{"id": "1214104399286992903", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-28T09:00:00Z", "msg": "265\nWTPZ42 KNHC 280854\nTCDEP2\n \nHurricane Polo Discussion Number  31\nNWS National Hurricane Center Miami FL       EP172026\n200 AM MST Mon Sep 28 2026\n \nPolo has remained fairly steady over the past 6 hours in terms of \nits overall convective structure.  The ragged eye and inner core \nhave perhaps only become slightly less impressive.  The TAFB current \nintensity number is 5.5/102 kt and recent UW-CIMSS objective \nestimates are in the 90-100 kt range.  The initial intensity is \nnudged downward to 100 kt.\n \nThe major hurricane is now moving north-northeastward at 9 kt on the\nwestern side of a mid-level ridge that is situated over northern\nMexico.  Polo is forecast to turn northeastward by this afternoon \nas a trough amplifies over California, taking the core of the \nhurricane over the Baja California Peninsula late this afternoon or \nevening.  Polo is then expected to briefly pass over the Gulf of \nCalifornia before making a second landfall in northwestern mainland \nMexico late tonight or early Tuesday morning.  The latest NHC \nforecast is on top of the previous forecast, but slightly slower, \nand lies close to the HFIP Corrected Consensus Approach (HCCA) \nguidance.\n\nThe SHIPS and UW-CIMSS analyses are currently diagnosing less than \n10 kt of vertical wind shear over Polo.  The shear is expected to \nincrease to about 15 to 18 kt by the time Polo makes landfall in \nBaja California Sur, but thermodynamic conditions aren't expected to \nchange much.  Most of the guidance indicates slight weakening over \nthe next 12 to 18 hours.  The most likely scenario for the intensity \nat landfall in Baja California is around 95 kt, but there is also a \nchance that Polo could maintain its current intensity until it makes \nlandfall.  Land interaction with the peninsula and an increase in \nwind shear should cause some weakening, but Polo is still expected \nto be a hurricane when it reaches mainland Mexico. After the second \nlandfall, rapid weakening is forecast over the rugged terrain of \nMexico.  The official intensity forecast is only slightly lower \nthan the previous one up until the first landfall, and then is \nsimilar to the previous forecast.  The NHC intensity forecast is in \ngood agreement with the majority of the guidance.\n \nAlthough Polo is expected to dissipate before it reaches the \nsouthern U.S., distant moisture associated with it and the \nPost-Tropical Cyclone Odalys will be transported into the \nsouthwestern United States during the next few days, and may \nindirectly contribute to a heavy rainfall and flash flood threat in \nthe region. See products issued by the Weather Prediction Center for \nmore information.\n \n \nKey Messages:\n \n1. Polo is forecast to make landfall on the west coast of the Baja\nCalifornia Peninsula near major hurricane strength late today, \nwithin the Hurricane Warning area. Conditions are expected to begin \nto deteriorate there this morning, making further preparations\ndifficult. Hurricane and tropical storm conditions are expected to\nspread across Baja California through today through tonight, and \ninto mainland Mexico late tonight into early Tuesday. A storm \nsurge is likely, especially in areas of onshore winds.\n \n2. Heavy rainfall associated with Polo will impact Baja California \nSur along with southern and central portions of Sonora today into \nTuesday. This rainfall may produce life-threatening flooding and \nmudslides, especially in areas of steep terrain. Moisture from Polo \nwill support heavy rainfall and flooding potential across the \nSouthwest U.S. into the Southern High Plains late today into \nTuesday.\n \n3. Dangerous surf and rip currents are likely along portions of\nthe northwest coast of Mexico and Baja California for the next\ncouple of days.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  28/0900Z 23.6N 113.8W  100 KT 115 MPH\n 12H  28/1800Z 24.8N 113.2W   95 KT 110 MPH\n 24H  29/0600Z 26.7N 111.6W   75 KT  85 MPH...EAST COAST OF BAJA\n 36H  29/1800Z 29.5N 109.4W   40 KT  45 MPH...INLAND\n 48H  30/0600Z...DISSIPATED\n \n"}