Alert archive / Colorado / Tornado Warnings in 1998

Tornado Warning 21, NWS Denver/Boulder, CO

July 23, 1998Washington County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jul 23, 1998, 4:12 PM MDT for Washington County, Colorado. It was in force for 33 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 23, 1998, 4:12 PM MDT (22:12 UTC)
Expired
Jul 23, 1998, 4:45 PM MDT
In force
33 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Washington County, CO

The radar

The Denver radar (KFTG), 120 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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.2 hours before the alert went out and 46 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 1998-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 81 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 1998-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.1939Sfc1 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
81 J/kg
Mixed-layer CIN
-228 J/kg
Mixed-layer LCL
1157 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

657 
WFUS1 KDEN 232215 RRA
TORDEN
COC121-232245-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
412 PM MDT THU JUL 23 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
     NORTH CENTRAL WASHINGTON COUNTY IN NORTHEAST COLORADO

* UNTIL 445 PM MDT

* AT 411 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM WITH A POSSIBLE TORNADO 8 MILES NORTHEAST OF MIDWAY...
  OR ABOUT 11 MILES NORTHWEST OF AKRON...MOVING EAST AT 10 MILES     
  PER HOUR.  A SECOND POSSIBLE TORNADO WAS LOCATED 13 MILES WEST OF  
  AKRON ALONG THE MORGAN-WASHINGTON LINE.

LOCATIONS IN THE WARNING INCLUDE...AKRON AND MIDWAY

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

LAT...LON 4042 10343 4008 10346 4012 10323 4024 10309
          4042 10313

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 4:08 PM MDTTornado WarningBOUAdams, Arapahoe37 min
Jul 23, 4:23 PM MDTTornado WarningBOUAdams, Arapahoe22 min
Jul 23, 4:41 PM MDTTornado WarningBOUMorgan, Washington34 min
Jul 23, 5:11 PM MDTFlash Flood WarningBOUAdams, Arapahoe2 hr
Jul 23, 5:12 PM MDTFlash Flood WarningBOUMorgan, Washington2 hr
Jul 23, 5:47 PM MDTTornado WarningBOUWashington28 min

Nearby

Tornado Warnings in Colorado, 1998Every tornado warning in 1998Tornadoes in 1998

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.