Alert archive / Colorado / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 49, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 4, 1987, 4:15 PM MDT for Arapahoe County, Colorado. It was in force for 60 min.
The area
The counties it named.
The facts
- Issued
- Jul 4, 1987, 4:15 PM MDT (22:15 UTC)
- Expired
- Jul 4, 1987, 5:15 PM MDT
- In force
- 60 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
County Arapahoe 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, 10.3 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.
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDEN 042217 COR
SVRDEN
COC001-005-042305-
BULLETIN...IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
415 PM MDT SAT JUL 04 1987
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 515 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF NORTHEAST COLORADO:
WESTERN ARAPAHOE
INCLUDING THE FOLLOWING TOWNS/CITIES:
AURORA
THE STORM IS LOCATED 20 MILES EAST OF DENVER.
AT 415 PM MDT RADAR INDICATED A SEVERE THUNDERSTORM IN THE EASTERN
PART OF AURORA. THIS STORM WAS ALMOST STATIONARY..AND HAS PRODUCED
HAIL AS LARGE AS 1 1/4 INCHES IN DIAMETER.
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.
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.
SEM
LAT..LON 3979 10489 3978 10452 3956 10453 3957 10487What 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, 42 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.
KAPLANThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 3, 9:00 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 60 min |
| Jul 3, 10:31 PM MDT | Severe Thunderstorm Warning | BOU | Morgan, Washington | 59 min |
| Jul 4, 4:04 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe | 56 min |
| Jul 4, 5:04 PM MDT | Severe Thunderstorm Warning | BOU | Morgan, Weld | 61 min |
| Jul 4, 5:45 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 60 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.