Alert archive / Colorado / Flash Flood Warnings in 1998

Flash Flood Warning 9, NWS Denver/Boulder, CO

July 25, 1998Clear Creek County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 25, 1998, 4:50 PM MDT for Clear Creek County, Colorado. It was in force for 115 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 25, 1998, 4:50 PM MDT (22:50 UTC)
Expired: Jul 25, 1998, 6:45 PM MDT
In force: 115 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Clear Creek County, CO

The radar

The Denver radar (KFTG), 84 km from the middle of the area, began a volume at 22:57 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, 10.8 hours before the alert went out and 196 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 114 J/kg
Mixed-layer CIN: -131 J/kg
Mixed-layer LCL: 1134 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: -29 m²/s²
0-3 km storm-relative helicity: -47 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 252253
FFWDEN
COC019-260045-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
450 PM MDT SAT JUL 25 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
     NORTHEASTERN CLEAR CREEK COUNTY IN CENTRAL COLORADO

* UNTIL 645 PM MDT

* AT 443 PM MDT...THE CLEAR CREEK SHERIFF DEPARTMENT REPORTED 
FLOODING IN THE VIRGINIA CREEK CANYON...ON THE NORTH SIDE OF IDAHO 
SPRINGS.  THUNDERSTORMS OVER EASTERN CLEAR CREEK COUNTY HAVE BEEN 
MOVING SLOWLY AND PRODUCING HEAVY RAIN.  

LOCATIONS IN THE WARNING INCLUDE...BLUE VALLEY...FLOYD HILL AND IDAHO
SPRINGS

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF CREEKS 
AND STREAMS...ROADS AND ROADSIDE CULVERTS IN EASTERN CLEAR CREEK COUNTY. 
THE HEAVY RAINS COULD ALSO TRIGGER ROCK AND MUDSLIDES IN STEEP 
TERRAIN.  IF FLASH FLOODING OCCURS...MOVE TO SAFETY BY ABANDONING 
CARS AND CLIMBING TO HIGHER GROUND. 

LAT...LON 3964 10557 3964 10543 3972 10542 3982 10559
DANKERS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 24, 8:28 PM MDT	Flash Flood Warning	BOU	Adams, Arapahoe	3 hr
Jul 25, 2:44 PM MDT	Tornado Warning	BOU	Larimer, Weld	26 min
Jul 25, 4:15 PM MDT	Severe Thunderstorm Warning	BOU	Logan	30 min
Jul 25, 4:29 PM MDT	Flash Flood Warning	BOU	Logan	3 hr
Jul 25, 5:03 PM MDT	Tornado Warning	BOU	Adams, Denver	27 min
Jul 25, 5:07 PM MDT	Flash Flood Warning	BOU	Morgan	3 hr
Jul 25, 5:35 PM MDT	Flash Flood Warning	BOU	Washington	2 hr
Jul 25, 5:41 PM MDT	Flash Flood Warning	BOU	Washington	2 hr

Nearby

Flash Flood Warnings in Colorado, 1998 Every 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.