Alert archive / Colorado / Tornado Warnings in 2015

Tornado Warning 53, NWS Denver/Boulder, CO

August 11, 2015Adams County, Denver County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Aug 11, 2015, 4:04 PM MDT for Adams County, Denver County, Colorado. It was in force for 26 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
Aug 11, 2015, 4:04 PM MDT (22:04 UTC)
Expired
Aug 11, 2015, 4:30 PM MDT
In force
26 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Adams County, CO, Denver County, CO

The radar

The Denver radar (KFTG), 14 km from the middle of the area, began a volume at 22:07 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 nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 10.1 hours before the alert went out and 127 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 12:00Z on 2015-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 12:00Z on 2015-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
7 J/kg
Mixed-layer CIN
-292 J/kg
Mixed-layer LCL
2089 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
62 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.

855 
WFUS55 KBOU 112204
TORBOU
COC001-031-112230-
/O.NEW.KBOU.TO.W.0053.150811T2204Z-150811T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
404 PM MDT TUE AUG 11 2015

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN DENVER COUNTY IN NORTHEASTERN COLORADO...
  SOUTHWESTERN ADAMS COUNTY IN NORTHEASTERN COLORADO...

* UNTIL 430 PM MDT

* AT 403 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED NEAR DENVER INTERNATIONAL AIRPORT...OR 13 MILES
  NORTHEAST OF DENVER...NEARLY STATONARY.

  HAZARD...TORNADO AND QUARTER SIZE HAIL. 

  SOURCE...WEATHER SPOTTERS REPORTED FUNNEL CLOUD. 

  IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
           SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. 
           DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE 
           DAMAGE IS LIKELY. 

* LOCATIONS IMPACTED INCLUDE...
  NORTHEASTERN DENVER...NORTHWESTERN AURORA...EASTERN COMMERCE
  CITY...DENVER INTERNATIONAL AIRPORT AND D.I.A. TERMINAL AND
  CONCOURSES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A BASEMENT OR AN INTERIOR ROOM ON THE LOWEST
FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF YOU ARE IN A MOBILE
HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE IN
DENVER.

&&

LAT...LON 3974 10469 3974 10484 3990 10473 3990 10462
TIME...MOT...LOC 2203Z 092DEG 6KT 3982 10473 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

COOPER
1 follow-up statement
722 
WWUS55 KBOU 112229
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
429 PM MDT TUE AUG 11 2015

COC001-031-112238-
/O.EXP.KBOU.TO.W.0053.000000T0000Z-150811T2230Z/
DENVER CO-ADAMS CO-
429 PM MDT TUE AUG 11 2015

...THE TORNADO WARNING FOR NORTHEASTERN DENVER AND SOUTHWESTERN ADAMS
COUNTIES WILL EXPIRE AT 430 PM MDT...
                
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER APPEARS CAPABLE OF PRODUCING A TORNADO.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.

LAT...LON 3974 10469 3974 10484 3990 10473 3990 10462
TIME...MOT...LOC 2226Z 092DEG 6KT 3982 10473 

$$

COOPER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 2:16 PM MDTAreal Flood AdvisoryBOULarimer3 hr
Aug 11, 3:14 PM MDTSpecial Weather StatementBOUDouglas46 min
Aug 11, 3:39 PM MDTSpecial Weather StatementBOUDenver51 min
Aug 11, 3:55 PM MDTTornado Warning Tornado observedBOUArapahoe35 min
Aug 11, 4:26 PM MDTSevere Thunderstorm WarningBOUArapahoe, Douglas10 min
Aug 11, 4:40 PM MDTAreal Flood AdvisoryBOUArapahoe, Denver, Douglas95 min

Nearby

Tornado Warnings in Colorado, 2015Every tornado warning in 2015Tornadoes in 2015

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.