Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 64, NWS Denver/Boulder, CO

June 13, 2021Adams County, Arapahoe County, Denver County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 13, 2021, 4:59 PM MDT for Adams County, Arapahoe County, Denver County, Colorado. It was in force for 31 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 13, 2021, 4:59 PM MDT (22:59 UTC)
Expired
Jun 13, 2021, 5:30 PM MDT
In force
31 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

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

The radar

The Denver radar (KFTG), 20 km from the middle of the area, began a volume at 23:00 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
Jun 13, 5:00 PM MDTHAIL 1.51 Nne Aurora, CO

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 12:00Z, 11.0 hours before the alert went out and 131 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 2021-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 827 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 2021-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.1939Sfc1 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
827 J/kg
Mixed-layer CIN
-387 J/kg
Mixed-layer LCL
1858 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
10 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

393 
WUUS55 KBOU 132259
SVRBOU
COC001-005-031-132330-
/O.NEW.KBOU.SV.W.0064.210613T2259Z-210613T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
459 PM MDT Sun Jun 13 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Western Arapahoe County in northeastern Colorado...
  East central Denver County in northeastern Colorado...
  Southwestern Adams County in northeastern Colorado...

* Until 530 PM MDT.

* At 458 PM MDT, a severe thunderstorm was located over northwestern
  Aurora, or 7 miles east of Denver, moving east at 15 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
           vehicles is expected.

* Locations impacted include...
  Northeastern Denver, Aurora, Arapahoe Park and Buckley AFB. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3965 10484 3978 10485 3983 10461 3960 10460
TIME...MOT...LOC 2258Z 266DEG 12KT 3974 10480 

HAIL...1.00IN
WIND...60MPH
 
$$

SCHLATTER
2 follow-up statements
270 
WWUS55 KBOU 132315
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
515 PM MDT Sun Jun 13 2021

COC031-132325-
/O.CAN.KBOU.SV.W.0064.000000T0000Z-210613T2330Z/
Denver CO-
515 PM MDT Sun Jun 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL DENVER COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3968 10482 3977 10482 3978 10477 3977 10477
      3977 10474 3980 10474 3982 10467 3981 10466
      3982 10465 3983 10461 3966 10467
TIME...MOT...LOC 2315Z 266DEG 12KT 3974 10472 

$$

COC001-005-132330-
/O.CON.KBOU.SV.W.0064.000000T0000Z-210613T2330Z/
Arapahoe CO-Adams CO-
515 PM MDT Sun Jun 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM MDT
FOR NORTHWESTERN ARAPAHOE AND SOUTH CENTRAL ADAMS COUNTIES...

At 515 PM MDT, a severe thunderstorm was located over northwestern
Aurora, or 11 miles east of Denver, moving east at 15 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Aurora and Buckley AFB. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3968 10482 3977 10482 3978 10477 3977 10477
      3977 10474 3980 10474 3982 10467 3981 10466
      3982 10465 3983 10461 3966 10467
TIME...MOT...LOC 2315Z 266DEG 12KT 3974 10472 

HAIL...1.00IN
WIND...<50MPH
 
$$

SCHLATTER
941 
WWUS55 KBOU 132323
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
523 PM MDT Sun Jun 13 2021

COC001-005-132332-
/O.EXP.KBOU.SV.W.0064.000000T0000Z-210613T2330Z/
Arapahoe CO-Adams CO-
523 PM MDT Sun Jun 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ARAPAHOE AND
SOUTH CENTRAL ADAMS COUNTIES WILL EXPIRE AT 530 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  there is still a 
severe thunderstorm warning in effect for Western Arapahoe County 
until 5:30 PM.

LAT...LON 3968 10482 3977 10482 3978 10477 3977 10477
      3977 10474 3980 10474 3982 10467 3981 10466
      3982 10465 3983 10461 3966 10467
TIME...MOT...LOC 2322Z 266DEG 12KT 3974 10472 

$$

SCHLATTER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 13, 4:02 PM MDTSpecial Weather StatementBOUDouglas43 min
Jun 13, 4:27 PM MDTSpecial Weather StatementBOUDenver33 min
Jun 13, 4:38 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver37 min
Jun 13, 5:14 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver31 min
Jun 13, 5:45 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver, Douglas31 min
Jun 13, 5:54 PM MDTSevere Thunderstorm WarningBOUWeld51 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2021Every severe thunderstorm warning in 2021

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.