Alert archive / Colorado / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 75, NWS Denver/Boulder, CO

July 20, 2000Adams County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 20, 2000, 4:54 PM MDT for Adams County, Colorado. It was in force for 51 min. No storm report in the archive falls 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.

The facts

Issued: Jul 20, 2000, 4:54 PM MDT (22:54 UTC)
Expired: Jul 20, 2000, 5:45 PM MDT
In force: 51 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Adams County, CO

The radar

The Denver radar (KFTG), 56 km from the middle of the area, began a volume at 22:54 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.

Issued	Product	Office	Lasted
Jul 20, 1:45 PM MDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.9 hours before the alert went out and 57 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: 409 J/kg
Mixed-layer CIN: -401 J/kg
Mixed-layer LCL: 1545 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

000 
WUUS55 KBOU 202254
SVRDEN
COC001-202345-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
454 PM MDT THU JUL 20 2000

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN ADAMS COUNTY IN NORTHEAST COLORADO

* UNTIL 545 PM MDT

* AT 454 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 6 MILES WEST OF SHAMROCK...OR ABOUT 29 MILES
  SOUTH OF FORT MORGAN...MOVING EAST AT 10 MPH.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...SHAMROCK.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM MDT THURSDAY EVENING
FOR NORTHEAST COLORADO. A TORNADO WATCH ALSO REMAINS IN EFFECT UNTIL
900 PM MDT THURSDAY EVENING FOR NORTHEASTERN COLORADO.

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 55 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

LAT...LON 3999 10402 3975 10402 3976 10373 3998 10372

KLEYLA

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 7:21 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan, Weld	24 min
Jul 19, 7:45 PM MDT	Severe Thunderstorm Warning	BOU	Morgan	45 min
Jul 19, 8:26 PM MDT	Severe Thunderstorm Warning	BOU	Morgan, Washington	34 min
Jul 20, 2:42 PM MDT	Tornado Warning	BOU	Weld	48 min
Jul 20, 3:16 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Elbert	44 min
Jul 20, 3:28 PM MDT	Tornado Warning	BOU	Weld	47 min
Jul 20, 3:54 PM MDT	Severe Thunderstorm Warning	BOU	Washington	51 min
Jul 20, 4:05 PM MDT	Tornado Warning	BOU	Morgan, Weld	40 min
Jul 20, 4:08 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Washington	52 min
Jul 20, 4:32 PM MDT	Severe Thunderstorm Warning	BOU	Washington	43 min
Jul 20, 4:39 PM MDT	Tornado Warning	BOU	Morgan	51 min
Jul 20, 4:51 PM MDT	Tornado Warning	BOU	Washington	24 min
Jul 20, 5:05 PM MDT	Severe Thunderstorm Warning	BOU	Morgan	40 min
Jul 20, 5:16 PM MDT	Tornado Warning	BOU	Washington	29 min
Jul 20, 5:18 PM MDT	Tornado Warning	BOU	Adams, Morgan	42 min
Jul 20, 5:44 PM MDT	Tornado Warning	BOU	Adams, Arapahoe, Washington	46 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2000 Every severe thunderstorm warning in 2000

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.