Alert archive / Colorado / Flash Flood Warnings in 1997

Flash Flood Warning 24, NWS Denver/Boulder, CO

July 29, 1997Logan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 29, 1997, 9:40 PM MDT for Logan County, Weld County, Colorado. It was in force for 80 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 29, 1997, 9:40 PM MDT (03:40 UTC)
Expired
Jul 29, 1997, 11:00 PM MDT
In force
80 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Logan County, CO, Weld County, CO

The radar

The Cheyenne radar (KCYS), 105 km from the middle of the area, began a volume at 03:44 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, 3.7 hours before the alert went out and 96 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 1997-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 154 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 00:00Z on 1997-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
154 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1447 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
67 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 300342
FFWDEN
COC123-075-300500-

BULLETIN...EMERGENCY ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
940 PM MDT TUE JUL 29 1997

...FLASH FLOOD WARNING HAS BEEN EXTENDED FOR NORTHEASTERN WELD AND 
EXTREME NORTHWESTERN LOGAN COUNTIES COLORADO...

A FLASH FLOOD WARNING FOR PEOPLE IN NORTHEASTERN WELD AND 
NORTHWESTERN LOGAN IN NORTHEAST COLORADO HAS BEEN EXTENDED UNTIL 
1100 PM MDT.   

THE WARNING COVERS THE FOLLOWING LOCATIONS
    ...THE PAWNEE NATIONAL GRASSLANDS...BUCKINGHAM...
    KEOTA...NEW RAYMER...WEST PLAINS AND PAWNEE PASS... 

AT 935 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
WIDE AREA OF VERY HEAVY RAINFALL OVER NORTHEASTERN WELD COUNTY AND 
EXTREME NORTHWEST LOGAN COUNTY.  RAINFALL RATES OF 1 1/2 TO 3 INCHES 
PER HOUR HAVE BEEN ESTIMATED WITH DOPPLER RADAR IN THE WARNING 
AREA.    

AN ADDITIONAL 1 TO 2 INCHES OF RAIN IS EXPECTED TO FALL IN THE 
WARNING AREA BY 1100 PM MDT AS THUNDERSTORMS HAVE SHOWN VERY LITTLE 
MOVEMENT IN THE PAST COUPLE OF HOURS.  

EXCESSIVE RUNOFF FROM THESE STORM WILL LIKELY CAUSE FLOODING OF 
SMALL CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND 
ARROYOS...AS WELL AS FARMLAND ALONG THE BANKLS OF CREEKS AND STREAMS. 
BE PREPARED TO MOVE QUICKLY TO HIGH GROUND IF FLOODING OCCURS. 

BAKER

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, Jul 29, 6:40 PM MDT, 3 hours before
COZ041-044-045-300100-

SPECIAL WEATHER STATEMENT      ...CORRECTION FOR MISSING WORD...
NATIONAL WEATHER SERVICE DENVER CO
638 PM MDT TUE JUL 29 1997

...SMALL STREAM FLOOD ADVISORY HAS EXPIRED...

THE SMALL STREAM FLOOD ADVISORY FOR SOUTHEASTERN DOUGLAS...EASTERN
ADAMS AND ARAPAHOE...AND SOUTHWEST MORGAN COUNTIES IN NORTHEAST
COLORADO HAS EXPIRED AS OF 615 PM MDT.

AT 635 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THAT
MOST OF THE THUNDERSTORM ACTIVITY HAD MOVED EAST OF THESE COUNTIES
NO LONGER POSING A THREAT FOR FLASH FLOODING.  HOWEVER...
THUNDERSTORMS MAY REFORM IN THESE AREAS LATER THIS EVENING AS THE
ATMOSPHERE REMAINS VERY MOIST AND UNSTABLE.

A FLANSH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MDT FOR ALL OF
NORTHEAST COLORADO.

BAKER
Special weather statement, Jul 29, 7:19 PM MDT, 2 hours 21 minutes before
COZ035-038-300145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
719 PM MDT TUE JUL 29 1997

...THUNDERSTORM MOVING TOWARD FORT COLLINS...

AT 715 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS ABOUT 15 MILES SOUTHWEST OF FORT COLLINS.  THESE STORMS
WERE MOVING NORTHEAST AT 15 MPH AND WILL BE MOVING INTO THE
HORSETOOTH RESERVOIR AND FORT COLLINS AREA BETWEEN 800 AND 815 PM.

AT THIS TIME...THE STORMS WERE PRODUCING RAINFALL AMOUNTS LESS THAN
1/2 INCH.  THIS WOULD CAUSE NO ADDITIONAL FLOODING PROBLEMS.
HOWEVER...THE STORMS COULD STILL INTENSIFY AS THEY MOVE OFF THE
FOOTHILLS.  PERSONS IN AND NEAR FORT COLLINS SHOULD BE ON THE
LOOKOUT FOR THE POTENTIAL OF ADDITIONAL HEAVY RAINFALL.

