Alert archive / Arizona / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 159, NWS Flagstaff, AZ

August 26, 2018Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 26, 2018, 2:31 PM MST for Coconino County, Arizona. It was in force for 29 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 26, 2018, 2:31 PM MST (21:31 UTC)
Expired: Aug 26, 2018, 3:00 PM MST
In force: 29 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.0 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 21:33 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.

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 26, 9:54 AM MST, 4 hours 37 minutes earlier.

Area forecast discussion, Aug 26, 9:54 AM MST, 4 hours 37 minutes before

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In the hours before

Special weather statement, Aug 26, 12:01 PM MST, 2 hours 30 minutes before

Special Weather Statement
National Weather Service Flagstaff AZ
1201 PM MST SUN AUG 26 2018

AZZ012-015-261930-
Little Colorado River Valley in Coconino County-Western Mogollon Rim-
1201 PM MST SUN AUG 26 2018

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

At 1200 PM MST, Doppler radar was tracking a strong thunderstorm near
Wupatki National Monument, or 28 miles north of Flagstaff, moving
northeast at 10 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Wupatki National Monument and Wupatki Visitors Center.

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.

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.

&&

LAT...LON 3547 11142 3556 11153 3573 11139 3559 11120
TIME...MOT...LOC 1900Z 218DEG 9KT 3557 11145

MCT

Special weather statement, Aug 26, 1:45 PM MST, 46 minutes before

Special Weather Statement
National Weather Service Flagstaff AZ
145 PM MST SUN AUG 26 2018

AZZ009-012-013-040-262130-
Little Colorado River Valley in Navajo County-
Little Colorado River Valley in Coconino County-
Northeast Plateaus and Mesas Hwy 264 Northward-
Northeast Plateaus and Mesas South of Hwy 264-
145 PM MST SUN AUG 26 2018

...SIGNIFICANT WEATHER ADVISORY FOR NAVAJO AND COCONINO COUNTIES
UNTIL 230 PM MST...

At 145 PM MST, Doppler radar was tracking strong thunderstorms along
a line extending from near Tuba City to 9 miles west of Tolani Lake.
Movement was east at 10 mph.

Dime size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Tuba City, Tolani Lake, Coalmine Canyon Chapter House, Tonalea,
Moenkopi, Hopi and Hopi Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3635 11096 3538 11058 3538 11107 3611 11134
TIME...MOT...LOC 2045Z 271DEG 8KT 3607 11124 3548 11100

MCT

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 25, 5:47 PM MST	Flash Flood Warning	FGZ	Apache	3 hr
Aug 26, 12:01 PM MST	Special Weather Statement	FGZ	Coconino	29 min
Aug 26, 1:45 PM MST	Special Weather Statement	FGZ		45 min
Aug 26, 2:58 PM MST	Special Weather Statement	FGZ	Coconino	32 min
Aug 26, 3:04 PM MST	Special Weather Statement	FGZ	Yavapai	26 min
Aug 26, 3:19 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	26 min
Aug 26, 3:56 PM MST	Flash Flood Warning	FGZ	Yavapai	2 hr
Aug 26, 4:14 PM MST	Special Weather Statement	FGZ	Navajo	31 min
Aug 26, 4:26 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	33 min
Aug 26, 4:30 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	45 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; radar from the NEXRAD Level II archive.