Alert archive / Colorado / Tornado Warnings in 1994

Tornado Warning 15, NWS Denver/Boulder, CO

August 11, 1994Adams County, Jefferson County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Aug 11, 1994, 5:38 PM MDT for Adams County, Jefferson County, Colorado. It was in force for 22 min.

The area

The counties it named.

The facts

Issued
Aug 11, 1994, 5:38 PM MDT (23:38 UTC)
Expired
Aug 11, 1994, 6:00 PM MDT
In force
22 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Adams County, CO, Jefferson County, CO

The radar

The Denver radar (KFTG), 22 km from the middle of the area, began a volume at 23:38 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Fort Carson/Butt, CO (KFCS), launched 12:00Z, 11.6 hours before the alert went out and 117 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 1994-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 46 joules per kilogram.LCLLFCEL10008507005003002001001 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 1994-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 square meters per square second.1939Sfc1 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
46 J/kg
Mixed-layer CIN
-163 J/kg
Mixed-layer LCL
1383 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
31 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 112340
TORDEN
COC001-059-120000-

BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
538 PM MDT THU AUG 11 1994

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A TORNADO
WARNING EFFECTIVE UNTIL 600 PM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTHEASTERN COLORADO
     EXTREME WEST CENTRAL ADAMS AND NORTHEASTERN JEFFERSON

INCLUDING THE FOLLOWING LOCATIONS
     ARVADA...NORTHGLENN...ROCKY FLATS...THORNTON AND
     WESTMINSTER

AT 538 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A POSSIBLE TORNADO 4 MILES NORTHWEST OF ARVADA ...OR ABOUT 15
MILES NORTHWEST OF DENVER.

AMATEUR RADIO WEATHER SPOTTERS REPORTED A TORNADO

A FUNNEL CLOUD WAS LOCATED OVER STANDLEY LAKE.

THE STORM WAS MOVING TO THE SOUTHEAST AT 10 TO 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 AWAY
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 dDENVER.

GARD...WSFO DENVER
LAT...LON 3980 10497 3984 10519 3995 10519 3992 10493

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, Aug 11, 2:50 PM MDT, 2 hours 48 minutes before
COZ036-037-112130-

SPECIAL WEATHER STATEMENT...CORRECTED TIME...
NATIONAL WEATHER SERVICE DENVER CO
250 PM MDT THU AUG 11 1994

AT 238 PM NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
AN AREA OF THUNDERSTORMS INCREASING ACROSS NORTHERN PARK INTO
SOUTHERN JEFFERSON COUNTIES.  THESE STORMS WERE MOVING EAST
AT 15 MPH.  RESIDENTS OF THE TOWNS OF GRANT...BAILEY...HIGHLAND PARK...
GLENELK...DECKERS...AND CONIFER SHOULD CONTINUE MONITORING THE
WEATHER THIS AFTERNOON.  THUNDERSTORMS WILL CONTINUE TO DROP HEAVY
RAIN AND SAMLL HAIL.  SOME LOCAL FLOODING WILL BE POSSIBLE.

REPORT ANY SEVERE WEATHER OR FLOODING TO YOUR LOCAL LAW ENFORCEMENT
OFFICIALS TO BE PASSED ON THE THE NATIONAL WEATHER SERVICE.

RTG
LAT...LON 3925 10487 3925 10532 3949 10528 3949 10485
Special weather statement, Aug 11, 3:30 PM MDT, 2 hours 8 minutes before
COZ036-040-112230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
330 PM MDT THU AUG 11 1994

...STRONG THUNDERSTORM OVER NORTHERN JEFFERSON COUNTY...

AT 326 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A STRONG THUNDERSTORM 5 MILES WEST OF WHITE RANCH OPEN SPACE ...OR
ABOUT 25 MILES WEST OF DENVER.  THE STORM WAS MOVING TO THE EAST
AT 10 MPH.

ALL PEOPLE IN THE NORTHERN JEFFERSON COUNTY PORTION OF METRO
DENVER...INCLUDING THE FOLLOWING LOCATIONS
     ARVADA...EDGEWATER...GOLDEN...LAKEWOOD...LEYDEN...MOUNTAIN
     VIEW...PLEASANT VIEW...ROCKY FLATS...WESTMINSTER...WHEAT
     RIDGE AND WHITE RANCH OPEN SPACE
SHOULD BE ALERT FOR HEAVY RAIN...FREQUENT DANGEROUS LIGHTNING...
SMALL HAIL AND STRONG GUSTY WINDS.

HEAVY RAIN MAY CAUSE STREET AND ROAD FLOODING.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES.  AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS
AS THEY MAY BE WASHED OUT.  WATER LEVELS OF SMALL STREAMS AND
RIVERS MAY ALSO RISE...INCLUDING LENA GULCH...THEREFORE SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

GARD...WSFO DENVER

LAT...LON 3972 10507 3971 10539 3990 10538 3991 10506
Special weather statement, Aug 11, 3:33 PM MDT, 2 hours 5 minutes before
COZ036-040-112230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
330 PM MDT THU AUG 11 1994

...STRONG THUNDERSTORM OVER NORTHERN JEFFERSON COUNTY...

AT 326 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A STRONG THUNDERSTORM 5 MILES WEST OF WHITE RANCH OPEN SPACE ...OR
ABOUT 25 MILES WEST OF DENVER.  THE STORM WAS MOVING TO THE EAST
AT 10 MPH.

