Alert archive / Arizona / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 111, NWS Flagstaff, AZ

September 11, 2026Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 11, 2026, 3:01 PM MST for Coconino County, Arizona. It was in force for 17 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: Sep 11, 2026, 3:01 PM MST (22:01 UTC)
Expired: Sep 11, 2026, 3:18 PM MST
In force: 17 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 22:01 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, 10.0 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: 843 J/kg
Mixed-layer CIN: -151 J/kg
Mixed-layer LCL: 1773 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 54 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 Flagstaff, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 11, 11:41 AM MST, 3 hours 20 minutes earlier.

Area forecast discussion, Sep 11, 11:41 AM MST, 3 hours 20 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

Special weather statement, Sep 11, 11:44 AM MST, 3 hours 17 minutes before

Special Weather Statement
National Weather Service Flagstaff AZ
1144 AM MST Fri Sep 11 2026

AZZ013-016-017-111915-
Little Colorado River Valley in Navajo County AZ-White Mountains
AZ-Eastern Mogollon Rim AZ-
1144 AM MST Fri Sep 11 2026 /1244 PM MDT Fri Sep 11 2026/

...A STRONG THUNDERSTORM WILL IMPACT AREAS NEAR SHOW LOW IN NAVAJO
COUNTY UNTIL 1215 PM MST /115 PM MDT/...

At 1144 AM MST /1244 PM MDT/, Doppler radar was tracking a strong
thunderstorm over Show Low, moving southeast at 10 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
  Show Low.

This includes the following highways...
State Route 260 near mile marker 345. Highway 60 between mile markers
336 and 347. State Route 77 between mile markers 343 and 348.

This includes the following recreation areas and campgrounds...
Fool Hollow Lake Recreation Area Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3433 11010 3435 11003 3435 10999 3423 10990
      3418 11010
TIME...MOT...LOC 1843Z 333DEG 7KT 3429 11004

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Humphreys

Local storm report, Sep 11, 1:57 PM MST, 1 hour 4 minutes before

Preliminary Local Storm Report
National Weather Service Flagstaff AZ
157 PM MST Fri Sep 11 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0135 PM     Flash Flood      4 NE Linden             34.32N 110.11W
09/11/2026                   Navajo             AZ   Law Enforcement

            Lone Pine Dam Rd at Linden Draw is closed
            due to flooding.

&&

JJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 11:44 AM MST	Special Weather Statement	FGZ		31 min
Sep 11, 12:10 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	35 min
Sep 11, 12:21 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	24 min
Sep 11, 12:31 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr
Sep 11, 1:31 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	29 min
Sep 11, 1:56 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	34 min
Sep 11, 2:31 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	29 min
Sep 11, 4:00 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila, Yavapai	30 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2026 Every severe thunderstorm 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.