Alert archive / California / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 29, NWS Sacramento, CA

April 21, 2026Glenn County, California

NWS Sacramento, CA issued this severe thunderstorm warning at Apr 21, 2026, 3:10 PM PDT for Glenn County, California. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 21, 2026, 3:10 PM PDT (22:10 UTC)
Expired
Apr 21, 2026, 4:00 PM PDT
In force
50 min
Issued by
NWS Sacramento, CA
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Glenn County, CA

The radar

The Beale AFB radar (KBBX), 66 km from the middle of the area, began a volume at 22:11 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 10.2 hours before the alert went out and 208 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Oakland, CA at 12:00Z on 2026-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 2026-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
8 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
557 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
-42 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Sacramento, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 1:28 PM PDTAreal Flood AdvisorySTOAmador, Calaveras, El Dorado, Nevada, Placer, Sacramento and 5 more6 hr
Apr 21, 3:20 PM PDTSevere Thunderstorm WarningSTOTehama40 min
Apr 21, 3:56 PM PDTSevere Thunderstorm WarningSTOButte, Glenn, Tehama49 min
Apr 21, 4:41 PM PDTSpecial Weather StatementSTOTehama34 min

Nearby

Severe Thunderstorm Warnings in California, 2026Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.