Alert archive / Colorado / Flash Flood Warnings in 1998

Flash Flood Warning 36, NWS Denver/Boulder, CO

August 21, 1998Arapahoe County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 21, 1998, 9:25 PM MDT for Arapahoe County, Elbert County, Colorado. It was in force for 95 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
Aug 21, 1998, 9:25 PM MDT (03:25 UTC)
Expired
Aug 21, 1998, 11:00 PM MDT
In force
95 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Arapahoe County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 44 km from the middle of the area, began a volume at 03:29 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, 3.4 hours before the alert went out and 97 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 1998-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 157 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 1998-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
157 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
2273 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDEN 220327
FFWDEN
COC005-039-220500-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
925 PM MDT FRI AUG 21 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS EXTENDED A 

* FLASH FLOOD WARNING FOR...
     NORTHWESTERN ELBERT COUNTY IN EAST CENTRAL COLORADO
     SOUTH CENTRAL ARAPAHOE COUNTY IN NORTHEAST COLORADO 

* UNTIL 1100 PM MDT

* AT 920 PM MDT...THE ELBERT COUNTY SHERIFF REPORTED COUNTY ROAD 50     
  BETWEEN ARAPAHOE AND ELBERT COUNTY STILL FLOODED AND CLOSED.  WATER   
  IN ELBERT COUNTY WAS SUBSIDING BUT THERE WAS STILL SOME FLOODING.     
  
A FEW SHOWERS CONTINUED TO MOVE ACROSS THE WARNING AREA...BUT 
ADDITIONAL RAINFALL WILL BE LESS THAN A HALF INCH.  IN THE WARNING AREA
UP TO 7 INCHES WAS INDICATED ON RADAR EARLIER THIS EVENING.  

PEOPLE ALONG COAL CREEK FROM NORTHWEST ELBERT COUNTY THROUGH CENTRAL 
ARAPAHOE COUNTY SHOULD BE AWARE THAT THE CREEK WILL REMAIN OUT OF ITS 
BANKS THIS EVENING...AND THE WATER LEVEL WILL BE SLOWLY LOWERING.  
PINEY CREEK IN ARAPAHOE COUNTY WILL LIKELY RUN HIGH FOR THE REMAINDER 
OF THE EVENING.  

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.

RTG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 7:15 PM MDTFlash Flood WarningBOUArapahoe, Elbert2 hr

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.