Alert archive / Colorado / Tornado Warnings in 1991

Tornado Warning 28, NWS Denver/Boulder, CO

June 1, 1991Larimer County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 1, 1991, 6:33 PM MDT for Larimer County, Colorado. It was in force for 27 min.

The area

The counties it named.

The facts

Issued
Jun 1, 1991, 6:33 PM MDT (00:33 UTC)
Expired
Jun 1, 1991, 7:00 PM MDT
In force
27 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County Larimer County, CO

The nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 0.6 hours before the alert went out and 209 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 00:00Z on 1991-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 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 00:00Z on 1991-06-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -342 square meters per square second.193958Sfc1 km3 km6 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
1289 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-342 m²/s²
0-3 km storm-relative helicity
-213 m²/s²
Significant tornado parameter
0.0
Supercell composite
-4.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDEN 020036 COR
TORDEN
COC069-020100-

BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING...CORRECTION TO CONTINUE WATCH
NATIONAL WEATHER SERVICE DENVER CO
633 PM MDT SAT JUN 01 1991

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A TORNADO
WARNING EFFECTIVE UNTIL 700 PM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTH CENTRAL COLORADO
     SOUTH CENTRAL LARIMER

INCLUDING THE FOLLOWING TOWNS/CITIES
     DRAKE...CARTER LAKE AREA...

AT 633 PM MDT RADAR INDICATED A POSSIBLE TORNADO 13 MILES SOUTHEAST OF
DRAKE ...OR ABOUT 22 MILES SOUTH OF FORT COLLINS.  THE PUBLIC REPORTED
TWO FUNNEL CLOUDS OVER CARTER LAKE AT 633 PM.

THE STORM PRODUCING THE TORNADO WAS MOVING AT ABOUT 20 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 SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR MOST OF NORTHEAST
COLORADO UNTIL 11 PM MDT.

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

ET

LAT...LON 4028 10513 4028 10528 4044 10541 4049 10516

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 1, 2:47 PM MDT, 3 hours 46 minutes before
COZ011-012200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
245 PM MDT SAT JUN 1 1991

...STRONG THUNDERSTORM IN FOOTHILLS NORTHWEST OF BOULDER...

AT 240 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM BETWEEN LYONS AND JAMESTOWN IN NORTHERN BOULDER
COUNTY...ABOUT 35 MILES NORTHWEST OF DENVER.  THIS STORM WAS MOVING TO
THE NORTHWEST AT 15 TO 20 MPH.

ALL PEOPLE IN NORTHERN BOULDER COUNTY AND SOUTHWESTERN LARIMER COUNTY
INCLUDING THE TOWNS OF JAMESTOWN...LYONS...RAYMOND...ALLENSPARK...
MEEKER PARK AND ESTES PARK SHOULD BE ALERT FOR DANGEROUS FREQUENT
LIGHTNING...HAIL AND STRONG GUSTY WINDS FROM THIS STORM UNTIL 400 PM
MDT THIS AFTERNOON.

HEAVY RAIN FROM THIS STORM WILL PRODUCE FLOODING OF NORMALLY DRY
GULCHES...SMALL STREAMS...HIGHWAYS...AND LOW LYING OR FLOOD PRONE
AREAS.  A FLASH FLOOD WATCH REMAINS IN EFFECT FOR MOST OF NORTHEAST
COLORADO UNTIL MIDNIGHT TONIGHT.

GARD...WSFO DENVER
Special weather statement, Jun 1, 4:02 PM MDT, 2 hours 31 minutes before
COZ011-012300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
400 PM MDT SAT JUN 1 1991

...STRONG THUNDERSTORMS OVER SOUTHWEST METRO DENVER...

AT 355 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS OVER THE SOUTHWEST PORTION OF THE DENVER METRO AREA
IN LAKEWOOD NEAR SOUTHWEST PLAZA SHOPPING CENTER.  PEA TO MARBLE
SIZE HAIL HAS BEEN REPORTED FROM THESE STORMS.  THE STORMS WERE MOVING
TO THE NORTHWEST AT 15 TO 20 MPH AND WILL BE MOVING OVER MORRISON...
EVERGREEN AND GOLDEN.

ALL PEOPLE IN WEST AND SOUTHWEST METRO DENVER SHOULD BE ALERT FOR
DANGEROUS FREQUENT LIGHTNING...HAIL AND STRONG GUSTY WINDS FROM THESE
STORMS UNTIL 500 PM MDT THIS AFTERNOON.

HEAVY RAIN FROM THIS STORM WILL PRODUCE FLOODING OF NORMALLY DRY
GULCHES...SMALL STREAMS...HIGHWAYS...STREETS...AND LOW LYING OR FLOOD
PRONE AREAS INCLUDING LENA GULCH.  A FLASH FLOOD WATCH REMAINS IN EFFECT
FOR MOST OF NORTHEAST COLORADOd UNTIL MIDNIGHT TONIGHT.

GARD...WSFO DENVER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 1, 6:07 PM MDTTornado WarningBOUBoulder38 min
Jun 1, 8:02 PM MDTFlash Flood WarningBOULarimer3 hr
Jun 1, 11:00 PM MDTFlash Flood WarningBOULarimer2 hr
Jun 2, 5:01 PM MDTTornado WarningBOUAdams, Larimer, Weld29 min
Jun 2, 5:01 PM MDTTornado WarningBOUDenver29 min
Jun 2, 5:27 PM MDTSevere Thunderstorm WarningBOUAdams, Boulder, Denver, Jefferson48 min
Jun 2, 5:27 PM MDTSevere Thunderstorm WarningBOUWeld48 min
Jun 2, 5:41 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington64 min
Jun 2, 5:45 PM MDTFlash Flood WarningBOUDenver75 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.