Tropical Cyclone Discussion
866 WTPZ45 KNHC 141449 TCDEP5 Hurricane Simon Discussion Number 29 NWS National Hurricane Center Miami FL EP202026 800 AM MST Wed Oct 14 2026 First-light visible imagery indicates that Simon has continued to lose organization during the last several hours. The low-level center is now located near the northern edge of the convective overcast due to the effects of northerly shear. However, there is still no microwave imagery of the storm to better diagnose the internal structure. The satellite intensity estimates have trended down, and based on this the initial intensity is reduced to a possibly generous 80 kt. The hurricane continues drifting southwest or 230/2 kt. For the next day or two, Simon is likely to continue drifting southwestward in an area of light steering currents, with the center remaining well offshore. After that time, the track forecast becomes less confident. While all of the global models agree that a mid- to upper-level trough should form west of Baja California after 48 h, there is poor agreement on the track forecasts for Simon during this time. The GFS and the regional hurricane models forecast that Simon will continue moving southward or southwestward through 72 h, followed by a slow movement toward the northwest. The remainder of the guidance favors a northwestward or north-northwestward turn between 36-48 h, with that motion continuing through the end of the forecast period. The new track forecast follows the latter scenario in anticipation that the center will try to follow convective bursts displaced to the north by southerly shear. The new forecast track is again adjusted west of the previous track, but it lies to the east of the HCCA corrected consensus and the Google DeepMind ensemble mean. Simon's small size makes it susceptible to intensity fluctuations based on the state of its compact inner core and small changes in the environmental conditions. The current northerly shear is forecast to diminish during the next 12-24 h, which may allow some modest re-intensification. By 36 h, increasing southerly to southwesterly upper-level flow between the trough to the northwest and Tropical Storm Trudy to the southeast should cause significant shear and aid in the entrainment of dry air. This should cause steady weakening, with Simon expected to weaken to a tropical storm as it approaches Baja California Sur. The system is likely to decay to a remnant low by 120 h as the shear and dry air cause the convection to dissipate. Simon continues to be a challenging storm to forecast, and confidence remains lower than normal given the weak steering, proximity to land, very small size, and significant model spread. Key Messages: 1. While Simon is no longer expected to bring hurricane conditions to Las Islas Marias, interests in west-central Mexico and Baja California Sur should continue to closely monitor the latest updates. Watches or warnings could be required for portions of Baja California Sur over the next day or two. 2. Large swells will likely affect portions of the coast of west-central Mexico and Baja California Sur over the next several days. These swells could cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 19.7N 108.1W 80 KT 90 MPH 12H 15/0000Z 19.5N 108.3W 85 KT 100 MPH 24H 15/1200Z 19.3N 108.3W 85 KT 100 MPH 36H 16/0000Z 19.2N 108.3W 80 KT 90 MPH 48H 16/1200Z 19.9N 108.7W 75 KT 85 MPH 60H 17/0000Z 21.2N 109.7W 65 KT 75 MPH 72H 17/1200Z 22.6N 110.6W 50 KT 60 MPH 96H 18/1200Z 24.5N 112.2W 35 KT 40 MPH 120H 19/1200Z 26.9N 113.6W 25 KT 30 MPH...POST-TROP/REMNT LOW