Alert archive / Colorado / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 21, NWS Denver/Boulder, CO

June 9, 2011Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 9, 2011, 1:53 AM MDT for Weld County, Colorado. It was in force for 37 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 9, 2011, 1:53 AM MDT (07:53 UTC)
Expired
Jun 9, 2011, 2:30 AM MDT
In force
37 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 39 km from the middle of the area, began a volume at 07:53 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 00:00Z, 7.9 hours before the alert went out and 156 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-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2011-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 124 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2011-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 207 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
124 J/kg
Mixed-layer CIN
-94 J/kg
Mixed-layer LCL
2926 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
207 m²/s²
0-3 km storm-relative helicity
305 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

976 
WUUS55 KBOU 090753
SVRBOU
COC123-090830-
/O.NEW.KBOU.SV.W.0021.110609T0753Z-110609T0830Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
153 AM MDT THU JUN 9 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 230 AM MDT

* AT 153 AM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL. 
  THIS STORM WAS LOCATED 16 MILES SOUTHWEST OF HEREFORD...OR 30 MILES
  NORTH OF GREELEY...MOVING NORTHEAST AT 30 MPH.

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

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 4100 10454 4099 10415 4069 10452 4081 10470
TIME...MOT...LOC 0753Z 214DEG 27KT 4084 10453
WIND...HAIL <50MPH 1.00IN

$$
1 follow-up statement
463 
WWUS55 KBOU 090814
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
214 AM MDT THU JUN 9 2011

COC123-090830-
/O.CON.KBOU.SV.W.0021.000000T0000Z-110609T0830Z/
WELD CO-
214 AM MDT THU JUN 9 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 AM MDT
FOR NORTH CENTRAL WELD COUNTY...

AT 213 AM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL. 
THIS STORM WAS LOCATED 8 MILES SOUTHWEST OF HEREFORD...OR 37 MILES
NORTHEAST OF GREELEY...MOVING NORTHEAST AT 30 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
HEREFORD. A BRIEF FUNNEL CLOUD IS ALSO POSSIBLE WITH THIS STORM. 

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 4100 10454 4099 10415 4069 10452 4081 10470
TIME...MOT...LOC 0813Z 241DEG 25KT 4089 10434
WIND...HAIL <50MPH 1.00IN

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 8, 6:11 PM MDTSevere Thunderstorm WarningBOUAdams49 min
Jun 8, 7:00 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Weld45 min
Jun 8, 7:41 PM MDTSevere Thunderstorm WarningBOUMorgan43 min
Jun 8, 8:25 PM MDTSpecial Weather StatementBOUWeld35 min
Jun 8, 8:32 PM MDTSevere Thunderstorm WarningBOUWeld43 min
Jun 8, 8:36 PM MDTSpecial Weather StatementBOUBoulder24 min
Jun 8, 9:12 PM MDTSevere Thunderstorm WarningBOULarimer, Weld48 min
Jun 8, 10:12 PM MDTAreal Flood AdvisoryBOULarimer93 min
Jun 8, 10:38 PM MDTSevere Thunderstorm WarningBOULarimer, Weld52 min
Jun 8, 11:26 PM MDTAreal Flood AdvisoryBOULarimer3 hr
Jun 9, 12:19 AM MDTFlash Flood WarningBOULarimer3 hr

Nearby

Severe Thunderstorm Warnings in Colorado, 2011Every severe thunderstorm warning 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.