Alert archive / Colorado / Flash Flood Warnings in 2011

Flash Flood Warning 25, NWS Denver/Boulder, CO

July 14, 2011Arapahoe County, Denver County, Jefferson County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 14, 2011, 3:22 PM MDT for Arapahoe County, Denver County, Jefferson County, Colorado. It was in force for 2 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 14, 2011, 3:22 PM MDT (21:22 UTC)
Expired
Jul 14, 2011, 5:32 PM MDT
In force
2 hr
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

Counties Arapahoe County, CO, Denver County, CO, Jefferson County, CO

The radar

The Denver radar (KFTG), 34 km from the middle of the area, began a volume at 21:23 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 14, 3:30 PM MDTFLOOD4 W Centennial, COSIGNIFICANT STREET FLOODING AND STANDING WATER OVER LOW LYING AREAS OF OVER ONE FOOT.
Jul 14, 3:35 PM MDTFLOOD5 Se Denver, COCARS STRANDED IN STANDING WATER OVER TWO FEET OF WATER AT THE INTERSECTIONS OF COLORADO AND YALE AND COLORADO AND MAXWELL.
Jul 14, 3:38 PM MDTFLOOD3 Ese Denver, COONE FOOT OF WATER ON THE INTERSECTION OF ALEMEDA AND HOLLY OVERFLOWING FROM NEARBY DITCH.

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, 9.4 hours before the alert went out and 147 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 2011-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 255 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 2011-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 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
255 J/kg
Mixed-layer CIN
-304 J/kg
Mixed-layer LCL
1170 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

733 
WGUS55 KBOU 142122
FFWBOU
COC005-031-059-150015-
/O.NEW.KBOU.FF.W.0025.110714T2122Z-110715T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
322 PM MDT THU JUL 14 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL JEFFERSON COUNTY IN NORTHEAST COLORADO
  WESTERN ARAPAHOE COUNTY IN NORTHEAST COLORADO
  SOUTHERN DENVER COUNTY IN NORTHEAST COLORADO

* UNTIL 615 PM MDT

* AT 320 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR ENGLEWOOD...OR 5 MILES
  SOUTH OF DENVER. THIS STORM WAS MOVING NORTH AT 5 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SHERIDAN...
  GREENWOOD VILLAGE...WESTERN CENTENNIAL...LITTLETON...SOUTHEASTERN
  LAKEWOOD...ENGLEWOOD...DENVER AND WESTERN AURORA.

DOPPLER RADAR ESTIMATES THAT THIS STORM WILL PRODUCE UP TO 2 INCHES 
OF RAIN IN A 30 TO 45 MINUTE PERIOD.  AN AUTOMATED RAIN GAUGE IN 
LITTLETON HAS ALREADY REPORTED 1 INCH OF RAIN IN 20 MINUTES.

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.

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.

&&

LAT...LON 3956 10514 3963 10512 3979 10493 3978 10491
      3980 10490 3980 10478 3977 10479 3977 10485
      3976 10485 3975 10488 3974 10481 3960 10490
      3956 10509

$$
BARJENBRUCH
3 follow-up statements
259 
WGUS75 KBOU 142157
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
357 PM MDT THU JUL 14 2011

COC059-142201-
/O.CAN.KBOU.FF.W.0025.000000T0000Z-110715T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JEFFERSON CO-
357 PM MDT THU JUL 14 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL
JEFFERSON COUNTY...

THE STORM HAS MOVED JUST EAST OF JEFFERSON COUNTY.

LAT...LON 3959 10506 3964 10504 3979 10493 3978 10491
      3980 10490 3980 10478 3977 10479 3977 10485
      3976 10486 3975 10488 3974 10481 3960 10490
      3957 10504

$$

COC005-031-150015-
/O.CON.KBOU.FF.W.0025.000000T0000Z-110715T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ARAPAHOE CO-DENVER CO-
357 PM MDT THU JUL 14 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MDT FOR
CENTRAL DENVER AND WESTERN ARAPAHOE COUNTIES...

