{"id": "1217927419657879555", "title": "Tropical Cyclone Discussion", "adv_date": "2026-10-11T21:00:00Z", "msg": "134\nWTPZ45 KNHC 112059\nTCDEP5\n \nHurricane Simon Discussion Number  18\nNWS National Hurricane Center Miami FL       EP202026\n300 PM CST Sun Oct 11 2026\n\nSimon is still a Category 4 hurricane, but appears to be feeling the \neffects of the nearby high terrain of the Serra Madre Mountains as \nthe inner core is brushing up against the Mexican coast. The eye \nremains observed on geostationary satellite imagery, but is more \ncloud filled than earlier with warmer surrounding cloud tops. While \nthe 18 UTC subjective Dvorak fix was still at T6.5/125 kt, the \nobjective intensity estimates have continued to fall, with values \nnow in the 109-115 kt range. Therefore, the initial intensity is \nbeing lowered to 115 kt for this advisory. An earlier Synthetic \nAperture Radar (SAR) RCM-1 pass was very useful to adjust the 34- \n50- and 64-kt radii of Simon as the hurricanes wind field continues \nto shrink in size. \n\nSimon has stubbornly maintained a north-northwestward motion, \nroughly parallel to the coastline, estimated at 335/5 kt. It is now \nlooking increasingly likely that Simon will avoid making a direct \nlandfall in the short-term, though its eastern inner core will \nlikely produce hurricane conditions as the storm continues to move \nnorth-northwestward from Playa Perula to Cabo Corrientes this \nafternoon and evening. The steering ridge centered over the Texas \ncoast is likely to maintain this motion now for the next several \ndays, though with some slowdown in the motion due to a weaker but \ncompeting ridge located to Simon's southwest. On Tuesday into \nWednesday, a large short-wave trough is forecast to move across the \nsouthwestern United States and this feature should provide enough \nsouthwesterly environmental flow to turn the hurricane to the \nnortheast, finally reaching the coast of Mexico in 60-72 h. Compared \nto this morning, the guidance has shifted westward and slower once \nagain, and there remain some outlier solutions like the GFS that \nwant to turn Simon southwestward beyond 48 h. However, the majority \nof the ensemble guidance (European-EPS, Google DeepMind) do show \nthis slow recurving solution back into Mexico. The NHC track \nforecast is a little bit west and slower for the first 36-48 h, but \nthen bends back to the previous forecast track thereafter, still \nshowing Simon moving inland and dissipating in the day 3-4 period.  \nThis forecast still remains low confidence. \n\nIntensity wise, it is now looking more likely that Simon will not \nweaken as much as originally expected, now that it is only brushing \nup against the coast instead of part of its inner core moving \ninland. Still, the high topography in Jalisco should still have a \nnegative effect, which has already been seen in Simon's wind field \nshrinking in size. The hurricane-regional models still show \nsignificant weakening over the next 12-24 h, even the ones that only \nskirt the coast of Mexico, and the NHC intensity forecast still \nshows a fast rate of weakening during that time. However, other \nenvironmental conditions remain very favorable, as shear stays under \n10 kt, and sea-surface temperatures warm to 31-32 C as Simon passes \nnorth of Cabo Corrientes and enters waters that have been unaffected \nby recent tropical cyclones (Polo and Rachel). However, there will \nbe a significant amount of nearby dry air and it remains to be seen \nhow intact Simon's inner core will remain over the next 24 h of near \nland interaction. The latest NHC intensity forecast now shows Simon \nmaintaining hurricane intensity, and this forecast could still be \nlow if the inner core remains more robust than the hurricane \nregional models are forecasting. This forecast is now on the higher \nend of the intensity guidance aids, but is under the SHIPS guidance \nthis cycle, and also remains low confidence. \n \nKey Messages:\n \n1. Catastrophic wind and life-threatening storm surge impacts are \nlikely along a portion of the west-central coast of Mexico, and a \nHurricane Warning is in effect from Punta San Telmo to El Roblito. \nResidents should continue to shelter in a safe room to ride out the \nstorm as the most significant hazards with Simon are now ongoing.\n\n2. Simon is now expected to approach the coast of west Mexico later \nthis week, where Hurricane conditions are now possible along the \ncoast of El Roblito to Bahia Tempehuaya. A Hurricane Watch is now in \neffect for this region. \n\n3. Heavy rainfall associated with Simon will impact portions of \nsouthwestern and west-central Mexico over the next few days. This \nrainfall will produce life-threatening flooding and mudslides, \nespecially in areas of steep terrain.\n \n4. Swells will affect portions of the southwestern and west-central\ncoast of Mexico over the next few days. These swells are likely to\ncause life-threatening surf and rip current conditions. Please\nconsult products from your local weather office.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  11/2100Z 19.6N 105.8W  115 KT 130 MPH\n 12H  12/0600Z 20.2N 106.1W   90 KT 105 MPH\n 24H  12/1800Z 21.0N 106.6W   80 KT  90 MPH\n 36H  13/0600Z 21.6N 106.9W   75 KT  85 MPH\n 48H  13/1800Z 22.2N 107.1W   75 KT  85 MPH\n 60H  14/0600Z 22.8N 107.0W   75 KT  85 MPH\n 72H  14/1800Z 23.4N 106.6W   75 KT  85 MPH\n 96H  15/1800Z 24.0N 105.9W   30 KT  35 MPH...POST-TROP/INLAND\n120H  16/1800Z...DISSIPATED\n \n"}