Alert archive / Colorado / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 21, NWS Denver/Boulder, CO

June 23, 1987Adams County, Denver County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 23, 1987, 2:54 PM MDT for Adams County, Denver County, Colorado. It was in force for 61 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jun 23, 1987, 2:54 PM MDT (20:54 UTC)
Expired: Jun 23, 1987, 3:55 PM MDT
In force: 61 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties

Counties Adams County, CO, Denver County, CO

The radar

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

What was reported inside it

Time	Report	Where	Remark
Jun 23, 3:25 PM MDT	Hail 1	Denver, CO

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 8.9 hours before the alert went out and 118 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 964 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 149 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 232056
SVRDEN
COC001-005-031-035-232155-
 
BULLETIN...IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
254 PM MDT TUE JUN 23 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 355 PM  MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF NORTHEAST COLORADO:
 
     WESTERN ADAMS
     WESTERN ARAPAHOE
     DENVER
     NORTHERN DOUGLAS
 
INCLUDING THE FOLLOWING TOWNS/CITIES:
 
     AURORA..COMMERCE CITY..ENGLEWOOD..LITTLETON..NORTHGLENN..
     PARKER..THORNTON..AND WESTMINSTER
 
THE STORM IS LOCATED VERY NEAR DENVER.
 
AT 250 PM MDT GOLF BALL SIZE HAIL WAS REPORTED IN LITTLETON.
THIS STORM IS MOVING TO THE EAST AT 15 MPH.  THIS SAME STORM
EARLIER PRODUCED FUNNEL CLOUDS IN JEFFERSON COUNTY. MARBLE SIZE HAIL
HAS BEEN REPORTED IN ARVADA WITH ANOTHER STRONG STORM WHICH IS MOVING
TO THE NORTHEAST.
 
REMEMBER..A SEVERE THUNDERSTORM CAN PRODUCE LARGE DAMAGING
HAIL..DAMAGING WINDS OF OVER 60 MPH..DEADLY LIGHTNING..AND
HEAVY RAINS THAT CAN QUICKLY FLOOD A LOW LYING AREA.
 
THESE STORMS CAN PRODUCE A TORNADO WITH LITTLE OR NO ADVANCE
WARNING..SO BE ON THE LOOKOUT AND BE PREPARED TO MOVE TO A PLACE
OF SAFETY IF ONE IS SPOTTED.
 
A TORNADO WATCH REMAINS IN EFFECT FOR MUCH OF EASTERN COLORADO TIL 8PM
MDT.

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  3996 10505 3996 10474 3951 10474 3952 10509

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 23, 2:20 PM MDT	Tornado Warning	BOU	Arapahoe, Douglas, Jefferson	30 min
Jun 23, 2:20 PM MDT	Tornado Warning	BOU	Denver	30 min
Jun 23, 2:34 PM MDT	Severe Thunderstorm Warning	BOU	Weld	56 min
Jun 23, 2:54 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Douglas	61 min
Jun 23, 3:17 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Douglas, Jefferson	58 min
Jun 23, 3:17 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver, Weld	58 min
Jun 23, 4:11 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan, Weld	59 min
Jun 23, 4:11 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Denver	59 min
Jun 23, 5:53 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe	42 min
Jun 23, 5:59 PM MDT	Tornado Warning	BOU	Weld	41 min

Nearby

Severe Thunderstorm Warnings in Colorado, 1987 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.