Alert archive / Colorado / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 110, NWS Denver/Boulder, CO

July 31, 1997Lincoln County, Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 31, 1997, 4:00 PM MDT for Lincoln County, Washington County, Colorado. It was in force for 60 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
Jul 31, 1997, 4:00 PM MDT (22:00 UTC)
Expired
Jul 31, 1997, 5:00 PM MDT
In force
60 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Lincoln County, CO, Washington County, CO

The radar

The Denver radar (KFTG), 91 km from the middle of the area, began a volume at 22:00 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 12:00Z, 10.0 hours before the alert went out and 44 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 1997-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 64 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 1997-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
64 J/kg
Mixed-layer CIN
-197 J/kg
Mixed-layer LCL
1163 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
9 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.

947 
WUUS1 KDEN 312202 RRA
SVRDEN
COC039-073-121-312300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
400 PM MDT THU JUL 31 1997

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 500 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...

IN NORTHEAST COLORADO
     SOUTHWESTERN WASHINGTON

IN EAST CENTRAL COLORADO
     NORTHEASTERN ELBERT AND NORTH CENTRAL LINCOLN

AT 400 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM OVER NORTHEASTERN ELBERT COUNTY...OR ABOUT 14
MILES NORTH OF LIMON.

THE STORM WAS MOVING NORTHEAST AT 25 MILES PER HOUR.

SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE 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 HEAVY RAIN IS OCCURRING WITH THIS STORM...FLOODING IS POSSIBLE.

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

LESZCYNSKI

LAT...LON 3960 10329 3932 10370 3946 10386 3975 10352

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, Jul 31, 10:00 AM MDT, 6 hours before
COZ030-032>050-010600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1000 AM MDT THU JUL 31 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...TROPICAL MONSOONAL MOISTURE FROM THE GULF OF MEXICO
WRAPPING AROUND AN UPPER RIDGE WILL CONTINUE TO STREAM ACROSS
COLORADO TODAY AND TONIGHT.  THIS WILL PROVIDE AMPLE MOISTURE FOR A
CONTINUED THREAT OF HEAVY THUNDERSTORM RAIN ACROSS THE AREA.

SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE AREA THIS
AFTERNOON AND CONTINUE INTO THE EVENING HOURS.  WHILE ONE OR TWO
SEVERE THUNDERSTORMS WITH LARGE HAIL AND STRONG GUSTY WINDS ARE
POSSIBLE THE GREATEST WEATHER THREAT WILL BE LOCALLY HEAVY RAIN.
RAINFALL OF 1.00 TO 3.00 INCHES AN HOUR IS POSSIBLE.  DUE TO
SATURATED SOIL MOISTURE FROM HEAVY RAINFALL OVER THE LAST SEVERAL DAYS
SOME FLOODING OF SMALL STREAMS...ROADWAYS AND LOW LYING OR FLOOD
PRONE AREAS REMAINS LIKELY.

WHILE A FLASH FLOOD WATCH IS NOT NEEDED AT THIS TIME...THE WEATHER
SITUATION WILL CONTINUE TO BE MONITORED CLOSELY THROUGHOUT THE DAY
AND NIGHT AND UPDATES WILL BE ISSUED AS REQUIRED.

GARD...WSFO DENVER
Special weather statement, Jul 31, 2:00 PM MDT, 2 hours before
COZ041-312045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
200 PM MDT THU JUL 31 1997

...THUNDERSTORMS WITH HEAVY RAIN IN WESTERN ELBERT COUNTY...

AT 155 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH HEAVY RAIN OVER WESTERN ELBERT COUNTY.  SMALL
HAIL IS ALSO POSSIBLE WITH THE STORMS.

THE STORMS WERE MOVING NORTHEAST AT 20 MILES PER HOUR.

DOPPLER RADAR ESTIMATED UP TO AN INCH AN HOUR HAD FALLEN SOUTHWEST
OF KIOWA.

PERSONS IN OR NEAR ELIZABETH AND KIOWA SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER
APPROACHES.

SOME ROADS MAY BE COVERED WITH WATER.  DO NOT ATTEMPT TO DRIVE
THROUGH WATER OF UNKNOWN DEPTH.

A FLASH FLOOD WATCH IS IN EFFECT FOR MUCH OF NORTHEAST COLORADO
UNTIL MIDNIGHT TONIGHT.

LESZCYNSKI
Special weather statement, Jul 31, 2:03 PM MDT, 1 hour 57 minutes before
COZ041-312045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
200 PM MDT THU JUL 31 1997

...THUNDERSTORMS WITH HEAVY RAIN IN WESTERN ELBERT COUNTY...

AT 155 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH HEAVY RAIN OVER WESTERN ELBERT COUNTY.  SMALL
HAIL IS ALSO POSSIBLE WITH THE STORMS.

THE STORMS WERE MOVING NORTHEAST AT 20 MILES PER HOUR.

DOPPLER RADAR ESTIMATED UP TO AN INCH AN HOUR HAD FALLEN SOUTHWEST
OF KIOWA.

PERSONS IN OR NEAR ELIZABETH AND KIOWA SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER
APPROACHES.

SOME ROADS MAY BE COVERED WITH WATER.  DO NOT ATTEMPT TO DRIVE 0
THROUGH WATER OF UNKNOWN DEPTH.

A FLASH FLOOD WATCH IS IN EFFECT FOR MUCH OF NORTHEAST COLORADO
UNTIL MIDNIGHT TONIGHT.

LESZCYNSKI

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 6:35 PM MDTFlash Flood WarningBOULogan, Weld3 hr
Jul 30, 8:05 PM MDTFlash Flood WarningBOUArapahoe, Denver115 min
Jul 31, 2:25 PM MDTSevere Thunderstorm WarningBOUElbert35 min
Jul 31, 3:28 PM MDTTornado WarningBOUElbert32 min
Jul 31, 4:00 PM MDTSevere Thunderstorm WarningBOUElbert60 min
Jul 31, 5:27 PM MDTFlash Flood WarningBOUMorgan2 hr
Jul 31, 5:30 PM MDTFlash Flood WarningBOULogan, Washington3 hr
Jul 31, 5:30 PM MDTFlash Flood WarningBOUDouglas2 hr

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.