Alert archive / Colorado / Flash Flood Warnings in 2014

Flash Flood Warning 33, NWS Denver/Boulder, CO

July 29, 2014Larimer County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 29, 2014, 5:05 PM MDT for Larimer County, Colorado. It was in force for 6 hr. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 29, 2014, 5:05 PM MDT (23:05 UTC)
Expired
Jul 29, 2014, 11:00 PM MDT
In force
6 hr
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

County Larimer County, CO

The radar

The Cheyenne radar (KCYS), 60 km from the middle of the area, began a volume at 23:07 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.

What was reported inside it

TimeReportWhereRemark
Jul 29, 5:08 PM MDTFLASH FLOOD10 Nnw Wellington, COINTERSECTION WASHED OUT AT COUNTY RD 15 AND 84 DUE TO WATER FLOWING OFF OF FIELDS.
Jul 29, 5:08 PM MDTFLASH FLOOD10 Nw Wellington, COINTERSECTION WASHED OUT AT COUNTY RD 15 AND 84 DUE TO WATER FLOWING OFF OF FIELDS.
Jul 29, 5:08 PM MDTFLASH FLOOD9 Nw Wellington, COEXTENSIVE FLOODING OF FIELDS WITH STANDING WATER IN FIELDS AND ON COUNTY ROADS. LAW ENFORCMENT NOTED SOME ROAD DAMAGE DUE TO WATER FLOWING OFF OF FIELDS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 11.1 hours before the alert went out and 214 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 12:00Z on 2014-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 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 12:00Z on 2014-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 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
11 J/kg
Mixed-layer CIN
-207 J/kg
Mixed-layer LCL
1262 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
45 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.

074 
WGUS55 KBOU 292305
FFWBOU
COC069-300500-
/O.NEW.KBOU.FF.W.0033.140729T2305Z-140730T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
505 PM MDT TUE JUL 29 2014

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN LARIMER COUNTY IN NORTH CENTRAL COLORADO...

* UNTIL 1100 PM MDT TUESDAY
    
* AT 456 PM MDT...DOPPLER RADAR INDICATED ADDITIONAL THUNDERSTORMS 
  WERE REDEVELOPING OVER NORTHEASTERN LARIMER COUNTY.  SATURATED 
  SOILS ALONG WITH SWOLLEN CREEKS AND STREAMS FROM HEAVY RAINFALL 
  EARLIER THIS AFTERNOON WILL FURTHER EXACERBATE THE SITUATION. 
  FLASH FLOODING WILL LIKELY REDEVELOP IN THIS AREA OVER THE NEXT 1 
  TO 3 HOURS...AS HEAVY RAINFALL ENSUES. EXCESSIVE RAINFALL OVER THE 
  WARNING AREA WILL CAUSE MUD SLIDES NEAR STEEP TERRAIN. THE MUD 
  SLIDE CAN CONSIST OF ROCK...MUD...VEGETATION AND OTHER LOOSE 
  MATERIALS.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  RED FEATHER LAKES...LIVERMORE AND VIRGINIA DALE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ROCK SLIDES AND DEBRIS FLOWS ARE LIKELY FROM THIS RAINFALL. DRIVERS
SHOULD BE ALERT FOR ROCKS...MUD...OR FLOOD WATERS ON ROADWAYS. PEOPLE
IN AREAS PRONE TO DEBRIS FLOWS SHOULD BE PREPARED TO MOVE TO SAFETY.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF FLOODING.  PLEASE REPORT FLOODING TO YOUR LOCAL LAW 
ENFORCEMENT AGENCY WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4077 10569 4099 10569 4100 10496 4074 10496

$$

COOPER
2 follow-up statements
823 
WGUS75 KBOU 300145
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
745 PM MDT TUE JUL 29 2014

COC069-300500-
/O.CON.KBOU.FF.W.0033.000000T0000Z-140730T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LARIMER CO-
745 PM MDT TUE JUL 29 2014

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM MDT FOR
NORTHEASTERN LARIMER COUNTY...

AT 740 PM MDT...DOPPLER RADAR INDICATED ADDITIONAL SHOWERS AND 
THUNDERSTORMS WERE CONTINUING TO MOVE ACROSS THE WARNED AREA.  
ALTHOUGH THE STORMS WERE WEAKER THAN THOSE THAT PRODUCED HEAVY RAIN 
EARLIER THIS AFTERNOON...THEY MAY STILL ALLOW FOR FLASH FLOODING TO 
OCCUR ALONG ALREADY SWOLLEN CREEKS AND STREAMS.  

