Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 35, NWS Denver/Boulder, CO

May 22, 2021Douglas County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 22, 2021, 1:56 PM MDT for Douglas County, Elbert County, Colorado. It was in force for 28 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
May 22, 2021, 1:56 PM MDT (19:56 UTC)
Expired
May 22, 2021, 2:24 PM MDT
In force
28 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Possible
Hail
1.25 in
Wind
60.0 mph

Counties Douglas County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 47 km from the middle of the area, began a volume at 19:59 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 22, 2:04 PM MDTHAIL 12 W The Pinery, CO0.375 INCH DEPTH ON GROUND, PEA TO QUARTER SIZED.

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 22, 12:20 PM MDTTornado WatchSPC8 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 7.9 hours before the alert went out and 139 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 2021-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1528 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

365 
WUUS55 KBOU 221956
SVRBOU
COC035-039-222045-
/O.NEW.KBOU.SV.W.0035.210522T1956Z-210522T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
156 PM MDT Sat May 22 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Northeastern Douglas County in northeastern Colorado...
  Northwestern Elbert County in east central Colorado...

* Until 245 PM MDT.

* At 156 PM MDT, a severe thunderstorm was located 4 miles south of
  Franktown, or 30 miles south of Denver, moving north at 25 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Castle Rock, Parker, Elizabeth, Ponderosa Park, The Pinery,
  Franktown and eastern Castle Pines.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM MDT for northeastern
and east central Colorado.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 3927 10490 3956 10485 3955 10445 3926 10449
TIME...MOT...LOC 1956Z 195DEG 20KT 3932 10475 

TORNADO...POSSIBLE
HAIL...1.25IN
WIND...60MPH
 
$$

RPK
1 follow-up statement
095 
WWUS55 KBOU 222024
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
224 PM MDT Sat May 22 2021

COC035-039-222034-
/O.CAN.KBOU.SV.W.0035.000000T0000Z-210522T2045Z/
Douglas CO-Elbert CO-
224 PM MDT Sat May 22 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DOUGLAS AND
NORTHWESTERN ELBERT COUNTIES IS CANCELLED...
                
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 has been cancelled.  However small hail, gusty
winds and heavy rain are still possible with this thunderstorm.

A Tornado Watch remains in effect until 800 PM MDT for northeastern
and east central Colorado.

LAT...LON 3927 10490 3956 10485 3955 10445 3926 10449
TIME...MOT...LOC 2022Z 195DEG 20KT 3947 10470 

$$

RPK

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 7:18 PM MDTSpecial Weather StatementBOUMorgan27 min
May 21, 10:57 PM MDTSpecial Weather StatementBOUPhillips, Sedgwick48 min
May 22, 1:11 PM MDTSevere Thunderstorm WarningBOUAdams, Logan, Morgan, Washington49 min
May 22, 1:28 PM MDTTornado Warning Tornado observedBOUMorgan17 min
May 22, 1:45 PM MDTTornado WarningBOUMorgan15 min
May 22, 1:54 PM MDTTornado Warning Tornado observedBOUMorgan, Washington36 min
May 22, 1:58 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Washington33 min
May 22, 2:05 PM MDTTornado WarningBOUAdams, Arapahoe25 min
May 22, 2:18 PM MDTSpecial Weather StatementBOUAdams42 min
May 22, 2:43 PM MDTTornado WarningBOULogan17 min
May 22, 2:46 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick44 min
May 22, 2:57 PM MDTSevere Thunderstorm WarningBOULogan, Sedgwick48 min
May 22, 3:01 PM MDTTornado WarningBOULogan29 min
May 22, 3:16 PM MDTTornado WarningBOULincoln29 min
May 22, 3:25 PM MDTSevere Thunderstorm WarningBOUWeld35 min
May 22, 3:48 PM MDTTornado WarningBOUElbert, Lincoln27 min
May 22, 3:53 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld26 min
May 22, 4:13 PM MDTTornado Warning Tornado observedBOUElbert, Lincoln32 min
May 22, 4:42 PM MDTTornado Warning Tornado observedBOUElbert, Lincoln33 min
May 22, 5:16 PM MDTTornado WarningBOUElbert, Lincoln29 min
May 22, 5:27 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln33 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.