Alert archive / California / Flash Flood Warnings in 2023

Flash Flood Warning 20, NWS Phoenix, AZ

September 1, 2023Riverside County, California

NWS Phoenix, AZ issued this flash flood warning at Sep 1, 2023, 4:45 AM PDT for Riverside County, California. It was in force for 4 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: Sep 1, 2023, 4:45 AM PDT (11:45 UTC)
Expired: Sep 1, 2023, 8:45 AM PDT
In force: 4 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Riverside County, CA

The radar

The San Diego radar (KNKX), 134 km from the middle of the area, began a volume at 11:47 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.

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 Phoenix, AZ wrote its last area forecast discussion before this flash flood warning went out at Sep 1, 3:56 AM PDT, 49 minutes earlier.

Area forecast discussion, Sep 1, 3:56 AM PDT, 49 minutes before

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In the hours before

Local storm report, Aug 31, 11:04 PM PDT, 5 hours 41 minutes before

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  <title>Service Notice</title>
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</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>
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Local storm report, Aug 31, 11:20 PM PDT, 5 hours 25 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>
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Local storm report, Aug 31, 11:53 PM PDT, 4 hours 52 minutes before

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<html lang="en">
<head>
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  <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, Sep 1, 12:12 AM PDT, 4 hours 33 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, Sep 1, 12:17 AM PDT, 4 hours 28 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, Sep 1, 12:26 AM PDT, 4 hours 19 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>

The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 31, 5:43 PM PDT	Special Weather Statement	PSR	Gila	47 min
Aug 31, 6:16 PM PDT	Severe Thunderstorm Warning	PSR	Gila	44 min
Aug 31, 7:05 PM PDT	Dust Storm Warning	PSR	Maricopa, Pinal	55 min
Aug 31, 7:15 PM PDT	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	45 min
Aug 31, 7:58 PM PDT	Areal Flood Advisory	PSR	Pinal	3 hr
Aug 31, 8:02 PM PDT	Severe Thunderstorm Warning Considerable damage threat	PSR	Maricopa, Pinal	73 min
Aug 31, 8:14 PM PDT	Dust Storm Warning	PSR	Maricopa, Pinal	31 min
Aug 31, 8:24 PM PDT	Special Weather Statement	PSR	Maricopa	66 min
Aug 31, 8:33 PM PDT	Dust Storm Warning	PSR	Maricopa, Pinal	83 min
Aug 31, 8:36 PM PDT	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	69 min
Aug 31, 8:47 PM PDT	Severe Thunderstorm Warning Considerable damage threat	PSR	Maricopa, Pinal	58 min
Aug 31, 9:11 PM PDT	Severe Thunderstorm Warning	PSR	Maricopa	35 min
Aug 31, 9:18 PM PDT	Areal Flood Advisory	PSR	Maricopa, Pinal	117 min
Aug 31, 9:45 PM PDT	Severe Thunderstorm Warning	PSR	Maricopa	60 min
Aug 31, 10:00 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Maricopa	3 hr
Aug 31, 10:12 PM PDT	Dust Storm Warning	PSR	La Paz, Maricopa	63 min
Aug 31, 11:05 PM PDT	Areal Flood Advisory	PSR	Maricopa	3 hr
Sep 1, 1:18 AM PDT	Areal Flood Warning	PSR	Maricopa	3 hr
Sep 1, 2:54 AM PDT	Areal Flood Warning	PSR	Maricopa	4 hr
Sep 1, 11:01 AM PDT	Special Weather Statement	PSR	Yuma	3 hr
Sep 1, 11:33 AM PDT	Severe Thunderstorm Warning	PSR	Maricopa, Yuma	42 min
Sep 1, 11:42 AM PDT	Flash Flood Warning Considerable damage threat	PSR	Yuma	3 hr
Sep 1, 12:06 PM PDT	Areal Flood Advisory	PSR	Maricopa, Yuma	3 hr
Sep 1, 12:19 PM PDT	Dust Storm Advisory	PSR	La Paz, Yuma	56 min
Sep 1, 12:23 PM PDT	Severe Thunderstorm Warning	PSR	La Paz, Yuma	52 min
Sep 1, 12:28 PM PDT	Flash Flood Warning Considerable damage threat	PSR	La Paz, Yuma	4 hr
Sep 1, 1:04 PM PDT	Dust Storm Warning	PSR	Yuma	86 min
Sep 1, 1:24 PM PDT	Flash Flood Warning Considerable damage threat	PSR	La Paz	6 hr
Sep 1, 1:59 PM PDT	Areal Flood Advisory	PSR	La Paz, Maricopa	3 hr
Sep 1, 2:03 PM PDT	Special Weather Statement	PSR		42 min
Sep 1, 2:31 PM PDT	Dust Storm Advisory	PSR	Yuma	119 min
Sep 1, 4:30 AM PDT	Areal Flood Advisory	PSR	Riverside	15 min
Sep 1, 12:58 PM PDT	Special Weather Statement	PSR	Imperial	3 hr
Sep 1, 1:06 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	39 min
Sep 1, 1:18 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Sep 1, 1:47 PM PDT	Dust Storm Advisory	PSR	Imperial	88 min
Sep 1, 1:50 PM PDT	Severe Thunderstorm Warning	PSR	Imperial, Riverside	55 min
Sep 1, 2:03 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Sep 1, 2:16 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Riverside, San Bernardino	6 hr
Sep 1, 2:57 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial, Riverside, San Bernardino	6 hr
Sep 1, 3:57 PM PDT	Special Weather Statement	PSR	Imperial	93 min

Nearby

Flash Flood Warnings in California, 2023 Every flash flood warning in 2023

Sources

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