Alert archive / Colorado / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 141, NWS Denver/Boulder, CO

August 26, 1997Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 26, 1997, 4:33 PM MDT for Washington County, Colorado. It was in force for 42 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
Aug 26, 1997, 4:33 PM MDT (22:33 UTC)
Expired
Aug 26, 1997, 5:15 PM MDT
In force
42 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County Washington County, CO

What was reported inside it

TimeReportWhereRemark
Aug 26, 5:15 PM MDTHail 2Akron, 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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.6 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 12:00Z on 1997-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 1997-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -57 square meters per square second.1939Sfc1 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
6 J/kg
Mixed-layer CIN
-296 J/kg
Mixed-layer LCL
2325 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-57 m²/s²
0-3 km storm-relative helicity
-28 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 262233 RRA
SVRDEN
COC121-262315-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
433 PM MDT TUE AUG 26 1997

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 515 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...

IN NORTHEAST COLORADO
     NORTHWESTERN WASHINGTON

INCLUDING THE FOLLOWING LOCATIONS
     PREWITT RESERVOIR

AT 431 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
SEVERE THUNDERSTORM 13 MILES SOUTH OF PREWITT RESERVOIR...OR ABOUT 12
MILES NORTHWEST OF AKRON.

THE STORM WAS MOVING NORTHEAST AT 15 MILES PER HOUR AND WILL BE 
MOVING TO PREWITT RESERVOIR BETWEEN 500 AND 515 PM.  

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

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

BARJENBRUCH

What forecasters said that day

The local office's own words before this severe thunderstorm 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 26, 11:15 AM MDT, 5 hours 18 minutes before
COZ030-032>050-260600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1115 AM MDT TUE AUG 26 1997

THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES

ADAMS     ARAPAHOE     BOULDER   CLEAR CREEK   DENVER       DOUGLAS
ELBERT    GILPIN       GRAND     JACKSON       JEFFERSON    LARIMER
LINCOLN   LOGAN        MORGAN    PARK          PHILLIPS     SEDGWICK
SUMMIT    WASHINGTON   WELD

SYNOPSIS: AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE MOUNTAINS
THIS AFTERNOON AND ACROSS THE WYOMING BORDER THIS EVENING.  PLENTY
OF MOISTURE AND DAYTIME HEATING WILL GIVE FUEL FOR THUNDERSTORMS
TODAY.  THE STRONGER STORMS WILL OCCUR MAINLY NORTH OF I-76 AND
PRODUCE LOCALLY HEAVY RAIN.  A FEW STORMS MAY REACH SEVERE LIMITS
BUT SPOTTER ACTIVATION IS NOT ANTICIPATED.

TA
Special weather statement, Aug 26, 3:34 PM MDT, 59 minutes before
COZ036-040-262210-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
335 PM MDT TUE AUG 26 1997

...STRONG THUNDERSTORM IN CENTRAL JEFFERSON COUNTY...

AT 335 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM PRODUCING HEAVY RAINFALL IN CENTRAL JEFFERSON
COUNTY.   THE STORM WAS MOVING EAST AT 15 MILES PER HOUR.

RADAR ESTIMATED RAINFALL RATES OF 1 TO 1.5 INCHES PER HOUR.  THIS
STORM WAS ALSO CAPABLE OF PRODUCING WIND GUSTS TO 45 MPH.

PERSONS IN OR NEAR ASPEN PARK...BUFFALO CREEK...CHATFIELD
RESERVOIR...CONIFER...INDIAN HILLS...MORRISON...PINE...ROXBOROUGH
PARK...SOUTH PLATTE AND TINY TOWN SHOULD BE ON THE LOOKOUT FOR THESE
HEAVY RAINS AND STRONG WINDS.

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.

RJK
Special weather statement, Aug 26, 3:35 PM MDT, 58 minutes before
COZ036-040-262210-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
335 PM MDT TUE AUG 26 1997

...STRONG THUNDERSTORM IN CENTRAL JEFFERSON COUNTY...

AT 335 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM PRODUCING HEAVY RAINFALL IN CENTRAL JEFFERSON
COUNTY.   THE STORM WAS MOVING EAST AT 15 MILES PER HOUR.

RADAR ESTIMATED RAINFALL RATES OF 1 TO 1.5 INCHES PER HOUR.  THIS
STORM WAS ALSO CAPABLE OF PRODUCING WIND GUSTS TO 45 MPH.

