Alert archive / Colorado / Flash Flood Warnings in 2001

Flash Flood Warning 21, NWS Denver/Boulder, CO

August 13, 2001Washington County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 13, 2001, 5:15 PM MDT for Washington County, Colorado. It was in force for 105 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 13, 2001, 5:15 PM MDT (23:15 UTC)
Expired
Aug 13, 2001, 7:00 PM MDT
In force
105 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Washington County, CO

The radar

The Denver radar (KFTG), 125 km from the middle of the area, began a volume at 23:17 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 11.3 hours before the alert went out and 248 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, N. Platte/Lee Bi, NE at 12:00Z on 2001-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 45 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 12:00Z on 2001-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.1939587897Sfc1 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
45 J/kg
Mixed-layer CIN
-225 J/kg
Mixed-layer LCL
1135 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
179 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

000 
WGUS55 KBOU 132317
FFWDEN
COC121-140100-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
515 PM MDT MON AUG 13 2001

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

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

* UNTIL 700 PM MDT

* AT 514 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN 6 MILES EAST OF ELBA...OR ABOUT 15 MILES
  SOUTHEAST OF AKRON. THE STORMS PRODUCING THE HEAVY RAIN WERE MOVING
  SLOWLY SOUTHEAST AT 5 MPH.  RADAR ESTIMATES UP TO 7 INCHES OF RAIN 
  HAS FALLEN JUST NORTHEAST OF ELBA OVER THE PAST FEW HOURS.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...ELBA.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE. IF YOUR VEHICLE STALLS ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

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.

LAT...LON 4003 10323 3989 10323 3989 10292 4004 10292

KLEYLA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 1:59 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver46 min
Aug 13, 2:17 PM MDTTornado WarningBOUAdams, Denver28 min
Aug 13, 2:30 PM MDTSevere Thunderstorm WarningBOUDouglas, Jefferson45 min
Aug 13, 2:46 PM MDTSevere Thunderstorm WarningBOUWashington29 min
Aug 13, 3:30 PM MDTFlash Flood WarningBOUWashington90 min
Aug 13, 4:02 PM MDTFlash Flood WarningBOUWashington88 min
Aug 13, 4:55 PM MDTFlash Flood WarningBOUWashington95 min

Nearby

Flash Flood Warnings in Colorado, 2001Every flash flood warning in 2001

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.