Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 2, NWS Denver/Boulder, CO

April 27, 2021Adams County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Apr 27, 2021, 12:49 PM MDT for Adams County, Weld County, Colorado. It was in force for 26 min. 3 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: Apr 27, 2021, 12:49 PM MDT (18:49 UTC)
Expired: Apr 27, 2021, 1:15 PM MDT
In force: 26 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Adams County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 14 km from the middle of the area, began a volume at 18:52 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

Time	Report	Where	Remark
Apr 27, 12:49 PM MDT	HAIL 0.5	8 E Denver Intl Airport, CO	AD08, GROUND COVERED WITH HAIL TO A DEPTH ABOUT 0.5 IN.
Apr 27, 1:00 PM MDT	HAIL 1	11 N Bennett, CO	REPORT VIA TWITTER. STROM CHASER DROVE THROUGH ONE INCH DIAMETER HAIL ON HIGHWAY 79.
Apr 27, 1:07 PM MDT	HAIL 0.25	8 N Manila Village, CO	0.5 INCH DEPTH OF HAIL.

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.

Issued	Product	Office	Lasted
Apr 27, 11:45 AM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 6.8 hours before the alert went out and 113 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3214 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

308 
WUUS55 KBOU 271849
SVRBOU
COC001-123-271915-
/O.NEW.KBOU.SV.W.0002.210427T1849Z-210427T1915Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
1249 PM MDT Tue Apr 27 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Southern Weld County in northeastern Colorado...
  Central Adams County in northeastern Colorado...

* Until 115 PM MDT.

* At 1248 PM MDT, a severe thunderstorm was located 8 miles northeast
  of D.I.A Terminal and Concourses, or 25 miles northeast of Denver,
  moving north at 10 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected. Hail may accumulate on 
           roadways causing hazardous travel.

* Locations impacted include...
  Northeastern Aurora, Hudson and Prospect Valley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4009 10434 3977 10438 3977 10463 3983 10463
      3983 10462 3987 10462 3987 10461 3990 10460
      3990 10463 4008 10463
TIME...MOT...LOC 1848Z 183DEG 8KT 3991 10452 

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

DANIELSON

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 27, 1:52 AM MDT	Severe Thunderstorm Warning	BOU	Washington	23 min
Apr 27, 3:16 AM MDT	Winter Storm Warning	BOU	Boulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 3 more	30 hr
Apr 27, 11:35 AM MDT	Special Weather Statement	BOU	Douglas	25 min
Apr 27, 11:55 AM MDT	Special Weather Statement	BOU	Elbert	50 min
Apr 27, 11:59 AM MDT	Special Weather Statement	BOU	Denver	31 min
Apr 27, 1:15 PM MDT	Special Weather Statement	BOU	Adams	45 min
Apr 27, 1:51 PM MDT	Special Weather Statement	BOU	Lincoln	39 min
Apr 27, 1:53 PM MDT	Special Weather Statement	BOU	Weld	37 min
Apr 27, 1:59 PM MDT	Severe Thunderstorm Warning	BOU	Weld	31 min
Apr 27, 2:02 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	28 min
Apr 27, 2:08 PM MDT	Winter Weather Advisory	BOU	Clear Creek, Douglas, Gilpin, Jefferson, Park	20 hr
Apr 27, 2:23 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	52 min
Apr 27, 2:43 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan	32 min
Apr 27, 2:49 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	41 min
Apr 27, 3:00 PM MDT	Special Weather Statement	BOU	Lincoln	45 min
Apr 27, 3:10 PM MDT	Special Weather Statement	BOU	Morgan	20 min
Apr 27, 3:13 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan, Washington	32 min
Apr 27, 3:28 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	47 min
Apr 27, 3:32 PM MDT	Special Weather Statement	BOU	Morgan	28 min
Apr 27, 3:41 PM MDT	Tornado Warning	BOU	Lincoln	34 min
Apr 27, 4:12 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	33 min
Apr 27, 4:16 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Morgan, Washington	17 min
Apr 27, 4:36 PM MDT	Tornado Warning	BOU	Lincoln	24 min
Apr 27, 5:19 PM MDT	Severe Thunderstorm Warning	BOU	Washington	26 min
Apr 27, 5:51 PM MDT	Special Weather Statement	BOU	Phillips	24 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2021 Every 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.