Alert archive / Colorado / Flash Flood Warnings in 2011

Flash Flood Warning 8, NWS Denver/Boulder, CO

July 7, 2011Boulder County, Gilpin County, Jefferson County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 7, 2011, 6:27 PM MDT for Boulder County, Gilpin County, Jefferson County, Colorado. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 7, 2011, 6:27 PM MDT (00:27 UTC)
Expired
Jul 7, 2011, 9:30 PM MDT
In force
3 hr
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

Counties Boulder County, CO, Gilpin County, CO, Jefferson County, CO

The radar

The Denver radar (KFTG), 73 km from the middle of the area, began a volume at 00:27 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, 0.5 hours before the alert went out and 183 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 2011-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 259 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, Denver, CO at 00:00Z on 2011-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 square meters per square second.1939Sfc1 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
259 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
1195 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

133 
WGUS55 KBOU 080027
FFWBOU
COC013-047-059-080330-
/O.NEW.KBOU.FF.W.0008.110708T0027Z-110708T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
627 PM MDT THU JUL 7 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN JEFFERSON COUNTY IN NORTHEAST COLORADO
  NORTHEASTERN GILPIN COUNTY IN CENTRAL COLORADO
  SOUTH CENTRAL BOULDER COUNTY IN NORTHEAST COLORADO

* UNTIL 930 PM MDT

* AT 624 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 3 MILES NORTH OF               
  PINECLIFFE...OR 29 MILES NORTHWEST OF DENVER. THUNDERSTORMS        
  CONTINUE TO DEVELOP OVER THE AREA AND ADDITIONAL RAINFALL IS       
  EXPECTED.


* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ORODELL...
  PINECLIFFE AND ASPEN SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. TURN AROUND...DO NOT DROWN.

RADAR ESTIMATES INDICATES 1.5 TO 2.5 INCHES OF RAIN HAS FALLEN SINCE 
4 PM...HEAVIEST 2 MILES SOUTHWEST OF ROLLINS AND 4 MILES NORTHEAST 
OF NEDERLAND. THE HEAVY RAINS COULD ALSO TRIGGER ROCK SLIDES OR 
DEBRIS FLOWS IN STEEP TERRAIN.

&&

LAT...LON 4003 10529 3983 10533 3982 10549 4002 10546

$$
1 follow-up statement
826 
WGUS75 KBOU 080326
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
926 PM MDT THU JUL 7 2011

COC013-047-059-080334-
/O.EXP.KBOU.FF.W.0008.000000T0000Z-110708T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JEFFERSON CO-GILPIN CO-BOULDER CO-
926 PM MDT THU JUL 7 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 930 PM MDT FOR SOUTH
CENTRAL BOULDER...NORTHEASTERN GILPIN AND NORTHWESTERN JEFFERSON
COUNTIES...

THE STORM THAT PROMPTED THE WARNING HAS EXITED THE AREA. THERE WILL 
STILL BE SCATTERED SHOWERS AND THUNDERSTORMS UNTIL MIDNIGHT...BUT 
OVERALL RAINFALL RATES WILL BE UP TO A THIRD OF AN INCH PER HOUR OR 
LESS. THE STORMS ARE ALSO MOVING QUICKLY ENOUGH TO RESULT IN A LOWER 
THREAT OF FLASH FLOODING. 

LAT...LON 4003 10529 3983 10533 3982 10549 4002 10546

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 6:07 PM MDTAreal Flood AdvisoryBOUBoulder, Gilpin, Jefferson83 min
Jul 7, 6:18 PM MDTFlash Flood WarningBOUBoulder3 hr
Jul 7, 6:35 PM MDTAreal Flood AdvisoryBOULarimer85 min
Jul 7, 7:28 PM MDTAreal Flood AdvisoryBOUBoulder2 hr
Jul 7, 7:38 PM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Denver2 hr
Jul 7, 8:02 PM MDTFlash Flood WarningBOUClear Creek, Gilpin97 min
Jul 7, 10:05 PM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Denver4 hr
Jul 7, 10:27 PM MDTRiver Flood AdvisoryBOUAdams14 hr
Jul 8, 1:21 PM MDTSevere Thunderstorm WarningBOUAdams, Broomfield, Denver, Jefferson39 min
Jul 8, 1:46 PM MDTSevere Thunderstorm WarningBOUAdams, Denver44 min
Jul 8, 2:07 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver34 min
Jul 8, 4:11 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln49 min
Jul 8, 4:39 PM MDTSevere Thunderstorm WarningBOULarimer, Weld24 min
Jul 8, 4:57 PM MDTSevere Thunderstorm WarningBOULincoln16 min
Jul 8, 5:11 PM MDTSevere Thunderstorm WarningBOUElbert21 min
Jul 8, 5:20 PM MDTAreal Flood AdvisoryBOUSummit4 days

Nearby

Flash Flood Warnings in Colorado, 2011Every flash flood warning in 2011

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.