Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 130, NWS Denver/Boulder, CO

August 19, 2021Adams County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 19, 2021, 2:46 PM MDT for Adams County, Weld County, Colorado. It was in force for 29 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 19, 2021, 2:46 PM MDT (20:46 UTC)
Expired
Aug 19, 2021, 3:15 PM MDT
In force
29 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Adams County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 31 km from the middle of the area, began a volume at 20:45 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 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, 8.8 hours before the alert went out and 124 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.

485 
WUUS55 KBOU 192046
SVRBOU
COC001-123-192115-
/O.NEW.KBOU.SV.W.0130.210819T2046Z-210819T2115Z/

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

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  South central Weld County in northeastern Colorado...
  North central Adams County in northeastern Colorado...

* Until 315 PM MDT.

* At 246 PM MDT, a severe thunderstorm was located near Hudson, or 24
  miles south of Greeley, moving northeast at 25 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.

* This severe thunderstorm will be near...
  Hudson around 255 PM MDT.
  Keenesburg around 305 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3992 10473 4012 10484 4024 10457 4003 10445
TIME...MOT...LOC 2046Z 230DEG 22KT 4006 10467 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

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, 2:59 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, 4:07 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUMorgan32 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.