Alert archive / Colorado / Flash Flood Warnings in 1998

Flash Flood Warning 5, NWS Denver/Boulder, CO

July 24, 1998Morgan County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 24, 1998, 3:07 PM MDT for Morgan County, Colorado. It was in force for 113 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 24, 1998, 3:07 PM MDT (21:07 UTC)
Expired
Jul 24, 1998, 5:00 PM MDT
In force
113 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Morgan County, CO

The radar

The Denver radar (KFTG), 72 km from the middle of the area, began a volume at 21:01 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, 9.1 hours before the alert went out and 63 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 1998-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 340 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 1998-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 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
340 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
751 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
-13 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 242110
FFWDEN
COC087-242300-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
307 PM MDT FRI JUL 24 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
     CENTRAL MORGAN COUNTY IN NORTHEAST COLORADO

* UNTIL 500 PM MDT

* AT 301 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS PRODUCING VERY HEAVY RAIN OVER CENTRAL MORGAN        
  COUNTY...OR ABOUT 5 MILES SOUTH AND SOUTHWEST OF FORT MORGAN.      
  THESE THUNDERSTORMS WERE NEARLY STATIONARY.  RADAR ESTIMATES UP TO 
  5 INCHES OF RAIN HAS OCCURRED IN THIS REGION DURING THE PAST FEW   
  HOURS.

RESIDENTS OVER CENTRAL MORGAN COUNTY THAT LIVE SOUTH AND SOUTHWEST 
OF FORT MORGAN AND ALONG BADGER CREEK SHOULD BE PREPARED FOR 
EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL 
CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND 
ARROYOS...AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS 
IMMINENT. MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT 
ATTEMPT TO CROSS BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS 
THE ROADWAY. NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL 
ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

LAT...LON 4013 10394 4013 10373 4022 10374 4021 10393

KLEYLA

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 24, 12:02 PM MDT, 3 hours 5 minutes before
COZ030-032>050-250600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1200 AM MDT FRI JUL 24 1998

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:  ABUNDANT MONSOONAL MOISTURE AT LOWER AND MID LEVELS
REMAINS IN PLACE OVER NORTHEAST COLORADO TODAY.  CLOUD COVER AND FOG
HAVE HELD BACK SURFACE TEMPERATURES THROUGH LATE THIS MORNING...BUT
AS INCREASING SUNBREAKS DURING THE AFTERNOON WILL ALLOW READINGS TO
BEGIN CLIMBING.  AS TEMPERATURES REACH THE UPPER 70S AND NEAR 80...
THE ATMOSPHERE WILL BECOME UNSTABLE WITH RAINSHOWERS AND
THUNDERSTORMS DEVELOPING.  VERY WEAK WINDS ABOVE THE SURFACE WILL
CAUSE DEVELOPING THUNDERSTORMS TO MOVE VERY SLOWLY.  THE HIGH LEVELS
OF MOISTURE IN THE ATMOSPHERE WILL CAUSE SHOWERS TO PRODUCE LOCALLY
HEAVY RAINFALL.  THE THREAT OF HAIL FROM THUNDERSTORMS IS MINIMAL...
BUT HEAVY RAINS COULD CAUSE LOCALIZED FLOODING PROBLEMS THROUGH THE
LATE AFTERNOON AND EVENING.

LATE MORNING SATELLITE PICTURES INDICATE THAT AREAS SOUTH OF I-76
HAVE BEEN RECEIVING MORE SUN THAN AREAS CLOSER TO THE FOOTHILLS.
THESE AREAS WILL HAVE THE WARMEST TEMPERATURES BY MID-AFTERNOON...
AND SHOULD BE WHERE THE STRONGEST STORMS DEVELOP.  MORGAN...
WASHINGTON...EASTERN ADAMS AND EASTERN ARAPAHOE COUNTIES WILL HAVE
THE HIGHEST THREAT OF RECEIVING HEAVY RAINS.  RAINFALL AMOUNTS OF 2
TO 3 INCHES IN ONE OR TWO HOURS WILL BE POSSIBLE.  THE HEAVY RAINS
FALLING ON ALREADY WET GROUND FROM PREVIOUS RAINFALL MAY LEAD TO
FLOODING PROBLEMS.  AREAS ALONG THE I-25 CORRIDOR WILL SEE SHOWERS
AND THUNDERSTORMS MOVE SLOWLY OFF THE FOOTHILLS.  SOIL MOISTURE
LEVELS ARE LOWER NEAR THE FOOTHILLS...SO A SLIGHTLY LOWER THREAT OF
FLOODING PROBLEMS EXISTS THERE.

