Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 138, NWS Denver/Boulder, CO

August 19, 2021Morgan County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 19, 2021, 4:07 PM MDT for Morgan County, Colorado. It was in force for 32 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, 2021, 4:07 PM MDT (22:07 UTC)
Expired
Aug 19, 2021, 4:39 PM MDT
In force
32 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Damage threat
Considerable
Hail
1.75 in
Wind
60.0 mph

County Morgan County, CO

The radar

The Denver radar (KFTG), 72 km from the middle of the area, began a volume at 22:11 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, 4:19 PM MDTHAIL 0.753 Sse Orchard, COREPORT FROM MPING: DIME (0.75 IN.).

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
Aug 19, 1:14 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.1 hours before the alert went out and 81 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 2021-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 246 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 2021-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -59 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
246 J/kg
Mixed-layer CIN
-241 J/kg
Mixed-layer LCL
927 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
-59 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

589 
WUUS55 KBOU 192207
SVRBOU
COC087-192300-
/O.NEW.KBOU.SV.W.0138.210819T2207Z-210819T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
407 PM MDT Thu Aug 19 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Northwestern Morgan County in northeastern Colorado...

* Until 500 PM MDT.

* At 407 PM MDT, a severe thunderstorm was located 5 miles west of
  Wiggins, or 19 miles west of Fort Morgan, moving northeast at 20
  mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees. People and 
           animals outdoors will be injured. Expect hail damage to 
           roofs, siding, windows, and vehicles.

* This severe thunderstorm will be near...
  Wiggins and Orchard around 425 PM MDT.

Other locations in the path of this severe thunderstorm include
Goodrich, Jackson Reservoir and Weldona.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4023 10391 4017 10415 4038 10415 4044 10394
TIME...MOT...LOC 2207Z 245DEG 16KT 4025 10417 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

RPK
1 follow-up statement
464 
WWUS55 KBOU 192239
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
439 PM MDT Thu Aug 19 2021

COC087-192249-
/O.CAN.KBOU.SV.W.0138.000000T0000Z-210819T2300Z/
Morgan CO-
439 PM MDT Thu Aug 19 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MORGAN COUNTY 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.

A Severe Thunderstorm Watch remains in effect until 800 PM MDT for
northeastern Colorado.

LAT...LON 4023 10391 4017 10415 4038 10415 4044 10394
TIME...MOT...LOC 2239Z 245DEG 16KT 4031 10400 

$$

RPK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 1:23 PM MDTSpecial Weather StatementBOULogan22 min
Aug 19, 2:01 PM MDTSpecial Weather StatementBOULogan29 min
Aug 19, 2:13 PM MDTSpecial Weather StatementBOUBroomfield17 min
Aug 19, 2:17 PM MDTSpecial Weather StatementBOUBroomfield28 min
Aug 19, 2:24 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUBoulder, Broomfield, Jefferson36 min
Aug 19, 2:30 PM MDTSevere Thunderstorm WarningBOUDouglas30 min
Aug 19, 2:39 PM MDTTornado WarningBOUAdams, Broomfield, Jefferson36 min
Aug 19, 2:46 PM MDTSevere Thunderstorm WarningBOUAdams, Weld29 min
Aug 19, 2:59 PM MDTAreal Flood AdvisoryBOUAdams61 min
Aug 19, 3:05 PM MDTTornado WarningBOUAdams, Weld25 min
Aug 19, 3:12 PM MDTTornado WarningBOUDouglas18 min
Aug 19, 3:14 PM MDTSevere Thunderstorm WarningBOUWeld31 min
Aug 19, 3:35 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert25 min
Aug 19, 3:42 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUWeld33 min
Aug 19, 3:44 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe31 min
Aug 19, 3:46 PM MDTTornado WarningBOUDouglas, Elbert14 min
Aug 19, 3:49 PM MDTSevere Thunderstorm WarningBOUPhillips41 min
Aug 19, 3:51 PM MDTSevere Thunderstorm WarningBOUSedgwick24 min
Aug 19, 3:55 PM MDTAreal Flood AdvisoryBOUArapahoe, Denver, Douglas22 min
Aug 19, 3:58 PM MDTAreal Flood AdvisoryBOUWeld30 min
Aug 19, 4:04 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert41 min
Aug 19, 4:06 PM MDTAreal Flood AdvisoryBOULogan54 min
Aug 19, 4:10 PM MDTAreal Flood AdvisoryBOUPhillips95 min
Aug 19, 4:17 PM MDTSevere Thunderstorm WarningBOUAdams43 min
Aug 19, 4:18 PM MDTSevere Thunderstorm WarningBOUElbert42 min
Aug 19, 4:25 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUPhillips35 min
Aug 19, 4:32 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUArapahoe28 min
Aug 19, 4:34 PM MDTTornado WarningBOUPhillips26 min
Aug 19, 4:52 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUArapahoe, Elbert23 min
Aug 19, 4:57 PM MDTAreal Flood AdvisoryBOULogan50 min
Aug 19, 4:57 PM MDTTornado WarningBOUPhillips33 min
Aug 19, 5:00 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan30 min
Aug 19, 5:04 PM MDTSevere Thunderstorm WarningBOULogan25 min
Aug 19, 5:09 PM MDTFlash Flood WarningBOUPhillips3 hr
Aug 19, 5:34 PM MDTSevere Thunderstorm WarningBOUPhillips26 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.