Alert archive / Colorado / Tornado Warnings in 1991

Tornado Warning 24, NWS Denver/Boulder, CO

June 1, 1991Washington County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 1, 1991, 1:01 AM MDT for Washington County, Colorado. It was in force for 29 min.

The area

The counties it named.

The facts

Issued
Jun 1, 1991, 1:01 AM MDT (07:01 UTC)
Expired
Jun 1, 1991, 1:30 AM MDT
In force
29 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County Washington County, CO

The nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 7.0 hours before the alert went out and 11 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 1991-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 169 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 00:00Z on 1991-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 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
169 J/kg
Mixed-layer CIN
-99 J/kg
Mixed-layer LCL
1122 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
160 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 010704
TORDEN
COC121-010730-

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

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A TORNADO
WARNING EFFECTIVE UNTIL 130 AM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTHEASTERN COLORADO
     NORTHEASTERN WASHINGTON

INCLUDING THE FOLLOWING TOWNS/CITIES
     OTIS

AT 1259 AM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
A POSSIBLE TORNADO 5 MILES NORTHEAST OF AKRON ...OR ABOUT 29 MILES SOUTH
OF STERLING.  THE STORM PRODUCING THE TORNADO WAS MOVING EAST
NORTHEAST AT 15 MPH.  THE STORM PRODUCED HAIL AS LARGE AS ONE AND A
HALF INCHES WHEN IT MOVED THROUGH AKRON.  

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 3 AM MDT.

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

RTG

LAT...LON 4008 10282 4012 10318 4039 10323 4042 10281

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, May 31, 9:19 PM MDT, 3 hours 42 minutes before
COZ011-010500-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
920 PM MDT FRI MAY 31 1991

...THUNDERSTORMS IN DOUGLAS COUNTY...

STRONG THUNDERSTORMS ARE DEVELOPING OVER DOUGLAS COUNTY LATE THIS
EVENING.  THE STRONGEST STORM WAS NORTHEAST OF PALMER LAKE OR ABOUT 40
MILES SOUTH OF DENVER AND WAS MOVING TO THE NORTH AT 25 MPH.

A LINE OF THUNDERSTORMS EXTENDED FROM THIS STRONG STORM NORTH TO NEAR
LITTLETON.  THIS LINE TOO WAS MOVING TO THE NORTH AT ABOUT 25 MPH.

HAIL...LIGHTNING...VERY HEAVY RAIN AND GUSTY WINDS ARE TO BE EXPECTED IN
CENTRAL DOUGLAS COUNTY WITHIN THE NEXT 30 TO 60 MINUTES.  THE SOUTHERN
SECTIONS OF THE DENVER METRO AREA WILL ALSO BE AFFECTED BY THIS LINE OF
STORMS BY 945 PM FRIDAY EVENING.

PERSONS IN THE PATH OF THESE STORMS SHOULD BE ON THE LOOKOUT FOR RAPIDLY
CHANGING WEATHER CONDITIONS AND MOVE TO SAFE SHELTER IF THREATENING
WEATHER APPROACHES.

ET
Local storm report, May 31, 10:05 PM MDT, 2 hours 56 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
1004 PM MDT FRI MAY 31 1991

PRELIMINARY STORM REPORTS FOR FRIDAY MAY 31 1991

TIME (MDT)  COUNTY/LOCATION                     EVENT

1505    WELD/5 1/2 MI WNW WELLINGTON    PEA SIZE HAIL

1532    DOUGLAS/LINCOLN & I25           GOLF BALL SIZE HAIL

1536    ARAPAHOE/ENGLEWOOD              3/4 INCH DIAMETER HAIL

1544    ARAPAHOE/I25 & COUNTY           HEAVY RAIN REPORTED BY HAM
        LINE ROAD                       "PROBABALY EXCEEDING 2 INCHES
                                        PER HOUR"

