Alta Sierra, CA Live Doppler Radar
Live radar for Alta Sierra, Nevada County: every NWS radar combined, rain, snow and ice colors, flash-flood risk, storm tracks and official warnings.
What weather hits Alta Sierra?
Since 1996, the National Weather Service has logged river or areal flooding on 20 days in the Northern Motherlode Between 1000-3000 ft forecast zone and Nevada County — the most common reported hazard around Alta Sierra, mostly in December and February. Next come debris flows (7 days) and flash flooding (4 days).
| Hazard | Days reported | Most recent | Worst on record |
|---|---|---|---|
| Flooding | 20 | Apr 2026 | Feb 8, 2017 · $3.6 million damage |
| Debris flows | 7 | Jun 2023 | Jan 10, 2017 · $1.1 million damage |
| Flash flooding | 4 | Aug 2025 | — |
| Lightning casualties & damage | 3 | Jul 2012 | Jul 23, 2012 · 1 death |
| Damaging thunderstorm winds | 2 | Feb 2023 | Feb 21, 2023 · $10,000 damage |
Source: NOAA NCEI Storm Events Database, 1996–2026 (the latest year is partial). A "day" is a date with at least one report in the Northern Motherlode Between 1000-3000 ft forecast zone and Nevada County; damage is as reported, not adjusted for inflation.
How much snow does Alta Sierra get?
A normal year brings about 8.6 inches of snow to Alta Sierra, based on NOAA's 1991–2020 climate normals for the Grass Valley #2 weather station 5.5 miles away. The snowiest month is usually February (3.0 in).
| Oct | Nov | Dec | Jan | Feb | Mar | Apr | May |
|---|---|---|---|---|---|---|---|
| 0.0 | 0.2 | 1.2 | 0.7 | 3.0 | 3.0 | 0.5 | 0.0 |
Normal snowfall in inches. TALON Pro compares this season's snow at your location with these normals as winter goes on.
Which radars cover Alta Sierra?
The closest NEXRAD Doppler radar is KBBX (Beale AFB, CA), about 40 miles northwest. Radar beams climb as they travel, so the height of the lowest scan over town decides how low in a storm the radar can see.
| Radar | Distance | Lowest beam over Alta Sierra | View |
|---|---|---|---|
| KBBX Beale AFB, CA | 40 mi northwest | 2,700 ft | Excellent — the lowest scan sees close to the ground |
| KDAX Sacramento, CA | 55 mi southwest | 4,000 ft | Good — most storms and steady rain or snow show clearly |
| KRGX Reno, NV | 95 mi east-northeast | 8,900 ft | Fair — the beam can pass over shallow snow and low-level rotation |
Beam height is the center of the 0.5° scan above the radar, with standard refraction. Mountains near a radar can block it further.
Tornado & hail history near Alta Sierra
Since 1950, NOAA has recorded 5 tornadoes within 25 miles of Alta Sierra. Most came in October and April. The strongest was an F1 on December 17, 1992, which passed about 22 miles northwest of town. The most recent was an EF0 on January 9, 2017, which touched down about 24 miles southwest of town.
Hail: 4 reports of 1-inch or larger hail within 25 miles since 1955; the largest was 1.00-inch hail on February 19, 2024.
Source: NOAA Storm Prediction Center — tornadoes 1950–2025, hail 1955–2025. Distances are to each tornado's track; ratings before February 2007 use the original Fujita scale.
On TALON you get Alta Sierra's live radar loop, rain/snow/ice colors, flash-flood risk, storm tracks with arrival times and NWS warnings free; close-up radar and rotation detection are part of TALON Pro.
Alta Sierra radar FAQ
Where is the nearest weather radar to Alta Sierra, CA?
KBBX (Beale AFB, CA), about 40 miles northwest. KDAX (Sacramento, CA) is 55 miles away and also covers the area.
How often does Alta Sierra flood?
Since 1996 the National Weather Service has logged river or areal flooding on 20 days in the Northern Motherlode Between 1000-3000 ft forecast zone and Nevada County. TALON's free flash-flood risk layer shows, every 2 minutes, how close the rain that has fallen is to what it takes to flood — turn it on under Layers.
Is TALON's radar for Alta Sierra free?
Yes — the US radar loop, rain/snow/ice colors, flash-flood risk, storm tracks and NWS warnings are free in any browser. Close-up radar, rotation detection and longer forecasts are part of TALON Pro.
Should I rely on radar for my safety?
No app replaces official warnings. When the National Weather Service issues a warning for Alta Sierra, follow it right away — see watch vs. warning.
Radar for nearby towns
- Colfax, CA radar 6 mi
- Grass Valley, CA radar 7 mi
- Nevada City, CA radar 9 mi
- Auburn, CA radar 16 mi
- Wheatland, CA radar 19 mi
- Lincoln, CA radar 22 mi
- Loomis, CA radar 23 mi
- Rocklin, CA radar 25 mi
- Roseville, CA radar 29 mi
- Marysville, CA radar 29 mi