A high impact winter storm passed over interior northern California bringing multiple feet of snow to the higher elevations in mountains, bountiful rain in the Valley, a mix of rain and snow for portions of the foothills, and dangerous travel conditions. High way closures and accidents were reported during the event, some directly related to the weather, while others are still under investigation.
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 STO wrote it up.
A high impact winter storm passed over interior northern California bringing multiple feet of snow to the higher elevations in mountains, bountiful rain in the Valley, a mix of rain and snow for portions of the foothills, and dangerous travel conditions. High way closures and accidents were reported during the event, some directly related to the weather, while others are still under investigation.
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 Sacramento, CA wrote its last area forecast discussion before the first event at Mar 14, 8:15 PM PST, 1 hour 45 minutes earlier.
Area Forecast Discussion National Weather Service Sacramento CA 915 PM PDT Sat Mar 14 2020 .Synopsis... Cold weather system will bring widespread rain and mountain snow this weekend into next week with mountain travel impacts and low snow levels. Below average temperatures continue through next week with unsettled weather at times. && .Discussion... The Evening Update: "Stout" upper low near 40n/128w focusing .70" PW plume from the S Bay area into the Siernev where orographics and favorable temps in the snow growth zone is resulting in widespread moderate to heavy snow over the passes. (10 inches new snow at BLU with 12" on the ground, as of 5 pm RTP.) Colfax and Oroville snow profiles indicate snow levels around 3 to 3.5 kft this evening, locally lower around 2500' at Sims along I-5 in Shasta Co where precip is much lighter compared to the Sierra. Generally, it looks as if the snow levels will remain above 3 kft over the Siernev until Sun nite. The upper low will move very little on Sun before dropping Swd along the CA coast Mon into Tue. This will continue widespread precip over the Sierra until Mon afternoon. The cold, unstable air mass associated with the upper low will be moving further inland overnite and Sun as waves of energy rotate around the upper low. Forecast soundings indicate some thin CAPE indicative of the possibility of small hail with the stronger cells. Forecast hodographs are also strongly sheared but when the soundings show a shallow "inverted-V" the hodographs straighten out, suggesting generally splitting cells. The high resolution REFs also suggest short-lived cells, and given the relatively cold surface temps (in the 50s) think that short- lived cells with small hail would be the dominate convective wx. JHM .Previous Discussion... A stout upper low currently spinning off the coast of southwestern Oregon will continue its slow migration southward over the next 24 to 48 hours. Relative to mid-March climatology, 500-mb heights will run around 2 to 2.5 standard deviations below average. The seasonably strong system is connected to a quasi-stationary surface front which currently sits along the I-80 corridor. Modest moisture pooling along this boundary has been the focus for occasional bands of showers, as well as a couple thunderstorms this morning and afternoon. To the north, a brief appearance of the Shasta County Convergence Zone bolstered thunderstorm activity earlier in the day with accumulating hail and locally heavy rainfall. Valley convection should gradually wind down by the early evening hours. Across the higher terrain, periods of heavy snow have halted traffic at times. Traveling into the Sierra this weekend is highly discouraged given the expectation of multiple feet of snow, near whiteout conditions, and treacherous road conditions. As the parent upper low pushes closer, stronger ascent with the trough combined with enhanced upslope flow will increase precipitation rates this evening into Sunday. Hourly snowfall rates should easily reach 2 to 3 inches, potentially higher at times within heftier bands. Snow levels are likely to hover between 3,000 and 3,500 feet, locally lowering during periods of heavy snow. By late Sunday into Monday, snow levels will lower further possibly bringing 4 to 8 inch accumulations into areas between 2,500 to 3,000 feet. These should be slightly lower up into the Shasta County mountains and southern Cascades, nearing 1,500 to 2,000 feet. When it is all said and done, several feet of snow is forecast across sections of the Sierra which includes the major mountain passes. This will also impact travelers going along I-5 where a foot or more is possible over Shasta County. Across the Valley, a decent convective pattern emerges on Sunday as the upper low further increases the vertical wind shear. Instability is the typical wild card when it comes to convection. If enough clearing can occur, a few semi-organized thunderstorms are possible, particularly during the afternoon hours. Overall, instability showers will be the primary focus with brief downpours and accumulating small hail in the beefier cores. The activity should gradually taper beyond sunset given the diminished instability. Overall rainfall totals will likely sit in the 0.50 to 2 inch range, while doubling into foothill locations. Would not be surprised to see some areas receive 4 to 6 inches of precipitation through early next week over orographically favored spots. With the mentioned system being a relatively slow mover, its influence will keep scattered showers in the forecast through Tuesday. Scattered thunderstorms are possible to commence the week but the shower coverage will decrease the days after as the upper low further exits the region. The overall pattern will remain cool and unsettled with high temperatures generally running around 10 to 15 degrees below climatology. ~BRO && .EXTENDED DISCUSSION (Wednesday THROUGH Saturday)... Precipitation chances continue throughout the end of next week into next weekend. Double barreled closed upper lows over CA continues to rotate around each other in a Fujiwhari effect during the middle of next week. Significant differences in related QPF during this period between deterministic models leads to a lowered confidence forecast at that time. Lows weaken and progress east Thursday as next upstream closed upper low approaches Friday into Saturday. This will lead to more unsettled weather into next weekend. PCH/HEC && .AVIATION... Areas of MVFR/IFR conditions possible within rain showers through the next 24 hours. Localized IFR conditions over the mountains as moderate to heavy snowfall expected through tomorrow with snow levels around 2000-3500 feet. Southwest Valley winds 10-15 kts, locally up to 20 kts with gusts up to 25-30 kts. Westerly mountain wind gusts up to 30 to 40 kts, locally higher. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 5 PM PDT Monday for Burney Basin / Eastern Shasta County-Motherlode-Mountains Southwestern Shasta County to Western Colusa County-Northeast Foothills/Sacramento Valley-Shasta Lake Area / Northern Shasta County-West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. &&
7 winter storm. Local standard time, as filed.
Ski resorts reported storm total snow amounts between 3 and 8 feet across the higher elevations of the Sierra.
Caltrans reported that Interstate 80 and highway 50 closed twice throughout the event due to vehicular accidents and stalled vehicles. The first event on March 15 noted that they received 2 feet of snow and that visibility was down to 30 feet.
Caltrans reported 77 inches, 6.5 feet, of snow at their Kingvale location.
A CoCoRaHS observe 3 miles east of Shingletown reported 34 inches of snow over the course of the storm.
A Cocorahs observer 1.5 miles south-southwest of Soda Springs reported 73 inches of new snow from March 15 through March 17.
Trained spotters for this event in Kyburz and Pacific House reported 29 inches and 26 inches of storm total snow.
The ASOS reported 62 inches of new snow through March 16.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2020Every state in 2020This day in weather historyWarnings in California, March 2020
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: 883314, 883315, 883316, 883317, 883318, 883319, 883320.