Alert archive / Arizona / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 50, NWS Phoenix, AZ

August 21, 2023Gila County, Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 21, 2023, 4:03 PM MST for Gila County, Maricopa County, Pinal County, Arizona. It was in force for 42 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: Aug 21, 2023, 4:03 PM MST (23:03 UTC)
Expired: Aug 21, 2023, 4:45 PM MST
In force: 42 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Gila County, AZ, Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 13 km from the middle of the area, began a volume at 23:02 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

Tuscon, AZ (KTUS), launched 12:00Z, 11.1 hours before the alert went out and 145 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: 414 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 1145 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.0

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 Phoenix, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 21, 2:50 PM MST, 1 hour 13 minutes earlier.

Area forecast discussion, Aug 21, 2:50 PM MST, 1 hour 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>

In the hours before

Special weather statement, Aug 21, 3:10 PM MST, 53 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
310 PM MST Mon Aug 21 2023

AZZ541-545-547>549-551>553-555>558-560>563-220100-
Fountain Hills/East Mesa-Mazatzal Mountains-Tonto Basin-Cave
Creek/New River-Northwest Pinal County-San Carlos-East
Valley-Southeast Valley/Queen Creek-Apache Junction/Gold
Canyon-Dripping Springs-Superior-Rio Verde/Salt
River-Pinal/Superstition Mountains-Southeast Gila County-New River
Mesa-Globe/Miami-
310 PM MST Mon Aug 21 2023

...STRONG TO SEVERE THUNDERSTORMS EXPECTED ACROSS GILA...MARICOPA AND
PINAL COUNTIES...

Conditions are favorable for the development of isolated to
scattered strong to severe thunderstorms through the rest of the
afternoon across eastern Maricopa, Pinal, and Gila Counties.

Wind gusts of 50 to 55 mph and half inch hail will be possible with
any strong storm with the possibility of a few isolated severe
thunderstorms.

Locations impacted include...
Mesa, Gilbert, Apache Junction, Florence, Fountain Hills, Coolidge,
Globe, Superior, Sycamore Creek, Roosevelt, East Mesa, Sunflower,
Gold Canyon, Sugarloaf Mountain, Ballantine Trailhead, Round Valley,
Queen Creek, San Carlos, Miami, and Gold Camp.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 3340 11041 3338 11045 3325 11044 3309 11085
      3324 11097 3278 11160 3401 11182 3401 11143
      3380 11115 3376 11099 3364 11092 3368 11084
      3366 11078 3379 11068 3385 11056 3383 11033
      3370 11016 3347 11006
TIME...MOT...LOC 2206Z 149DEG 26KT 3313 11049

CK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 3:10 PM MST	Special Weather Statement	PSR	Gila	3 hr
Aug 21, 4:37 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa, Pinal	38 min
Aug 20, 5:12 PM MST	Areal Flood Warning	PSR	Imperial, Riverside	16 hr
Aug 20, 5:34 PM MST	Areal Flood Warning	PSR	Imperial	15 hr
Aug 20, 7:43 PM MST	Areal Flood Warning	PSR	Imperial, Riverside, San Bernardino	13 hr

Nearby

Severe Thunderstorm Warnings in Arizona, 2023 Every severe thunderstorm 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.