Alert archive / Colorado / Flash Flood Warnings in 1998

Flash Flood Warning 27, NWS Denver/Boulder, CO

August 8, 1998Morgan County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 8, 1998, 7:12 PM MDT for Morgan County, Colorado. It was in force for 93 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
Aug 8, 1998, 7:12 PM MDT (01:12 UTC)
Expired
Aug 8, 1998, 8:45 PM MDT
In force
93 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 01:11 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, 1.2 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 1998-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 105 joules per kilogram.LCLEL10008507005003002001001 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 1998-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
105 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
3401 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
94 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 090115
FFWDEN
COC087-090245-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
712 PM MDT SAT AUG 8 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

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

* UNTIL 845 PM MDT

* AT 705 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN OVER TWELVE-MILE CORNER...OR ABOUT 12 MILES        
  SOUTH OF FORT MORGAN.  RADAR ESTIMATES THAT UP TO 3 INCHES OF RAIN 
  HAS OCCURRED OVER PORTIONS OF SOUTHERN MORGAN COUNTY IN THE PAST   
  HOUR.

LOCATIONS IN THE WARNING INCLUDE ADENA SCHOOL AND TWELVE-MILE 
CORNER

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 4019 10400 4002 10401 4002 10356 4024 10362

KLEYLA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 6:20 PM MDTFlash Flood WarningBOUMorgan85 min
Aug 8, 6:25 PM MDTSevere Thunderstorm WarningBOUMorgan50 min
Aug 8, 8:59 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe31 min
Aug 9, 3:35 AM MDTFlash Flood WarningBOULincoln3 hr
Aug 9, 3:38 AM MDTFlash Flood WarningBOULincoln3 hr
Aug 9, 3:02 PM MDTSevere Thunderstorm WarningBOUDouglas43 min
Aug 9, 3:32 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert43 min
Aug 9, 3:38 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert52 min
Aug 9, 3:48 PM MDTTornado WarningBOUAdams27 min
Aug 9, 3:57 PM MDTTornado WarningBOUMorgan, Weld48 min
Aug 9, 4:01 PM MDTSevere Thunderstorm WarningBOUWashington44 min
Aug 9, 4:33 PM MDTFlash Flood WarningBOUAdams, Morgan117 min
Aug 9, 4:43 PM MDTTornado WarningBOUAdams, Morgan, Weld32 min
Aug 9, 4:49 PM MDTFlash Flood WarningBOUWashington86 min
Aug 9, 4:52 PM MDTSevere Thunderstorm WarningBOULincoln, Washington38 min
Aug 9, 5:21 PM MDTFlash Flood WarningBOULincoln, Washington99 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.