IF HEAVY RAIN DOES DEVELOP...FLOODING OF CREEKS AND STREAMS...
STREETS...DITCHES...AND OTHER LOW LYING AREAS CAN BE EXPECTED.
STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL NEWS MEDIA FOR THE
LATEST UPDATES AND POSSIBLE WARNINGS.

BARJENBRUCH
Special weather statement, Jul 29, 7:20 PM MDT, 2 hours 20 minutes before
COZ035-038-300145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
719 PM MDT TUE JUL 29 1997

...THUNDERSTORM MOVING TOWARD FORT COLLINS...

AT 715 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS ABOUT 15 MILES SOUTHWEST OF FORT COLLINS.  THESE STORMS
WERE MOVING NORTHEAST AT 15 MPH AND WILL BE MOVING INTO THE
HORSETOOTH RESERVOIR AND FORT COLLINS AREA BETWEEN 800 AND 815 PM.

AT THIS TIME...THE STORMS WERE PRODUCING RAINFALL AMOUNTS LESS THAN
1/2 INCH.  THIS WOULD CAUSE NO ADDITIONAL FLOODING PROBLEMS.
HOWEVER...THE STORMS COULD STILL INTENSIFY AS THEY MOVE OFF THE
FOOTHILLS.  PERSONS IN AND NEAR FORT COLLINS SHOULD BE ON THE
LOOKOUT FOR THE POTENTIAL OF ADDITIONAL HEAVY RAINFALL.

IF HEAVY RAIN DOES DEVELOP...FLOODING OF CREEKS AND STREAMS...
STREETS...DITCHES...AND OTHER LOW LYING AREAS CAN BE EXPECTED.
STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL NEWS MEDIA FOR THE
LATEST UPDATES AND POSSIBLE WARNINGS.

BARJENBRUCH
Special weather statement, Jul 29, 7:40 PM MDT, 2 hours before
COZ046-047-049-300240-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
740 PM MDT TUE JUL 29 1997

...THUNDERSTORMS CAPABLE OF VERY HEAVY RAINFALL MOVING INTO SOUTHWEST
   WASHINGTON AND NORTHERN AND CENTRAL LINCOLN COUNTIES...

A LINE OF THUNDERSTORMS WILL DRIFT VERY SLOWLY ACROSS SOUTHWESTERN
WASHINGTON AND NORTHERN AND CENTRAL LINCOLN COUNTIES PRODUCING VERY
HEAVY RAIN AND SMALL HAIL.

AT 735 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE
HEAVIEST RAINFALL OVER OPEN RANGELAND ALONG INTERSTATE 70...10 MILES
NORTH OF LIMON.

THESE STORMS WERE MOVING EAST-NORTHEAST AT 15 MILES PER HOUR.

A SECOND AREA OF THUNDERSTORMS FROMING OVER CENTRAL LINCOLN COUNTY
JUST SOUTH OF HUGO WERE DEVELOPING RAPIDLY AND WERE MOVING NORTHWEST
AT 10 MILES PER HOUR.  THESE STORMS ARE EXPECTED TO COLLIDE WITH
STORMS OVER NORTHERN LINCOLN COUNTY IN THE NEXT 30 MINUTES.
TORRENTIAL RAIN MAY DEVELOP WHEN THIS OCCURS LIKELY PROMPTING
ISSUANCE OF A FLASH FLOOD WARNING.

PERSONS IN OR NEAR ANTON...ARRIBA...BOYERO...ELBA...GENOA...HUGO...
LAST CHANCE...LIMON...LINDON...THURMAN...WOODLIN SCHOOL AND WOODROW

SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND BE PREPARED
MOVE TO HIGH GROUND IF FLOODING OCCURS.

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.

BAKER
Special weather statement, Jul 29, 8:50 PM MDT, 50 minutes before
COZ039-040-043-300600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
850 PM MDT TUE JUL 29 1997

...FLASH FLOOD WATCH CANCELLED FOR BOULDER...DENVER AND SOUTHERN
WELD COUNTIES...

THE FLASH FLOOD WATCH FOR THE DENVER METRO AREA AND BOULDER AREAS
AS WELL AS WELD COUNTY SOUTH OF GREELEY HAS BEEN TERMINATED.  ONLY
SCATTERED SHOWERS OR THUNDERSTORMS ARE EXPECTED TO ENTER THIS AREA
AND RAINFALL ASSOCIATED WITH ANY SHOWERS OR THUNDERSTORMS WILL BE
LIGHT...THAT IS LESS THAN 1/2 INCH.

ALTHOUGH THE FLASH FLOOD WATCH HAS BEEN CANCELLED FOR THE DENVER
AND BOULDER AND GREELEY AREAS...THE REST OF NORTHEAST COLORADO
INCLUDING THE FOOTHILLS OF LARIMER COUNTY AS WELL AS DOUGLAS AND
ELBERT COUNTIES REMAINS UNDER A FLASH FLOOD WATCH UNTIL MIDNIGHT.

