Alert archive / Colorado / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 501
The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2011, 12:31 PM MDT for 17 counties in Colorado; 14 counties in Nebraska. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 18, 2011, 12:31 PM MDT (18:31 UTC)
- Expired
- Jun 18, 2011, 8:00 PM MDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 31 counties
Bent County, CO, Cheyenne County, CO, Crowley 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, Otero County, CO, Phillips County, CO, Prowers County, CO, Pueblo County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Arthur County, NE, Banner County, NE, Box Butte County, NE, Chase County, NE, Cheyenne County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Grant County, NE, Keith County, NE, Kimball County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE
The radar
The Denver radar (KFTG), 123 km from the middle of the area, began a volume at 18:31 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
- 50%
- 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
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
25 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 12:32 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe, Washington | 43 min |
| Jun 18, 12:57 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Elbert | 48 min |
| Jun 18, 1:20 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Washington | 40 min |
| Jun 18, 1:37 PM MDT | Tornado Warning | BOU | Elbert, Lincoln | 36 min |
| Jun 18, 1:39 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 66 min |
| Jun 18, 1:51 PM MDT | Severe Thunderstorm Warning | CYS | Scotts Bluff, Sioux | 26 min |
| Jun 18, 1:57 PM MDT | Tornado Warning | CYS | Scotts Bluff, Sioux | 17 min |
| Jun 18, 2:08 PM MDT | Severe Thunderstorm Warning | BOU | Elbert, Lincoln | 52 min |
| Jun 18, 2:19 PM MDT | Severe Thunderstorm Warning | LBF | Garden | 56 min |
| Jun 18, 2:21 PM MDT | Severe Thunderstorm Warning | CYS | Cheyenne | 19 min |
| Jun 18, 2:27 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 48 min |
| Jun 18, 2:38 PM MDT | Severe Thunderstorm Warning | GLD | Yuma | 41 min |
| Jun 18, 2:44 PM MDT | Severe Thunderstorm Warning | GLD | Kit Carson, Yuma | 61 min |
| Jun 18, 2:46 PM MDT | Tornado Warning | BOU | Lincoln | 29 min |
| Jun 18, 3:08 PM MDT | Severe Thunderstorm Warning | GLD | Cheyenne, Kit Carson | 67 min |
| Jun 18, 3:15 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 30 min |
| Jun 18, 3:16 PM MDT | Tornado Warning | GLD | Cheyenne, Kit Carson | 44 min |
| Jun 18, 3:28 PM MDT | Severe Thunderstorm Warning | GLD | Kit Carson, Yuma | 62 min |
| Jun 18, 3:45 PM MDT | Severe Thunderstorm Warning | LBF | Arthur | 45 min |
| Jun 18, 3:57 PM MDT | Tornado Warning | GLD | Cheyenne, Kit Carson | 48 min |
| Jun 18, 4:01 PM MDT | Severe Thunderstorm Warning | GLD | Kit Carson | 59 min |
| Jun 18, 4:28 PM MDT | Tornado Warning | GLD | Cheyenne | 47 min |
| Jun 18, 4:38 PM MDT | Tornado Warning | PUB | Kiowa | 52 min |
| Jun 18, 5:13 PM MDT | Tornado Warning | GLD | Cheyenne | 47 min |
| Jun 18, 5:25 PM MDT | Tornado Warning | PUB | Kiowa | 50 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
Denver, CO (KDNR), launched 12:00Z, 6.5 hours before the alert went out and 53 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
- 110 J/kg
- Mixed-layer CIN
- -160 J/kg
- Mixed-layer LCL
- 1171 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 55 m²/s²
- 0-3 km storm-relative helicity
- 52 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 17, 7:27 PM MDT | Mesoscale Discussion | SPC | Bent, Cheyenne, Crowley, Kiowa, Lincoln, Prowers | 93 min |
| Jun 18, 11:45 AM MDT | Mesoscale Discussion | SPC | Adams, Arapahoe, Cheyenne, Elbert, Kit Carson, Lincoln and 7 more | 2 hr |
| Jun 18, 4:15 PM MDT | Mesoscale Discussion | SPC | Cheyenne, Kiowa, Kit Carson, Phillips, Prowers, Sedgwick and 1 more | 90 min |
| Jun 17, 6:09 PM MDT | Severe Thunderstorm Watch | SPC | Burt, Cass, Cuming, Dakota, Dodge, Douglas and 6 more | 3 hr |
| Jun 18, 1:07 AM MDT | Mesoscale Discussion | SPC | Pawnee | 53 min |
| Jun 18, 4:36 PM MDT | Severe Thunderstorm Watch | SPC | Buffalo, Custer, Dawson, Franklin, Frontier, Furnas and 14 more | 7 hr |
Nearby
Severe Thunderstorm Watches in Colorado, 2011Severe Thunderstorm Watches in Nebraska, 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.