Alert archive / Colorado / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 113, NWS Denver/Boulder, CO

July 6, 20115 counties in Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 6, 2011, 5:06 PM MDT for 5 counties in Colorado. It was in force for 39 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: Jul 6, 2011, 5:06 PM MDT (23:06 UTC)
Expired: Jul 6, 2011, 5:45 PM MDT
In force: 39 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Adams County, CO, Logan County, CO, Morgan County, CO, Washington County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 100 km from the middle of the area, began a volume at 23:07 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 6, 2:56 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.1 hours before the alert went out and 52 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: 161 J/kg
Mixed-layer CIN: -159 J/kg
Mixed-layer LCL: 1212 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: 90 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.

469 
WUUS55 KBOU 062306
SVRBOU
COC001-075-087-121-123-062345-
/O.NEW.KBOU.SV.W.0113.110706T2306Z-110706T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
506 PM MDT WED JUL 6 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN WASHINGTON COUNTY IN NORTHEAST COLORADO
  MORGAN COUNTY IN NORTHEAST COLORADO
  SOUTHWESTERN LOGAN COUNTY IN NORTHEAST COLORADO
  EASTERN ADAMS COUNTY IN NORTHEAST COLORADO
  EAST CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 545 PM MDT

* AT 506 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING PING PONG BALL
  SIZE HAIL...AND DAMAGING WINDS UP TO ABOUT 60 MPH.  THESE STORMS
  WERE LOCATED ALONG A LINE EXTENDING FROM 11 MILES NORTHWEST OF
  PAWNEE PASS TO 5 MILES WEST OF LEADER...OR ALONG A LINE EXTENDING
  FROM 21 MILES NORTHWEST OF STERLING TO 31 MILES SOUTHWEST OF FORT
  MORGAN...MOVING EAST AT 25 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WOODROW...
  WILLARD...TWELVE-MILE CORNER...STONEHAM...SNYDER...SHAMROCK...
  PREWITT RESERVOIR...PAWNEE PASS...MERINO...LOGAN CORNERS...LOG LANE
  VILLAGE...LEADER...HOYT...HILLROSE...GARY...FORT MORGAN...BRUSH...
  ATWOOD...ANTELOPE SPRINGS...ADENA SCHOOL...ADENA AND STERLING.

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 4063 10310 4019 10345 4002 10353 3975 10379
      3983 10425 4080 10367
TIME...MOT...LOC 2306Z 290DEG 23KT 4075 10352 3990 10410
WIND...HAIL 60MPH 1.50IN

$$

1 follow-up statement

285 
WWUS55 KBOU 062336
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
536 PM MDT WED JUL 6 2011

COC123-062346-
/O.CAN.KBOU.SV.W.0113.000000T0000Z-110706T2345Z/
WELD CO-
536 PM MDT WED JUL 6 2011

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL WELD COUNTY IS
CANCELLED...

LAT...LON 4025 10383 4069 10335 4063 10310 4019 10345
      4002 10353 3975 10379 3983 10425 4004 10412
TIME...MOT...LOC 2336Z 290DEG 23KT 4068 10328 3983 10387

$$

COC001-075-087-121-062345-
/O.CON.KBOU.SV.W.0113.000000T0000Z-110706T2345Z/
WASHINGTON CO-MORGAN CO-LOGAN CO-ADAMS CO-
536 PM MDT WED JUL 6 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM MDT
FOR EASTERN ADAMS...SOUTH CENTRAL LOGAN...MORGAN AND NORTHWESTERN
WASHINGTON COUNTIES...

AT 536 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING PING PONG BALL SIZE
HAIL...AND DAMAGING WINDS UP TO ABOUT 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM 5 MILES NORTH OF LOGAN CORNERS TO
6 MILES SOUTHWEST OF SHAMROCK...OR ALONG A LINE EXTENDING FROM 8
MILES NORTHWEST OF STERLING TO 29 MILES SOUTH OF FORT MORGAN...MOVING
EAST AT 25 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WOODROW...WILLARD...TWELVE-MILE CORNER...SNYDER...SHAMROCK...PREWITT
RESERVOIR...MERINO...LOGAN CORNERS...LEADER...HOYT...HILLROSE...
GARY...FORT MORGAN...BRUSH...ATWOOD...ADENA SCHOOL...ADENA AND
STERLING.

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 4025 10383 4069 10335 4063 10310 4019 10345
      4002 10353 3975 10379 3983 10425 4004 10412
TIME...MOT...LOC 2336Z 290DEG 23KT 4068 10328 3983 10387
WIND...HAIL 60MPH 1.50IN

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 6:02 PM MDT	Special Weather Statement	BOU	Morgan	28 min
Jul 5, 7:12 PM MDT	Special Weather Statement	BOU	Logan, Washington	33 min
Jul 5, 7:29 PM MDT	Areal Flood Advisory	BOU	Morgan	91 min
Jul 5, 7:47 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Washington	43 min
Jul 5, 8:33 PM MDT	Special Weather Statement	BOU	Phillips	27 min
Jul 5, 11:07 PM MDT	Areal Flood Advisory	BOU	Grand	36 hr
Jul 6, 3:48 AM MDT	Flash Flood Watch	BOU	Boulder, Larimer	15 hr
Jul 6, 2:00 PM MDT	Special Weather Statement	BOU	Douglas	30 min
Jul 6, 2:58 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	48 min
Jul 6, 3:28 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Elbert	47 min
Jul 6, 4:02 PM MDT	Special Weather Statement	BOU	Weld	28 min
Jul 6, 4:33 PM MDT	Tornado Warning	BOU	Logan, Weld	42 min
Jul 6, 5:00 PM MDT	Severe Thunderstorm Warning	BOU	Washington	33 min
Jul 6, 5:26 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver, Weld	49 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2011 Every 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.