Alert archive / Wyoming / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 220

May 3, 200710 counties in Wyoming

The Storm Prediction Center issued this severe thunderstorm watch at May 3, 2007, 2:49 PM MDT for 10 counties in Wyoming. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 3, 2007, 2:49 PM MDT (20:49 UTC)
Expired
May 3, 2007, 8:22 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Campbell County, WY, Converse County, WY, Crook County, WY, Goshen County, WY, Johnson County, WY, Laramie County, WY, Niobrara County, WY, Platte County, WY, Sheridan County, WY, Weston County, WY

The radar

The Cheyenne radar (KCYS), 176 km from the middle of the area, began a volume at 20:51 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
10%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
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

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

IssuedProductOfficeCountiesLasted
May 3, 3:54 PM MDTSevere Thunderstorm WarningCYSConverse36 min
May 3, 3:59 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse31 min
May 3, 4:48 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse, Platte27 min
May 3, 5:03 PM MDTSevere Thunderstorm WarningCYSLaramie42 min
May 3, 5:16 PM MDTSevere Thunderstorm WarningCYSPlatte29 min
May 3, 5:41 PM MDTSevere Thunderstorm WarningCYSLaramie64 min
May 3, 5:44 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte31 min
May 3, 6:46 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie59 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

Riverton, WY (KRIW), launched 12:00Z, 8.8 hours before the alert went out and 230 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, Riverton, WY at 12:00Z on 2007-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 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, Riverton, WY at 12:00Z on 2007-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.1939587897Sfc1 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
10 J/kg
Mixed-layer CIN
-101 J/kg
Mixed-layer LCL
1895 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
51 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
May 3, 1:35 PM MDTMesoscale DiscussionSPCSheridan25 min
May 3, 2:20 PM MDTMesoscale DiscussionSPCAlbany, Campbell, Converse, Goshen, Laramie, Niobrara and 2 more85 min

Nearby

Severe Thunderstorm Watches in Wyoming, 2007Every severe thunderstorm watch in 2007

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.