A series of Pacific storms moved across California and brought periods of rain, scattered thunderstorms, heavy mountain snow, and gusty winds to northern California. Several feet of snow was reported across the Sierra which lead to significant travel impacts.
Every event with a place to put it. 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 STO wrote it up.
A series of Pacific storms moved across California and brought periods of rain, scattered thunderstorms, heavy mountain snow, and gusty winds to northern California. Several feet of snow was reported across the Sierra which lead to significant travel impacts. Heavy rain and thunderstorms also caused travel impacts as area roadways became flooded and localized mudslides occurred. Gusty winds downed some trees and power lines.
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 Apr 4, 2:42 AM PST, 4 hours 3 minutes earlier.
Area Forecast Discussion National Weather Service Sacramento CA 342 AM PDT Sat Apr 4 2020 .Synopsis... The first of a pair storm systems arrives into NorCal this morning. Rain, gusty winds, chances for thunderstorms, heavy mountain snow, and travel issues are forecast into early next week. Below average temperatures likely through Tuesday with a gradual warm up thereafter. && .Discussion... Precipitation is currently spreading into northwest California this morning, with perhaps some showers and virga hitting the western portion of our CWA. Chances for rain and snow, above 4500 feet, will gradually become more widespread throughout the day. The Winter Storm Warning remains in effect elevations above 4500 feet, with the coastal range starting at 5AM while the Sierra's warning begins at 11AM. 6 to 12 inches of snow accumulation is expected today, with higher amounts expected for tomorrow as the stronger and more potent wave moves through. Valley and foothill rain for today will range from a couple hundredths down to the northern San Joaquin Valley to nearly an inch up in Redding and some foothill communities. The bulk of this wet weather is expected to occur this morning and into the afternoon, with showers possibly lingering through the evening and overnight hours. On the heels of the initial shortwave will be a much stronger, colder system set to arrive on tomorrow. 500-mb temperatures are expected to run between -29 and -32C which is fairly anomalous for early April. While the colder plume of air aloft stays just offshore, there will be many impacts across interior Northern California. The mountains can expect a brunt of the more high- impact level issues which includes potential road closures, chain controls, snow-covered roads, and whiteout conditions at times. 2 to 3 inch hourly snow rates are a distinct possibility with tomorrow's snow totals alone possibly reaching 2 feet. For those who must travel, tomorrow (Sunday) will be a treacherous day on the roads so plan accordingly. Storm snow totals could easily reach 2 to 3 feet, locally up to 4 feet by Monday morning. Across the Valley and foothills, Sunday could prove to be a very active day. Simulated radar imagery shows some periods of locally heavy rainfall tracking through the region, especially over the foothill locations. Some ponding on roads can be expected although not anticipating any hydrologic issues given how dry the region has been this winter. Total Valley rainfall is expected to run between 1 to 2 inches, running on the higher side of the range over the northern Sacramento Valley. 2 to 4 inches will be more commonplace into the foothills given the flow getting augmented by the terrain. On the thunderstorm realm, fairly impressive vertical shear profiles set up over the west side of the Valley. Model soundings and hodographs support the threat for a few more organized storms capable of small hail, gusty winds, and perhaps a weak tornado or two. The wild card is the available instability which will be dependent on the amount of clearing which can take place. Aside from the threat for precipitation, breezy southerly winds will dominate the weekend, particularly on Sunday with gusts likely in the 30 to 40 mph range. On Monday, the upper low will fill some but remains a slow mover as it drifts toward the south. This will keep showers in the forecast with a particular focus over the mountains where a Winter Storm Warning will remain in effect into the morning hours. Snow levels do drop to around 3,000 to 4,000 feet on