Alert archive / Colorado / Tornado Warnings in 2011

Tornado Warning 35, NWS Denver/Boulder, CO

August 19, 2011Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Aug 19, 2011, 6:07 PM MDT for Morgan County, Weld County, Colorado. It was in force for 23 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
Aug 19, 2011, 6:07 PM MDT (00:07 UTC)
Expired
Aug 19, 2011, 6:30 PM MDT
In force
23 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon

Counties Morgan County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 80 km from the middle of the area, began a volume at 00:10 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

TimeReportWhereRemark
Aug 19, 6:27 PM MDTHAIL 1Orchard, COHEAVY RAIN BUT MOSTLY PEA TO MARBLE SIZE HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 0.1 hours before the alert went out and 96 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 2011-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 33 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2011-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -24 square meters per square second.19395878Sfc1 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
33 J/kg
Mixed-layer CIN
-149 J/kg
Mixed-layer LCL
2731 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
107 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.

261 
WFUS55 KBOU 200007
TORBOU
COC087-123-200030-
/O.NEW.KBOU.TO.W.0035.110820T0007Z-110820T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
607 PM MDT FRI AUG 19 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN MORGAN COUNTY IN NORTHEAST COLORADO
  CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 630 PM MDT

* AT 607 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 4 MILES
  NORTHWEST OF ORCHARD...OR 21 MILES NORTHWEST OF FORT MORGAN. THIS
  STORM WAS MOVING SOUTHEAST AT 10 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WELDONA...
  RIVERSIDE RESERVOIR...ORCHARD...JACKSON RESERVOIR AND GOODRICH.

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.

&&

LAT...LON 4052 10398 4035 10393 4028 10429 4045 10431
TIME...MOT...LOC 0007Z 238DEG 10KT 4039 10415

$$
2 follow-up statements
604 
WWUS55 KBOU 200014
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
614 PM MDT FRI AUG 19 2011

COC087-123-200030-
/O.CON.KBOU.TO.W.0035.000000T0000Z-110820T0030Z/
MORGAN CO-WELD CO-
614 PM MDT FRI AUG 19 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR CENTRAL
WELD AND NORTHWESTERN MORGAN COUNTIES...

AT 614 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS STORM WAS
LOCATED 4 MILES WEST OF ORCHARD...OR 21 MILES WEST OF FORT MORGAN.
THIS STORM WAS MOVING SOUTHEAST AT 15 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WELDONA...RIVERSIDE RESERVOIR...ORCHARD...JACKSON RESERVOIR AND
GOODRICH.

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.

&&

LAT...LON 4052 10398 4035 10393 4028 10429 4045 10431
TIME...MOT...LOC 0014Z 239DEG 12KT 4036 10417

$$
804 
WWUS55 KBOU 200029
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
629 PM MDT FRI AUG 19 2011

COC087-123-200040-
/O.EXP.KBOU.TO.W.0035.000000T0000Z-110820T0030Z/
MORGAN CO-WELD CO-
629 PM MDT FRI AUG 19 2011

...THE TORNADO WARNING FOR CENTRAL WELD AND NORTHWESTERN MORGAN
COUNTIES HAS EXPIRED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE AREA.

LAT...LON 4052 10398 4035 10393 4028 10429 4045 10431
TIME...MOT...LOC 0030Z 239DEG 12KT 4039 10411

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 6:28 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld25 min
Aug 19, 6:41 PM MDTSpecial Weather StatementBOUAdams34 min

Nearby

Tornado Warnings in Colorado, 2011Every tornado warning in 2011Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.