Alert archive / Colorado / Flash Flood Warnings in 2011

Flash Flood Warning 22, NWS Denver/Boulder, CO

July 13, 2011Boulder County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 13, 2011, 11:16 PM MDT for Boulder 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 13, 2011, 11:16 PM MDT (05:16 UTC)
Expired: Jul 14, 2011, 2:04 AM MDT
In force: 3 hr
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Flood severity: None

County Boulder County, CO

The radar

The Denver radar (KFTG), 76 km from the middle of the area, began a volume at 05:15 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, 5.3 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 856 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 2153 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: -31 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

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

873 
WGUS55 KBOU 140516
FFWBOU
COC013-140815-
/O.NEW.KBOU.FF.W.0022.110714T0516Z-110714T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING...CORRECTION
NATIONAL WEATHER SERVICE DENVER CO
1116 PM MDT WED JUL 13 2011

...CORRECTION FOR FOURMILE BURN AREA...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  THE FOURMILE BURN AREA IN CENTRAL BOULDER COUNTY IN
   NORTHEAST COLORADO

* UNTIL 215 AM MDT

* AT 1114 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 2 MILES SOUTH OF WALLSTREET...
  OR 31 MILES NORTHWEST OF DENVER. THIS STORM WAS MOVING NORTHEAST AT
  10 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  WALLSTREET...SUNSHINE...SUMMERVILLE...SALINA...CRISMAN AND GOLD
  HILL.

DOPPLER RADAR ESTIMATES THAT THIS STORM MAY PRODUCE A HALF INCH OF 
RAIN IN 15 MINUTES OR LESS AS IT MOVES ACROSS THE BURN AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL WILL CAUSE FLASH FLOODING OF CREEKS...STREAMS...AND
DITCHES IN THE FOURMILE BURN AREA. SOME DRAINAGE BASINS AFFECTED BY
EXCESSIVE RUNOFF INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE 
CANYON CREEK. WATER WILL BE FLOWING DOWN ROADWAYS. ADDITIONAL ROCK 
SLIDES OR DEBRIS FLOWS CAN ALSO BE EXPECTED.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4007 10543 4008 10533 4004 10532 4003 10531
      4002 10534 4001 10542

$$
BARJENBRUCH

5 follow-up statements

935 
WGUS75 KBOU 140527
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1127 PM MDT WED JUL 13 2011

COC013-140815-
/O.CON.KBOU.FF.W.0022.000000T0000Z-110714T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
1127 PM MDT WED JUL 13 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 215 AM MDT FOR THE 
FOURMILE BURN AREA IN CENTRAL BOULDER COUNTY...

AT 1123 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAIN FROM A THUNDERSTORM NEAR SALINA...OR ABOUT 31 MILES
NORTHWEST OF DENVER. THIS STORM WAS MOVING NORTHEAST AT 10 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WALLSTREET...SUNSHINE...SUMMERVILLE...SALINA...CRISMAN AND GOLD HILL.

DOPPLER RADAR ESTIMATES THAT THIS STORM MAY PRODUCE A HALF INCH OF 
RAIN IN 15 MINUTES OR LESS AS IT MOVES ACROSS THE BURN AREA.

THE RAIN WILL BE ENDING BY 1135 PM.  HOWEVER...THE VERY HEAVY 
RAINFALL WILL MEAN VERY RAPID RESPONSE TIME TO STREAMFLOWS AS WELL 
AS DEBRIS FLOWS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL WILL CAUSE FLASH FLOODING OF CREEKS...STREAMS...AND
DITCHES IN THE FOURMILE BURN AREA. SOME DRAINAGE BASINS AFFECTED BY
EXCESSIVE RUNOFF INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE 
CANYON CREEK. WATER WILL BE FLOWING DOWN ROADWAYS. ADDITIONAL ROCK 
SLIDES OR DEBRIS FLOWS CAN ALSO BE EXPECTED.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

IF YOU BECOME STRANDED IN YOUR VEHICLE...ABANDON IT AND CLIMB TO 
HIGHER GROUND FOR YOUR SAFETY.

&&

LAT...LON 4007 10543 4008 10533 4004 10532 4003 10531
      4002 10534 4001 10542

$$

053 
WGUS75 KBOU 140542
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1142 PM MDT WED JUL 13 2011

COC013-140815-
/O.CON.KBOU.FF.W.0022.000000T0000Z-110714T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
1142 PM MDT WED JUL 13 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 215 AM MDT FOR THE 
FOURMILE BURN AREA IN CENTRAL BOULDER COUNTY...

AT 1138 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAIN FROM A THUNDERSTORM 3 MILES NORTHEAST OF SUNSHINE...
OR ABOUT 32 MILES NORTHWEST OF DENVER. THIS STORM WAS MOVING 
NORTHEAST AT 10 MPH AND HAD MOVED OUT OF THE BURN AREA.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WALLSTREET...SUNSHINE...SUMMERVILLE...SALINA...CRISMAN AND GOLD HILL.

