Alert archive / Colorado / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 6, NWS Denver/Boulder, CO

May 23, 1987Adams County, Arapahoe County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 23, 1987, 4:12 PM MDT for Adams County, Arapahoe County, Weld County, Colorado. It was in force for 63 min.

The area

The counties it named.

The facts

Issued
May 23, 1987, 4:12 PM MDT (22:12 UTC)
Expired
May 23, 1987, 5:15 PM MDT
In force
63 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Adams County, CO, Arapahoe County, CO, Weld 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, 10.2 hours before the alert went out and 98 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

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm 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, 1 hour 21 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, 3:11 PM MDTTornado WarningBOUArapahoe, Douglas29 min

Nearby

Severe Thunderstorm Warnings in Colorado, 1987Every severe thunderstorm warning 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.