Alert archive / Colorado / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 1, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Apr 11, 2012, 4:44 PM MDT for Adams County, Arapahoe County, Denver County, Colorado. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Apr 11, 2012, 4:44 PM MDT (22:44 UTC)
- Expired
- Apr 11, 2012, 5:11 PM MDT
- In force
- 27 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 50.0 mph
Counties Adams County, CO, Arapahoe County, CO, Denver County, CO
The radar
The Denver radar (KFTG), 32 km from the middle of the area, began a volume at 22:47 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.
The nearest sounding before it
Denver, CO (KDNR), launched 12:00Z, 10.7 hours before the alert went out and 144 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
- 9 J/kg
- Mixed-layer CIN
- -468 J/kg
- Mixed-layer LCL
- 724 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 48 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
272 WUUS55 KBOU 112244 SVRBOU COC001-005-031-112330- /O.NEW.KBOU.SV.W.0001.120411T2244Z-120411T2330Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE DENVER CO 444 PM MDT WED APR 11 2012 THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHWESTERN ARAPAHOE COUNTY IN NORTHEAST COLORADO WESTERN ADAMS COUNTY IN NORTHEAST COLORADO WESTERN DENVER COUNTY IN NORTHEAST COLORADO * UNTIL 530 PM MDT * AT 444 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL. THIS STORM WAS LOCATED 2 MILES SOUTHEAST OF ENGLEWOOD...OR 7 MILES SOUTH OF DENVER...MOVING NORTH AT 25 MPH. * LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SHERIDAN... GREENWOOD VILLAGE...BARR LAKE...WESTERN CENTENNIAL...THORNTON... EASTERN NORTHGLENN...NORTHERN LITTLETON...ENGLEWOOD...CENTRAL DENVER...COMMERCE CITY AND WESTERN AURORA. PRECAUTIONARY/PREPAREDNESS ACTIONS... IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN EXCESS OF 58 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN. && LAT...LON 3996 10496 3996 10473 3958 10489 3958 10504 TIME...MOT...LOC 2244Z 202DEG 24KT 3963 10497 WIND...HAIL <50MPH 1.25IN $$
1 follow-up statement
696 WWUS55 KBOU 112311 SVSBOU SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 511 PM MDT WED APR 11 2012 COC001-005-031-112319- /O.CAN.KBOU.SV.W.0001.000000T0000Z-120411T2330Z/ ARAPAHOE CO-ADAMS CO-DENVER CO- 511 PM MDT WED APR 11 2012 ...THE SEVERE THUNDERSTORM WARNING FOR WESTERN DENVER...WESTERN ADAMS AND SOUTHWESTERN ARAPAHOE COUNTIES IS CANCELLED... THE SEVERE THUNDERSTORM WARNING HAS BEEN CANCELLED AND HAS BEEN REPLACED WITH A TORNADO WARNING...WHICH IS IN EFFECT FOR NORTHWESTERN ARAPAHOE COUNTY...WESTERN ADAMS COUNTY AND EASTERN DENVER COUNTY...UNTIL 530 PM MDT. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS. IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING LARGE DAMAGING HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS. LAT...LON 3996 10496 3996 10473 3958 10489 3958 10504 TIME...MOT...LOC 2309Z 202DEG 24KT 3978 10489 $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 11, 4:56 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver | 32 min |
| Apr 11, 5:06 PM MDT | Tornado Warning | BOU | Adams, Arapahoe, Denver | 24 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 2012Every severe thunderstorm warning in 2012
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.