A persistent large upper ridge centered over the Great Basin provided the area with an extended period of much warmer than normal temperatures between August 26 and September 3. High temperatures ranged mainly from 106 to 112 degrees at many locations each day between August 26 and September 3 across the San Joaquin Valley, the southern Sierra foothills and the Kern County Deserts while morning…
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS HNX wrote it up.
A persistent large upper ridge centered over the Great Basin provided the area with an extended period of much warmer than normal temperatures between August 26 and September 3. High temperatures ranged mainly from 106 to 112 degrees at many locations each day between August 26 and September 3 across the San Joaquin Valley, the southern Sierra foothills and the Kern County Deserts while morning lows ranged from the mid 70's to the lower 80's.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Hanford, CA wrote its last area forecast discussion before the first event at Aug 26, 2:26 AM PST, 7 hours 34 minutes earlier.
Area Forecast Discussion National Weather Service San Joaquin Valley - Hanford CA 326 AM PDT Sat Aug 26 2017 .SYNOPSIS...A building upper level ridge of high pressure centered over the Great Basin will bring dry weather and well above normal temperatures to the central California interior through at least Tuesday. Isolated afternoon thunderstorms are possible near the Sierra crest by the middle of next week. && .DISCUSSION...A very long stretch of triple digit heat is in store for the San Joaquin Valley, lower foothills and the Kern county desert. Yesterday was just the beginning of it. When this spell of very hot weather will come to an end is uncertain. The models agree that a strong upper level ridge of high pressure (596+ DM) will remain parked over the Great Basin for the next 7 days or longer. One thing that is certain is that this ridge will build over central California during the next 48 hours and remain firmly in control through Tuesday. During this period, high temps will average a good 10 degrees above normal throughout the CWA. Monday and Tuesday will be absolute scorchers in the San Joaquin Valley, lower foothills and desert where thermometer readings could top the 110 degree mark in the hottest locations. It's been a few weeks since the weather has been this hot, so folks need to be mindful of how quickly the onset of heat exhaustion and/or heat stroke can be if they're outdoors and not properly hydrated, particularly during the hottest part of the day. The heat should ease somewhat over most of the central California interior toward the middle of next week as the high pressure ridge weakens and a short wave trough in the northern branch moves into the Pacific Northwest. That doesn't mean the San Joaquin Valley, lower foothills and the desert will escape triple digits, however, a feeble onshore flow will bring some marine air through the Sacramento Delta Wednesday through Thursday and perhaps cool Merced county into the upper 90s. If so, it will be a lucky break for residents in the northern valley. Once the upper level trough exits the Pacific Northwest and moves into Idaho and Montana, the Great Basin high will build back over central California later in the week and bring and surely bring an uptick in temperatures. Once this happens, it looks as though this ridge will dominate the pattern across central California through the Labor Day weekend with a continuation of triple digit heat in the valley, lower foothills and desert. Another thing this high pressure ridge will do is suppress afternoon convection over the Sierra. Nonetheless, there will still be enough atmopheric moisture present to generate cumulus buildups over the high Sierra each of the next few afternoons. During the middle of next week the trough in the northern branch could generate just enough lift to produce isolated afternoon thunderstorms along the Sierra crest, especially near Yosemite. Finally, it remains to be seen if any tropical moisture finds its way into California later next week. With an upper level ridge so strongly entrenched over the Great Basin, tropical moisture will have difficulty getting this far north. We'll monitor it, but at this time the heat, as well as the fire danger, will be a much bigger concern over the central California interior. && .AVIATION...Areas of smoke are possible Near Yosemite National Park in association with the South Fork Wildfire. Otherwise VFR conditions can be expected over much of the central CA interior during the next 24 hours. && .AIR QUALITY ISSUES... Please see the SFOAQAHNX for an Air Quality Alert. On Saturday August 26 2017... Unhealthy for sensitive groups in Fresno... Kern... Kings... Madera and Tulare Counties and Sequoia National Park and Forest. Further information is available at Valleyair.org && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is high. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.php for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... Excessive Heat Warning from 11 AM Sunday to 9 PM PDT Tuesday BELOW 5000 FEET FOR THE CAZ095. Excessive Heat Warning from 11 AM Sunday to 9 PM PDT Tuesday CAZ089>094. Excessive Heat Warning from 11 AM Sunday to 9 PM PDT Tuesday CAZ098-099. && public...Durfee avn/fw...Bean synopsis...Durfee weather.gov/hanford
8 heat. Local standard time, as filed.
High temperatures were between 106 and 112 degrees at several locations from August 26 through August 31.
High temperatures were between 106 and 112 degrees at several locations from August 26 through August 31.
High temperatures were between 106 and 112 degrees at several locations from August 26 through August 31.
High temperatures were between 106 and 112 degrees at several locations from August 26 through August 31.
High temperatures were between 104 and 110 degrees at several locations from August 26 through August 31.
High temperatures were between 104 and 110 degrees at several locations from August 26 through August 31.
High temperatures were between 106 and 112 degrees at several locations from August 26 through August 31.
High temperatures were between 106 and 112 degrees at several locations from August 26 through August 31.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2017Every state in 2017This day in weather historyWarnings in California, August 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 717868, 717869, 717870, 717871, 717872, 717873, 717874, 717875.