Alert archive / Colorado / Tornado Warnings in 2014

Tornado Warning 17, NWS Denver/Boulder, CO

May 21, 2014Adams County, Arapahoe County, Denver County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 21, 2014, 1:56 PM MDT for Adams County, Arapahoe County, Denver County, Colorado. It was in force for 34 min. 6 reports 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
May 21, 2014, 1:56 PM MDT (19:56 UTC)
Expired
May 21, 2014, 2:30 PM MDT
In force
34 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.25 in

Counties Adams County, CO, Arapahoe County, CO, Denver County, CO

The radar

The Denver radar (KFTG), 32 km from the middle of the area, began a volume at 20:00 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
May 21, 2:05 PM MDTTORNADOW Aurora, CO
May 21, 2:10 PM MDTTORNADO3 Sw Aurora, CORAIN WRAPPED
May 21, 2:25 PM MDTHAIL 0.75Aurora, COMINOR STREET FLOODING
May 21, 2:30 PM MDTHAIL 0.5Aurora, COCOVERED THE GROUND TO A DEPTH OF 6 INCHES
May 21, 2:30 PM MDTTORNADO4 Ne Aurora, CO
May 21, 2:30 PM MDTTORNADOE Denver, 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.

IssuedProductOfficeLasted
May 21, 12:34 PM MDTTornado WatchSPC8 hr

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 7.9 hours before the alert went out and 143 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 2014-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 268 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 2014-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 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
268 J/kg
Mixed-layer CIN
-75 J/kg
Mixed-layer LCL
786 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.3

Open this sounding in Storm Lab

The text

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

079 
WFUS55 KBOU 211956
TORBOU
COC001-005-031-212030-
/O.NEW.KBOU.TO.W.0017.140521T1956Z-140521T2030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
156 PM MDT WED MAY 21 2014

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN ARAPAHOE COUNTY IN NORTHEAST COLORADO...
  CENTRAL DENVER COUNTY IN NORTHEAST COLORADO...
  WESTERN ADAMS COUNTY IN NORTHEAST COLORADO...

* UNTIL 230 PM MDT
    
* AT 156 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED OVER COMMERCE CITY...OR 6 MILES NORTHEAST OF 
  DENVER...MOVING NORTHEAST AT 10 MPH. THIS TORNADO WARNING REPLACES 
  THE SEVERE THUNDERSTORM WARNING THAT WAS IN EFFECT. 

  HAZARD...TORNADO AND HALF DOLLAR SIZE HAIL. 

  SOURCE...RADAR INDICATED ROTATION. 

  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...
  DENVER...NORTHWESTERN AURORA...SOUTHERN THORNTON...EASTERN
  ARVADA...SOUTHERN WESTMINSTER...COMMERCE CITY...SOUTHEASTERN
  NORTHGLENN...BRIGHTON...EASTERN ENGLEWOOD...GREENWOOD VILLAGE...
  FEDERAL HEIGHTS...SOUTHWESTERN DENVER INTERNATIONAL AIRPORT AND
  BARR LAKE.

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 IN A MOBILE HOME...A
VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND
PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3998 10479 3974 10468 3962 10495 3982 10506
      3984 10505 3985 10505
TIME...MOT...LOC 1956Z 226DEG 9KT 3981 10490 

TORNADO...RADAR INDICATED
HAIL...1.25IN

$$

DANKERS
2 follow-up statements
297 
WWUS55 KBOU 212008
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
208 PM MDT WED MAY 21 2014

COC001-005-031-212030-
/O.CON.KBOU.TO.W.0017.000000T0000Z-140521T2030Z/
ARAPAHOE CO-DENVER CO-ADAMS CO-
208 PM MDT WED MAY 21 2014

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 230 PM MDT FOR
NORTHWESTERN ARAPAHOE...CENTRAL DENVER AND WESTERN ADAMS COUNTIES...
    
