ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM Potential Tropical Cyclone Sixteen-E Discussion Number 2 NWS National Hurricane Center Miami FL EP162023 400 AM CDT Sun Oct 08 2023 This system has become a bit better organized since the last advisory with increased convection near the cloud system center. Still, there's not much curvature to the thunderstorm activity and no clear signs that the system has become a tropical cyclone, although it is closer than yesterday. So the system will remain a potential tropical cyclone, and the initial wind speed is held at 25 kt, consistent with earlier ship data. Much of this forecast is based on the previous NHC prediction since there hasn't been a lot of in situ or microwave data overnight. The initial motion estimate remains northwest at 6 kt. The system is forecast to turn north-northwestward late today between a mid-level ridge to its east and Tropical Storm Lidia to its west. This motion should bring the center of the system near the southern coast of Mexico in about 36-48 hours. The GFS seems unrealistically fast with landfall in less than 24 hours given the flow regime. Only a small adjustment to the left was made to the previous forecast, near but slower than the consensus aids. The disturbance has some chance to intensify over very warm waters in moderate shear conditions. Model guidance has generally come down, however, but this appears to be due to the GFS-based guidance having too fast of a forward speed, which limits the system's time over water, rather than a change in the near-term environment. Little change was made to the previous forecast, though this prediction is now on the higher side of the guidance envelope. Key Messages: 1. The disturbance is expected to become a tropical storm before it approaches the coast of southern Mexico on Monday. A tropical storm watch remains in effect, and tropical storm warnings could be required later today for a portion of the coast of southern Mexico. 2. Heavy rains from this system will likely produce flash and urban flooding, along with possible mudslides in areas of higher terrain across the states of Guerrero and Michoacan. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 14.5N 100.7W 25 KT 30 MPH...POTENTIAL TROP CYCLONE 12H 08/1800Z 15.3N 101.2W 30 KT 35 MPH...TROPICAL CYCLONE 24H 09/0600Z 16.1N 101.5W 35 KT 40 MPH 36H 09/1800Z 16.9N 101.6W 45 KT 50 MPH 48H 10/0600Z 17.9N 101.6W 40 KT 45 MPH...INLAND 60H 10/1800Z 19.0N 101.5W 25 KT 30 MPH...POST-TROP/INLAND 72H 11/0600Z...DISSIPATED $$ Forecaster Blake NNNN