Alert archive / Colorado / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 139, NWS Denver/Boulder, CO

August 23, 1997Phillips County, Sedgwick County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 23, 1997, 6:11 PM MDT for Phillips County, Sedgwick County, Colorado. It was in force for 34 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued
Aug 23, 1997, 6:11 PM MDT (00:11 UTC)
Expired
Aug 23, 1997, 6:45 PM MDT
In force
34 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Phillips County, CO, Sedgwick County, CO

The radar

The Goodland radar (KGLD), 165 km from the middle of the area, began a volume at 00:11 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.

What was reported inside it

TimeReportWhereRemark
Aug 23, 6:30 PM MDTHail 0.75Sedgwick, 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 00:00Z, 0.2 hours before the alert went out and 120 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 1997-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1142 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1997-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.193958Sfc1 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
1142 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
2544 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
119 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.

506 
WUUS1 KDEN 240014 RRA
SVRDEN
COC095-115-240045-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
611 PM MDT SAT AUG 23 1997

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 645 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...

IN NORTHEAST COLORADO
     NORTH CENTRAL PHILLIPS AND SOUTH CENTRAL SEDGWICK

INCLUDING THE FOLLOWING LOCATIONS
     FAIRFIELD

AT 611 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 7 MILES NORTHEAST OF FAIRFIELD...OR ABOUT 13
MILES SOUTHWEST OF JULESBURG.

THE STORM WAS MOVING SOUTH AT 15 MILES PER HOUR.

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.

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

THIS WARNING REPLACES THE EARLIER WARNING FOR CENTRAL PHILLIPS 
COUNTY.

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

LAT...LON 4082 10235 4063 10235 4064 10256 4085 10245

GIMMESTAD

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 23, 3:20 PM MDT, 2 hours 51 minutes before
COZ046-232215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
320 PM MDT SAT AUG 23 1997

...STRONG THUNDERSTORM IN NORTH CENTRAL LINCOLN COUNTY...

AT 317 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES NORTH OF GENOA...OR ABOUT 13 MILES
NORTHEAST OF LIMON.

THE STORM WAS MOVING SOUTH AT 5 MILES PER HOUR.

PERSONS IN OR NEAR GENOA

A SPOTTER REPORTED MARBLE SIZED HAIL WITH THE STORM.  IN ADDITION
RADAR INDICATED THE STORM MAY HAVE PRODUCED UP TO 1 INCH OF
RAINFALL.  DANGEROUS LIGHTNING AND STRONG WIND GUSTS TO 40 MPH ARE
POSSIBLE WITH THIS STORM.

BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF
SAFETY IMMIDIATELY.  HEAVY RAINS MAY FLOOD LOW LYING AREAS.  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.

FMC
Special weather statement, Aug 23, 3:23 PM MDT, 2 hours 48 minutes before
COZ046-232215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
320 PM MDT SAT AUG 23 1997

...STRONG THUNDERSTORM IN NORTH CENTRAL LINCOLN COUNTY...

AT 317 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES NORTH OF GENOA...OR ABOUT 13 MILES
NORTHEAST OF LIMON.

THE STORM WAS MOVING SOUTH AT 5 MILES PER HOUR.

PERSONS IN OR NEAR GENOA

A SPOTTER REPORTED MARBLE SIZED HAIL WITH THE STORM.  IN ADDITION
RADAR INDICATED THE STORM MAY HAVE PRODUCED UP TO 1 INCH OF
RAINFALL.  DANGEROUS LIGHTNING AND STRONG WIND GUSTS TO 40 MPH ARE
POSSIBLE WITH THIS STORM.

BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF
SAFETY IMMIDIATELY.  HEAVY RAINS MAY FLOOD LOW LYING AREAS.  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.

FM:C
Special weather statement, Aug 23, 3:25 PM MDT, 2 hours 46 minutes before
COZ046-232215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO...CORRECTED
325 PM MDT SAT AUG 23 1997

...STRONG THUNDERSTORM IN NORTH CENTRAL LINCOLN COUNTY...

AT 317 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES NORTH OF GENOA...OR ABOUT 13 MILES
NORTHEAST OF LIMON.

THE STORM WAS MOVING SOUTH AT 5 MILES PER HOUR.

A SPOTTER REPORTED MARBLE SIZED HAIL WITH THE STORM.  IN ADDITION
RADAR INDICATED THE STORM MAY HAVE PRODUCED UP TO 2 INCHES OF
RAINFALL.  DANGEROUS LIGHTNING AND STRONG WIND GUSTS TO 40 MPH ARE
POSSIBLE WITH THIS STORM.

PERSONS IN OR NEAR GENOA SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER AND MOVE TO A PLACE OF SAFETY IMMIDIATELY.

HEAVY RAINS MAY FLOOD LOW LYING AREAS.  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.

FMC
Special weather statement, Aug 23, 3:26 PM MDT, 2 hours 45 minutes before
COZ046-232215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO...CORRECTED
325 PM MDT SAT AUG 23 1997

...STRONG THUNDERSTORM IN NORTH CENTRAL LINCOLN COUNTY...

AT 317 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES NORTH OF GENOA...OR ABOUT 13 MILES
NORTHEAST OF LIMON.

THE STORM WAS MOVING SOUTH AT 5 MILES PER HOUR.

A SPOTTER REPORTED MARBLE SIZED HAIL WITH THE STORM.  IN ADDITION
RADAR INDICATED THE STORM MAY HAVE PRODUCED UP TO 2 INCHES OF
RAINFALL.  DANGEROUS LIGHTNING AND STRONG WIND GUSTS TO 40 MPH ARE
POSSIBLE WITH THIS STORM.

PERSONS IN OR NEAR GENOA SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER AND MOVE TO A PLACE OF SAFETY IMMIDIATELY.

HEAVY RAINS MAY FLOOD LOW LYING AREAS.  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
THREATEbNED BY FLOOD WATERS.

FMC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 6:45 PM MDTSevere Thunderstorm WarningBOUPhillips45 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; radar from the NEXRAD Level II archive.