Alert archive / Arizona / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 106, NWS Flagstaff, AZ

August 11, 2018Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 11, 2018, 12:41 PM MST for Coconino County, Arizona. It was in force for 49 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 11, 2018, 12:41 PM MST (19:41 UTC)
Expired: Aug 11, 2018, 1:30 PM MST
In force: 49 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 19:44 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, 7.7 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-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: 409 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 617 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 124 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 11, 10:13 AM MST, 2 hours 28 minutes earlier.

Area forecast discussion, Aug 11, 10:13 AM MST, 2 hours 28 minutes before

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In the hours before

Local storm report, Aug 11, 7:45 AM MST, 4 hours 56 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
745 AM MST SAT AUG 11 2018

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

0355 PM     HAIL             5 S WILLIAMS            35.19N 112.18W
08/10/2018  M1.00 INCH       COCONINO           AZ   TRAINED SPOTTER

            STARTED AS PEA SIZED AT 3:50PM MST,
            PROGRESSED TO QUARTER SIZE.

&&

TM

Local storm report, Aug 11, 8:48 AM MST, 3 hours 53 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>
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Local storm report, Aug 11, 9:31 AM MST, 3 hours 10 minutes before

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      <div class="status" id="status">Temporary Notice</div>
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Local storm report, Aug 11, 11:50 AM MST, 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1150 AM MST SAT AUG 11 2018

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

1148 AM     HAIL             2 SW PARKS              35.25N 111.98W
08/11/2018  E0.50 INCH       COCONINO           AZ   NWS EMPLOYEE

            HALF INCH HAIL REPORTED ON I-40 NEAR MILE
            POST 175.

&&

TM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 5:24 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	51 min
Aug 10, 6:12 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	48 min
Aug 10, 6:14 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	46 min
Aug 10, 6:29 PM MST	Special Weather Statement	FGZ	Coconino	31 min
Aug 10, 6:41 PM MST	Special Weather Statement	FGZ		49 min
Aug 10, 6:52 PM MST	Areal Flood Advisory	FGZ	Coconino, Yavapai	3 hr
Aug 10, 7:02 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	43 min
Aug 10, 7:28 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	47 min
Aug 10, 7:43 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	62 min
Aug 10, 7:59 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	46 min
Aug 10, 8:31 PM MST	Severe Thunderstorm Warning	FGZ	Gila	44 min
Aug 10, 9:10 PM MST	Severe Thunderstorm Warning	FGZ	Gila	65 min
Aug 10, 9:41 PM MST	Severe Thunderstorm Warning	FGZ	Gila	34 min
Aug 10, 10:32 PM MST	Special Weather Statement	FGZ		28 min
Aug 10, 11:12 PM MST	Flash Flood Warning	FGZ	Navajo	3 hr
Aug 10, 11:21 PM MST	Special Weather Statement	FGZ		39 min
Aug 11, 12:41 AM MST	Special Weather Statement	FGZ		49 min
Aug 11, 1:30 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	45 min
Aug 11, 2:19 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	41 min
Aug 11, 2:26 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	24 min
Aug 11, 3:11 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	49 min
Aug 11, 3:28 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	32 min
Aug 11, 3:31 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	14 min
Aug 11, 3:42 PM MST	Areal Flood Advisory	FGZ	Gila, Navajo	3 hr
Aug 11, 3:52 PM MST	Flash Flood Warning	FGZ	Coconino	3 hr
Aug 11, 4:05 PM MST	Severe Thunderstorm Warning	FGZ	Gila	40 min
Aug 11, 4:19 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	12 min
Aug 11, 4:42 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	48 min
Aug 11, 4:47 PM MST	Special Weather Statement	FGZ		13 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2018 Every 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.