Alert archive / Colorado / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 77, NWS Denver/Boulder, CO

June 27, 2012Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 27, 2012, 5:18 PM MDT for Washington 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: Jun 27, 2012, 5:18 PM MDT (23:18 UTC)
Expired: Jun 27, 2012, 5:45 PM MDT
In force: 27 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Washington County, CO

The radar

The Goodland radar (KGLD), 128 km from the middle of the area, began a volume at 23:17 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, 11.3 hours before the alert went out and 39 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3667 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: -20 m²/s²
0-3 km storm-relative helicity: 23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

288 
WUUS55 KBOU 272318
SVRBOU
COC121-272345-
/O.NEW.KBOU.SV.W.0077.120627T2318Z-120627T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
518 PM MDT WED JUN 27 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL WASHINGTON COUNTY IN NORTHEAST COLORADO

* UNTIL 545 PM MDT

* AT 518 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL. 
  THIS STORM WAS LOCATED 12 MILES SOUTH OF OTIS...OR 20 MILES
  SOUTHEAST OF AKRON...MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO OTIS.

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 4026 10280 3993 10280 3986 10290 4012 10304
TIME...MOT...LOC 2318Z 242DEG 26KT 3999 10287
WIND...HAIL <50MPH 1.00IN

$$

1 follow-up statement

957 
WWUS55 KBOU 272346
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
546 PM MDT WED JUN 27 2012

COC121-272356-
/O.EXP.KBOU.SV.W.0077.000000T0000Z-120627T2345Z/
WASHINGTON CO-
546 PM MDT WED JUN 27 2012

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL WASHINGTON COUNTY
HAS EXPIRED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE AREA. 
GUSTY WINDS TO 40 MPH AND SMALL HAIL CAN STILL BE EXPECTED. 

LAT...LON 4026 10280 3993 10280 3986 10290 4012 10304
TIME...MOT...LOC 2318Z 242DEG 26KT 3999 10287

$$

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 27, 10:19 AM MDT	Red Flag Warning	BOU	Boulder, Clear Creek, Douglas, Gilpin, Jefferson, Larimer and 1 more	10 hr
Jun 27, 4:10 PM MDT	Flash Flood Warning	BOU	Larimer	2 hr
Jun 27, 4:19 PM MDT	Severe Thunderstorm Warning	BOU	Morgan, Washington	41 min
Jun 27, 4:49 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Morgan, Washington, Weld	41 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2012 Every 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.