AT 205 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR COMMERCE CITY...OR 7 MILES NORTHEAST OF DENVER... 
MOVING NORTHEAST AT 10 MPH. AN ADDITIONAL THUNDERSTORM CELL OVER THE 
SOUTHERN PARTS OF DENVER WILL PRODUCE HAIL UP TO DIME SIZE AND MAY 
ALSO PRODUCE SOME FUNNEL CLOUDS.  

A TORNADO HAS BEEN REPORTED ON THE GROUND AT TOWER ROAD AND SMITH 
ROAD.  THE TORNADO IS PROBABLY WRAPPED IN VERY HEAVY RAINFALL. 

HAZARD...TORNADO AND HALF DOLLAR SIZE HAIL. 

SOURCE...RADAR INDICATED ROTATION. 

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...
DENVER...NORTHWESTERN AURORA...SOUTHERN THORNTON...EASTERN ARVADA...
SOUTHERN WESTMINSTER...COMMERCE CITY...SOUTHEASTERN NORTHGLENN...
BRIGHTON...EASTERN ENGLEWOOD...GREENWOOD VILLAGE...FEDERAL HEIGHTS...
SOUTHWESTERN DENVER INTERNATIONAL AIRPORT AND BARR LAKE.

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 IN A MOBILE HOME...A
VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND
PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3998 10479 3974 10468 3962 10495 3982 10506
      3984 10505 3985 10505
TIME...MOT...LOC 2005Z 227DEG 9KT 3982 10488 

TORNADO...RADAR INDICATED
HAIL...1.25IN

$$

DANKERS
827 
WWUS55 KBOU 212028
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
228 PM MDT WED MAY 21 2014

COC001-005-031-212036-
/O.EXP.KBOU.TO.W.0017.000000T0000Z-140521T2030Z/
ARAPAHOE CO-DENVER CO-ADAMS CO-
228 PM MDT WED MAY 21 2014

...THE TORNADO WARNING FOR NORTHWESTERN ARAPAHOE...CENTRAL DENVER AND
WESTERN ADAMS COUNTIES WILL EXPIRE AT 230 PM MDT...
        
THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE AREA.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.  HOWEVER SMALL HAIL
AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS THUNDERSTORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM MDT WEDNESDAY EVENING
FOR NORTHEAST COLORADO.

REMEMBER...A TORNADO WARNING STILL REMAINS IN EFFECT FOR CENTAL 
ADAMS AND CENTRAL ARAPAHOE COUNTIES UNTIL 245 PM MDT. 

LAT...LON 3998 10479 3974 10468 3962 10495 3982 10506
      3984 10505 3985 10505
TIME...MOT...LOC 2023Z 226DEG 9KT 3982 10488 

$$

DANKERS

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 6:19 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Elbert, Lincoln, Washington41 min
May 20, 10:51 PM MDTSpecial Weather StatementBOUWeld39 min
May 20, 11:43 PM MDTSpecial Weather StatementBOUWeld62 min
May 20, 11:51 PM MDTAreal Flood AdvisoryBOUMorgan, Weld114 min
May 21, 6:47 AM MDTAreal Flood AdvisoryBOUMorgan3 hr
May 21, 1:00 PM MDTSevere Thunderstorm WarningBOUJefferson45 min
May 21, 1:36 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver39 min
May 21, 2:21 PM MDTSevere Thunderstorm WarningBOUAdams, Denver39 min
May 21, 2:23 PM MDTTornado WarningBOUAdams, Arapahoe, Denver22 min
May 21, 2:42 PM MDTTornado WarningBOUAdams, Arapahoe33 min
May 21, 3:18 PM MDTTornado Warning Tornado observedBOUAdams, Arapahoe, Denver27 min
May 21, 3:47 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe28 min
May 21, 3:57 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert48 min
May 21, 4:18 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe42 min
May 21, 4:57 PM MDTTornado WarningBOUAdams48 min
May 21, 5:34 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington41 min

Nearby

Tornado Warnings in Colorado, 2014Every tornado warning in 2014Tornadoes in 2014

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.