Alert archive / Utah / Flash Flood Warnings in 2026

Flash Flood Warning 39, NWS Grand Junction, CO

July 21, 2026San Juan County, Utah

NWS Grand Junction, CO issued this flash flood warning at Jul 21, 2026, 6:19 PM MDT for San Juan County, Utah. 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: Jul 21, 2026, 6:19 PM MDT (00:19 UTC)
Expired: Jul 21, 2026, 10:15 PM MDT
In force: 4 hr
Issued by: NWS Grand Junction, CO
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County San Juan County, UT

The radar

The Grand Junction radar (KGJX), 212 km from the middle of the area, began a volume at 00:21 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

Grand Junction, CO (KGJT), launched 00:00Z, 0.3 hours before the alert went out and 202 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: 771 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 3633 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 95 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

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 Grand Junction, CO wrote its last area forecast discussion before this flash flood warning went out at Jul 21, 5:52 PM MDT, 27 minutes earlier.

Area forecast discussion, Jul 21, 5:52 PM MDT, 27 minutes before

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In the hours before

Local storm report, Jul 21, 4:51 PM MDT, 1 hour 28 minutes before

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    <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.
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Special weather statement, Jul 21, 5:11 PM MDT, 1 hour 8 minutes before

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    <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.
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Local storm report, Jul 21, 5:29 PM MDT, 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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Special weather statement, Jul 21, 5:29 PM MDT, 50 minutes before

<!doctype html>
<html lang="en">
<head>
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  <meta name="viewport" content="width=device-width, initial-scale=1">
  <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.
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Special weather statement, Jul 21, 5:34 PM MDT, 45 minutes before

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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>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Jul 21, 5:53 PM MDT, 26 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>

The office that day

Everything else NWS Grand Junction, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 6:21 PM MDT	Special Weather Statement	GJT	Montezuma	24 min
Jul 21, 6:32 PM MDT	Special Weather Statement	GJT	Mesa	28 min
Jul 21, 7:01 PM MDT	Special Weather Statement	GJT	Mesa	29 min
Jul 22, 1:17 AM MDT	Flood Watch	GJT	Archuleta, Delta, Dolores, Eagle, Garfield, Gunnison and 12 more	26 hr
Jul 22, 11:04 AM MDT	Areal Flood Advisory	GJT	Ouray	10 hr
Jul 22, 12:43 PM MDT	Flash Flood Warning Considerable damage threat	GJT	San Miguel	3 hr
Jul 22, 1:46 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Montrose	3 hr
Jul 22, 2:08 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Montrose	3 hr
Jul 22, 3:23 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Garfield	3 hr
Jul 22, 3:59 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Mesa	3 hr
Jul 22, 4:00 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Rio Blanco	4 hr
Jul 22, 4:06 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Garfield	3 hr
Jul 22, 4:34 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Garfield	3 hr
Jul 22, 4:39 PM MDT	Special Weather Statement	GJT	Routt	36 min
Jul 22, 4:49 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Dolores, Montezuma	3 hr
Jul 22, 5:02 PM MDT	Areal Flood Warning	GJT	Mesa	3 hr
Jul 22, 5:26 PM MDT	Flash Flood Warning Considerable damage threat	GJT	San Miguel	3 hr
Jul 21, 6:10 PM MDT	Flash Flood Warning	GJT	San Juan	3 hr
Jul 21, 6:14 PM MDT	Flash Flood Warning	GJT	San Juan	4 hr
Jul 21, 6:26 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Grand, San Juan	3 hr
Jul 21, 6:44 PM MDT	Special Weather Statement	GJT	San Juan	31 min
Jul 21, 7:11 PM MDT	Areal Flood Advisory	GJT	Grand	2 hr
Jul 21, 7:22 PM MDT	Special Weather Statement	GJT	San Juan	23 min
Jul 22, 2:28 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Grand	6 hr

Nearby

Flash Flood Warnings in Utah, 2026 Every flash flood 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.