Alert archive / Colorado / Flash Flood Warnings in 1998

Flash Flood Warning 33, NWS Denver/Boulder, CO

August 9, 1998Washington County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 9, 1998, 6:17 PM MDT for Washington County, Colorado. It was in force for 88 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 9, 1998, 6:17 PM MDT (00:17 UTC)
Expired
Aug 9, 1998, 7:45 PM MDT
In force
88 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Washington County, CO

The radar

The Goodland radar (KGLD), 121 km from the middle of the area, began a volume at 00:19 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, 0.3 hours before the alert went out and 22 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 1998-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 325 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 1998-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
325 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
2136 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
73 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 100023
FFWDEN
COC121-100145-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
617 PM MDT SUN AUG 9 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
     SOUTHEASTERN WASHINGTON COUNTY IN NORTHEAST COLORADO

* UNTIL 745 PM MDT

* AT 608 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
VERY HEAVY RAIN MOVING BACK INTO EASTERN WASHINGTON COUNTY WITH 2 TO 
3 INCHES OF RAIN HAVE FALLEN DURING THE PAST HOUR. 

* THIS WARNING REPLACES THE PREVIOUS FLASH FLOOD WARNING FOR CENTRAL 
WASHINGTON COUNTY AND HAS BEEN EXPANDED FURTHER SOUTHWARD TO JUST 
SOUTH OF THURMAN. 

RADAR HAS ESTIMATED RAINFALL OF 4 TO 5 INCHES OF 
RAIN DURING THE PAST FEW HOURS...WHILE LARGE HAIL HAVE ALSO FALLEN.
LOCATIONS IN THE WARNING INCLUDE...ARICKAREE SCHOOL AND COPE

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DHRY WASHES AND
ARROYOS...AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

ENTREKIN

LAT...LON 3959 10317 3957 10282 4002 10282 4004 10309

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.