A cold low pressure system dropped southeast out of the Gulf of Alaska on December 15 and into the Pacific Northwest on December 16 pushing a cold front through central California. Most of the precipitation with this system fell just ahead of the frontal boundary with much of the Sierra Nevada and adjacent foothills picking up between a quarter to a half inch of liquid precipitation with the…
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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 cold low pressure system dropped southeast out of the Gulf of Alaska on December 15 and into the Pacific Northwest on December 16 pushing a cold front through central California. Most of the precipitation with this system fell just ahead of the frontal boundary with much of the Sierra Nevada and adjacent foothills picking up between a quarter to a half inch of liquid precipitation with the precipitation falling as snow above 3500 feet. Several stations in the Sierra Nevada estimated between 2 and 4 inches of new snowfall. Most of the San Joaquin Valley picked up between 1 and 3 tenths of an inch of rainfall. The main impact from this system; however, was a period a brief strong wind gusts along the West Side Hills and in the mountains in Kern County. Several stations reported wind gusts exceeding 40 mph while a few low impact indicator sites measured gusts exceeding 60 mph.
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 Dec 16, 1:21 AM PST, 29 minutes earlier.
Area Forecast Discussion National Weather Service Hanford CA 121 AM PST Thu Dec 16 2021 .SYNOPSIS... Valley rain and mountain snow will occur through early this afternoon due to a storm system passing through. A cool airmass in the storm's wake will lead to near freezing temperatures in rural areas of the San Joaquin Valley Friday and Saturday night. Another storm system may bring valley rain and mountain snow next week. && .DISCUSSION... Latest radar imagery shows the main rainband/cold front associated with this storm system just to the north of the forecast area, but it is shifting southward. For us, this will lead to light to moderate valley rain this morning and mountain snow. The forecast looks to be on track in regards to precip totals as well, with snowfall in the Sierra Nevada generally 1-2 feet, with isolated amounts of 3 feet in the higher elevations near YNP. Rainfall totals in the valley will range between one- tenth of an inch in the south valley near Bakersfield to 3 tenths of an inch near Merced. The front will exit the area by this evening, which may lead to periodic breezy conditions in the Kern County Desert. A chilly airmass will follow this system, leading to cold weather Friday through Sunday morning. In fact, many areas in the SJ Valley may not see highs get much above 46-48 degrees Friday or Saturday. Of course, this means morning lows will be quite cold as well. Currently, NBM guidance is showing lows near or below freezing Friday night and Saturday night, especially in rural areas of the valley. High temperatures begin to rebound Sunday afternoon due to ridging aloft. Warming continues into Monday, where Afternoon highs should be near normal, with highs in the mid 50s expected. Also on Sunday, ensemble guidance is showing a trough of low pressure dipping down from the Gulf of Alaska. This trough has the potential to bring another round of valley rain and mountain snow to the region starting late Monday. Guidance seems to point towards a ridge building over the upper low, forming a Rex Block scenario. For us, this may lead to a few days of unsettled weather as the upper low meanders off the coastline. Details on how this unfolds are still not quite clear at this time though as it's still several days away. && .AVIATION... MVFR to IFR conditions are likely through 22z Thursday due to mountain snow and valley rain. Thereafter, VFR conditions will prevail across the CA Interior. && .AIR QUALITY ISSUES... None. && .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... Winter Storm Warning until 1 PM PST this afternoon for CAZ323- 326>330. Winter Weather Advisory until 10 AM PST this morning for CAZ324. && public...Bollenbacher aviation....Bollenbacher weather.gov/hanford
The national radar mosaic for the moment the first event began.
5 high wind. Local standard time, as filed.
The PG&E station at Joaquin Ridge measured a peak wind gust of 61 mph.
The Blue Max RAWS measured a peak wind gust of 59 mph.
The Bear Peak RAWS measured a peak wind gust of 65 mph.
The Jawbone Canyon RAWS measured a peak wind gust of 60 mph.
The Bird Springs Pass RAWS measured a peak wind gust of 74 mph.
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, December 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: 989050, 989055, 989057, 989053, 989056.