Alert archive / Colorado / Flash Flood Warnings in 2011

Flash Flood Warning 21, NWS Denver/Boulder, CO

July 13, 2011Boulder County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 13, 2011, 11:15 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, 11:15 PM MDT (05:15 UTC)
Expired: Jul 14, 2011, 2:15 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.

021 
WGUS55 KBOU 140515
FFWBOU
COC013-140815-
/O.NEW.KBOU.FF.W.0021.110714T0515Z-110714T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
1115 PM MDT WED JUL 13 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  THE HAYMAN 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

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, 11:16 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.