Alert archive / Colorado / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 50, NWS Denver/Boulder, CO

July 4, 1987Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 4, 1987, 5:04 PM MDT for Morgan County, Weld County, Colorado. It was in force for 61 min.

The area

The counties it named.

The facts

Issued
Jul 4, 1987, 5:04 PM MDT (23:04 UTC)
Expired
Jul 4, 1987, 6:05 PM MDT
In force
61 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Morgan 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, 11.1 hours before the alert went out and 95 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 1987-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 362 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 1987-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -24 square meters per square second.19395878Sfc1 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
362 J/kg
Mixed-layer CIN
-341 J/kg
Mixed-layer LCL
1220 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
38 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, Jul 4, 3:33 PM MDT, 1 hour 31 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
335 PM MDT SAT JUL 4 1987

           ...THUNDERSTORMS IN NORTHEAST COLORADO...

THUNDERSTORMS HAVE DEVELOPED IN CENTRAL ADAMS COUNTY NORTH OF BYERS.
ADDITIONAL THUNDERSTORM DEVELOPMENT IS EXPECTED BETWEEN NOW AND 430 PM
MDT IN CENTRAL AND WESTERN ADAMS AND ARAPAHOE COUNTIES...DENVER
COUNTY...SOUTHEAST WELD COUNTY AND NORTHERN DOUGLAS COUNTY.

SEVERE WEATHER IS NOT ANTICIPATED BUT THE STRONGEST STORMS COULD PRODUCE
STRONG GUSTY WINDS TO 40 MPH OR MORE...BRIEF HEAVY RAINS AND SMALL HAIL.

KAPLAN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 3, 9:00 PM MDTSevere Thunderstorm WarningBOUWeld60 min
Jul 3, 10:31 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington59 min
Jul 4, 4:04 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe56 min
Jul 4, 4:15 PM MDTSevere Thunderstorm WarningBOUArapahoe60 min
Jul 4, 5:45 PM MDTSevere Thunderstorm WarningBOUWeld60 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.