ALL PEOPLE IN THE NORTHERN JEFFERSON COUNTY PORTION OF METRO
DENVER...INCLUDING THE FOLLOWING LOCATIONS
     ARVADA...EDGEWATER...GOLDEN...LAKEWOOD...LEYDEN...MOUNTAIN
     VIEW...PLEASANT VIEW...ROCKY FLATS...WESTMINSTER...WHEAT
     RIDGE AND WHITE RANCH OPEN SPACE
SHOULD BE ALERT FOR HEAVY RAIN...FREQUENT DANGEROUS LIGHTNING...
SMALL HAIL AND STRONG GUSTY WINDS.

HEAVY RAIN MAY CAUSE STREET AND ROAD FLOODING.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES.  AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS
AS THEY MAY BE WASHED OUT.  WATER LEVELS OF SMALL STREAMS AND
RIVERS MAY ALSO RISE...INCLUDING LENA GULCH...THEREFORE SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

GARD...WSFO DENVER

LAT...LON 3972 10507 3971 10539 3990 10538 3991 10506
Special weather statement, Aug 11, 4:34 PM MDT, 1 hour 4 minutes before
COZ035-039-112330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
434 PM MDT THU AUG 11 1994

...STRONG THUNDERSTORM OVER BOULDER COUNTY...

AT 434 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A THUNDERSTORM OVER JAMESTOWN ...OR ABOUT 37 MILES SOUTHWEST OF
FORT COLLINS.

ALL PEOPLE IN BOULDER COUNTY INCLUDING THE FOLLOWING LOCATIONS
     BOULDER...ERIE...GOLD HILL...JAMESTOWN...LONGMONT...NIWOT
     AND RAYMOND
SHOULD BE ALERT FOR HEAVY RAIN...FREQUENT DANGEROUS LIGHTNING...HAIL
AND STRONG GUSTY WINDS TIL 530 PM MDT THIS AFTERNOON.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES.  AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS
AS THEY MAY BE WASHED OUT.  WATER LEVELS OF SMALL STREAMS AND
RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF
THREATENED BY FLOOD WATERS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR NORTH
CENTRAL...NORTHEASTERN AND EAST CENTRAL COLORADO UNTIL 1000PM
MDT.

GARD...WSFO DENVER

LAT...LON 4000 10507 4004 10547 4015 10547 4023 10507
Special weather statement, Aug 11, 4:37 PM MDT, 1 hour 1 minute before
COZ035-039-112330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
434 PM MDT THU AUG 11 1994

...STRONG THUNDERSTORM OVER BOULDER COUNTY...

AT 434 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A THUNDERSTORM OVER JAMESTOWN ...OR ABOUT 37 MILES SOUTHWEST OF
FORT COLLINS.

ALL PEOPLE IN BOULDER COUNTY INCLUDING THE FOLLOWING LOCATIONS
     BOULDER...ERIE...GOLD HILL...JAMESTOWN...LONGMONT...NIWOT
     AND RAYMOND
SHOULD BE ALERT FOR HEAVY RAIN...FREQUENT DANGEROUS LIGHTNING...HAIL
AND STRONG GUSTY WINDS TIL 530 PM MDT THIS AFTERNOON.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES.  AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS
AS THEY MAY BE WASHED OUT.  WATER LEVELS OF SMALL STREAMS AND
RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF
THREATENED BY FLOOD WATERS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR NORTH
CENTRAL...NORTHEASTERN AND EAST CENTRAL COLORADO UNTIL 1000PM
MDT.

GARD...WSFO DENVER

LAT...LON 4000 10507 4004 10547 4015 10547 4023 10507
Special weather statement, Aug 11, 4:42 PM MDT, 56 minutes before
COZ036-040-112345-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
445PM MDT THU AUG 11 1994

...STRONG THUNDERSTORMS OVER NORTHERN JEFFERSON COUNTY...

AT 438 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A THUNDERSTORM 3 MILES NORTH OF BERGEN PARK ...OR ABOUT 24
MILES WEST OF DENVER.  THE STORM WAS MOVING TO THE EAST AT
10 MPH.

ALL PEOPLE IN NORTHERN JEFFERSON COUNTY INCLUDING THE FOLLOWING
LOCATIONS
     ARVADA...BERGEN PARK...EDGEWATER...GOLDEN...IDLEDALE...
     KITTREDGE...LAKEWOOD...LEYDEN...MORRISON...PLEASANT VIEW...
     RED ROCKS PARK...WESTMINSTER...WHEAT RIDGE AND WHITE RANCH
     OPEN SPACE
SHOULD BE ALERT FOR HEAVY RAIN...HAIL...FREQUENT DANGEROUS LIGHTNING
AND STRONG GUSTY WINDS UNTIL 545 PM MDT THIS AFTERNOON.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES.  AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS
AS THEY MAY BE WASHED OUT.  WATER LEVELS OF SMALL STREAMS...INCLUDING
LENA GULCH...AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF
THREATENED BY FLOOD WATERS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR NORTH
CENTRAL...NORTHEASTERN AND EAST CENTRAL COLORADO UNTIL 1000PM
MDT.

GARD...WSFO DENVER

LAT...LON 3961 10511 3967 10538 3981 10539 3989 10506

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 10:08 PM MDTSevere Thunderstorm WarningBOULarimer37 min
Aug 11, 1:35 PM MDTSevere Thunderstorm WarningBOUDouglas25 min
Aug 11, 4:22 PM MDTSevere Thunderstorm WarningBOUAdams, Weld38 min
Aug 11, 5:16 PM MDTSevere Thunderstorm WarningBOUBoulder, Jefferson44 min

Nearby

Tornado Warnings in Colorado, 1994Every tornado warning in 1994Tornadoes in 1994

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; radar from the NEXRAD Level II archive.