EXCESSIVE RAINFALL OVER THE WARNING AREA WILL CAUSE MUD SLIDES NEAR 
STEEP TERRAIN. THE MUD SLIDE CAN CONSIST OF ROCK...MUD...VEGETATION 
AND OTHER LOOSE MATERIALS.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
RED FEATHER LAKES...LIVERMORE AND VIRGINIA DALE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DRIVERS SHOULD BE ALERT FOR ROCKS...MUD...OR FLOOD WATERS ON 
ROADWAYS. PEOPLE IN AREAS PRONE TO DEBRIS FLOWS SHOULD BE PREPARED 
TO MOVE TO SAFETY.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 4077 10569 4099 10569 4100 10496 4074 10496

$$

COOPER
404 
WGUS75 KBOU 300256
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
856 PM MDT TUE JUL 29 2014

COC069-300304-
/O.CAN.KBOU.FF.W.0033.000000T0000Z-140730T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LARIMER CO-
856 PM MDT TUE JUL 29 2014

...THE FLASH FLOOD WARNING FOR NORTHEASTERN LARIMER COUNTY IS
CANCELLED...

THE HEAVY RAIN HAS ENDED...AND FLOODING IS NO LONGER EXPECTED TO 
POSE A THREAT.  ADDITIONAL THUNDERSTORMS HOWEVER MAY MOVE BACK INTO 
THE REGION LATE TONIGHT AND WEDNESDAY MORNING.

LAT...LON 4077 10569 4099 10569 4100 10496 4074 10496

$$

COOPER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 7:20 PM MDTAreal Flood AdvisoryBOUWeld2 hr
Jul 28, 10:31 PM MDTAreal Flood AdvisoryBOULarimer119 min
Jul 29, 12:02 PM MDTAreal Flood AdvisoryBOULarimer88 min
Jul 29, 12:20 PM MDTFlash Flood WarningBOULarimer3 hr
Jul 29, 12:29 PM MDTAreal Flood AdvisoryBOUElbert91 min
Jul 29, 1:36 PM MDTFlash Flood WarningBOULarimer3 hr
Jul 29, 1:48 PM MDTAreal Flood AdvisoryBOUArapahoe, Elbert3 hr
Jul 29, 1:59 PM MDTAreal Flood AdvisoryBOULarimer2 hr
Jul 29, 2:10 PM MDTAreal Flood AdvisoryBOULarimer3 hr
Jul 29, 2:11 PM MDTAreal Flood AdvisoryBOUAdams, Weld3 hr
Jul 29, 2:35 PM MDTAreal Flood AdvisoryBOULarimer, Weld3 hr
Jul 29, 2:42 PM MDTAreal Flood AdvisoryBOUAdams, Denver3 hr
Jul 29, 2:44 PM MDTFlash Flood WarningBOULarimer6 hr
Jul 29, 3:08 PM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Denver, Douglas, Jefferson3 hr
Jul 29, 3:16 PM MDTFlash Flood WarningBOULarimer, Weld3 hr
Jul 29, 3:17 PM MDTAreal Flood AdvisoryBOULincoln3 hr
Jul 29, 3:26 PM MDTFlash Flood WarningBOUWeld3 hr
Jul 29, 3:33 PM MDTAreal Flood AdvisoryBOUMorgan3 hr
Jul 29, 3:43 PM MDTAreal Flood AdvisoryBOUWeld3 hr
Jul 29, 4:11 PM MDTAreal Flood AdvisoryBOUMorgan3 hr
Jul 29, 4:12 PM MDTAreal Flood AdvisoryBOUMorgan, Washington, Weld3 hr
Jul 29, 4:45 PM MDTAreal Flood AdvisoryBOULincoln3 hr
Jul 29, 5:18 PM MDTAreal Flood AdvisoryBOULogan, Washington, Weld3 hr
Jul 29, 5:55 PM MDTAreal Flood AdvisoryBOUElbert, Lincoln3 hr

Nearby

Flash Flood Warnings in Colorado, 2014Every flash flood warning in 2014

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.