PERSONS IN OR NEAR ASPEN PARK...BUFFALO CREEK...CHATFIELD
RESERVOIR...CONIFER...INDIAN HILLS...MORRISON...PINE...ROXBOROUGH
PARK...SOUTH PLATTE AND TINY TOWN SHOULD BE ON THE LOOKOUT FOR THESE
HEAVY RAINS AND STRONG WINDS.

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.

RJK
Special weather statement, Aug 26, 3:57 PM MDT, 36 minutes before
COZ042-048-262300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
357 PM MDT TUE AUG 26 1997

...STRONG THUNDERSTORM IN NORTHEASTERN WELD COUNTY...

AT 355 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM 14 MILES SOUTHWEST OF WESTPLAINS...OR ABOUT 30 MILES
WEST OF STERLING.

THE STORM WAS MOVING NORTHEAST AT 15 MILES PER HOUR...AND WILL
PRODUCE DANGEROUS LIGHTNING...MARBLE SIZED HAIL...AND BETWEEN
1 AND 2 INCHES OF RAIN IN 30 MINUTES.

PERSONS IN EXTREME NORTHEAST WELD COUNTY AND EXTREME NORTHWEST LOGAN
COUNTY...INCLUDING THE TOWN OF WESTPLAINS...SHOULD BE ON THE LOOKOUT
FOR THREATENING WEATHER.  MOVE TO A PLACE OF SAFETY IF BAD WEATHER
APPROACHES.

BARJENBRUCH
Special weather statement, Aug 26, 4:18 PM MDT, 15 minutes before
COZ036-040-041-262300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER COLORADO
418 PM MDT TUE AUG 26 1997

...STRONG THUNDERSTORMS PUSHING EAST ACROSS DOUGLAS COUNTY...

AT 418 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER SEDALIA...OR ABOUT 23 MILES SOUTH OF DENVER.
THE STORM WAS MOVING EAST AT 25 MILES PER HOUR.

RADAR ESTIMATED RAINFALL RATES OF 1 TO 1.5 INCHES PER HOUR.  THIS
STORM WAS ALSO CAPABLE OF PRODUCING WIND GUSTS TO 45 MPH AS WELL AS
HAIL UP TO 1/2 INCH IN DIAMETER.

PERSONS IN OR NEAR SOUTHERN ENGLEWOOD...LITTLETON...BEVERLY HILLS...
CASTLE ROCK...DEVILS HEAD...ELIZABETH...FRANKTOWN...HIGHLANDS
RANCH...LARKSPUR...LOUVIERS...PARKER...PERRY PARK...PONDEROSA PARK...
ROXBOROUGH PARK...SEDALIA...SURREY RIDGE AND THE PINERY SHOULD BE ON
THE LOOKOUT FOR HEAVY RAINS...SMALL HAIL...AND STRONG WIND GUSTS.

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.

RJK
Special weather statement, Aug 26, 4:19 PM MDT, 14 minutes before
COZ036-040-041-262300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER COLORADO
418 PM MDT TUE AUG 26 1997

...STRONG THUNDERSTORMS PUSHING EAST ACROSS DOUGLAS COUNTY...

AT 418 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER SEDALIA...OR ABOUT 23 MILES SOUTH OF DENVER.
THE STORM WAS MOVING EAST AT 25 MILES PER HOUR.

RADAR ESTIMATED RAINFALL RATES OF 1 TO 1.5 INCHES PER HOUR.  THIS
STORM WAS ALSO CAPABLE OF PRODUCING WIND GUSTS TO 45 MPH AS WELL AS
HAIL UP TO 1/2 INCH IN DIAMETER.

PERSONS IN OR NEAR SOUTHERN ENGLEWOOD...LITTLETON...BEVERLY HILLS...
CASTLE ROCK...DEVIL'S HEAD...ELIZABETH...FRANKTOWN...HIGHLANDS
RANCH...LARKSPUR...LOUVIERS...PARKER...PERRY PARK...PONDEROSA PARK...
ROXBOROUGH PARK...SEDALIA...SURREY RIDGE AND THE PINERY SHOULD BE ON
THE LOOKOUT FOR HEAVY RAINS...SMALL HAIL...AND STRONG WIND GUSTS.

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.

RJK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 4:55 PM MDTSevere Thunderstorm WarningBOULogan50 min
Aug 26, 5:15 PM MDTSevere Thunderstorm WarningBOUWashington45 min
Aug 26, 5:58 PM MDTSevere Thunderstorm WarningBOUWashington47 min

Nearby

Severe Thunderstorm Warnings in Colorado, 1997Every severe thunderstorm warning in 1997

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.