AT 351 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY
HEAVY RAIN FROM A THUNDERSTORM NEAR ENGLEWOOD...OR ABOUT 6 MILES
SOUTH OF DENVER. THIS STORM WAS MOVING NORTHEAST AT 10 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
SHERIDAN...GREENWOOD VILLAGE...WESTERN CENTENNIAL...LITTLETON...
ENGLEWOOD...EASTERN DENVER AND WESTERN AURORA.

DOPPLER RADAR AND RAIN GAUGE ESTIMATES THAT 1.5 INCHES OF RAIN HAS 
FALLEN IN THE SOUTHEAST PART OF DENVER WITH THE HEAVIEST RAINFALL 
CENTERED AROUND COLORADO AND HAMPDEN. 

DENVER COUNTY EMERGENCY OPERATIONS CENTER REPORTED THAT SOME CARS 
WERE STRANDED NEAR THE INTERSECTIONS OF COLORADO AND YALE...AS WELL 
AS COLORADO AND MAXWELL.  

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.

MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS
BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS THE ROADWAY.
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO
ESCAPE RISING WATER CLIMB TO HIGHER GROUND.

&&

LAT...LON 3959 10506 3964 10504 3979 10493 3978 10491
      3980 10490 3980 10478 3977 10479 3977 10485
      3976 10486 3975 10488 3974 10481 3960 10490
      3957 10504

$$
BARJENBRUCH
999 
WGUS75 KBOU 142301
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
501 PM MDT THU JUL 14 2011

COC005-031-150015-
/O.CON.KBOU.FF.W.0025.000000T0000Z-110715T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ARAPAHOE CO-DENVER CO-
501 PM MDT THU JUL 14 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MDT FOR
CENTRAL DENVER AND WESTERN ARAPAHOE COUNTIES...

AT 440 PM MDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED CARS HAD 
BEEN IMPACTED BY FLOODING ON ARAPAHOE ROAD EAST OF UNIVERSITY 
BLVD...UNIVERSITY BLVD NORTH OF ARAPAHOE ROAD ...DRY CREEK FROM 
BROADWAY TO MONACO PARKWAY...AND HAMPDEN AVENUE IN CHERRY HILLS. 

AUTOMATED GAUGES INDICATE THAT THE POWERS PARK DETENTION POND IN 
LITTLETON ROSE TO 11.81 FEET AT 428 PM MDT. AT 11 FEET...WATER FLOWS 
FROM THE DETENTION POND INTO THE WEST END OF POWERS PARK AND AT 12 
FEET THE INTERSECTION OF SOUTH HURON STREET AND WEST BERRY AVENUE 
FLOODS.

NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THAT ADDITIONAL  
THUNDERSTORMS WITH MODERATE TO HEAVY RAIN ARE APPROACHING THE AREA. 
THESE STORMS WERE MOVING NORTHEAST AT 10 MPH. THESE STORMS MAY 
PRODUCE 0.5 TO 1 INCH OF RAINFALL IN 30 TO 60 MINUTES.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
SHERIDAN...GREENWOOD VILLAGE...WESTERN CENTENNIAL...LITTLETON...
ENGLEWOOD...EASTERN DENVER AND WESTERN AURORA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS
BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS THE ROADWAY.
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO
ESCAPE RISING WATER CLIMB TO HIGHER GROUND.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT
THURSDAY EVENING FOR NORTHEASTERN COLORADO.

&&

LAT...LON 3959 10506 3964 10504 3979 10493 3978 10491
      3980 10490 3980 10478 3977 10479 3977 10485
      3976 10486 3975 10488 3974 10481 3960 10490
      3957 10504

$$
128 
WGUS75 KBOU 142332
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
532 PM MDT THU JUL 14 2011

COC005-031-142340-
/O.CAN.KBOU.FF.W.0025.000000T0000Z-110715T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ARAPAHOE CO-DENVER CO-
532 PM MDT THU JUL 14 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL DENVER AND
WESTERN ARAPAHOE COUNTIES...

