Alert archive / California / Red Flag Warnings in 2026

Red Flag Warning 1, NWS Sacramento, CA

May 15, 202618 counties in California

NWS Sacramento, CA issued this red flag warning at May 15, 2026, 10:51 AM PDT for 18 counties in California. It took effect at May 16, 2026, 5:00 AM PDT. It was in force for 63 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 15, 2026, 10:51 AM PDT (17:51 UTC)
In effect from
May 16, 2026, 5:00 AM PDT
Expired
May 18, 2026, 8:00 PM PDT
In force
63 hr
Issued by
NWS Sacramento, CA

Counties Amador County, CA, Butte County, CA, Calaveras County, CA, Colusa County, CA, El Dorado County, CA, Glenn County, CA, Nevada County, CA, Placer County, CA, Sacramento County, CA, San Joaquin County, CA, Shasta County, CA, Solano County, CA, Stanislaus County, CA, Sutter County, CA, Tehama County, CA, Tuolumne County, CA, Yolo County, CA, Yuba County, CA

The radar

The Sacramento radar (KDAX), 54 km from the middle of the area, began a volume at 17:51 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

Reno, NV (KREV), launched 12:00Z, 5.9 hours before the alert went out and 280 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, Reno, NV at 12:00Z on 2026-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Reno, NV at 12:00Z on 2026-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2477 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

Nearby

Red Flag Warnings in California, 2026Every red flag 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.