{"id": "1217358324933001223", "title": "Tropical Cyclone Discussion", "adv_date": "2026-10-09T21:00:00Z", "msg": "826\nWTPZ43 KNHC 092044\nTCDEP3\n \nTropical Storm Rachel Discussion Number  51\nNWS National Hurricane Center Miami FL       EP182026\n200 PM PDT Fri Oct 09 2026\n \nRachel is producing limited convection this afternoon, with \nrelatively shallow, warm cloud tops confined to the northern and \neastern semicircles. A scatterometer pass at 1753 UTC showed peak \nsatellite-derived winds of 37 kt. Satellite intensity estimates from \nUW-CIMSS and TAFB range between 26 and 41 kt. Using this data, the \ninitial intensity is lowered to 40 kt for this advisory.\n \nThe system is starting to gradually increase its forward speed and \nis moving at an estimated 055/5 kt. Rachel should begin to \naccelerate toward the northeast and then north-northeast tonight and \ntomorrow, embedded within the flow of a deepening mid- to \nupper-level trough approaching the western United States. On the \nforecast track, the system is expected to move inland over northern \nBaja California late Saturday or early Sunday before continuing \nnorth-northeastward into the southwestern United States on Sunday. \nTrack guidance remains similar to the previous cycle, with the \nhurricane regional models, the GFS, and the ECMWF on the left side \nof the envelope, and the GDMI and HCCA on the right. The NHC track \nforecast is essentially an update of the previous one and lies in \nthe middle of the guidance envelope. Note that there will be a sharp \ngradient in the wind field, with the strongest winds anticipated to \nremain primarily in the eastern and southern semicircles of the \ncirculation.\n \nRachel continues to struggle to produce anything more than shallow \nconvection, as the system is embedded within a dry and stable air \nmass over cool sea surface temperatures. However, as the system \nbegins to accelerate northeastward, a favorable trough interaction \nis expected, along with an increase in mid-level relative humidity. \nAlso, sea surface temperatures just offshore of the western Baja \nCalifornia peninsula are anomalously warm for this time of year. \nGiven these conditions, Rachel is expected to produce intermittent \nbursts of convection and strengthen, up until landfall, even though \nvertical wind shear will increase significantly as the system \napproaches the coast. Once inland, rapid weakening is expected, and \nthe system is forecast to become post-tropical over the southwestern \nUnited States. The latest NHC intensity forecast is similar to the \nprevious advisory and lies near the upper end of the guidance \nenvelope, although some of the hurricane regional models and the \nHCCA are slightly higher than the official forecast just offshore at \n36 h.\n \nKey Messages:\n \n1. Rachel is expected to approach the coast of the northern Baja \nCalifornia Peninsula and extreme Southern California at tropical \nstorm strength Saturday night.  Tropical storm conditions are \nexpected over portions of western Baja California, Mexico where \nTropical Storm Warnings are in effect. Tropical storm conditions are \npossible in extreme Southern California and eastern Baja California \nwhere a Tropical Storm Watch is in effect.\n \n2. Damaging wind gusts associated with Rachel and its remnants are\nexpected to spread over portions of northwestern Mexico and interior\nportions of the Southwest United States, especially in areas of\nhigher terrain, Saturday night and Sunday.\n \n3. Rachel and its moisture will spread over portions of the\nSouthwest United States and northern Baja California peninsula\nthrough this weekend. This will lead to increasing coverage of\nrainfall and for the potential for significant flash and urban\nflooding.\n \n4. Swells partly generated by Rachel will continue to build along\nthe coast of Southern California and northern Baja California.\nThese swells are likely to cause life-threatening surf and rip\ncurrent conditions, as well as moderate to isolated major coastal\nflooding, through early next week.  Please consult products from\nyour local weather office.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  09/2100Z 23.3N 124.0W   40 KT  45 MPH\n 12H  10/0600Z 24.2N 122.4W   45 KT  50 MPH\n 24H  10/1800Z 26.7N 119.4W   50 KT  60 MPH\n 36H  11/0600Z 30.9N 117.2W   55 KT  65 MPH\n 48H  11/1800Z 36.4N 115.0W   40 KT  45 MPH...POST-TROP/INLAND\n 60H  12/0600Z...DISSIPATED\n \n"}