Alert archive / Arizona / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 142, NWS Flagstaff, AZ

August 14, 2018Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 14, 2018, 1:31 PM MST for Coconino County, Arizona. It was in force for 20 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 14, 2018, 1:31 PM MST (20:31 UTC)
Expired
Aug 14, 2018, 1:51 PM MST
In force
20 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Hail
1.25 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 20:34 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.5 hours before the alert went out and 68 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-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 12:00Z on 2018-08-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 89 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2018-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
89 J/kg
Mixed-layer CIN
-174 J/kg
Mixed-layer LCL
1840 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
99 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 Aug 14, 10:28 AM MST, 3 hours 3 minutes earlier.

Area forecast discussion, Aug 14, 10:28 AM MST, 3 hours 3 minutes before
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In the hours before

Local storm report, Aug 14, 8:56 AM MST, 4 hours 35 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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    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Special weather statement, Aug 14, 12:06 PM MST, 1 hour 25 minutes before
Special Weather Statement
National Weather Service Flagstaff AZ
1206 PM MST TUE AUG 14 2018

AZZ012-015-141930-
Little Colorado River Valley in Coconino County-Western Mogollon Rim-
1206 PM MST TUE AUG 14 2018

...SIGNIFICANT WEATHER ADVISORY FOR COCONINO COUNTY UNTIL 1230 PM
MST...

At 1205 PM MST, Doppler radar was tracking a strong thunderstorm near
Doney Park, or 11 miles northeast of Flagstaff. this storm was nearly
stationary.

Dime size hail and winds to 40 mph will be possible with this storm.

Locations impacted include...
Sunset Crater Volcano National Monument and Doney Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3534 11136 3521 11144 3527 11154 3539 11153
TIME...MOT...LOC 1905Z 130DEG 0KT 3531 11147

KD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 5:15 PM MSTAreal Flood AdvisoryFGZYavapai2 hr
Aug 13, 6:44 PM MSTSpecial Weather StatementFGZ46 min
Aug 13, 6:53 PM MSTSevere Thunderstorm WarningFGZApache22 min
Aug 13, 7:06 PM MSTSpecial Weather StatementFGZ24 min
Aug 13, 7:23 PM MSTSevere Thunderstorm WarningFGZApache, Navajo37 min
Aug 13, 7:42 PM MSTSevere Thunderstorm WarningFGZApache, Navajo33 min
Aug 13, 8:14 PM MSTSevere Thunderstorm WarningFGZNavajo31 min
Aug 13, 8:22 PM MSTSevere Thunderstorm WarningFGZApache23 min
Aug 14, 12:06 PM MSTSpecial Weather StatementFGZ24 min
Aug 14, 1:37 PM MSTSpecial Weather StatementFGZYavapai23 min
Aug 14, 2:40 PM MSTSpecial Weather StatementFGZ35 min
Aug 14, 2:51 PM MSTSpecial Weather StatementFGZ24 min
Aug 14, 3:02 PM MSTAreal Flood AdvisoryFGZCoconino118 min
Aug 14, 3:40 PM MSTAreal Flood AdvisoryFGZGila3 hr
Aug 14, 3:47 PM MSTSevere Thunderstorm WarningFGZGila, Navajo28 min
Aug 14, 4:01 PM MSTSevere Thunderstorm WarningFGZGila22 min
Aug 14, 4:58 PM MSTSpecial Weather StatementFGZ32 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2018Every severe thunderstorm warning in 2018

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.