Alert archive / Colorado / Tornado Warnings in 1991

Tornado Warning 33, NWS Denver/Boulder, CO

June 9, 1991Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 9, 1991, 3:51 PM MDT for Weld County, Colorado. It was in force for 39 min.

The area

The counties it named.

The facts

Issued
Jun 9, 1991, 3:51 PM MDT (21:51 UTC)
Expired
Jun 9, 1991, 4:30 PM MDT
In force
39 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County Weld County, CO

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 9.9 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-pSkew-T log-p diagram, Denver, CO at 12:00Z on 1991-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Denver, CO at 12:00Z on 1991-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 square meters per square second.193958Sfc1 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
2 J/kg
Mixed-layer CIN
-512 J/kg
Mixed-layer LCL
2648 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
63 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 092153
TORDEN
COC123-092230-

BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
351 PM MDT SUN JUN 09 1991

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A TORNADO
WARNING EFFECTIVE UNTIL 430 PM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTHEASTERN COLORADO
     NORTHEASTERN WELD

INCLUDING THE FOLLOWING TOWNS/CITIES
     GROVER

AT 351 PM MDT RADAR INDICATED A POSSIBLE TORNADO 8 MILES EAST OF GROVER
...OR ABOUT 46 MILES NORTHEAST OF GREELEY.  AT 351 THE PUBLIC REPORTED A
TORNADO AT ABOUT THE SAME LOCATION.

THE STORM PRODUCING THE TORNADO WAS MOVING TO THE EAST-SOUTHEAST AT 15
MPH.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT.  GET
UNDER A WORKBENCH OR OTHER PIECE OF STURDY FURNITURE.  IF NO
BASEMENT IS AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE
BUILDING IN AN INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET.  USE
BLANKETS OR PILLOWS TO COVER YOUR BODY AND ALWAYS STAY FROM
WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER.  IF NO SHELTER IS AVAILABLE...LIE FLAT IN
THE NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH
YOUR HANDS.

A TORNADO WATCH REMAINS IN EFFECT FOR NORTHEAST COLORADO TIL 900 PM.

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT
AGENCY RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
FORECAST OFFICE IN DENVER.

MCQUEEN
LAT...LON 4064 10359 4072 10422 4098 10426 4098 10360

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, 3:05 PM MDT, 46 minutes before
COZ011-012-013-014-092200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
305 PM MDT SUN JUN 9 1991

...TORNADO WATCH FOR MOST OF NORTHEAST COLORADO TIL 900 PM MDT...

AT 305 PM MDT RADAR WAS SHOWING A STRONG THUNDERSTORM OVER NORTHERN
LARIMER COUNTY ABOUT 30 MILES NORTH OF FORT COLLINS.  THIS STORM WAS
MOVING TO THE EAST-SOUTHEAST AT 25 MPH AND WILL CROSS EXTREME NORTHEAST
LARIMER COUNTY BY 400 PM.

A FEW OTHER THUNDERSTORMS WERE DEVELOPING OVER EASTERN LARIMER AND
WESTERN WELD COUNTY...AND SOUTHERN PARTS OF DOUGLAS AND ARAPAHOE
COUNTIES.  THESE STORMS WERE MOVING EAST AT 25 MPH.

A TORNADO WATCH IS IN EFFECT UNTIL 900 PM FOR MOST OF NORTHEAST
COLORADO.  IN THE DENVER METRO AREA...THIS IS TO THE EAST OF SHERIDAN
BOULEVARD.

LISTEN TO NOAA WEATHER RADIO...OR LOCAL RADIO AND T.V....FOR UPDATES OR
WARNINGS THIS AFTERNOON AND EVENING.

MCQUEEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 8, 6:30 PM MDTSevere Thunderstorm WarningBOULogan, Phillips45 min
Jun 9, 3:35 PM MDTSevere Thunderstorm WarningBOUWeld55 min
Jun 9, 4:30 PM MDTTornado WarningBOUWeld45 min
Jun 9, 5:10 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe35 min
Jun 9, 5:12 PM MDTSevere Thunderstorm WarningBOUAdams, Denver, Jefferson48 min
Jun 9, 5:16 PM MDTTornado WarningBOUWeld59 min
Jun 9, 5:59 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver61 min

Nearby

Tornado Warnings in Colorado, 1991Every tornado warning in 1991Tornadoes in 1991

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.