Alert archive / Colorado / Tornado Warnings in 2009

Tornado Warning 28, NWS Denver/Boulder, CO

June 11, 2009Adams County, Arapahoe County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 11, 2009, 2:27 PM MDT for Adams County, Arapahoe County, Colorado. It was in force for 48 min. 1 report 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 11, 2009, 2:27 PM MDT (20:27 UTC)
Expired: Jun 11, 2009, 3:15 PM MDT
In force: 48 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon

Counties Adams County, CO, Arapahoe County, CO

The radar

The Denver radar (KFTG), 46 km from the middle of the area, began a volume at 20:27 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 11, 2:30 PM MDT	HAIL 1	Deer Trail, 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 11, 2:00 PM MDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.5 hours before the alert went out and 70 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: 116 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 697 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 75 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.

000 
WFUS55 KBOU 112027
TORBOU
COC001-005-112115-
/O.NEW.KBOU.TO.W.0028.090611T2027Z-090611T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
227 PM MDT THU JUN 11 2009

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN ARAPAHOE COUNTY IN NORTHEAST COLORADO
  SOUTHEASTERN ADAMS COUNTY IN NORTHEAST COLORADO

* UNTIL 315 PM MDT

* AT 226 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 4 MILES EAST OF
  BYERS...OR 39 MILES NORTHWEST OF LIMON. THIS STORM WAS MOVING EAST
  AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SHAMROCK...
  JOLLY RANCH...DEER TRAIL AND BYERS.

DAMAGING WINDS UP TO 70 MPH AND HAIL AROUND 1 INCH IN DIAMETER CAN
ALSO BE EXPECTED FROM THIS STORM

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SAFE SHELTER IS AVAILABLE...LIE FLAT IN
THE NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR
HANDS.

&&

LAT...LON 3957 10425 3986 10419 3990 10371 3957 10371
TIME...MOT...LOC 2026Z 254DEG 16KT 3971 10415

$$
BARJENBRUCH

1 follow-up statement

000 
WWUS55 KBOU 112117
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
317 PM MDT THU JUN 11 2009

COC001-005-112126-
/O.EXP.KBOU.TO.W.0028.000000T0000Z-090611T2115Z/
ARAPAHOE CO-ADAMS CO-
317 PM MDT THU JUN 11 2009

...THE TORNADO WARNING FOR SOUTHEASTERN ADAMS AND EASTERN ARAPAHOE
COUNTIES HAS EXPIRED...

THIS STORM HAS WEAKENED AND MOVED INTO WASHINGTON COUNTY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM MDT THURSDAY EVENING
FOR NORTHEASTERN COLORADO.

LAT...LON 3957 10425 3986 10419 3990 10371 3957 10371
TIME...MOT...LOC 2027Z 254DEG 16KT 3971 10414

$$
BARJENBRUCH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 10, 6:20 PM MDT	Tornado Warning	BOU	Larimer, Weld	25 min
Jun 10, 6:47 PM MDT	Areal Flood Advisory	BOU	Adams, Arapahoe, Washington	88 min
Jun 10, 6:49 PM MDT	Tornado Warning	BOU	Weld	26 min
Jun 10, 6:54 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	51 min
Jun 11, 1:12 PM MDT	Tornado Warning	BOU	Arapahoe, Douglas, Elbert	48 min
Jun 11, 1:32 PM MDT	Areal Flood Advisory	BOU	Douglas, Elbert	88 min
Jun 11, 1:41 PM MDT	Tornado Warning	BOU	Adams, Arapahoe, Elbert	49 min
Jun 11, 1:58 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan	42 min
Jun 11, 2:25 PM MDT	Areal Flood Advisory	BOU	Arapahoe	95 min
Jun 11, 3:36 PM MDT	Severe Thunderstorm Warning	BOU	Washington	54 min
Jun 11, 4:30 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	47 min

Nearby

Tornado Warnings in Colorado, 2009 Every tornado warning in 2009 Tornadoes in 2009

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.