Alert archive / Colorado / Flash Flood Warnings in 1997

Flash Flood Warning 40, NWS Denver/Boulder, CO

August 4, 1997Morgan County, Washington County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 4, 1997, 12:10 AM MDT for Morgan County, Washington County, Colorado. It was in force for 3 hr. 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 4, 1997, 12:10 AM MDT (06:10 UTC)
Expired
Aug 4, 1997, 3:00 AM MDT
In force
3 hr
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Morgan County, CO, Washington County, CO

The radar

The Denver radar (KFTG), 118 km from the middle of the area, began a volume at 06:14 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, 6.2 hours before the alert went out and 59 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 1997-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 239 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 1997-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
239 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
2651 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
27 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 040611
FFWDEN
COC087-121-040900-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
1210 AM MDT MON AUG 4 1997

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A FLASH FLOOD
WARNING EFFECTIVE UNTIL 300 AM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTHEAST COLORADO
     NORTHEASTERN MORGAN AND NORTHWESTERN WASHINGTON

INCLUDING THE FOLLOWING LOCATIONS
     AKRON...ANTELOPE SPRINGS...BRUSH...HILLROSE...MIDWAY...
     PREWITT RESERVOIR AND SNYDER

AT 1206 AM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH TORRENTIAL RAIN OCCURRING BETWEEN AKRON AND 
HILLROSE.  NATIONAL WEATHER SERVICE RADAR INDICATES AROUND 3 INCHES 
OF RAIN HAS ALREADY FALLEN BETWEEN HILLROSE AND MESSEX IN LESS THAN 
AN HOUR.  THE STORMS PRODUCING THIS TORRENTIAL RAIN WERE MOVING 
SOUTH AT 10 MPH.  

A WEATHER SPOTTER AT HILLROSE ALSO REPORTED 3 INCHES OF RAIN IN THE 
PAST 45 MINUTES.  

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL 
CREEKS AND STREAMS...ROADS AND HIGHWAYS...NORMALLY DRY WASHES 
AND ARROYOS...AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND 
STREAMS.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. 
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE 
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
SWIFTLY FLOWING WATERS OR WATERS OfF UNKNOWN DEPTH BY FOOT OR BY 
AUTOMOBILE. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK 
HIGHER GROUND.

BARJENBRUCH 

LAT...LON 4042 10303 4011 10327 4027 10370 4051 10376
          4052 10350 4045 10350

What forecasters said that day

The local office's own words before this flash flood 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 4, 12:10 AM MDT, 0 minutes before
COZ043-040700-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1210 AM MDT MON AUG 4 1997

...STRONG WINDS ASSOCIATED WITH A GUST FRONT FROM THUNDERSTORMS
MOVING ACROSS SOUTHERN WELD COUNTY...

AT 1205 AM MDT A GUST FRONT WAS MOVING ACROSS SOUTHERN WELD COUNTY
AND EXTENDED FROM SOUTH OF GREELEY TO NEAR HARDIN.  THIS GUST FRONT
WILL PRODUCE WINDS OF 20 TO 40 MPH WITH A FEW GUSTS TO 50 MPH
POSSIBLE.  THIS GUST FRONT WILL BE NEAR A DACONO TO HUDSON TO
KEENESBURG LINE BY 1230 AM.

PERSONS OVER SOUTHERN WELD COUNTY SHOULD BE PREPARED FOR A BRIEF
PERIOD OF STRONG WINDS FOR THE NEXT 30 MINUTES AS THIS GUST FRONT
MOVES ACROSS THE AREA.

KLEYLA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 2:05 AM MDTFlash Flood WarningBOUMorgan, Washington115 min

Nearby

Flash Flood Warnings in Colorado, 1997Every flash flood 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.