Alert archive / Colorado / Flash Flood Warnings in 2012

Flash Flood Warning 16, NWS Denver/Boulder, CO

July 7, 2012Boulder County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 7, 2012, 3:45 PM MDT for Boulder County, Colorado. It was in force for 90 min. 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 7, 2012, 3:45 PM MDT (21:45 UTC)
Expired
Jul 7, 2012, 5:15 PM MDT
In force
90 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

County Boulder County, CO

The radar

The Denver radar (KFTG), 82 km from the middle of the area, began a volume at 21:45 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 7, 4:40 PM MDTFLASH FLOOD2 Ese Nederland, COMAGNOLIA ROAD IS WASHED OUT.
Jul 7, 5:15 PM MDTHEAVY RAIN 2.922 Ene Nederland, CO
Jul 7, 5:15 PM MDTHEAVY RAIN 3.112 Ene Nederland, CO

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

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 9.8 hours before the alert went out and 191 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 2012-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 64 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 12:00Z on 2012-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
64 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
805 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
91 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.

633 
WGUS55 KBOU 072145
FFWBOU
COC013-072315-
/O.NEW.KBOU.FF.W.0016.120707T2145Z-120707T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
345 PM MDT SAT JUL 7 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL BOULDER COUNTY IN NORTHEAST COLORADO

* UNTIL 515 PM MDT

* AT 339 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A THUNDERSTORM 3 MILES NORTHEAST OF           
  NEDERLAND...OR 33 MILES NORTHWEST OF DENVER. THIS STORM WAS SLOWLY 
  MOVING EAST.  

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO NEDERLAND.

AUTOMATED RAIN GAUGES AT SAINT ANTONS INDICATE 1.81 INCHES OF RAIN 
IN AN HOUR. WITH THE SLOW STORM MOVEMENT ADDITIONAL HEAVY RAIN IS 
LIKELY.  

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.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY AS THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY. DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A
FEW INCHES OF RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR
VEHICLE. TURN AROUND...DO NOT DROWN.

&&

LAT...LON 4002 10551 4002 10540 3996 10539 3994 10547
      3996 10551

$$
2 follow-up statements
486 
WGUS75 KBOU 072204
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
404 PM MDT SAT JUL 7 2012

COC013-072315-
/O.CON.KBOU.FF.W.0016.000000T0000Z-120707T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
404 PM MDT SAT JUL 7 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM MDT FOR SOUTH
CENTRAL BOULDER COUNTY...

AT 403 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY
HEAVY RAIN FROM A THUNDERSTORM OVER NEDERLAND...OR ABOUT 33 MILES
NORTHWEST OF DENVER. THIS STORM WAS NEARLY STATIONARY.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
NEDERLAND.

AUTOMATED RAIN GAUGES AT SAINT ANTON INDICATE THAT 2.40 INCHES OF 
RAIN HAS FALLEN.  WITH THE SLOW STORM MOVEMENT MORE HEAVY RAIN IS 
EXPECTED.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY AS THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY. DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A
FEW INCHES OF RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR
VEHICLE. TURN AROUND...DO NOT DROWN.

&&

LAT...LON 4002 10551 4002 10540 3996 10539 3994 10547
      3996 10551

$$
137 
WGUS75 KBOU 072321
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
521 PM MDT SAT JUL 7 2012

COC013-072330-
/O.EXP.KBOU.FF.W.0016.000000T0000Z-120707T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
521 PM MDT SAT JUL 7 2012

...THE FLASH FLOOD WARNING HAS EXPIRED FOR SOUTH CENTRAL BOULDER
COUNTY...

THE STORM THAT PROMPTED THE WARNING NEAR NEDERLAND HAS WEAKENED AND 
IS NO LONGER EXPECTED TO PRODUCE FLASH FLOODING.

LAT...LON 4002 10551 4002 10540 3996 10539 3994 10547
      3996 10551

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 6:29 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Elbert43 min
Jul 6, 6:57 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington50 min
Jul 6, 8:26 PM MDTAreal Flood AdvisoryBOUMorgan, Washington94 min
Jul 6, 8:41 PM MDTFlash Flood WatchBOUArapahoe, Boulder, Broomfield, Clear Creek, Douglas, Elbert and 8 more32 hr
Jul 6, 8:56 PM MDTFlash Flood WarningBOULarimer3 hr
Jul 6, 9:01 PM MDTAreal Flood AdvisoryBOUWashington59 min
Jul 6, 9:06 PM MDTFlash Flood WarningBOUBoulder97 min
Jul 6, 9:46 PM MDTSevere Thunderstorm WarningBOULogan, Washington44 min
Jul 6, 11:20 PM MDTAreal Flood AdvisoryBOULogan, Washington, Weld115 min
Jul 7, 3:08 PM MDTAreal Flood AdvisoryBOUBoulder97 min
Jul 7, 3:23 PM MDTAreal Flood AdvisoryBOUClear Creek97 min
Jul 7, 3:41 PM MDTFlash Flood WarningBOUBoulder94 min
Jul 7, 3:57 PM MDTFlash Flood WarningBOUClear Creek93 min
Jul 7, 4:19 PM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Denver, Douglas, Jefferson86 min
Jul 7, 4:30 PM MDTAreal Flood AdvisoryBOUBoulder90 min
Jul 7, 4:36 PM MDTAreal Flood AdvisoryBOULarimer84 min
Jul 7, 4:49 PM MDTAreal Flood AdvisoryBOULarimer86 min
Jul 7, 4:53 PM MDTFlash Flood WarningBOUBoulder106 min
Jul 7, 5:01 PM MDTAreal Flood AdvisoryBOUBoulder119 min
Jul 7, 5:35 PM MDTAreal Flood AdvisoryBOUBoulder85 min
Jul 7, 5:59 PM MDTAreal Flood AdvisoryBOULarimer91 min

Nearby

Flash Flood Warnings in Colorado, 2012Every flash flood warning in 2012

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.