Alert archive / Arizona / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 21, NWS Flagstaff, AZ

July 18, 2017Coconino County, Gila County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 18, 2017, 2:17 PM MST for Coconino County, Gila County, Arizona. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 18, 2017, 2:17 PM MST (21:17 UTC)
Expired: Jul 18, 2017, 2:45 PM MST
In force: 28 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Coconino County, AZ, Gila County, AZ

The radar

The Flagstaff radar (KFSX), 49 km from the middle of the area, began a volume at 21:19 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, 9.3 hours before the alert went out and 122 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: 172 J/kg
Mixed-layer CIN: -284 J/kg
Mixed-layer LCL: 1310 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

497 
WUUS55 KFGZ 182117
SVRFGZ
AZC005-007-182145-
/O.NEW.KFGZ.SV.W.0021.170718T2117Z-170718T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
217 PM MST TUE JUL 18 2017

The National Weather Service in Flagstaff has issued a

* Severe Thunderstorm Warning for...
  Gila County in east central Arizona...
  Coconino County in north central Arizona...

* Until 245 PM MST

* At 217 PM MST, severe thunderstorms were located along a line
  extending from 6 miles east of Haigler Creek to near Young, moving
  west at 10 mph.

  HAZARD...Quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Damage to vehicles is expected. 

* Locations impacted include...
  Haigler Creek, Young, Hunter Creek, Christopher Creek, Christopher
  Creek Campground, Alderwood Campground, Airplane Flat Campground,
  Sharp Creek Campground, Forest Road 171 Campground, Haigler Canyon
  Campground and Rim Campground.

This includes the following highways...
 State Route 288 between mile markers 294 and 311.
 State Route 260 between mile markers 272 and 281.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3433 11105 3397 11119 3394 11090 3428 11077
TIME...MOT...LOC 2117Z 099DEG 9KT 3425 11086 3403 11095 

HAIL...1.00IN
WIND...<50MPH
 
$$

MAS

1 follow-up statement

085 
WWUS55 KFGZ 182137
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
237 PM MST TUE JUL 18 2017

AZC005-007-182145-
/O.EXP.KFGZ.SV.W.0021.000000T0000Z-170718T2145Z/
Gila-Coconino-
237 PM MST TUE JUL 18 2017

...THE SEVERE THUNDERSTORM WARNING FOR GILA AND COCONINO COUNTIES
WILL EXPIRE AT 245 PM MST...

The cluster of thunderstorms near Young have weakened and the warning 
will be allowed to expire. These storms are still producing very 
heavy rain and small hail. Use caution if traveling in this area.

LAT...LON 3433 11105 3397 11119 3394 11090 3428 11077
TIME...MOT...LOC 2135Z 099DEG 9KT 3426 11091 3404 11100 

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 5:09 PM MST	Flash Flood Warning	FGZ	Yavapai	3 hr
Jul 17, 5:37 PM MST	Flash Flood Warning	FGZ	Yavapai	3 hr
Jul 17, 5:56 PM MST	Flash Flood Warning	FGZ	Yavapai	3 hr
Jul 17, 6:28 PM MST	Areal Flood Advisory	FGZ	Navajo	2 hr
Jul 17, 7:10 PM MST	Flash Flood Warning	FGZ	Navajo	2 hr
Jul 18, 3:32 AM MST	Flash Flood Watch	FGZ	Apache, Coconino, Gila, Navajo, Yavapai	40 hr
Jul 18, 12:06 PM MST	Special Weather Statement	FGZ	Yavapai	24 min
Jul 18, 12:44 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	31 min
Jul 18, 1:04 PM MST	Areal Flood Advisory	FGZ	Yavapai	3 hr
Jul 18, 1:19 PM MST	Flash Flood Warning	FGZ	Coconino, Navajo	3 hr
Jul 18, 2:21 PM MST	Areal Flood Advisory	FGZ	Coconino	114 min
Jul 18, 2:33 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	27 min
Jul 18, 2:58 PM MST	Flash Flood Warning	FGZ	Coconino, Gila, Navajo	3 hr
Jul 18, 2:58 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	15 min
Jul 18, 3:05 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	3 min
Jul 18, 3:13 PM MST	Flash Flood Warning	FGZ	Coconino	3 hr
Jul 18, 3:21 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	15 min
Jul 18, 3:37 PM MST	Flash Flood Warning	FGZ	Coconino	3 hr
Jul 18, 4:24 PM MST	Flash Flood Warning	FGZ	Yavapai	3 hr
Jul 18, 4:24 PM MST	Flash Flood Warning	FGZ	Coconino	3 hr

Nearby

Severe Thunderstorm Warnings in Arizona, 2017 Every severe thunderstorm warning in 2017

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.