeastern Mexico during the next few days. FORECAST POSITIONS AND MAX WINDS INIT 19/1500Z 13.3N 91.9W 30 KT 35 MPH 12H 20/0000Z 13.7N 93.2W 35 KT 40 MPH 24H 20/1200Z 13.5N 94.2W 40 KT 45 MPH 36H 21/0000Z 13.3N 94.9W 45 KT 50 MPH 48H 21/1200Z 13.3N 96.1W 50 KT 60 MPH 72H 22/1200Z 13.8N 99.5W 50 KT 60 MPH 96H 23/1200Z 16.0N 103.0W 55 KT 65 MPH 120H 24/1200Z 19.0N 105.5W 55 KT 65 MPH $$ Forecaster Berg