Monday. Throughout the remainder of the day, instability-driven showers are likely to fire with the activity waning into the evening hours. Given the close proximity of the parent low to the coast, additional thunderstorm chances exist but should be weaker given more limited vertical shear. Tuesday, conditions will start to dry out with showers potentially lingering over the Sierra. The upper low will be tracking farther south which will eventually lead to the Pacific high nudging it's way back in to norCal. We'll see temperatures start return closer to normal for some areas, with the departure from normal being anywhere zero to fifteen below the seasonal average. More seasonal weather is currently expected for Wednesday. ~BRO/KR && .EXTENDED DISCUSSION (Wednesday THROUGH Saturday)... Deep closed low forecast to be to our south during the second half of next week keeping a threat of showers across the northern Sierra Nevada, mainly to the south of Lake Tahoe. Drier weather with northerly flow expected across the remainder of the region with gradually milder temperatures. Highs expected to be above average by next weekend as ensembles in decent agreement indicating ridging from the eastern Pacific building into NorCal. && .AVIATION... Weather system moves into NorCal today with widespread MVFR, with local IFR, conditions developing by around 18Z. Snow levels 045-055. Areas southerly wind gusts 20-30 kts developing by 18Z. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 11 AM this morning to 11 AM PDT Monday for Burney Basin / Eastern Shasta County-Mountains Southwestern Shasta County to Western Colusa County-Shasta Lake Area / Northern Shasta County-West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. &&
The national radar mosaic for the moment the first event began.
12 flood, 5 winter storm, 3 winter weather. Local standard time, as filed.
A COOP observer in Chester measured a storm total of 6 inches over 48 hours, 5 inches over the past 24 hours, at elevation 2,900 feet.
Caltrans measured a storm total of 31 inches of snow at Soda Springs, elevation 6,800 feet.
Caltrans reported a storm total of 28 inches of snow at their maintenance yard in Kingvale at an elevation of 6,100 feet.
A CoCoRaHs observer reported 18 inches of new snow 1.5 SSW of Soda Springs. Elevation 6,768 feet.
Storm total of 34 inches reported by Caltrans at Hwy 207 summit at 8,000 feet.
A trained storm spotter measured 10 inches of snow in Kyburz over 24 hours, elevation 4,000 feet.
Caltrans reported a storm total of 32 inches of snow at their Cabbage Patch maintenance yard, at 6,700 feet.
A COOP observer at Pacific House reported 7 inches of snow over 24 hours, elevation 3,400 feet. Report came in on April 6.
California Highway Patrol reported 2 feet of water flooding between I80 W and Madison Avenue near North Highlands, CA.
California Highway Patrol reported 8 inches of water flooding the roadway between Eastern Ave and Marconi Ave.
California Highway Patrol reported 1 1/2 feet of water flowing across all lanes between Interstate 80 East and Auburn Boulevard near North Highlands.
California Highway Patrol reported roadway flooding between Sutters Gold Drive and Manlove Road in Rosemont, CA.
California Highway Patrol reported roadway flooding near Whitney Avenue in Carmichael, CA.
California Highway Patrol reported flooding in roadway between PFE road and Walerga Road near Antelope, CA. Nearby small creek is rising.
California Highway Patrol reported roadway flooding between Roseville Road and Antelope Road in Antelope, CA.
California Highway Patrol reported roadway flooding between Kiefer Blvd and Rosemont Drive in Rosemont, CA.
California Highway Patrol reported roadway flooding between Sunrise Blvd and Wildridge Dr in Fair Oaks, CA.
California Highway Patrol reported roadway flooding between Green Valley Rd and Lotus Rd near Rescue.
California Highway Patrol reported roadway flooding between State Route 88 and Raven Road in Pioneer, CA. Eastbound lanes are completely flooded. Westbound lanes are partially flooded.
California Highway Patrol reported roadway flooding at State Route 4 and Pool Station Road.
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, April 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: 891254, 891247, 891248, 891249, 891250, 891251, 891252, 891255, 891258, 891261, 891266, 891267, 891268, 891269, 891270, 891271, 891272, 891273, 891275, 891276.