Alert archive / Colorado / Tornado Warnings in 1991

Tornado Warning 25, NWS Denver/Boulder, CO

June 1, 1991Jefferson County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 1, 1991, 4:36 PM MDT for Jefferson County, Colorado. It was in force for 24 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jun 1, 1991, 4:36 PM MDT (22:36 UTC)
Expired
Jun 1, 1991, 5:00 PM MDT
In force
24 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County Jefferson County, CO

What was reported inside it

TimeReportWhereRemark
Jun 1, 4:45 PM MDTHail 1.75Jefferson, CO
Jun 1, 5:07 PM MDTHail 1Jefferson, CO

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 10.6 hours before the alert went out and 176 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 1991-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 1991-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 square meters per square second.1939587897Sfc1 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
3 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
1108 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
201 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 012238
TORDEN
COC059-012300-

BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
436 PM MDT SAT JUN 01 1991

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A TORNADO
WARNING EFFECTIVE UNTIL 500 PM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTHEASTERN COLORADO
     NORTHERN JEFFERSON

INCLUDING THE FOLLOWING TOWNS/CITIES
     ARVADA...GOLDEN...LAKEWOOD...MOUNTAIN VIEW...PLEASANT VIEW
     ...WESTMINSTER AND WHEAT RIDGE

AT 436 PM MDT THE PUBLIC REPORTED FUNNEL CLOUDS 
IN THE CITY OF LAKEWOOD ...OR ABOUT 10 MILES WEST OF DENVER

THE STORM PRODUCING THE TORNADO WAS MOVING TO THE NORTHWEST AT 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.

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

GARD...WSFO DENVER

LAT...LON 3970 10507 3971 10532 3991 10532 3990 10507

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, 1 hour 49 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, 34 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
May 31, 6:09 PM MDTSevere Thunderstorm WarningBOUBoulder, Jefferson51 min
May 31, 6:12 PM MDTSevere Thunderstorm WarningBOUDouglas48 min
May 31, 6:46 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe59 min
May 31, 7:43 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe62 min
May 31, 8:38 PM MDTSevere Thunderstorm WarningBOUMorgan67 min
May 31, 9:06 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe39 min
May 31, 9:37 PM MDTTornado WarningBOUMorgan38 min
May 31, 9:44 PM MDTSevere Thunderstorm WarningBOUAdams, Weld46 min
May 31, 10:02 PM MDTTornado WarningBOUAdams, Arapahoe, Washington28 min
May 31, 10:25 PM MDTTornado WarningBOULogan, Morgan, Washington35 min
May 31, 10:26 PM MDTTornado WarningBOUAdams, Washington34 min
May 31, 10:38 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe52 min
May 31, 10:48 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe42 min
May 31, 11:00 PM MDTTornado WarningBOUMorgan, Washington45 min
May 31, 11:05 PM MDTTornado WarningBOULogan, Washington40 min
May 31, 11:33 PM MDTSevere Thunderstorm WarningBOUAdams, Weld42 min
May 31, 11:49 PM MDTSevere Thunderstorm WarningBOUWashington26 min
May 31, 11:51 PM MDTTornado WarningBOULogan24 min
Jun 1, 12:15 AM MDTSevere Thunderstorm WarningBOUWashington30 min
Jun 1, 12:15 AM MDTSevere Thunderstorm WarningBOUWeld45 min
Jun 1, 12:26 AM MDTTornado WarningBOUWashington34 min
Jun 1, 1:01 AM MDTTornado WarningBOUWashington29 min
Jun 1, 4:05 PM MDTSevere Thunderstorm WarningBOUDenver, Jefferson40 min
Jun 1, 4:05 PM MDTSevere Thunderstorm WarningBOUDouglas40 min
Jun 1, 4:57 PM MDTSevere Thunderstorm WarningBOUAdams, Boulder, Denver, Jefferson48 min
Jun 1, 5:20 PM MDTFlash Flood WarningBOUAdams, Jefferson115 min
Jun 1, 5:33 PM MDTTornado WarningBOUBoulder, Jefferson27 min
Jun 1, 5:44 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver, Jefferson46 min
Jun 1, 5:44 PM MDTSevere Thunderstorm WarningBOUBoulder, Weld46 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.