Areas of dense fog reformed in the center portion of the San Joaquin Valley during the afternoon of November 22. With skies becoming clear and light wind prevailing over the valley, the fog became more extensive overnight and spread across the valley and became widespread.
Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
Areas of dense fog reformed in the center portion of the San Joaquin Valley during the afternoon of November 22. With skies becoming clear and light wind prevailing over the valley, the fog became more extensive overnight and spread across the valley and became widespread. The fog lifted into a low cloud deck during the late morning and completely dissipated by early afternoon.
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 Nov 22, 3:42 PM PST, 1 hour 3 minutes earlier.
Area Forecast Discussion...Updated National Weather Service Hanford CA 342 PM PST Mon Nov 22 2021 Updated Air Quality Issues section .SYNOPSIS... Dry weather will continue through the middle of next week. A low pressure system will produce cooler temperatures for the middle of this week. Moisture trapped in the San Joaquin Valley will continue to create episodes of nighttime and morning fog. && .DISCUSSION... High pressure which had prevailed over central CA for the past few days has been displaced eastward as an upper shortwave approaches our area from the southwest. This system will bring increased mid/high clouds to our area later this afternoon and this evening. Meanwhile, some fog and low clouds have persisted into the afternoon the center portion of the San Joaquin Valley most noticeably along the State Route 99 corridor between Bakersfield and Madera to 25 miles west of State Route 99. The fog and low clouds have been dissipating and we expected the low clouds and fog to clear out by late afternoon today. The fog is not expected to be as prevalent tonight and Wednesday morning as a result of the system that will move through our area later today and early tonight which as the increased mid level clouds will inhibit as much radiation cooling from taking place as we have experienced on Sunday morning and again this morning. Following the passage of the shortwave tonight, another large upper high pressure ridge will amplify in the EPAC near 135W on Tuesday and Tuesday night producing a noticable northerly flow over our area. This will result in cooler temperatures most noticably during the nighttime hours and should provide for enough mixing to inhibit the formation of widespread fog in the San Joaquin Valley through Wednesday. The ridge is progged to shift inland on Thanksgiving Day which will allow for a some recovery in daytime temperatures. The medium range ensemble means continue to maintain upper high pressure over CA Friday through the early part of next week. This will result in a continuation of dry weather across our area and provide for a warming trend across our area with daytime temperatures expected to rise to above normal levels by the weekend. The one uncertainty that remains during this period is how much will fog impact the San Joaquin Valley during a period of high travel volume with skies expected to be mainly clear and winds expected to be light which will favor nighttime and morning fog. && .AVIATION... In the San Joaquin Valley, widespread MVFR visibility with areas of IFR visibility due to haze/mist. Areas of LIFR conditions in fog and low clouds between 08Z and 20Z Tuesday. VFR conditions will prevail elsewhere across the Central CA interior for the next 24 hours. && .AIR QUALITY ISSUES... On Tuesday, November 23rd, 2021, fireplace/wood stove burning status is: no burning unless registered in Fresno, Kern, Kern (Greater Frazier Park area), Madera, and Tulare Counties, as well as in Sequoia National Park and Forest. Further information is available at Valleyair.org. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low, medium, and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES...None. && public...DS aviation....JDB weather.gov/hanford
The national radar mosaic for the moment the first event began.
7 dense fog. Local standard time, as filed.
Visibility below a quarter mile was reported in Hanford. Several webcams showed visibility below 1000 feet.
Visibility below a quarter mile was reported in Visalia and Porterville. Several webcams showed visibility below 1000 feet.
Visibility below a quarter mile was reported in Delano. Several webcams showed visibility below 1000 feet.
Visibility below a quarter mile was reported in Atwater, Merced and Madera. Several webcams showed visibility below 1000 feet.
Several webcams showed visibility below 1000 feet.
Visibility below a quarter mile was reported in Lemoore. Several webcams showed visibility below 1000 feet.
Visibility below a quarter mile was reported in Fresno. Several webcams showed visibility below 1000 feet.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, November 2021
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: 986455, 986456, 986454, 986451, 986458, 986452, 986453.