Alert archive / Colorado / Tornado Warnings in 1987

Tornado Warning 1, NWS Denver/Boulder, CO

May 23, 1987Arapahoe County, Douglas County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 23, 1987, 3:11 PM MDT for Arapahoe County, Douglas County, Colorado. It was in force for 29 min.

The area

The counties it named.

The facts

Issued
May 23, 1987, 3:11 PM MDT (21:11 UTC)
Expired
May 23, 1987, 3:40 PM MDT
In force
29 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Arapahoe County, CO, Douglas County, CO

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 9.2 hours before the alert went out and 127 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 1987-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 1987-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939587897Sfc1 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
2 J/kg
Mixed-layer CIN
-186 J/kg
Mixed-layer LCL
733 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
43 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.

000 
TTAA00 KDEN 232112
TORDEN
COC005-035-232140-
 
BULLETIN...EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
311 PM MDT SAT MAY 23 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING
EFFECTIVE UNTIL 340 PM  MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES OF NORTHEAST COLORADO:
 
     SOUTHWESTERN ARAPAHOE
     NORTHWESTERN DOUGLAS
 
INCLUDING THE FOLLOWING TOWNS/CITIES:
 
     ENGLEWOOD...SOUTHERN AURORA
 
THE STORM IS LOCATED 15 MILES SOUTH OF DENVER.
 
AT 310 PM MDT SEVERAL FUNNEL CLOUD REPORTS WEST OF PARKER.
 
IN HOMES GO TO THE BASEMENT OR INTO A CLOSET OR BATHROOM.
IN SCHOOLS..HIGH RISES AND HOSPITALS GO TO AN INTERIOR
HALLWAY ON THE LOWEST FLOOR.  IF IN MOBILE HOMES OR VEHICLES..
EVACUATE THEM AND GO TO A SUBSTANTIAL SHELTER.  IF NO SHELTER
IS AVAILABLE..LIE FLAT IN THE NEAREST DITCH OR OTHER LOW SPOT.
IN ALL CASES..STAY AWAY FROM WINDOWS..DOORS AND OUTSIDE WALLS.
 
TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT
AGENCY RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE
IN DENVER..OR CALL YOUR REPORT TO THE NATIONAL WEATHER SERVICE
AT 361-0663.  DO NOT CALL THIS NUMBER FOR INFORMATION.
 
KAPLAN
 
LAT..LON  3968 10498 3969 10478 3949 10482 3951 10504

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 23, 2:51 PM MDT, 20 minutes before
SPECIAL WEATHER STATEMENT...NOWCAST
NATIONAL WEATHER SERVICE DENVER CO
252 PM MDT SAT MAY 23 1987

...THUNDERSTORMS BUILDING TO SOUTH AND WEST OF DENVER METRO AREA...

AT 245 PM THUNDERSTORMS HAD BEGUN TO BUILD RATHER RAPIDLY FROM WESTERN
ARAPAHOE COUNTY ACROSS NORTHERN DOUGLAS COUNTY INTO SOUTHERN AND CENTRAL
JEFFERSON COUNTIES.

CONDITIONS APPEAR FAVORABLE FOR CONTINUED INTENSIFICATION OF THESE
STORMS BETWEEN NOW AND 400 PM.  THE THUNDERSTORMS WILL BE MOVING TO
THE NORTH-NORTHEAST AND WILL LIKELY AFFECT MUCH OF THE DENVER
METRO AREA DURING THE REMAINDER OF THE AFTERNOON. THEY COULD BECOME
SEVERE RATHER QUICKLY...SO KEEP A CLOSE EYE ON LOCAL WEATHER CONDITIONS.

KAPLAN

The office that day

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

IssuedProductOfficeCountiesLasted
May 23, 4:12 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Weld63 min

Nearby

Tornado Warnings in Colorado, 1987Every tornado warning in 1987Tornadoes in 1987

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.