Alert archive / Arizona / Severe Thunderstorm Watches in 2008

Severe Thunderstorm Watch 896

September 10, 20085 counties in Arizona

The Storm Prediction Center issued this severe thunderstorm watch at Sep 10, 2008, 11:47 AM MST for 5 counties in Arizona. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Sep 10, 2008, 11:47 AM MST (18:47 UTC)
Expired
Sep 10, 2008, 7:00 PM MST
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties La Paz County, AZ, Maricopa County, AZ, Mohave County, AZ, Yavapai County, AZ, Yuma County, AZ

The radar

The Flagstaff radar (KFSX), 186 km from the middle of the area, began a volume at 18:47 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
20%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 10, 11:54 AM MSTSevere Thunderstorm WarningFGZCoconino, Yavapai36 min
Sep 10, 12:59 PM MSTSevere Thunderstorm WarningPSRYuma46 min
Sep 10, 3:05 PM MSTSevere Thunderstorm WarningPSRLa Paz, Yuma55 min
Sep 10, 3:36 PM MSTSevere Thunderstorm WarningPSRLa Paz54 min
Sep 10, 3:52 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal38 min
Sep 10, 4:22 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal38 min
Sep 10, 4:31 PM MSTSevere Thunderstorm WarningPSRLa Paz46 min
Sep 10, 5:23 PM MSTSevere Thunderstorm WarningFGZYavapai37 min
Sep 10, 5:45 PM MSTSevere Thunderstorm WarningPSRMaricopa32 min
Sep 10, 6:28 PM MSTSevere Thunderstorm WarningPSRMaricopa47 min
Sep 10, 6:56 PM MSTSevere Thunderstorm WarningPSRMaricopa34 min

Discussions around it

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

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 6.8 hours before the alert went out and 165 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, Phoenix, AZ at 12:00Z on 2008-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 755 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 2008-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
755 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1658 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 10, 10:57 AM MSTMesoscale DiscussionSPCCoconino, La Paz, Maricopa, Navajo, Yavapai93 min
Sep 10, 4:15 PM MSTMesoscale DiscussionSPCGila, La Paz, Maricopa, Mohave, Pinal, Yavapai60 min

Nearby

Severe Thunderstorm Watches in Arizona, 2008Every severe thunderstorm watch in 2008

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.