000 WTPZ42 KNHC 110232 TCDEP2 Tropical Storm Aletta Discussion Number 22 NWS National Hurricane Center Miami FL EP022018 800 PM PDT Sun Jun 10 2018 Aletta is maintaining its sheared structure. Although cloud tops have warmed over the past few hours, the tropical storm is still producing persistent convection in the northwestern quadrant. Dvorak classifications from TAFB and SAB have not changed since 6 hours ago, so the intensity has been held at 40 kt. No change has been made to the intensity forecast. Aletta has been moving along a tongue of moderately warm water, which may have allowed convection to persist up to this point, but the cyclone will soon cross a sharp SST gradient and enter into a much more stable environment. Once that occurs, the cyclone will likely lose all convection and become a remnant low, gradually spinning down over the course of a few days. While not explicitly shown in this forecast, it is possible that Aletta will dissipate by the middle to end of the week. The tropical storm has been moving toward the west-northwest, or 285/6 kt, this evening, but a westward motion is expected to resume overnight. All of the dynamical models continue to indicate that Aletta will be steered slowly westward by a mid-level ridge to the north for the next 24 to 36 hours. After that time, a turn toward the west-southwest will likely occur as the low-level tradewinds become the dominant steering feature. From day 3 onward, the cyclone is expected to become trapped in light low-level flow between a high pressure system to the northwest and Hurricane Bud to the east, so the NHC forecast shows little to no movement. The official track forecast has been adjusted slightly northward for the first 36 hours due to Aletta's recent short-term west-northwestward motion, but is not significantly changed from the previous advisory and remains close to TVCN and HCCA. FORECAST POSITIONS AND MAX WINDS INIT 11/0300Z 16.8N 116.2W 40 KT 45 MPH 12H 11/1200Z 16.9N 117.2W 35 KT 40 MPH 24H 12/0000Z 16.9N 118.3W 30 KT 35 MPH 36H 12/1200Z 16.7N 119.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 13/0000Z 16.4N 119.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 14/0000Z 16.2N 120.2W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 15/0000Z 16.0N 120.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 16/0000Z 16.0N 120.5W 15 KT 15 MPH...POST-TROP/REMNT LOW $$ Forecaster Zelinsky