Alert archive / Colorado / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 49, NWS Denver/Boulder, CO

June 4, 2001Adams County, Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 4, 2001, 2:51 PM MDT for Adams County, Morgan County, Weld County, Colorado. It was in force for 39 min. 2 reports came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Jun 4, 2001, 2:51 PM MDT (20:51 UTC)
Expired: Jun 4, 2001, 3:30 PM MDT
In force: 39 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Adams County, CO, Morgan County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 32 km from the middle of the area, began a volume at 20:52 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
Jun 4, 3:14 PM MDT	Hail 0.75	Bennett, CO
Jun 4, 3:32 PM MDT	Hail 1	Bennett, CO

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.9 hours before the alert went out and 102 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: 454 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 650 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS55 KBOU 042051
SVRDEN
COC001-087-123-042130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
251 PM MDT MON JUN 4 2001

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL ADAMS COUNTY IN NORTHEAST COLORADO
  EXTREME SOUTHWESTERN MORGAN COUNTY IN NORTHEAST COLORADO
  SOUTH CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 330 PM MDT

* AT 251 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 9 MILES SOUTH OF KEENESBURG...OR ABOUT 29 MILES
  NORTHEAST OF DENVER...MOVING EAST AT 15 MPH.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...
KEENESBURG...PROSPECT VALLEY...RIVERSIDE RESERVOIR AND ROGGEN.

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE
WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE
SUCH AS A BASEMENT OR SMALL INTERIOR ROOM IF A TORNADO IS SPOTTED.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

LAT...LON 3998 10465 3985 10456 3983 10404 4003 10412
          4036 10415 4031 10462

RJK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 3, 6:21 PM MDT	Severe Thunderstorm Warning	BOU	Douglas, Elbert	39 min
Jun 3, 6:36 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe	39 min
Jun 3, 6:54 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver	51 min
Jun 3, 7:05 PM MDT	Severe Thunderstorm Warning	BOU	Weld	40 min
Jun 3, 7:20 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Douglas, Elbert	40 min
Jun 3, 7:25 PM MDT	Severe Thunderstorm Warning	BOU	Boulder, Larimer, Weld	50 min
Jun 3, 7:45 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver	45 min
Jun 3, 7:45 PM MDT	Severe Thunderstorm Warning	BOU	Weld	45 min
Jun 3, 11:00 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver, Weld	45 min
Jun 4, 3:30 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan, Weld	45 min
Jun 4, 4:10 PM MDT	Tornado Warning	BOU	Adams, Arapahoe, Washington	35 min
Jun 4, 4:10 PM MDT	Tornado Warning	BOU	Morgan	35 min
Jun 4, 4:45 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Washington	45 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.