Alert archive / Colorado / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 130, NWS Denver/Boulder, CO

August 16, 1997Logan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 16, 1997, 8:40 PM MDT for Logan County, Weld County, Colorado. It was in force for 30 min. No storm report in the archive falls 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.

The facts

Issued
Aug 16, 1997, 8:40 PM MDT (02:40 UTC)
Expired
Aug 16, 1997, 9:10 PM MDT
In force
30 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Logan County, CO, Weld County, CO

The radar

The Cheyenne radar (KCYS), 116 km from the middle of the area, began a volume at 02:42 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

Denver, CO (KDNR), launched 00:00Z, 2.7 hours before the alert went out and 98 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 1997-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1611 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 00:00Z on 1997-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
1611 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1576 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
-15 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.

369 
WUUS1 KDEN 170238 RRA
SVRDEN
COC075-123-170310-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
840 PM MDT SAT AUG 16 1997

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 910 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...

IN NORTHEAST COLORADO
     NORTHEASTERN WELD AND WEST CENTRAL LOGAN

INCLUDING THE FOLLOWING LOCATIONS
     LOGAN CORNERS...PAWNEE PASS AND WESTPLAINS

AT 840 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 12 MILES WEST OF WESTPLAINS...OR ABOUT 29 MILES 
WEST OF STERLING.  THE STORM WAS MOVING EAST-SOUTHEAST AT 25 MILES 
PER HOUR.  THIS STORM HAS PRODUCED LARGE HAIL...WIND GUSTS IN EXCESS 
OF 60 MPH AND POSSIBLE FUNNEL CLOUDS.

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.

HAIL...INTENSE RAIN AND STRONG DAMAGING WINDS ARE LIKELY WITH THIS
STORM. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM PASSES.

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 4053 10335 4072 10383 4091 10386 4089 10337

RJK

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 16, 4:35 PM MDT, 4 hours 5 minutes before
COZ035-036-038-039-040-043-162330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
435 PM MDT SAT AUG 16 1997

...SCATTERED THUNDERSTORMS DEVELOPING IN THE FOOTHILLS LATE THIS
AFTERNOON...

AT 430 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES EAST OF BOULDER...OR ABOUT 24 MILES
NORTHWEST OF DENVER.

THE STORM WAS MOVING SOUTHEAST AT 15 MILES PER HOUR.

PERSONS IN OR NEAR ARVADA...BOULDER...BROOMFIELD...LONGMONT...
ELDORADO SPRINGS...ERIE...JAMESTOWN...LAFAYETTE...LOUISVILLE...NIWOT
...ROCKY FLATS AND SUPERIOR

SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE
OF SAFETY IF BAD WEATHER APPROACHES.  DANGEROUS LIGHTNING...SMALL
HAIL...LOCALLY HEAVY RAIN...AND GUSTY WINDS WILL OCCUR WITH THIS
STORM.

RADAR INDICATED THIS STORM HAD PRODUCED UP TO 1 INCH OF RAINFALL IN
THE LAST HOUR.  ELSEWHERE SCATTERED THUNDERSTORMS WILL CONTINUE TO
DEVELOP OVER THE FOOTHILLS LATE THIS AFTERNOON AND DRIFT INTO THE
URBAN CORRIDOR.

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

FMC
Special weather statement, Aug 16, 4:37 PM MDT, 4 hours 3 minutes before
COZ035-036-038-039-040-043-162330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
435 PM MDT SAT AUG 16 1997

...SCATTERED THUNDERSTORMS DEVELOPING IN THE FOOTHILLS LATE THIS
AFTERNOON...

AT 430 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES EAST OF BOULDER...OR ABOUT 24 MILES
NORTHWEST OF DENVER.

THE STORM WAS MOVING SOUTHEAST AT 15 MILES PER HOUR.

PERSONS IN OR NEAR ARVADA...BOULDER...BROOMFIELD...LONGMONT...
ELDORADO SPRINGS...ERIE...JAMESTOWN...LAFAYETTE...LOUISVILLE...NIWOT
...ROCKY FLATS AND SUPERIOR

SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE
OF SAFETY IF BAD WEATHER APPROACHES.  DANGEROUS LIGHTNING...SMALL
HAIL...LOCALLY HEAVY RAIN...AND GUSTY WINDS WILL OCCUR WITH THIS
STORM.

RADAR INDICATED THIS STORM HAD PRODUCED UP TO 1 INCH OF RAINFALL IN
THE LAST HOUR.  ELSEWHERE SCATTERED THUNDERSTORMS WILL CONTINUE TO
DEVELOP OVER THE FOOTHILLS LATE THIS AFTERNOON AND DRIFT INTO THE
URBAN CORRIDOR.

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

FMC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 6:00 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver, Douglas, Jefferson45 min
Aug 16, 6:51 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington39 min
Aug 16, 7:28 PM MDTTornado WarningBOUAdams32 min
Aug 16, 7:38 PM MDTSevere Thunderstorm WarningBOUWeld22 min
Aug 16, 7:48 PM MDTSevere Thunderstorm WarningBOUWashington27 min
Aug 16, 7:59 PM MDTSevere Thunderstorm WarningBOUWeld46 min
Aug 16, 8:17 PM MDTSevere Thunderstorm WarningBOULincoln, Washington28 min
Aug 16, 8:31 PM MDTSevere Thunderstorm WarningBOULarimer, Weld44 min
Aug 16, 9:10 PM MDTSevere Thunderstorm WarningBOUWeld50 min
Aug 16, 9:34 PM MDTSevere Thunderstorm WarningBOUBoulder, Larimer31 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.