Alert archive / Colorado / Tornado Warnings in 1991

Tornado Warning 37, NWS Denver/Boulder, CO

June 10, 1991Douglas County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 10, 1991, 3:28 PM MDT for Douglas County, Colorado. It was in force for 47 min. 1 report 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 10, 1991, 3:28 PM MDT (21:28 UTC)
Expired
Jun 10, 1991, 4:15 PM MDT
In force
47 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County Douglas County, CO

What was reported inside it

TimeReportWhereRemark
Jun 10, 3:52 PM MDTTornado F0Douglas, 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

Fort Carson/Butt, CO (KFCS), launched 12:00Z, 9.5 hours before the alert went out and 75 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, Fort Carson/Butt, CO at 12:00Z on 1991-06-10Temperature 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, Fort Carson/Butt, CO at 12:00Z on 1991-06-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -39 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
1843 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-39 m²/s²
0-3 km storm-relative helicity
-21 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 102128
TORDEN
COC035-102215-

BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
328 PM MDT MON JUN 10 1991

THE NATIONAL WEATHER SERVICE IN DENVER HAS REISSUED A TORNADO
WARNING EFFECTIVE NOW UNTIL 415 PM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTHEASTERN COLORADO
     DOUGLAS

INCLUDING THE FOLLOWING TOWNS/CITIES
     CASTLE ROCK...FRANKTOWN AND LARKSPUR

AT 328 PM MDT RADAR WAS STILL INDICATING A POSSIBLE TORNADO 3 MILES
NORTHEAST OF LARKSPUR ...OR ABOUT 35 MILES SOUTH OF DENVER.

THE STORM PRODUCING THE TORNADO WAS MOVING VERY SLOWLY TO THE SOUTHEAST.

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 EASTERN
COLORADO TIL 900 PM MDT.

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 3914 10466 3914 10509 3941 10495 3947 10467

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 10, 1:09 PM MDT, 2 hours 19 minutes before
COZ011-102100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
110 PM MDT JUN 10 1991

...STRONG THUNDERSTORMS BUILDING OVER FOOTHILLS WEST OF DENVER...

AT 100 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED STRONG
THUNDERSTORMS DEVELOPING OVER THE FOOTHILLS 30 MILES WEST OF DENVER.
THE STRONGEST STORM WAS LOCATED 10 MILES SOUTHWEST OF EVERGREEN.  THESE
STORMS WERE MOVING SLOWLY TO THE EAST AT 10 TO 15 MPH.

ALL PEOPLE IN EASTERN CLEAR CREEK AND WEST CENTRAL JEFFERSON COUNTIES...
INCLUDING EVERGREEN AND CONIFER SHOULD BE ALERT FOR DANGEROUS FREQUENT
LIGHTNING...HAIL AND STRONG GUSTY WINDS FROM THESE STORMS UNTIL 230
PM MDT THIS AFTERNOON.  HEAVY RAIN MAY PRODUCE LOCAL FLOODING OF
HIGHWAYS...NORMALLY DRY GULCHES AND LOW LYING OR FLOOD PRONE AREAS.
DRIVERS SHOULD BE ALERT FOR MUD AND ROCK SLIDES IN FOOTHILLS CANYONS.

STAY TUNED TO NATIONAL WEATHER SERVICE RADIO AND OTHER MASS MEDIA
COMMUNICATIONS FOR LATER STATEMENTS AND POSSIBLE WARNINGS.

GARD...WSFO DENVER
Special weather statement, Jun 10, 1:59 PM MDT, 1 hour 29 minutes before
COZ011-102200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
2PM MDT JUN 10 1991

...THUNDERSTORMS CONTINUE TO BUILD ALONG FRONT RANGE...

AT 2PM THUNDERSTORMS CONTINUED TO BUILD ALONG THE FRONT RANGE
FROM SOUTHERN LARIMER COUNTY TO SOUTHERN JEFFERSON COUNTY AND MOVE
TOWARD THE EAST SOUTHEAST AT AROUND 15 MILES AN HOUR. SMALL
HAIL AND STRONG WINDS HAVE BEEN REPORTED WITH THESE STORMS AND LIGHTNING
STARTED A FIRE NEAR CONIFER. CURRENT INDICATIONS ARE THAT ONE OR
TWO OF THESE STORMS  COULD PRODUCE UP TO AN INCH OF RAIN IN AN HOUR AS
THEY MOVE ACROSS THE DENVER METROPOLITAN AREA DURING THE NEXT SEVERAL
HOURS BUT NOTHING MORE THAN LOCALIZED STREET FLOODING IS ANTICIPATED AT
THE_ PRESENT TIME...ALTHOUGH SMALL HAIL AND LOCALLY STRONG WINDS
SHOULD BE EXPECTED WITH THE STORMS.

FURTHER STATEMENTS WILL BE ISSUED AS CONDITIONS REQUIRE.

LET
Special weather statement, Jun 10, 2:39 PM MDT, 49 minutes before
COZ011-102200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
240 PM MDT MON JUN 10 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT TIL 900 PM MDT FOR THE FRONT
   RANGE...NORTHEAST PLAINS...AND PALMER DIVIDE...
...VERY STRONG THUNDERSTORM NEAR RUSTIC IN WESTERN LARIMER COUNTY...

AT 240 PM MDT RADAR WAS SHOWING A VERY STRONG THUNDERSTORM ABOUT 8 MILES
NORTHWEST OF RUSTIC IN WESTERN LARIMER COUNTY...OR ABOUT 35 MILES WEST-
NORTHWEST OF FORT COLLINS.

AN INTENSE THUNDERSTORM WAS ALSO OVER EXTREME SOUTHERN JEFFERSON COUNTY
AND SOUTHWESTERN DOUGLAS COUNTY NEAR DECKERS.

NEW THUNDERSTORMS WERE ALSO DEVELOPING OVER NORTH-CENTRAL WELD COUNTY.

THUNDERSTORMS WERE MOVING TO THE EAST-SOUTHEAST AT 10 MPH AND APPEAR TO
HAVE CONSIDERABLE POTENTIAL FOR BOTH HAIL AND HEAVY RAIN.

KEEP LISTENING FOR LATER STATEMENTS OR WARNINGS.

MCQUEEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 10, 2:44 PM MDTSevere Thunderstorm WarningBOUDouglas46 min
Jun 10, 2:53 PM MDTTornado WarningBOUDouglas37 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.