Strong high pressure remained over central California on January 14. Areas of fog developed in the San Joaquin Valley during the evening of January 14 with clear skies, light winds and inversion conditions present.
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.
Strong high pressure remained over central California on January 14. Areas of fog developed in the San Joaquin Valley during the evening of January 14 with clear skies, light winds and inversion conditions present. The fog spread southward during the early morning of January 15 and impacted the central portion of the San Joaquin Valley mainly from State Route 198 northward and resulted in several school districts either opening late or delaying or cancelling bus service as visibility was reduced to a few hundred feet in some locations. The fog lifted into a low cloud deck by late morning which 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 Jan 14, 4:00 PM PST, 2 hours 20 minutes earlier.
Area Forecast Discussion National Weather Service Hanford CA 400 PM PST Thu Jan 14 2021 .UPDATE... Updated AIR QUALITY ISSUES section. && .SYNOPSIS...A dry, tranquil weather pattern can be expected through Sunday with night and morning fog in the San Joaquin Valley. High temperatures will be well above normal this weekend with relatively chilly nights. A cold front will bring a slight chance of showers to the high Sierra Monday and may be followed by strong and gusty northeast winds in the foothills and higher elevations of the Sierra from Fresno county northward Monday night into Tuesday. Otherwise, temperatures will trend cooler next week with continued dry weather. && .DISCUSSION...January is nearly half over and little or no precipitation has fallen yet over the central California interior. The snowpack over the southern Sierra, which is usually abundant at this time of year, is only a paltry 30 percent of normal. Except for a slight chance of a few showers near the Sierra crest Monday, the next 7 days are going to be dry and will undoubtedly push the central California interior deeper into its drought. The models are finally offering some hope that wet weather could return by the end of next week, but right now it's just a long shot. Nonetheless, it's the most encouraging news we've seen with the models in weeks, so stay tuned. In the short term, an upper level ridge of high pressure parked off the central California coast will remain in control for the next few days. The ridge will keep skies mostly clear through the weekend although areas of low clouds and fog will frequent the San Joaquin Valley each night and morning. The fog will certainly impact valley motorists with visibilities as low as 200 feet in some areas during the hours before and after daybreak. We've issued a dense fog advisory accordingly for the San Joaquin Valley for tonight and most of Friday morning. A recurrence of night and morning fog seems likely this weekend underneath the upper level ridge. Otherwise, temperatures will warm to Springlike levels the next few afternoons. Highs should be well into the 60s in the San Joaquin Valley and possibly top 70 degrees in the warmest locations. In the Sierra foothills, thermometer readings will climb well into the 70s during the next few afternoons. The nights will be relatively chilly during this period. The models show an interesting wrinkle in the pattern that did not appear a few short days ago. It's a weak upper level disturbance that is forecast to drop down the eastern side of the upper level ridge over the Pacific Sunday night. Although this feature is limited on moisture, it could bring a few showers or snow flurries to the higher elevations of the Sierra on Martin Luther King, Jr day on its way southward into southern California. In its wake, a strong northeast to southwest oriented upper level jet (140 knots) will move in over central California Monday night into Tuesday. The orientation of this upper level jet could support strong and gusty Mono-like winds in the foothills and higher elevations of the Sierra during this period. There is only medium confidence right now that this will happen, but it's certainly something we'll need to monitor. Otherwise, this offshore flow will bring a dry and much cooler air mass into the CWA by Tuesday. A short wave ridge will build into central California by Tuesday evening and turn winds aloft to a northwesterly direction by the middle of next week. Temperatures during this period will be more seasonable, but still slightly above normal over much of the CWA on days 6 and 7. As we've already suggested earlier in this discussion, a cold storm originating in the Gulf of Alaska is forecast to track southeastward later next week. If it continues on that course (big "if"), it could bring showers and much cooler weather into parts of the CWA by the 23rd of January. Don't count on that just yet. The models have done this before only to back off on that idea, so stay tuned. && .AVIATION... IFR conditions with areas of LIFR/VLIFR in fog are likely in the San Joaquin Valley between 08z and 19z Friday with MVFR conditions prevailing outside of this period in the San Joaquin Valley through 00z Saturday. VFR conditions can be expected over the remainder of the central California interior during the next 24 hours. && .AIR QUALITY ISSUES... On Friday January 15 2021...Unhealthy in Kings County. Unhealthy for sensitive groups in Fresno...Kern...Madera and Merced Counties. Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Kings... Merced and Tulare Counties. No Burning For All in Fresno... Kern and Madera Counties. 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 medium. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory from midnight tonight to 11 AM PST Friday for CAZ180>189. && synopsis...Durfee public/aviation/fw...Durfee PIO/IDSS...BSO weather.gov/hanford
3 dense fog. Local standard time, as filed.
Merced and Madera reported visibility below a quarter mile. Several school districts either opened late or delayed or cancelled bus service due to dense fog.
Hanford reported visibility below a quarter mile. Several school districts either opened late or delayed or cancelled bus service due to dense fog. California Highway Patrol paced traffic on SR 198 from the Tulare County border to Armona between 0551 PST and 0710 PST with visibility reported below 500 feet.
Lemoore reported visibility below a quarter mile. Several school districts either opened late or delayed or cancelled bus service due to dense fog.
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, January 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: 929020, 929024, 929021.