Alert archive / Colorado / Tornado Warnings in 2017
Tornado Warning 9, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this tornado warning at Jun 12, 2017, 3:15 PM MDT for Weld County, Colorado. It was in force for 30 min. 4 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jun 12, 2017, 3:15 PM MDT (21:15 UTC)
- Expired
- Jun 12, 2017, 3:45 PM MDT
- In force
- 30 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 2.0 in
County Weld County, CO
The radar
The Cheyenne radar (KCYS), 52 km from the middle of the area, began a volume at 21:19 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 was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 12, 3:18 PM MDT | HAIL 1 | Nunn, CO | |
| Jun 12, 3:38 PM MDT | HAIL 2.5 | 8 N Severance, CO | |
| Jun 12, 3:43 PM MDT | HAIL 1 | Nunn, CO | |
| Jun 12, 3:45 PM MDT | HAIL 2.75 | 9 N Windsor, CO |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 12, 1:11 PM MDT | Tornado Watch | SPC | 8 hr |
The nearest sounding before it
Denver, CO (KDEN), launched 12:00Z, 9.3 hours before the alert went out and 162 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
- 697 J/kg
- Mixed-layer CIN
- -160 J/kg
- Mixed-layer LCL
- 1130 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 50 m²/s²
- 0-3 km storm-relative helicity
- 153 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
244
WFUS55 KBOU 122115
TORBOU
COC123-122145-
/O.NEW.KBOU.TO.W.0009.170612T2115Z-170612T2145Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
315 PM MDT MON JUN 12 2017
The National Weather Service in Denver Colorado has issued a
* Tornado Warning for...
Northwestern Weld County in northeastern Colorado...
* Until 345 PM MDT
* At 315 PM MDT, a severe thunderstorm capable of producing a tornado
was located 4 miles west of Pierce, or 12 miles northeast of Fort
Collins, moving northeast at 30 mph.
HAZARD...Tornado and hail up to two inches in diameter.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.
* Locations impacted include...
Severance and Nunn.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This Tornado Warning replaces the Severe Thunderstorm Warning issued
for the same area.
Motorists should not take shelter under highway overpasses. If you
cannot safely drive away from the tornado, as a last resort, either
park your vehicle and stay put, or abandon your vehicle and lie down
in a low lying area and protect yourself from flying debris.
&&
LAT...LON 4057 10486 4065 10494 4087 10479 4076 10460
TIME...MOT...LOC 2115Z 218DEG 26KT 4063 10484
TORNADO...RADAR INDICATED
HAIL...2.00IN
$$
BAKERThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 11, 9:09 PM MDT | Severe Thunderstorm Warning | BOU | Phillips | 51 min |
| Jun 11, 9:13 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 28 min |
| Jun 12, 11:07 AM MDT | Areal Flood Advisory | BOU | Grand | 24 hr |
| Jun 12, 2:29 PM MDT | Severe Thunderstorm Warning | BOU | Larimer, Weld | 46 min |
| Jun 12, 2:36 PM MDT | Severe Thunderstorm Warning | BOU | Larimer | 39 min |
| Jun 12, 3:08 PM MDT | Severe Thunderstorm Warning | BOU | Larimer | 26 min |
| Jun 12, 3:26 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 36 min |
| Jun 12, 3:45 PM MDT | Tornado Warning | BOU | Weld | 30 min |
| Jun 12, 3:46 PM MDT | Tornado Warning | BOU | Weld | 29 min |
| Jun 12, 4:13 PM MDT | Tornado Warning | BOU | Weld | 32 min |
| Jun 12, 4:35 PM MDT | Tornado Warning | BOU | Weld | 25 min |
Nearby
Tornado Warnings in Colorado, 2017Every tornado warning in 2017Tornadoes in 2017
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.