Alert archive / Colorado / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 82, NWS Denver/Boulder, CO

June 24, 1997Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 24, 1997, 5:11 PM MDT for Weld County, Colorado. It was in force for 49 min. 2 reports 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
Jun 24, 1997, 5:11 PM MDT (23:11 UTC)
Expired
Jun 24, 1997, 6:00 PM MDT
In force
49 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Weld County, CO

The radar

The Denver radar (KFTG), 64 km from the middle of the area, began a volume at 23:10 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
Jun 24, 5:17 PM MDTHail 0.75La Salle, CO
Jun 24, 5:47 PM MDTHail 0.75Masters, 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, 11.2 hours before the alert went out and 114 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 1997-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 210 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 12:00Z on 1997-06-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
210 J/kg
Mixed-layer CIN
-271 J/kg
Mixed-layer LCL
2200 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
-34 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.

339 
WUUS1 KDEN 242313 RRA
SVRDEN
COC123-250000-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
511 PM MDT TUE JUN 24 1997

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

IN NORTHEAST COLORADO
     CENTRAL WELD

INCLUDING THE FOLLOWING LOCATIONS
     EASTERN GREELEY...BARNESVILLE...GILL...KERSEY...     
LUCERNE...MILTON RESERVOIR AND RIVERSIDE RESERVOIR

AT 504 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 4 MILES SOUTHEAST OF EVANS...OR ABOUT 8 MILES
SOUTHEAST OF GREELEY.

THE STORM WAS MOVING EAST AT 15 MILES PER HOUR.

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS OVER 60
MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

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.

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 4020 10421 4018 10468 4051 10472 4051 10447
          4053 10420

KLEYLA

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, Jun 24, 11:15 AM MDT, 5 hours 56 minutes before
COZ030-032>050-260600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1115 AM MDT TUE JUN 24 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:  IT WILL BE A VERY ACTIVE AFTERNOON AND EVENING FOR
CONVECTION OVER NORTHEAST COLORADO.  SEVERAL FACTORS WILL COME
TOGETHER TO PRODUCE WIDESPREAD...POSSIBLY SEVERE THUNDERSTORMS WITH
HEAVY RAIN...ESPECIALLY EAST OF GREELEY TO LIMON LINE THIS
EVENING.

SOUTHEAST WINDS WILL CONTINUE TO FEED MOIST AIR ACROSS NORTHEAST
COLORADO INTO SOUTHEAST WYOMING.  A WEAK UPPER TROUGH WILL ALSO HELP
FOCUS THE THUNDERSTORMS IN NORTHEAST COLORADO LATE THIS AFTERNOON
AND EVENING.  A SURFACE LOW WILL STRENGTHEN EAST OR NORTHEAST OF
DENVER WHICH WILL ALSO ACT AS A FOCUS FOR THUNDERSTORMS.  WINDS WILL
TURN CLOCKWISE WITH HEIGHT...SO THUNDERSTORMS WILL ALSO BE CAPABLE
OF PRODUCING TORNADOES.

THUNDERSTORMS WILL RAPIDLY FORM OVER THE HIGHER TERRAIN...THE
FOOTHILLS...PALMER DIVIDE AND CHEYENNE RIDGE EARLY THIS AFTERNOON...
AND DEVELOP TO THE PLAINS BEFORE 2PM.  BY EVENING... THUNDERSTORMS
SHOULD BEGIN DECREASING OVER THE URBAN CORRIDOR...WHILE
THUNDERSTORMS BECOME WIDESPREAD TO THE NORTHEAST OF GREELEY AND
LIMON.  WE WILL HAVE TO WATCH FOR...TORNADOES...LARGE HAIL...AND
POSSIBLE FLOODING.

SPOTTERS WILL LIKELY BE ACTIVATED AROUND 1PM.

RTG
Special weather statement, Jun 24, 11:45 AM MDT, 5 hours 26 minutes before
COZ030-032>050-270600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER COLORADO
1145 AM MDT TUE JUN 24 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: THE SURFACE AIRMASS HAS SLIGHTLY DRIED TODAY FROM
YESTERDAY AND THERE HAS BEEN SOME SLIGHT WARMING ALOFT.  IN SPITE
OF THESE TWO FACTORS THERE IS STILL ENOUGH MOISTURE PRESENT FOR
THUNDERSTORM DEVELOPMENT WHEN COUPLED WITH THE EXPECTED SIGNIFICANT
DAYTIME HEATING.  SOUTHEAST SURFACE FLOW SHOULD CONTINUE TO DEVELOP
AND INCREASE OVER THE PLAINS THIS AFTERNOON CREATING A CONVERGENCE
LINE FOR THUNDERSTORMS TO DEVELOP UPON TO THE EAST OF THE DENVER
METRO AREA.   EXPECT STORMS TO DEVELOP OVER THE HIGHER TERRAIN BY
1:30 PM...AND OUT OVER THE PLAINS BY 4 PM.  SOME OF THE STORMS MAY
BE SEVERE OVER MOST OF THE PLAINS...DUE TO LARGE HAIL AND STRONG
WINDS.  THE BEST THREAT OF SEVERE WEATHER WILL BE OVER LINCOLN...
WASHINGTON...LOGAN....PHILLIPS...AND SEDGWICK COUNTIES.

SPOTTER ACTIVATION MAY BE NEEDED AFTER 3 PM.         RJK

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 23, 6:59 PM MDTTornado WarningBOUAdams, Arapahoe31 min
Jun 23, 8:14 PM MDTSevere Thunderstorm WarningBOUWeld46 min
Jun 23, 9:00 PM MDTSevere Thunderstorm WarningBOUWeld45 min
Jun 24, 3:11 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert49 min
Jun 24, 3:58 PM MDTSevere Thunderstorm WarningBOUElbert47 min
Jun 24, 4:40 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln50 min
Jun 24, 4:43 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld32 min
Jun 24, 5:15 PM MDTSevere Thunderstorm WarningBOUMorgan30 min
Jun 24, 5:26 PM MDTSevere Thunderstorm WarningBOUWashington49 min
Jun 24, 5:36 PM MDTSevere Thunderstorm WarningBOULincoln39 min
Jun 24, 5:50 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld40 min
Jun 24, 5:54 PM MDTSevere Thunderstorm WarningBOULincoln36 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.