AUTOMATED RAIN GAUGES SHOW THIS STORM PRODUCED BETWEEN 0.15 AND  
0.30 INCH OF RAIN IN THE BURN AREA.  HOWEVER...THERE MAY HAVE BEEN A 
NARROW STRIP IN THE MIDDLE OF THE BURN AREA OF 0.40 TO 0.50 INCH 
BETWEEN THOSE AUTOMATED GAUGES.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL WILL CAUSE FLASH FLOODING OF CREEKS...STREAMS...AND
DITCHES IN THE FOURMILE BURN AREA. SOME DRAINAGE BASINS AFFECTED BY
EXCESSIVE RUNOFF INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE 
CANYON CREEK. WATER WILL BE FLOWING DOWN ROADWAYS. ADDITIONAL ROCK 
SLIDES OR DEBRIS FLOWS CAN ALSO BE EXPECTED.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

IF YOU BECOME STRANDED IN YOUR VEHICLE...ABANDON IT AND CLIMB TO 
HIGHER GROUND FOR YOUR SAFETY.

&&

LAT...LON 4007 10543 4008 10533 4004 10532 4003 10531
      4002 10534 4001 10542

$$
BARJENBRUCH

518 
WGUS75 KBOU 140615
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1215 AM MDT THU JUL 14 2011

COC013-140815-
/O.CON.KBOU.FF.W.0022.000000T0000Z-110714T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
1215 AM MDT THU JUL 14 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 215 AM MDT FOR THE 
FOURMILE BURN AREA IN CENTRAL BOULDER COUNTY...

AT 1210 AM MDT...BOULDER COUNTY EMERGENCY MANAGEMENT REPORTED THAT
STORM RUNOFF ALONG GOLD RUN OVERTOPPED A SECTION OF ROAD BY A FEW 
INCHES.  THE AMOUNT OF RAIN OBSERVED WITH THIS LATEST STORM WAS 
CONSIDERABLY LESS THAN THE STORM EARLIER TONIGHT.  AS A RESULT...THE 
MAGNITUDE OF RUNOFF IS EXPECTED TO BE LESS THAN THAT OBSERVED 
WEDNESDAY EVENING.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WALLSTREET...SUNSHINE...SUMMERVILLE...SALINA...CRISMAN AND GOLD HILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL WILL CAUSE FLASH FLOODING OF CREEKS...STREAMS...AND
DITCHES IN THE FOURMILE BURN AREA. SOME DRAINAGE BASINS AFFECTED BY
EXCESSIVE RUNOFF INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE
CANYON CREEK. WATER WILL BE FLOWING DOWN ROADWAYS. ROCK SLIDES OR
DEBRIS FLOWS CAN ALSO BE EXPECTED.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4007 10543 4008 10533 4004 10532 4003 10531
      4002 10534 4001 10542

$$
BARJENBRUCH

774 
WGUS75 KBOU 140653
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1253 AM MDT THU JUL 14 2011

COC013-140815-
/O.CON.KBOU.FF.W.0022.000000T0000Z-110714T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
1253 AM MDT THU JUL 14 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 215 AM MDT FOR THE 
FOURMILE BURN AREA IN CENTRAL BOULDER COUNTY...

A SHORT BURST OF HEAVY RAINFALL HAS PRODUCED CONSIDERABLE MORE 
RUNOFF FROM THE FOURMILE BURN AREA.  A REMOTE STREAMFLOW CAMERA NOW
INDICATES THAT RUNOFF AMOUNTS WILL BE SIMILAR TO THOSE OBSERVED 
EARLIER WEDNESDAY EVENING.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WALLSTREET...SUNSHINE...SUMMERVILLE...SALINA...CRISMAN AND GOLD HILL.
THIS WARNING ALSO INCLUDES FOURMILE CREEK DOWNSTREAM TO WHERE IT 
EMPTIES INTO BOULDER CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL WILL CAUSE FLASH FLOODING OF CREEKS...STREAMS...AND
DITCHES IN THE FOURMILE BURN AREA. SOME DRAINAGE BASINS AFFECTED BY
EXCESSIVE RUNOFF INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE
CANYON CREEK. WATER WILL BE FLOWING DOWN ROADWAYS. ROCK SLIDES OR
DEBRIS FLOWS CAN ALSO BE EXPECTED.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4007 10543 4008 10533 4004 10532 4003 10531
      4002 10534 4001 10542

$$
BARJENBRUCH

872 
WGUS75 KBOU 140804
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
204 AM MDT THU JUL 14 2011

COC013-140807-
/O.CAN.KBOU.FF.W.0022.000000T0000Z-110714T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
204 AM MDT THU JUL 14 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL BOULDER
COUNTY...

