Alert archive / Arizona / Severe Thunderstorm Watches in 2014

Severe Thunderstorm Watch 507

September 27, 2014Coconino County, Mohave County, Yavapai County, Arizona; Clark County, Lincoln County, Nevada

The Storm Prediction Center issued this severe thunderstorm watch at Sep 27, 2014, 3:16 AM MST for Coconino County, Mohave County, Yavapai County, Arizona; Clark County, Lincoln County, Nevada. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Sep 27, 2014, 3:16 AM MST (10:16 UTC)
Expired
Sep 27, 2014, 11:00 AM MST
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt

Counties Coconino County, AZ, Mohave County, AZ, Yavapai County, AZ, Clark County, NV, Lincoln County, NV

The radar

The Las Vegas radar (KESX), 126 km from the middle of the area, began a volume at 10:16 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Sep 27, 4:59 AM MSTFlash Flood WarningVEFMohave3 hr
Sep 27, 5:25 AM MSTFlash Flood WarningVEFMohave3 hr
Sep 27, 7:03 AM MSTSevere Thunderstorm WarningVEFMohave42 min
Sep 27, 7:18 AM MSTSevere Thunderstorm WarningVEFMohave27 min
Sep 27, 7:59 AM MSTSevere Thunderstorm WarningVEFMohave19 min
Sep 27, 8:10 AM MSTFlash Flood WarningVEFMohave2 hr
Sep 27, 8:16 AM MSTFlash Flood WarningVEFMohave3 hr
Sep 27, 8:40 AM MSTFlash Flood WarningVEFMohave4 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 10.3 hours before the alert went out and 164 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 00:00Z on 2014-09-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 674 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 00:00Z on 2014-09-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.193958Sfc1 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
674 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
1353 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
9 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 26, 9:34 PM MSTMesoscale DiscussionSPCMohave2 hr
Sep 27, 1:44 AM MSTMesoscale DiscussionSPCMohave2 hr
Sep 27, 7:12 AM MSTMesoscale DiscussionSPCCoconino, Mohave, Yavapai2 hr
Sep 27, 9:53 AM MSTMesoscale DiscussionSPCCoconino, Maricopa, Yavapai67 min
Sep 27, 10:21 AM MSTSevere Thunderstorm WatchSPCCoconino, Gila, Maricopa, Navajo, Pinal, Yavapai8 hr
Sep 27, 1:40 PM MSTMesoscale DiscussionSPCCoconino, Gila, Maricopa, Navajo, Pinal, Yavapai2 hr
Sep 27, 4:08 PM MSTMesoscale DiscussionSPCGila, Graham, Navajo, Pinal2 hr

Nearby

Severe Thunderstorm Watches in Arizona, 2014Severe Thunderstorm Watches in Nevada, 2014Every severe thunderstorm watch in 2014

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.