Alert archive / Colorado / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 22, NWS Denver/Boulder, CO

July 9, 1986Logan County, Washington County, Yuma County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 9, 1986, 2:53 PM MDT for Logan County, Washington County, Yuma County, Colorado. It was in force for 52 min.

The area

The counties it named.

The facts

Issued
Jul 9, 1986, 2:53 PM MDT (20:53 UTC)
Expired
Jul 9, 1986, 3:45 PM MDT
In force
52 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Logan County, CO, Washington County, CO, Yuma 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, 8.9 hours before the alert went out and 49 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 1986-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1986-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1985 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
11 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 092053
SVRDEN
COC075-092145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
253 PM MDT WED JUL 9 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 345 PM MDT FOR PEOPLE IN THE FOLLOWING 
COUNTY OF

NORTHEAST COLORADO...SOUTHEAST LOGAN

THIS WARNING INCLUDES THE FOLLOWING TOWNS AND CITIES... FLEMING AND
GALIEN COLORADO

AT 240PM MDT RADAR INDICATED A SEVERE THUNDERSTORM JUST W OF FLEMING
COLORADO OR ABOUT 10 TO 15 MILES EAST NORTHEAST OF STERLING COLORADO
THIS THUNDERSTORM IS MOVING TO THE SOUTHEAST ABOUT 10-15 MPH.

IF SEVERE WEATHER APPROACHES YOUR AREA..GO TO A STURDY SHELTER AWAY
FROM CREEK BEDS AND OTHER LOW AREAS PRONE TO FLOODING.  REMEMBER...
A SEVERE THUNDERSTORM CAN PRODUCE LARGE 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 REPORTS TO THE NATIONAL WEATHER SERVICE IN DENVER...OR
CALL YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN DENVER AT
361-0663.  DO NOT CALL THIS NUMBER FOR INFORMATION.

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 9, 1:33 PM MDT, 1 hour 20 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
130PM MDT   WEDNESDAY   JULY 9 1986

           ...THUNDERSTORM IN LOGAN COUNTY...

A STRONG THUNDERSTORM HAS FORMED AND REMAINED NEARLY STATIONARY IN
WESTERN LOGAN COUNTY OF COLORADO.  THIS STORM WAS LOCATED ABOUT 10 MILES
NORTH NORTHWEST OF STERLING COLORADO.  HEAVY RAIN...GUSTY WINDS AND HAIL
ARE LIKELY WITH THIS THUNDERSTORM.

PERSONS IN LOGAN COUNTY NORTH OF STERLING COLORADO ESPECIALLY IN THE
AREA OF WEST PLAINS...BUCHANAN...PADRONI AND NORTH STERLING RESERVOIR
SHOULD BE ALERT FOR THREATENING WEATHER AND TAKE APPROPRIATE ACTION.

SINCE THE THUNDERSTORM IS NEARLY STATIONARY HEAVY RAIN COULD CAUSE SMALL
CREEKS...SUCH AS CEDAR CREEK...IN WESTERN LOGAN COUNTY TO RUN NEAR
BANKFUL.  LOCAL FLOODING OF STREETS MAY OCCUR AS WELL.  MOTORISTS IN
THE AREA SHOULD EXERCISE CAUTION.  CAMPERS AND PERSONS PARTICIPATING
IN OUTDOOR ACTIVITIES SHOULD AVOID LOW LYING AREAS IN CASE PONDING OF
WATER OCCURS.

A FEW OTHER THUNDERSTORMS HAVE DEVELOPED IN EASTERN COLORADO IN THE PAST
HOUR.  A MODERATE THUNDERSTORM IS LOCATED IN WESTERN WELD COUNTY IN THE
NUNN...AULT AND WINDSOR AREA ABOUT 15 MILES EAST OF FORT COLLINS.

FRANSON
Special weather statement, Jul 9, 2:33 PM MDT, 20 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
230PM MDT   WEDNESDAY   JULY 9 1986

           ...TWO INTENSE THUNDERSTORMS IN LOGAN COUNTY...

TWO INTENSE THUNDERSTORMS ARE RUMBLING OVER LOGAN COUNTY.  AT 215PM MDT
ONE THUNDERSTORM WAS LOCATED 8-10 MILES NORTHEAST OF STERLING JUST EAST
OF ILLIFF COLORADO.  THIS THUNDERSTORM HAS BEGUN TO MOVE FINALLY AND IS
HEADING TO THE EAST ABOUT 10 MPH.  THE OTHER THUNDERSTORM IS LOCATED
ON THE COLORADO NEBRASKA BORDER ABOUT 25-30 MILES NORTHWEST OF STERLING
OR 10-15 MILES WEST OF PEETZ COLORADO.  IT WAS APPARENTLY MOVING EAST
BUT THE SPEED HAS NOT YET BEEN DETERMINED.  HEAVY RAIN...HAIL AND STRONG
GUSTY WINDS ACCOMPANY THESE THUNDERSTORMS.

PERSONS IN NORTHERN LOGAN COUNTY SHOULD WATCH FOR THREATENING WEATHER
AND TAKE APPROPRIATE ACTION IF NECESSARY.  MOTORISTS IN LOGAN COUNTY
SHOULD USE CAUTION AS LOCAL FLOODING OF ROADS AND LOW LYING AREAS IS
POSSIBLE DUE TO THE HEAVY RAIN ASSOCIATED WITH THESE THUNDERSTORMS.
CAMPERS AND PERSONS ENGAGED IN OUTDOOR ACTIVITIES SHOULD AVOID LOW AREAS
SINCE FLOODING MAY OCCUR.  ALL PERSONS SHOULD MONITOR LOCAL RADIO AND
TV BROADCASTS OR NOAA WEATHER RADIO FOR LATER UPDATES AND ADVISORIES.

THESE THUNDERSTORMS ARE MOVING RATHER SLOWLY AND ARE CAPABLE OF DUMPING
LARGE AMOUNTS OF RAIN IN A SHORT TIME.  FLOODING OF STREETS AND LOW
LYING AREAS IS POSSIBLE.  PERSONS SHOULD STAY CLEAR OF SMALL STREAMS AS
THEY MAY RUN BANKFULL FOR THE NEXT FEW HOURS.

FRANSON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 3:49 PM MDTSevere Thunderstorm WarningBOUPhillips56 min
Jul 9, 5:45 PM MDTSevere Thunderstorm WarningBOUYuma60 min

Nearby

Severe Thunderstorm Warnings in Colorado, 1986Every severe thunderstorm warning in 1986

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.