THE STORM THAT PROMPTED THE WARNING HAS EXITED THE AREA.

FLOOD WATERS HAVE ALSO SUBSIDED AND FLASH FLOODING IS NO LONGER 
EXPECTED.  RUNOFF FROM THE LATE EVENING THUNDERSTORM THAT MOVED OVER 
THE BURN AREA PRODUCED A RISE ON FOURMILE CREEK THAT WAS COMPARABLE 
TO FLOWS EXPERIENCED EARLIER WEDNESDAY EVENING.  THE PEAK OF THE 
RUNOFF HAS MADE ITS WAY DOWN BOULDER CREEK AND OUT OF THE CANYON.  
REPORTS OF SOME DEBRIS FLOWS AND WASHED OUT DRIVEWAYS HAVE BEEN 
RECEIVED DUE TO THE HEAVY RAIN SHOWERS THAT MOVED OVER THE FOURMILE 
BURN AREA. 

IT APPEARS THAT THUNDERSTORMS WITH HEAVY RAIN WILL BE POSSIBLE OVER 
THE FOURMILE BURN AREA AGAIN THURSDAY AFTERNOON AND EVENING.  
CONTINUE TO MONITOR NEWS MEDIA OUTLETS FOR THE LATEST POSSIBLE 
WATCHES AND WARNINGS.  

LAT...LON 4007 10543 4008 10533 4004 10532 4003 10531
      4002 10534 4001 10542

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 13, 6:17 PM MDT	Flash Flood Warning	BOU	Boulder	3 hr
Jul 13, 6:32 PM MDT	Areal Flood Advisory	BOU	Adams, Arapahoe, Denver, Jefferson	43 min
Jul 13, 6:40 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver, Jefferson	19 min
Jul 13, 6:54 PM MDT	Areal Flood Advisory	BOU	Grand	22 hr
Jul 13, 7:13 PM MDT	Severe Thunderstorm Warning	BOU	Boulder, Larimer	34 min
Jul 13, 7:34 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	26 min
Jul 13, 7:59 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	28 min
Jul 13, 8:08 PM MDT	Flash Flood Warning	BOU	Boulder	103 min
Jul 13, 8:37 PM MDT	Areal Flood Advisory	BOU	Boulder	75 min
Jul 13, 9:01 PM MDT	Severe Thunderstorm Warning	BOU	Douglas, Jefferson	44 min
Jul 13, 9:05 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver	55 min
Jul 13, 9:28 PM MDT	Areal Flood Advisory	BOU	Adams, Arapahoe, Broomfield, Denver, Douglas, Jefferson	77 min
Jul 13, 9:55 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Weld	33 min
Jul 13, 10:58 PM MDT	Areal Flood Advisory	BOU	Arapahoe, Douglas	92 min
Jul 13, 11:15 PM MDT	Flash Flood Warning	BOU	Boulder	3 hr
Jul 13, 11:48 PM MDT	Areal Flood Advisory	BOU	Adams, Morgan, Washington	87 min
Jul 14, 12:35 AM MDT	Areal Flood Advisory	BOU	Adams, Arapahoe, Morgan, Washington	81 min
Jul 14, 5:25 AM MDT	Flash Flood Watch	BOU	Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver and 10 more	16 hr
Jul 14, 11:03 AM MDT	Areal Flood Advisory	BOU	Morgan, Weld	71 hr
Jul 14, 1:00 PM MDT	Flash Flood Warning	BOU	Boulder	3 hr
Jul 14, 1:10 PM MDT	Special Weather Statement	BOU	Jefferson	35 min
Jul 14, 1:48 PM MDT	Areal Flood Advisory	BOU	Douglas	87 min
Jul 14, 1:57 PM MDT	Severe Thunderstorm Warning	BOU	Douglas, Elbert	48 min
Jul 14, 2:09 PM MDT	Flash Flood Warning	BOU	Boulder	2 hr
Jul 14, 2:40 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Denver, Douglas	50 min
Jul 14, 3:02 PM MDT	Areal Flood Advisory	BOU	Arapahoe, Denver	26 min
Jul 14, 3:22 PM MDT	Flash Flood Warning	BOU	Arapahoe, Denver, Jefferson	2 hr
Jul 14, 3:28 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver	47 min
Jul 14, 4:00 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe	22 min
Jul 14, 4:16 PM MDT	Areal Flood Advisory	BOU	Arapahoe, Elbert	89 min
Jul 14, 4:31 PM MDT	Areal Flood Advisory	BOU	Grand	71 hr
Jul 14, 5:10 PM MDT	Areal Flood Advisory	BOU	Boulder	55 min
Jul 14, 5:21 PM MDT	Special Weather Statement	BOU	Adams	24 min

Nearby

Flash Flood Warnings in Colorado, 2011 Every 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.