FLASH FLOODING IS NO LONGER EXPECTED.

LARGE STREAMS INCLUDING CHERRY CREEK...SAND CREEK...AND THE SOUTH 
PLATTE RIVER WILL CONTINUE TO RUN HIGH FOR THE NEXT COUPLE HOURS.  
SOME TRAILS AND BIKE PATHS MAY BE CLOSED.

LAT...LON 3959 10506 3964 10504 3979 10493 3978 10491
      3980 10490 3980 10478 3977 10479 3977 10485
      3976 10486 3975 10488 3974 10481 3960 10490
      3957 10504

$$
BARJENBRUCH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 6:17 PM MDTFlash Flood WarningBOUBoulder3 hr
Jul 13, 6:32 PM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Denver, Jefferson43 min
Jul 13, 6:40 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver, Jefferson19 min
Jul 13, 6:54 PM MDTAreal Flood AdvisoryBOUGrand22 hr
Jul 13, 7:13 PM MDTSevere Thunderstorm WarningBOUBoulder, Larimer34 min
Jul 13, 7:34 PM MDTSevere Thunderstorm WarningBOULarimer26 min
Jul 13, 7:59 PM MDTSevere Thunderstorm WarningBOULarimer, Weld28 min
Jul 13, 8:08 PM MDTFlash Flood WarningBOUBoulder103 min
Jul 13, 8:37 PM MDTAreal Flood AdvisoryBOUBoulder75 min
Jul 13, 9:01 PM MDTSevere Thunderstorm WarningBOUDouglas, Jefferson44 min
Jul 13, 9:05 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver55 min
Jul 13, 9:28 PM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Broomfield, Denver, Douglas, Jefferson77 min
Jul 13, 9:55 PM MDTSevere Thunderstorm WarningBOUAdams, Weld33 min
Jul 13, 10:58 PM MDTAreal Flood AdvisoryBOUArapahoe, Douglas92 min
Jul 13, 11:15 PM MDTFlash Flood WarningBOUBoulder3 hr
Jul 13, 11:16 PM MDTFlash Flood WarningBOUBoulder3 hr
Jul 13, 11:48 PM MDTAreal Flood AdvisoryBOUAdams, Morgan, Washington87 min
Jul 14, 12:35 AM MDTAreal Flood AdvisoryBOUAdams, Arapahoe, Morgan, Washington81 min
Jul 14, 5:25 AM MDTFlash Flood WatchBOUAdams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver and 10 more16 hr
Jul 14, 11:03 AM MDTAreal Flood AdvisoryBOUMorgan, Weld71 hr
Jul 14, 1:00 PM MDTFlash Flood WarningBOUBoulder3 hr
Jul 14, 1:10 PM MDTSpecial Weather StatementBOUJefferson35 min
Jul 14, 1:48 PM MDTAreal Flood AdvisoryBOUDouglas87 min
Jul 14, 1:57 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert48 min
Jul 14, 2:09 PM MDTFlash Flood WarningBOUBoulder2 hr
Jul 14, 2:40 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver, Douglas50 min
Jul 14, 3:02 PM MDTAreal Flood AdvisoryBOUArapahoe, Denver26 min
Jul 14, 3:28 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver47 min
Jul 14, 4:00 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe22 min
Jul 14, 4:16 PM MDTAreal Flood AdvisoryBOUArapahoe, Elbert89 min
Jul 14, 4:31 PM MDTAreal Flood AdvisoryBOUGrand71 hr
Jul 14, 5:10 PM MDTAreal Flood AdvisoryBOUBoulder55 min
Jul 14, 5:21 PM MDTSpecial Weather StatementBOUAdams24 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.