SPOTTER ACTIVATION IS NOT EXPECTED THIS AFTERNOON...BUT SKYWARN
SPOTTERS ARE ASKED TO RELAY ANY HEAVY RAIN OR FLOODING REPORTS TO
THE NATIONAL WEATHER SERVICE IN DENVER.

DANKERS

t
Special weather statement, Jul 24, 1:49 PM MDT, 1 hour 18 minutes before
COZ033-035-242030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
149 PM MDT FRI JUL 24 1998

...STRONG THUNDERSTORM DEVELOPING IN CENTRAL LARIMER COUNTY EARLY
THIS AFTERNOON...

AT 145 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTH OF RUSTIC...OR ABOUT 28 MILES
NORTHWEST OF FORT COLLINS...MOVING SOUTHEAST AT 5 TO 10 MILES PER
HOUR.  THIS STORM WAS PRODUCING VERY HEAVY RAIN UP TO 2 INCHES PER
HOUR...SMALL HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING.

PERSONS IN OR NEAR RED FEATHER LAKES AND RUSTIC SHOULD BE ON THE
LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD
WEATHER APPROACHES.

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.

KL,EYLA
Special weather statement, Jul 24, 1:49 PM MDT, 1 hour 18 minutes before
COZ033-035-242030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
149 PM MDT FRI JUL 24 1998

...STRONG THUNDERSTORM DEVELOPING IN CENTRAL LARIMER COUNTY EARLY
THIS AFTERNOON...

AT 145 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTH OF RUSTIC...OR ABOUT 28 MILES
NORTHWEST OF FORT COLLINS...MOVING SOUTHEAST AT 5 TO 10 MILES PER
HOUR.  THIS STORM WAS PRODUCING VERY HEAVY RAIN UP TO 2 INCHES PER
HOUR...SMALL HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING.

PERSONS IN OR NEAR RED FEATHER LAKES AND RUSTIC SHOULD BE ON THE
LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD
WEATHER APPROACHES.

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.

KL,EYLA
Special weather statement, Jul 24, 3:02 PM MDT, 5 minutes before
COZ036-242130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
302 PM MDT FRI JUL 24 1998

...THUNDERSTORMS DEVELOPING IN SOUTHERN JEFFERSON COUNTY NEAR
BUFFALO CREEK...

AT 257 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS DEVELOPING RAPIDLY NEAR BUFFALO CREEK.  THESE STORMS
MAY PRODUCE UP TO 1 1/2 INCHES OF RAIN IN LESS THAN AN HOUR ALONG
WITH DANGEROUS LIGHTNING.

PERSONS IN THE TOWN OF BUFFALO CREEK AND ALONG THE CREEK ITSELF
SHOULD BE PREPARED FOR HEAVY RAINS WHICH MAY FLOOD LOW LYING AREAS.
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.

KLEYLA
Special weather statement, Jul 24, 3:02 PM MDT, 5 minutes before
COZ036-242130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
302 PM MDT FRI JUL 24 1998

...THUNDERSTORMS DEVELOPING IN SOUTHERN JEFFERSON COUNTY NEAR
BUFFALO CREEK...

AT 257 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS DEVELOPING RAPIDLY NEAR BUFFALO CREEK.  THESE STORMS
MAY PRODUCE UP TO 1 1/2 INCHES OF RAIN IN LESS THAN AN HOUR ALONG
WITH DANGEROUS LIGHTNING.

PERSONS IN THE TOWN OF BUFFALO CREEK AND ALONG THE CREEK ITSELF
SHOULD BE PREPARED FOR HEAVY RAINS WHICH MAY FLOOD LOW LYING AREAS.
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.

KLEYLA

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 3:52 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert28 min
Jul 24, 3:54 PM MDTTornado WarningBOUAdams, Arapahoe36 min
Jul 24, 5:10 PM MDTFlash Flood WarningBOUWeld95 min

Nearby

Flash Flood Warnings in Colorado, 1998Every flash flood warning in 1998

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.