1547    ARAPAHOE/I25 & ORCHARD ROAD     1 INCH DIAMETER HAIL

1549    ARAPAHOE/I25 & ORCHARD ROAD     3/4 INCH DIAMETER HAIL

1550    ARAPAHOE/ILIFF & I225           3/4 INCH HAIL

1554    ARAPAHOE/ALAMEDA & BUCKLEY      PEA TO MARBLE SIZE HAIL

1555    ARAPAHOE/CENTRAL AURORA         PEA TO MARBLE SIZE HAIL

1558    ARAPAHOE/MISSISSIPPI &          PEA TO MARBLE SIZE HAIL
        BUCKLEY                         1 INCH DEEP

1604    ARAPAHOE/ILIFF & TELURIDE       1 INCH DIAMETER HAIL

1604    ARAPAHOE/MISSISSIPPI &          1/2 INCH DIAMETER HAIL
        TOWER

1606    ARAPAHOE/CHERRY CREEK LAKE      1/2 INCH DIAMETER HAIL

1624    ARAPAHOE/DRY CREEK &            1 INCH DIAMETER HAIL
        YOSEMITE

1628    ARAPAHOE/BUCKLEY NATIONAL       NATIONAL GUARD REPORTED FUNNEL
        GUARD BASE                      SOUTH WEST OF BUCKLEY

1637    ARAPAHOE/DRY CREEK &            3/4 INCH HAIL .38 INCHES OF RAIN
        YOSEMITE                        IN 20 MINUTES

1640    DOUGLAS/CASTLEROCK              1/2 INCH DIAMETER HAIL

1645    ADAMS/WATKINS                   1 INCH DIAMETER HAIL

1659    DOUGLAS/3 MILES SOUTH EAST      MARBLE TO 1 INCH DIAMETER HAIL
        OF PARKER

1700    DOUGLAS/5 MILES EAST SOUTH      1 INCH DIAMETER HAIL
        EAST OF PARKER

1700    DOUGLAS/3 MILES SOUTH EAST      MARBLE SIZE HAIL
        OF PARKER

1706    DOUGLAS/2 MILES NORTH EAST      MARBLE SIZE HAIL
        OF PARKER

1743    ELBERT/HIGHWY 86                MARBLE SIZE HAIL

1753    ELBERT/PARKER HIGHLAND          1 INCH DIAMETER HAIL
        ESTATES

1801    ELBERT/2 MILES SOUTH OF         GOLF BALL SIZE HAIL
        RAPAHOE COUNTY LINE

1807    JEFFERSON/NORTH WEST CORNER     1/2 TO 3/4 INCH HAIL
        OF ROCKY FLATS

1808    ARAPAHOE/10 MILES SOUTH         MARBLE SIZE HAIL 2 INCHES DEEP
        WEST OF BYERS

1812    BOULDER/28TH & DIAGONAL         HEAVY RAIN GREATER THAN 1 INCH
                                        PER HOUR WITH SOME STREET
                                        FLOODING

1843    ADAMS/3 MILES WEST OF BENNETT   HEAVY RAIN GREATER THAN 1 INCH
                                        PER HOUR

1847    JEFFERSON/58TH & RALSTON ROAD   MARBLE SIZE HAIL

1849    ELBERT/ELIZABETH                1 INCH DIAMETER HAIL 1 1/2
                                        INCHES DEEP

1908    ADAMS/BENNETT                   MARBLE SIZE HAIL

1919    DOUGLAS/2 MILES NORTH EAST      MARBLE SIZE HAIL
        OF PARKER

1921    ELBERT/KIOWA                    MARBLE SIZE HAIL

SIMMONS
Special weather statement, May 31, 10:11 PM MDT, 2 hours 50 minutes before
COZ011-010600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1015 PM MDT FRI MAY 31 1991

...THUNDERSTORMS IN DENVER AREA...

AT 1010 PM MDT FRIDAY EVENING STRONG THUNDERSTORMS CONTINUED TO DEVELOP
OVER THE DENVER METRO AREA.  HAIL...VERY HEAVY RAIN...LIGHTNING AND
GUSTY WINDS WILL ACCOMPANY THESE STORMS AS THEY MOVE THROUGH THE DENVER
AREA OVER THE NEXT HOUR OR TWO.

THE RAIN AND HAIL ASSOCIATED WITH THESE STORMS WILL BE SUFFICIENT TO
FLOOD LOW LYING AREAS...UNDERPASSES...INTERSECTIONS AND SMALL CREEKS AND
STREAMS.

PERSONS IN THE DENVER AREA SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER AND MOVE TO SAFE SHELTER IF BAD WEATHER APPROACHES.  AVOID
DRIVING THROUGH S)TANDING WATER.

ET

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, 4:05 PM MDTSevere Thunderstorm WarningBOUDenver, Jefferson40 min
Jun 1, 4:05 PM MDTSevere Thunderstorm WarningBOUDouglas40 min
Jun 1, 4:36 PM MDTTornado WarningBOUJefferson24 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; the sounding from the Mesonet's radiosonde archive.