A NUMBER OF FLASH FLOOD WARNINGS OR URBAN AND SMALL STREAM FLOOD
ADVISORIES HAVE BEEN ISSUED FOR PORTIONS OF NORTHEAST COUNTY
INCLUDING LARIMER COUNTY NEAR FORT COLLINS...MORGAN AND NORTHEAST
WELD AND WESTERN LOGAN COUNTIES AND LINCOLN COUNTY.

CONTINUE TO MONITOR LOCAL NEWS SOURCES AND NOAA WEATHER RADIO FOR
THE LATEST WEATHER WARNINGS AND BULLETINS.  REMEMBER THAT MOST
RIVERS AND STREAMS ARE ALREADY RUNNING HIGH AND THAT SOILS IN MOST
OF THE FRONT RANGE AND NORTHEAST COLORADO ARE SATURATED SO HEAVY
RAIN WILL RESULT IN IMMEDIATE RUNOFF AND RAPID RISING WATER LEVELS
IN STREAMS AND CREEKS.

END...BOODA...WSFO DENVER
Special weather statement, Jul 29, 8:54 PM MDT, 46 minutes before
COZ039-040-043-300600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
850 PM MDT TUE JUL 29 1997

...FLASH FLOOD WATCH CANCELLED FOR BOULDER...DENVER AND SOUTHERN
WELD COUNTIES...

THE FLASH FLOOD WATCH FOR THE DENVER METRO AREA AND BOULDER AREAS
AS WELL AS WELD COUNTY SOUTH OF GREELEY HAS BEEN TERMINATED.  ONLY
SCATTERED SHOWERS OR THUNDERSTORMS ARE EXPECTED TO ENTER THIS AREA
AND RAINFALL ASSOCIATED WITH ANY SHOWERS OR THUNDERSTORMS WILL BE
LIGHT...THAT IS LESS THAN 1/2 INCH.

ALTHOUGH THE FLASH FLOOD WATCH HAS BEEN CANCELLED FOR THE DENVER
AND BOULDER AND GREELEY AREAS...THE REST OF NORTHEAST COLORADO
INCLUDING THE FOOTHILLS OF LARIMER COUNTY AS WELL AS DOUGLAS AND
ELBERT COUNTIES REMAINS UNDER A FLASH FLOOD WATCH UNTIL MIDNIGHT.

A NUMBER OF FLASH FLOOD WARNINGS OR URBAN AND SMALL STREAM FLOOD
ADVISORIES HAVE BEEN ISSUED FOR PORTIONS OF NORTHEAST COUNTY
INCLUDING LARIMER COUNTY NEAR FORT COLLINS...MORGAN AND NORTHEAST
WELD AND WESTERN LOGAN COUNTIES AND LINCOLN COUNTY.

CONTINUE TO MONITOR LOCAL NEWS SOURCES AND NOAA WEATHER RADIO FOR
THE LATEST WEATHER WARNINGS AND BULLETINS.  REMEMBER THAT MOST
RIVERS AND STREAMS ARE ALREADY RUNNING HIGH AND THAT SOILS IN MOST
OF THE FRONT RANGE AND NORTHEAST COLORADO ARE SATURATED SO HEAVY
RAIN WILL RESULT IN IMMEDIATE RUNOFF AND RAPID RISING WATER LEVELS
IN STREAMS AND CREEKS.

END...BOODA...WSFO DENVER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 6:24 PM MDTFlash Flood WarningBOUElbert96 min
Jul 29, 7:03 PM MDTFlash Flood WarningBOULogan, Weld72 min
Jul 29, 7:59 PM MDTFlash Flood WarningBOUElbert, Lincoln2 hr
Jul 29, 8:00 PM MDTFlash Flood WarningBOULogan, Weld90 min
Jul 29, 8:15 PM MDTFlash Flood WarningBOULarimer3 hr
Jul 29, 8:20 PM MDTFlash Flood WarningBOUMorgan55 min
Jul 29, 9:20 PM MDTFlash Flood WarningBOUMorgan40 min
Jul 29, 9:55 PM MDTFlash Flood WarningBOUElbert, Lincoln2 hr
Jul 29, 10:10 PM MDTFlash Flood WarningBOUMorgan50 min
Jul 29, 10:50 PM MDTFlash Flood WarningBOULogan, Morgan, Washington, Weld2 hr
Jul 29, 11:26 PM MDTFlash Flood WarningBOUElbert, Lincoln2 hr
Jul 30, 2:25 PM MDTFlash Flood WarningBOULarimer110 min
Jul 30, 3:25 PM MDTFlash Flood WarningBOUBoulder, Clear Creek, Gilpin, Jefferson2 hr
Jul 30, 4:05 PM MDTFlash Flood WarningBOUBoulder, Jefferson115 min
Jul 30, 4:05 PM MDTSevere Thunderstorm WarningBOUBoulder, Jefferson115 min
Jul 30, 4:30 PM MDTFlash Flood WarningBOULogan14 hr

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.