Alert archive / Colorado / Flash Flood Warnings in 1997

Flash Flood Warning 33, NWS Denver/Boulder, CO

July 30, 1997Logan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 30, 1997, 6:35 PM MDT for Logan County, Weld 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: Jul 30, 1997, 6:35 PM MDT (00:35 UTC)
Expired: Jul 30, 1997, 9:30 PM MDT
In force: 3 hr
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 00:38 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, 0.6 hours before the alert went out and 109 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 312 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 1001 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 127 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDEN 310035
FFWDEN
COC075-123-310330-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
635PM MDT WED JUL 30 1997

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A FLASH FLOOD
WARNING EFFECTIVE UNTIL 930 PM MDT FOR PEOPLE IN THE FOLLOWING
COUNTIES

IN NORTHEAST COLORADO
     NORTHEASTERN WELD AND NORTHWESTERN LOGAN

INCLUDING THE FOLLOWING LOCATIONS
     NORTH STERLING RESERVOIR AND WESTPLAINS

AT 626 PM MDT WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN
IN THE NORTHEAST CORNER OF WELD COUNTY OVER THE PAWNEE BUTTES AREA.

RADAR INDICATES THAT 2 INCHES OF RAIN HAVE FALLEN BETWEEN 530 AND 
630 PM MDT.  SINCE SOILS ARE ALREADY SATURATED RUNOFF WILL OCCUR
IMMEDIATELY AND WATER LEVELS IN SMALL STREAMS AND CREEKS WILL RISE
TO BANKFULL STAGE IN A VERY SHORT PERIOD OF TIME.

THE MAIN AREA OF CONCERN IS ALONG AND NEAR STREAMS FROM THE WYOMING
BORDER DOWNSTREAM TO STERLING RESERVOIR IN LOGAN COUNTY.  THE MAIN
STREAMS OF CONCERN ARE TWO MILE CREEK...GEORGE CREEK AND CEDAR CREEK.

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 OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

END@...BOODA...WSFO DENVER 

LAT...LON 4077 10317 4063 10360 4099 10395 4101 10354

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 8:05 PM MDT	Flash Flood Warning	BOU	Arapahoe, Denver	115 min
Jul 31, 2:25 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	35 min
Jul 31, 3:28 PM MDT	Tornado Warning	BOU	Elbert	32 min
Jul 31, 4:00 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln, Washington	60 min
Jul 31, 4:00 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	60 min
Jul 31, 5:27 PM MDT	Flash Flood Warning	BOU	Morgan	2 hr
Jul 31, 5:30 PM MDT	Flash Flood Warning	BOU	Logan, Washington	3 hr
Jul 31, 5:30 PM MDT	Flash Flood Warning	BOU	Douglas	2 hr

Nearby

Flash Flood Warnings in Colorado, 1997 Every 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.