Alert archive / Colorado / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 586
The Storm Prediction Center issued this severe thunderstorm watch at Jul 2, 2011, 3:20 PM MDT for 19 counties in Colorado. It took effect at Jul 2, 2011, 3:25 PM MDT. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 2, 2011, 3:20 PM MDT (21:20 UTC)
- In effect from
- Jul 2, 2011, 3:25 PM MDT
- Expired
- Jul 3, 2011, 12:00 AM MDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
Counties Adams County, CO, Arapahoe County, CO, Cheyenne County, CO, Crowley County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Kiowa County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Pueblo County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO, Yuma County, CO
The radar
The Denver radar (KFTG), 70 km from the middle of the area, began a volume at 21:21 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
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
19 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 2, 3:52 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 38 min |
| Jul 2, 4:41 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 64 min |
| Jul 2, 4:45 PM MDT | Severe Thunderstorm Warning | BOU | Adams | 30 min |
| Jul 2, 5:05 PM MDT | Tornado Warning | BOU | Washington | 25 min |
| Jul 2, 5:16 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Morgan, Washington | 59 min |
| Jul 2, 5:31 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 44 min |
| Jul 2, 5:42 PM MDT | Severe Thunderstorm Warning | GLD | Cheyenne | 48 min |
| Jul 2, 5:44 PM MDT | Tornado Warning | BOU | Washington | 31 min |
| Jul 2, 5:58 PM MDT | Severe Thunderstorm Warning | BOU | Elbert, Lincoln | 62 min |
| Jul 2, 6:04 PM MDT | Severe Thunderstorm Warning | GLD | Yuma | 36 min |
| Jul 2, 6:10 PM MDT | Severe Thunderstorm Warning | GLD | Yuma | 65 min |
| Jul 2, 6:13 PM MDT | Severe Thunderstorm Warning | GLD | Cheyenne | 32 min |
| Jul 2, 6:16 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 29 min |
| Jul 2, 6:20 PM MDT | Tornado Warning | GLD | Yuma | 25 min |
| Jul 2, 6:38 PM MDT | Severe Thunderstorm Warning | GLD | Yuma | 37 min |
| Jul 2, 6:43 PM MDT | Tornado Warning | GLD | Yuma | 17 min |
| Jul 2, 7:03 PM MDT | Severe Thunderstorm Warning | GLD | Kit Carson, Yuma | 23 min |
| Jul 2, 7:09 PM MDT | Flash Flood Warning | GLD | Yuma | 4 hr |
| Jul 2, 7:31 PM MDT | Flash Flood Warning | GLD | Kit Carson | 3 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
Denver, CO (KDNR), launched 12:00Z, 9.3 hours before the alert went out and 45 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.
- Mixed-layer CAPE
- 1031 J/kg
- Mixed-layer CIN
- -97 J/kg
- Mixed-layer LCL
- 1074 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 10 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 4.9
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 2, 12:47 PM MDT | Mesoscale Discussion | SPC | Adams, Arapahoe, Boulder, Broomfield, Cheyenne, Denver and 10 more | 58 min |
| Jul 2, 5:26 PM MDT | Mesoscale Discussion | SPC | Adams, Arapahoe, Cheyenne, Crowley, Denver, Douglas and 11 more | 2 hr |
Nearby
Severe Thunderstorm Watches in Colorado, 2011Every severe thunderstorm watch in 2011
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.