Alert archive / California / Flash Flood Warnings in 2025

Flash Flood Warning 3, NWS Sacramento, CA

December 21, 2025Shasta County, California

NWS Sacramento, CA issued this flash flood warning at Dec 21, 2025, 4:43 PM PST for Shasta County, California. It was in force for 5 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: Dec 21, 2025, 4:43 PM PST (00:43 UTC)
Expired: Dec 21, 2025, 10:04 PM PST
In force: 5 hr
Issued by: NWS Sacramento, CA
Area: Storm-based polygon
Flood severity: None

County Shasta County, CA

The radar

The Beale AFB radar (KBBX), 145 km from the middle of the area, began a volume at 00:48 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 00:00Z, 0.7 hours before the alert went out and 338 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 736 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 188 m²/s²
0-3 km storm-relative helicity: 181 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Dec 21, 1:32 PM PST, 3 hours 11 minutes earlier.

Area forecast discussion, Dec 21, 1:32 PM PST, 3 hours 11 minutes before

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In the hours before

Local storm report, Dec 21, 2:40 PM PST, 2 hours 3 minutes before

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Local storm report, Dec 21, 2:52 PM PST, 1 hour 51 minutes before

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Local storm report, Dec 21, 2:53 PM PST, 1 hour 50 minutes before

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Local storm report, Dec 21, 3:06 PM PST, 1 hour 37 minutes before

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      <h1 id="headline">This service is currently unavailable.</h1>
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        Please try again in a few minutes.
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Local storm report, Dec 21, 3:08 PM PST, 1 hour 35 minutes before

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      <h1 id="headline">This service is currently unavailable.</h1>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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      <p id="message2">
        Please try again in a few minutes.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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Local storm report, Dec 21, 3:53 PM PST, 50 minutes before

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<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
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The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 21, 10:04 PM PST	Areal Flood Warning	STO	Shasta	14 hr
Dec 22, 8:29 AM PST	River Flood Warning	STO	Tehama	8 hr
Dec 22, 10:15 AM PST	Winter Storm Warning	STO		4 days
Dec 22, 10:25 AM PST	High Wind Watch	STO		19 hr
Dec 22, 11:01 AM PST	Areal Flood Advisory	STO	Alpine, Amador, El Dorado, Nevada, Placer	5 hr

Nearby

Flash Flood Warnings in California, 2025 Every flash flood warning in 2025

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.