Alert archive / Colorado / Severe Thunderstorm Watches in 2018
Severe Thunderstorm Watch 246
The Storm Prediction Center issued this severe thunderstorm watch at Jun 30, 2018, 2:03 PM MDT for 12 counties in Colorado; 8 counties in Nebraska; Goshen County, Laramie County, Wyoming. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 30, 2018, 2:03 PM MDT (20:03 UTC)
- Expired
- Jun 30, 2018, 8:50 PM MDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 22 counties
Adams County, CO, Arapahoe County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO, Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sioux County, NE, Goshen County, WY, Laramie County, WY
The radar
The Cheyenne radar (KCYS), 106 km from the middle of the area, began a volume at 20:03 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
- 50%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 2:55 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 22 min |
| Jun 30, 3:23 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 37 min |
| Jun 30, 3:39 PM MDT | Severe Thunderstorm Warning | CYS | Cheyenne, Kimball | 36 min |
| Jun 30, 3:40 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 25 min |
| Jun 30, 3:59 PM MDT | Severe Thunderstorm Warning | BOU | Larimer, Weld | 31 min |
| Jun 30, 4:04 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 26 min |
| Jun 30, 4:09 PM MDT | Severe Thunderstorm Warning | CYS | Cheyenne, Morrill | 52 min |
| Jun 30, 4:30 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 30 min |
| Jun 30, 4:42 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 32 min |
| Jun 30, 4:43 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 17 min |
| Jun 30, 4:57 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 33 min |
| Jun 30, 5:07 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 21 min |
| Jun 30, 5:13 PM MDT | Severe Thunderstorm Warning | BOU | Morgan, Weld | 33 min |
| Jun 30, 5:39 PM MDT | Severe Thunderstorm Warning | PUB | El Paso, Teller | 36 min |
| Jun 30, 5:41 PM MDT | Severe Thunderstorm Warning | PUB | El Paso | 34 min |
| Jun 30, 6:08 PM MDT | Severe Thunderstorm Warning | BOU | Elbert | 37 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 (KDEN), launched 12:00Z, 8.1 hours before the alert went out and 129 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
- 189 J/kg
- Mixed-layer CIN
- -224 J/kg
- Mixed-layer LCL
- 806 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- -36 m²/s²
- 0-3 km storm-relative helicity
- -44 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 1:03 PM MDT | Mesoscale Discussion | SPC | Adams, Broomfield, Larimer, Logan, Morgan, Phillips and 3 more | 87 min |
| Jun 30, 4:40 PM MDT | Mesoscale Discussion | SPC | Adams, Arapahoe, Denver, Douglas, Elbert, El Paso and 9 more | 2 hr |
| Jun 30, 5:09 PM MDT | Severe Thunderstorm Watch | SPC | Cheyenne, Kit Carson, Yuma | 7 hr |
| Jun 29, 8:37 PM MDT | Mesoscale Discussion | SPC | Franklin, Furnas, Gosper, Harlan, Kearney, Phelps and 2 more | 113 min |
| Jun 30, 12:35 AM MDT | Mesoscale Discussion | SPC | Antelope, Arthur, Banner, Blaine, Brown, Garden and 12 more | 85 min |
| Jun 30, 11:40 AM MDT | Mesoscale Discussion | SPC | Boone, Burt, Butler, Clay, Colfax, Cuming and 19 more | 3 hr |
| Jun 30, 12:39 PM MDT | Severe Thunderstorm Watch | SPC | Burt, Butler, Cass, Dodge, Douglas, Gage and 12 more | 7 hr |
| Jun 30, 2:11 PM MDT | Mesoscale Discussion | SPC | Adams, Boone, Buffalo, Chase, Clay, Custer and 29 more | 94 min |
| Jun 30, 2:26 PM MDT | Severe Thunderstorm Watch | SPC | Adams, Arthur, Blaine, Buffalo, Chase, Cherry and 39 more | 8 hr |
| Jun 30, 2:40 PM MDT | Mesoscale Discussion | SPC | Cass, Dodge, Douglas, Lancaster, Otoe, Sarpy and 3 more | 2 hr |
| Jun 30, 3:40 PM MDT | Mesoscale Discussion | SPC | Nemaha, Pawnee, Richardson | 95 min |
| Jun 30, 5:09 PM MDT | Mesoscale Discussion | SPC | Adams, Arthur, Blaine, Buffalo, Butler, Cass and 46 more | 96 min |
Nearby
Severe Thunderstorm Watches in Colorado, 2018Severe Thunderstorm Watches in Nebraska, 2018Severe Thunderstorm Watches in Wyoming, 2018Every severe thunderstorm watch in 2018
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.