Alert archive / Colorado / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 29, NWS Denver/Boulder, CO

June 6, 1997Adams County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 6, 1997, 4:25 PM MDT for Adams County, Colorado. It was in force for 50 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
Jun 6, 1997, 4:25 PM MDT (22:25 UTC)
Expired
Jun 6, 1997, 5:15 PM MDT
In force
50 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Adams County, CO

The radar

The Denver radar (KFTG), 38 km from the middle of the area, began a volume at 22:28 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 6, 4:35 PM MDTHail 0.75Henderson, 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

Fort Carson/Butt, CO (KFCS), launched 12:00Z, 10.4 hours before the alert went out and 142 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 1997-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 42 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 1997-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
42 J/kg
Mixed-layer CIN
-358 J/kg
Mixed-layer LCL
1036 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
10 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 062227
SVRDEN
COC001-013-059-123-062315-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
425 PM MDT FRI JUN 6 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
     SOUTHEASTERN BOULDER...NORTHEASTERN JEFFERSON...NORTHWESTERN
     ADAMS AND SOUTHWESTERN WELD

INCLUDING THE FOLLOWING LOCATIONS
     BOULDER...BROOMFIELD...COMMERCE CITY...NORTHGLENN...THORNTON
     ...WESTMINSTER...BARR LAKE...BRIGHTON...DACONO...ERIE...
     FEDERAL HEIGHTS...FIRESTONE...FREDERICK...LAFAYETTE...
     LOUISVILLE AND SUPERIOR

AT 423 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 3 MILES NORTHEAST OF THORNTON...OR ABOUT 11 MILES
NORTH OF DENVER.

THE STORM WAS NEARLY STATIONARY BUT OTHER STORMS ARE EXPECTED TO DEVELOP.

THESE SEVERE THUNDERSTORMS MAY PRODUCE SHORT LIVED TORNADOES WITH
LITTLE OR NO ADVANCE WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN
A STURDY STRUCTURE SUCH AS A BASEMENT OR SMALL INTERIOR ROOM IF A
TORNADO IS SPOTTED.

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 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.

TA

LAT...LON 3997 10475 3981 10480 3979 10493 3984 10516
          4003 10529 4017 10492

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 6, 10:58 AM MDT, 5 hours 27 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
11AM MDT FRIDAY JUNE 6 1997

...HIGH AND FAST RIVERS AGAIN THIS WEEKEND...

HIGH RIVER LEVELS IN NORTHEASTERN COLORADO WILL BE THE RULE
THROUGHOUT THE COMING WEEKEND. THERE WILL BE LITTLE OR NO ADDITION
OF WATER TO THE RIVERS DUE TO SNOWMELT...BUT LOCALLY HEAVY RAINS ARE
FORECAST OVER THE AREA THROUGH SUNDAY AND THESE MAY PRODUCE FLASH
FLOODING ON SMALLER STREAMS. PERSONS ON OR NEAR RIVERS AND STREAMS
IN NORTHEASTERN COLORADO THIS WEEKEND SHOULD BE ALERT FOR RAPID
RISES IN RIVER LEVELS.

RESERVOIR RELEASES CONTINUE TO ACCOUNT FOR MUCH OF THE HIGH WATER
DOWNSTREAM OF DAMS THROUGHOUT THE AREA. THESE RELEASES ARE BEING
CLOSELY MONITORED AND ANY FLOODING RESULTING FROM THEM SHOULD BE
MINOR UNLESS SIGNIFICANT RAIN FALLS IN THE VICINITY.

TO REPEAT...THE NEXT FEW DAYS WILL SEE THE HIGHEST RIVER LEVELS OF
THE SEASON ON MOST STREAMS IN NORTHEASTERN COLORADO AND ANYONE ON OR
NEAR THEM SHOULD EXERCISE CAUTION. IN ADDITION...MUD AND ROCK SLIDES
MAY BE A CONCERN IN SOME BACK COUNTRY AREAS.

TUNNELL
Special weather statement, Jun 6, 11:19 AM MDT, 5 hours 6 minutes before
COZ030-032>050-070600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1115 AM MDT FRI JUN 6 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:  SUFFICIENT MOISTURE FOR THUNDERSTORMS CONTAINING HEAVY
RAIN WILL CONTINUE TO FEED INTO THE AREA TODAY AND TONIGHT IN DEEP
UPSLOPE FLOW.  HEAVY RAIN AND SMALL HAIL WILL BE THE MAIN THREATS
WITH THE THUNDERSTORMS AS THE FLOW ALOFT OVER COLORADO REMAINS
WEAK.

