Alert archive / Arizona / Flash Flood Warnings in 2026

Flash Flood Warning 151, NWS Flagstaff, AZ

September 12, 2026Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 12, 2026, 2:36 PM MST for Coconino County, Arizona. It was in force for 3 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 12, 2026, 2:36 PM MST (21:36 UTC)
Expired: Sep 12, 2026, 5:30 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 21:37 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

Phoenix, AZ (KPSR), launched 12:00Z, 9.6 hours before the alert went out and 268 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: 178 J/kg
Mixed-layer CIN: -203 J/kg
Mixed-layer LCL: 1843 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 44 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 Flagstaff, AZ wrote its last area forecast discussion before this flash flood warning went out at Sep 12, 1:43 PM MST, 53 minutes earlier.

Area forecast discussion, Sep 12, 1:43 PM MST, 53 minutes before

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In the hours before

Local storm report, Sep 12, 11:21 AM MST, 3 hours 15 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.
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</body>
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The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 5:00 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	8 hr
Sep 11, 5:27 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila	33 min
Sep 11, 5:36 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	24 min
Sep 11, 6:00 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	30 min
Sep 11, 6:04 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	3 hr
Sep 11, 6:13 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Navajo	5 hr
Sep 11, 6:33 PM MST	Special Weather Statement	FGZ		27 min
Sep 11, 8:58 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Gila	3 hr
Sep 12, 12:48 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Sep 12, 12:56 PM MST	Severe Thunderstorm Warning	FGZ	Apache	34 min
Sep 12, 3:58 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	32 min
Sep 12, 4:14 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Sep 12, 4:24 PM MST	Special Weather Statement	FGZ		36 min
Sep 12, 4:46 PM MST	Special Weather Statement	FGZ		29 min

Nearby

Flash Flood Warnings in Arizona, 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.