Alert archive / Colorado / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 42, NWS Denver/Boulder, CO

July 2, 1987Douglas County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 2, 1987, 5:45 PM MDT for Douglas County, Colorado. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
Jul 2, 1987, 5:45 PM MDT (23:45 UTC)
Expired
Jul 2, 1987, 6:45 PM MDT
In force
60 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County 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

Fort Carson/Butt, CO (KFCS), launched 12:00Z, 11.8 hours before the alert went out and 75 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, Fort Carson/Butt, CO at 12:00Z on 1987-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 38 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, Fort Carson/Butt, CO at 12:00Z on 1987-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
38 J/kg
Mixed-layer CIN
-352 J/kg
Mixed-layer LCL
1943 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
76 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 2, 2:59 PM MDT, 2 hours 46 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
300 PM MDT THU JUL 2 1987

   ...STRONG THUNDERSTORMS DEVELOPING ALONG THE FRONT RANGE...

AT 255 PM MDT RADAR INDICATED THUNDERSTORMS DEVELOPING ALONG THE FRONT
RANGE.  THE STRONGEST STORMS WERE OVER LITTLETON IN WESTERN ARAPAHOE
COUNTY.. AND ABOUT 10 MILES NORTHWEST OF BOULDER IN BOULDER COUNTY.
THE STORMS ARE MOVING TOWARD THE EAST AT 10 TO 20 MPH.

THE LITTLETON STORM HAS PRODUCED HAIL HALF AN INCH IN DIAMETER.

THESE TWO STORMS MAY PRODUCE LOCAL BRIEF HEAVY RAIN..HAIL..AND STRONG
GUSTY WINDS THIS AFTERNOON..AND OTHER THUNDERSTORMS ARE LIKELY TO
DEVELOP.

MARKKANEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 7:13 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick42 min
Jul 1, 9:09 PM MDTSevere Thunderstorm WarningBOULarimer51 min
Jul 2, 3:02 PM MDTSevere Thunderstorm WarningBOUArapahoe, Douglas53 min
Jul 2, 3:34 PM MDTTornado WarningBOUAdams26 min
Jul 2, 4:02 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Weld63 min
Jul 2, 4:46 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington59 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.