THUNDERSTORMS WILL INITIATE OVER THE MOUNTAINS EARLY THIS AFTERNOON
AND REMAIN NEARLY STATIONARY IN THE UPSLOPE FLOW.  THEREFORE...
HOURLY RAINFALL RATES OF 1 TO 2 INCHES PER HOUR ARE LIKELY.  MOST
THUNDERSTORMS ARE EXPECTED TO STAY IN AND CLOSE TO THE HIGHER
TERRAIN TODAY BUT A FEW MAY DEVELOP IN THE URBAN CORRIDOR AND ON THE
PLAINS THIS AFTERNOON AND EVENING.  THESE LOWER ELEVATION STORM WILL
ALSO HAVE THE POTENTIAL FOR HEAVY RAIN...HAIL AND GUSTY WINDS UPTO
40 MPH.

ALTHOUGH THUNDERSTORMS ARE NOT EXPECTED TO REACH SEVERE LEVELS TODAY
AND TONIGHT...HEAVY RAIN ESPECIALLY IN THE HIGH COUNTRY NEEDS TO BE
MONITORED.  SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY.

FREDIN
Special weather statement, Jun 6, 2:09 PM MDT, 2 hours 16 minutes before
COZ030-032>050-070600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
205 PM MDT FRI JUN 6 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:  SUFFICIENT MOISTURE FOR THUNDERSTORMS CONTAINING HEAVY
RAIN WILL CONTINUE TO FEED INTO THE AREA TODAY AND TONIGHT IN DEEP
UPSLOPE FLOW.  HEAVY RAIN AND HAIL WILL BE THE MAIN THREATS WITH THE
THUNDERSTORMS AS THE FLOW ALOFT OVER COLORADO REMAINS WEAK.

THUNDERSTORMS HAVE DEVELOPED RAPIDLY OVER THE URBAN CORRIDOR AREA
EARLY THIS AFTERNOON AND HAVE A HISTORY OF PRODUCING HEAVY
RAIN...LARGE HAIL AND FUNNEL CLOUDS.  THE POTENTIAL EXISTS FOR
THUNDERSTORMS TO PASS THROUGH THE AREA INTO THE EVENING HOURS.
HOURLY RAINFALL RATES OF 1 TO 2 INCHES PER HOUR AND HAIL UPTO 2
INCHES IN DIAMETER ARE LIKELY WITH THE THUNDERSTORMS.

THEREFORE...SPOTTER ACTIVATION WILL BE NEEDED FOR THE REST OF THE
AFTERNOON INTO THE EVENING.

FREDIN
Special weather statement, Jun 6, 2:42 PM MDT, 1 hour 43 minutes before
COZ036-035-037-041-039-038-040-062300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
240 PM MDT FRI JUN 6 1997

...HEAVY RAINS MOVING INTO THE FOOTHILLS...

THUNDERSTORMS WITH HEAVY RAINS ARE MOVING INTO THE FOOTHILLS OF
LARIMER...BOULDER...JEFFERSON...DOUGLAS...CLEAR CREEK...GILPIN AND
PARK COUNTIES.

RADAR AND PRECIPITATION GAUGES SHOW THAT UPWARDS OF AN INCH OF RAIN
HAS FALLEN FROM SOME OF THESE STORMS OVER THE DENVER METRO AREA AND
SOME OF THE HIGHER FOOTHILLS LOCATIONS.  WITH RIVERS ALREADY RUNNING
HIGH FROM SNOWMELT...THESE HEAVY RAINS COULD CAUSE SOME OF THE
RIVERS TO RISE RAPIDLY LATER TODAY AND TONIGHT WHICH COULD LEADING
TO MORE SIGNIFICANT FLOODING.

PERSONS LIVING OR TRAVELING NEAR STREAMS ALONG THE FRONT RANGE OF
NORTHEAST COLORADO SHOULD BE ON THE LOOKOUT FOR RAPIDLY RISING RIVER
LEVELS THIS AFTERNOON AND TONIGHT AND BE PREPARED TO TAKE QUICK
ACTION SHOULD MORE SIGNIFICANT FLOODING OCCUR.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 6, 1:36 PM MDTSevere Thunderstorm WarningBOUAdams, Denver39 min
Jun 6, 1:56 PM MDTSevere Thunderstorm WarningBOUArapahoe, Douglas, Jefferson34 min
Jun 6, 1:56 PM MDTSevere Thunderstorm WarningBOUAdams, Denver34 min
Jun 6, 2:35 PM MDTSevere Thunderstorm WarningBOUBoulder25 min
Jun 6, 3:37 PM MDTSevere Thunderstorm WarningBOUJefferson38 min
Jun 6, 4:25 PM MDTSevere Thunderstorm WarningBOUBoulder, Jefferson, Weld50 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.