A large upper trough that was associated with a deep upper low that dropped out of the Gulf of Alaska on November 7 before pushing through southwestern Canada on November 8 and 9 pushed a moist cold front through central California between the evening of November 8 and the early afternoon of November 9. This system brought between three quarters of an inch to an inch and a quarter of liquid…
Every event with a place to put it; 9 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.
A large upper trough that was associated with a deep upper low that dropped out of the Gulf of Alaska on November 7 before pushing through southwestern Canada on November 8 and 9 pushed a moist cold front through central California between the evening of November 8 and the early afternoon of November 9. This system brought between three quarters of an inch to an inch and a quarter of liquid precipitation to the Yosemite Park area. Further south in the Sierra Nevada Nevada and Madera and Fresno Counties, several stations measured between a half inch and an inch of liquid precipitation while the Sierra foothills generally picked up between half an inch and an inch of rain north of Kings Canyon. South of Kings Canyon, several stations measured between a quarter inch and a half inch of liquid precipitation. The snow level was around 7500 feet for much of this event and several SNOTELS above 7500 feet picked up an estimated 4 to 6 inches of new snow. Most of the San Joaquin Valley picked up between one and three tenths of an inch of rainfall with locally higher amounts being reported in the Fresno area. Rainfall amounts in Kern County were generally a tenth of an inch or less. This storm also produced a period of increased winds over the Kern County Mountains and Deserts on November 9 with several locations reporting brief gusts exceeding 40 mph and a few low impact indicator sites briefly exceeding 60 mph. The precipitation moved out of the area by early afternoon on November 9 and the winds diminished later in the afternoon as the frontal system moved out of the area.
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 8, 3:46 PM PST, 6 hours 14 minutes earlier.
Area Forecast Discussion National Weather Service Hanford CA 346 PM PST Mon Nov 8 2021 .UPDATE...Updated air quality issues section. && .SYNOPSIS... An approaching storm system will bring rainfall to parts of the San Joaquin Valley and Sierra foothills as well as snowfall mainly above 7,000 feet to areas primarily north of Kern County tonight through Tuesday afternoon. The remainder of the week will be dry with slightly above average temperatures. Tule fog will be possible in the San Joaquin Valley Wednesday through the weekend. && .DISCUSSION... Eastern Pacific impulse moving through the westerly flow aloft associated with a deep parent low located just off-shore of the western Canadian coastline will bring valley rainfall and mountain snows to the area later this evening. Current satellite imagery shows the northern part of the easterly moving impulse moving into northern California and the remainder will continue to approach central California this evening. This will increase chances of precipitation for the northern parts of the CWA. Unfortunately, Kern County looks to mainly be left out of the action aside from a few light showers perhaps. The precipitation as usual will trend from little in the south to more in the north and heavier amounts in the higher elevations due to the orographic forcing. A trace of rainfall from northern Kern County to a bit more than half an inch of rainfall in the Merced area is expected while the western SJV will see a trace to four tenths of precipitation while in the Sierra foothills about an inch of rainfall will fall. In the mountains mainly above 7000 feet and from about the Tulare/Fresno County line northward thorough Yosemite N.P. snowfall will accumulate from 6 to 12 inches and even some localized amounts in the highest elevations of 15 to 18 inches will be possible. A Winter Weather Advisory is in effect beginning at 10 pm tonight until 4 pm tomorrow afternoon to address this event and mountain roads will be slick. So if venturing up in these areas it would be advisable to carry snow chains and take it slow on the wet roads. Campers and hikers should be prepared for winter conditions, the wet nature of the snow can also cause more weight on tree limbs which could fall due to the added weight. So definitely keep this in mind when setting camp and stay away from underneath trees if possible. Snow levels this evening will start out around 6000 feet but by tomorrow morning will be close to 9000 feet. So a few snow showers this evening around the 6000 foot elevation would be possible but will quickly transition to rainfall. Any remaining precipitation will begin to dissipate tomorrow afternoon and early evening as the system moves east into the Four Corners region. Ridging will be right on it's heels and this brings the next concern of nighttime/morning fog to the area. Any rainfall received from the passing system will allow ample moisture to create development of fog. Synoptically speaking, the best fog development time frame looks to be Friday and Saturday as we get the ridge axis optimal alignment but nighttime and morning fog will be possible Wednesday after the system has exited and through the weekend as ridging is in close proximity to the region. So be sure to give yourself plenty of travel time later this week and keep an eye on the forecast for the latest developments. Temperatures through the forecast period look to remain slightly below to near normal levels, which current normal high temperature values for Fresno is 69 degrees, and 70 degrees for Bakersfield. && .AVIATION...Precipitation spreading in from the northwest after 00Z Tuesday with mountain obscuring IFR conditions developing over the Sierra Nevada after 00z Tuesday. MVFR in rainfall and haze for the San Joaquin Valley from 06z through 20z Tuesday. Otherwise, VFR conditions will prevail elsewhere over the central California interior during the next 24 hours. && .AIR QUALITY ISSUES... On Tuesday November 9 2021... Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Fresno County. 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 an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 10 PM this evening to 4 PM PST Tuesday for CAZ323-326>328. && public...Andersen aviation....Andersen weather.gov/hanford
The national radar mosaic for the moment the first event began.
5 winter weather, 4 high wind. Local standard time, as filed.
Several higher elevations SNOTELS picked up an estimated 4 and 6 inches of new snowfall.
Several higher elevations SNOTELS picked up an estimated 4 and 6 inches of new snowfall.
Several higher elevations SNOTELS picked up an estimated 4 and 6 inches of new snowfall.
Several higher elevations SNOTELS picked up an estimated 4 and 6 inches of new snowfall.
Several higher elevations SNOTELS picked up an estimated 4 and 6 inches of new snowfall.
The Bear Peak RAWS measured a peak wind gust of 58 mph.
The Bird Springs Pass RAWS measured a peak wind gust of 62 mph.
The Blue Max RAWS measured a peak wind gust of 70 mph.
The Jawbone Canyon RAWS measured a peak wind gust of 62 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, 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: 985128, 985129, 985130, 985131, 985132, 984843, 984844, 984845, 984878.