Alert archive / Colorado / Tornado Warnings in 1986

Tornado Warning 4, NWS Denver/Boulder, CO

June 9, 19864 counties in Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 9, 1986, 9:49 AM MDT for 4 counties in Colorado. It was in force for 26 min.

The area

The counties it named.

The facts

Issued: Jun 9, 1986, 9:49 AM MDT (15:49 UTC)
Expired: Jun 9, 1986, 10:15 AM MDT
In force: 26 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Jefferson 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, 3.8 hours before the alert went out and 125 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: 66 J/kg
Mixed-layer CIN: -104 J/kg
Mixed-layer LCL: 1055 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 100 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 091549
TORDEN
COC001-005-013-059-091615-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
949 AM MDT MON JUN 9 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 1015 AM MDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

NORTHEAST COLORADO...WESTERN ADAMS...EXTREME WESTERN ARAPAHOE...
 SOUTHEAST BOULDER AND EXTREME NORTHEAST JEFFERSON

THIS WARNING INCLUDES THE FOLLOWING TOWNS AND CITIES... NORTH AND
EAST PORTIONS OF THE DENVER METRO AREA.

SEVERAL FUNNEL CLOUDS AND TORNADOES HAVE BEEN REPORTED IN THE NORTH
AND EAST SECTIONS OF THE DENVER METRO AREA.

TAKE COVER IMMEDIATELY IF THREATENING WEATHER APPROACHES.

IN HOMES GO TO THE BASEMENT OR INTO A CLOSET OR BATHROOM.  IN SCHOOLS
...HIGH RISES AND HOSPITALS GO TO AN INTERIOR HALLWAY ON THE LOWEST
FLOOR.  IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GO TO A
SUBSTANTIAL SHELTER.  IF NO SHELTER IS AVAILABLE..LIE FLAT IN THE
NEAREST DITCH...GULLY OR OTHER LOW SPOT.
<
IN ALL CASES...STAY AWAY FROM WINDOWS...DOORS AND OUTSIDE WALLS.
PROTECT YOUR HEAD AND FACE.  TRY TO GET UNDER SOMETHING STURDY.

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.

THALER

What forecasters said that day

The local office's own words before this tornado 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, Jun 9, 4:53 AM MDT, 4 hours 56 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
450 AM MDT MON JUN 9 1986

...SEVERE WEATHER AND HEAVY RAIN POSSIBLE IN EASTERN COLORADO...

INTENSE THUNDERSTORMS ARE POSSIBLE OVER EASTERN COLORADO AGAIN THIS
AFTERNOON INTO TONIGHT.  DAMAGING WINDS...LARGE HAIL...HEAVY RAIN
AND DANGEROUS LIGHTNING ARE POSSIBLE WITH THE THUNDERSTORMS.  SEVERE
THUNDERSORMS CAN SPAWN TORNADOES.

PERSONS IN COLORADO...ESPECIALLY EAST OF THE CONTINENTAL DIVIDE
SHOULD KEEP THEMSELVES INFORMED ON THE LATEST WEATHER DEVELOPMENTS
TODAY AND TONIGHT AND BE PREPARED TO TAKE ACTION SHOULD WATCHES OR
WARNINGS BECOME NECESSARY.

THE COMBINATION OF MOIST UNSTABLE AIR OVER EASTERN COLORADO AND STORM
MOVING OVER THE STATE FROM THE WEST WILL TRIGGER THUNDERSTORMS THIS
AFTERNOON AND EVENING.  THE ATMOSPHERE IS EXPECTED TO BECOME VERY
UNSTABLE ESPECIALLY OVER EASTERN COLORADO AND POTENTIALLY VIOLENT
THUNDERSTORMS ARE POSSIBLE.

ALL INTERESTS SHOULD MONITOR NOAA WEATHER RADIO OR LOCAL RADIO AND
TELEVISION FOR UPDATED WEATHER INFORMATION AND FORECASTS.

BALINT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 8, 6:00 PM MDT	Severe Thunderstorm Warning	BOU	Washington	60 min
Jun 9, 10:27 AM MDT	Tornado Warning	BOU	Weld	23 min
Jun 9, 3:46 PM MDT	Tornado Warning	BOU	Adams, Arapahoe	24 min

Nearby

Tornado Warnings in Colorado, 1986 Every tornado warning in 1986 Tornadoes 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.