Alert archive / California / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 5, NWS San Francisco Bay Area, CA

February 4, 2025City and County of San Francisco, San Mateo County, California

NWS San Francisco Bay Area, CA issued this severe thunderstorm warning at Feb 4, 2025, 3:59 PM PST for City and County of San Francisco, San Mateo County, California. It was in force for 16 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: Feb 4, 2025, 3:59 PM PST (23:59 UTC)
Expired: Feb 4, 2025, 4:15 PM PST
In force: 16 min
Issued by: NWS San Francisco Bay Area, CA
Area: Storm-based polygon
Hail: 0.0 in
Wind: 60.0 mph

Counties City and County of San Francisco, CA, San Mateo County, CA

The radar

The San Francisco radar (KMUX), 67 km from the middle of the area, began a volume at 00:02 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, 12.0 hours before the alert went out and 22 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 658 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 352 m²/s²
0-3 km storm-relative helicity: 522 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 severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Francisco Bay Area, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at Feb 4, 3:54 PM PST, 5 minutes earlier.

Area forecast discussion, Feb 4, 3:54 PM PST, 5 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

In the hours before

Local storm report, Feb 4, 3:43 PM PST, 16 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Special weather statement, Feb 4, 3:46 PM PST, 13 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Feb 4, 3:52 PM PST, 7 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Feb 4, 3:53 PM PST, 6 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Feb 4, 3:57 PM PST, 2 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Feb 4, 3:58 PM PST, 1 minute before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

The office that day

Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 3, 10:23 PM PST	Areal Flood Advisory	MTR	Marin, Napa, Sonoma	3 hr
Feb 3, 10:45 PM PST	Areal Flood Advisory	MTR	Marin, Sonoma	7 hr
Feb 3, 10:51 PM PST	Areal Flood Advisory	MTR	City and County of San Francisco	3 hr
Feb 3, 10:59 PM PST	Areal Flood Advisory	MTR	Alameda, Contra Costa	8 hr
Feb 3, 11:10 PM PST	Areal Flood Warning	MTR	Sonoma	40 hr
Feb 4, 1:44 AM PST	Areal Flood Advisory	MTR	City and County of San Francisco	8 hr
Feb 4, 2:05 AM PST	River Flood Warning	MTR	Sonoma	61 hr
Feb 4, 3:02 AM PST	Areal Flood Advisory	MTR	City and County of San Francisco, San Mateo, Santa Cruz	5 hr
Feb 4, 3:47 AM PST	Areal Flood Advisory	MTR	Santa Clara, Santa Cruz	6 hr
Feb 4, 7:09 AM PST	Areal Flood Advisory	MTR	Sonoma	14 hr
Feb 4, 7:13 AM PST	Areal Flood Advisory	MTR	Alameda, Contra Costa	3 hr
Feb 4, 8:44 AM PST	Areal Flood Advisory	MTR	Marin, Napa, Sonoma	11 hr
Feb 4, 10:07 AM PST	Areal Flood Advisory	MTR	Marin	11 hr
Feb 4, 12:54 PM PST	Frost Advisory	MTR	Marin, Napa, Sonoma	20 hr
Feb 4, 1:30 PM PST	Special Marine Warning	MTR		30 min
Feb 4, 1:36 PM PST	Severe Thunderstorm Warning Considerable damage threat	MTR	Marin, Sonoma	39 min
Feb 4, 1:48 PM PST	Areal Flood Advisory	MTR	Marin, Sonoma	6 hr
Feb 4, 2:00 PM PST	Special Marine Warning	MTR		30 min
Feb 4, 2:13 PM PST	Areal Flood Advisory	MTR	City and County of San Francisco, San Mateo	6 hr
Feb 4, 2:15 PM PST	Severe Thunderstorm Warning Considerable damage threat	MTR	Marin	45 min
Feb 4, 2:31 PM PST	Special Marine Warning	MTR		29 min
Feb 4, 3:03 PM PST	Severe Thunderstorm Warning Considerable damage threat	MTR	Marin, City and County of San Francisco, San Mateo	27 min
Feb 4, 3:05 PM PST	Areal Flood Warning	MTR	Sonoma	9 hr
Feb 4, 3:07 PM PST	Special Marine Warning	MTR		23 min
Feb 4, 3:20 PM PST	Special Marine Warning	MTR		25 min
Feb 4, 3:29 PM PST	Severe Thunderstorm Warning Considerable damage threat	MTR	Marin, City and County of San Francisco, San Mateo	31 min
Feb 4, 3:41 PM PST	Special Marine Warning	MTR		34 min
Feb 4, 3:46 PM PST	Special Weather Statement	MTR	Santa Cruz	29 min

Nearby

Severe Thunderstorm Warnings in California, 2025 Every severe thunderstorm 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.