Alert archive / Colorado / Flash Flood Warnings in 2016

Flash Flood Warning 8, NWS Denver/Boulder, CO

August 30, 2016Boulder County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 30, 2016, 9:25 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: Aug 30, 2016, 9:25 PM MDT (03:25 UTC)
Expired: Aug 31, 2016, 12:00 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), 70 km from the middle of the area, began a volume at 03:27 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 (KDEN), launched 00:00Z, 3.4 hours before the alert went out and 179 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: 88 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 2313 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -5 m²/s²
0-3 km storm-relative helicity: 36 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

071 
WGUS55 KBOU 310325
FFWBOU
COC013-310600-
/O.NEW.KBOU.FF.W.0008.160831T0325Z-160831T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
925 PM MDT TUE AUG 30 2016

THE NATIONAL WEATHER SERVICE IN DENVER COLORADO HAS ISSUED A

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

* UNTIL MIDNIGHT MDT

* AT 923 PM MDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN JUST WEST OF BOULDER IN THE BETASSO PRESERVE AREA. UP
  TO TWO INCHES OF RAIN HAVE ALREADY FALLEN...AND ANOTHER INCH OF
  RAIN CAN BE EXPECTED. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* FLASH FLOODING WILL REMAIN OVER MAINLY RURAL AREAS OF SOUTH CENTRAL
  BOULDER COUNTY.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...SOUTH BOULDER
CREEK...BEAR CANYON CREEK...FOURMILE CREEK AND BOULDER CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS.  THE HEAVY RAINS COULD
ALSO TRIGGER ROCK SLIDES OR DEBRIS FLOWS IN STEEP TERRAIN.

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.

&&

LAT...LON 3998 10528 3994 10538 4002 10536 4004 10532

$$

BARJENBRUCH

2 follow-up statements

660 
WGUS75 KBOU 310416
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1016 PM MDT TUE AUG 30 2016

COC013-310600-
/O.CON.KBOU.FF.W.0008.000000T0000Z-160831T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
1016 PM MDT TUE AUG 30 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL MIDNIGHT MDT FOR
SOUTH CENTRAL BOULDER COUNTY...

AT 1006 PM MDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
HEAVY RAIN IN THE WARNED AREA WERE GRADUALLY WEAKENING. UP TO THREE
INCHES OF RAIN HAVE ALREADY FALLEN IN THE BETASSO PRESERVE AREA WEST
OF BOULDER.

BOULDER COUNTY EMERGENCY MANAGEMENT REPORTED EXCESSIVE RUNOFF AND
DEBRIS IN THE WATER NEAR THE BOTTOM OF FOURMILE CREEK WHERE IT DUMPS
INTO BOULDER CREEK NEAR HIGHWAY 119. SOME RISE WILL OCCUR ON BOULDER
CREEK THROUGH BOULDER AND MAY AFFECT BIKE PATHS...BUT FLASH FLOODING
IS NOT ANTICIPATED AT THIS TIME IN THE CITY OF BOULDER.

FLASH FLOODING WILL REMAIN OVER MAINLY RURAL AREAS OF SOUTH CENTRAL
BOULDER COUNTY.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...BEAR CANYON
CREEK AND FOURMILE CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS.  THE HEAVY RAINS COULD
ALSO TRIGGER ROCK SLIDES OR DEBRIS FLOWS IN STEEP TERRAIN.

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.

&&

LAT...LON 3998 10528 3994 10538 4002 10536 4004 10532

$$

BARJENBRUCH

706 
WGUS75 KBOU 310502
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1102 PM MDT TUE AUG 30 2016

COC013-310508-
/O.CAN.KBOU.FF.W.0008.000000T0000Z-160831T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
1102 PM MDT TUE AUG 30 2016

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL BOULDER COUNTY IS
CANCELLED...

THE HEAVY RAIN HAS ENDED AND FLOOD WATERS HAVE RECEDED. FLOODING IS
NO LONGER EXPECTED TO POSE A THREAT. BOULDER COUNTY EMERGENCY
MANAGEMENT REPORTED NO FLOODING PROBLEMS WITH ONLY SOME MINOR DEBRIS
ON FOURMILE ROAD. 

LAT...LON 3998 10528 3994 10538 4002 10536 4004 10532

$$

ENTREKIN

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 30, 7:14 PM MDT	Special Weather Statement	BOU	Douglas	46 min
Aug 30, 7:30 PM MDT	Areal Flood Advisory	BOU	Arapahoe, Denver, Douglas	2 hr
Aug 30, 7:54 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver, Jefferson	36 min
Aug 30, 8:06 PM MDT	Areal Flood Advisory	BOU	Adams, Jefferson	3 hr
Aug 30, 8:20 PM MDT	Flash Flood Warning	BOU	Adams	3 hr
Aug 30, 8:55 PM MDT	Areal Flood Advisory	BOU	Boulder, Gilpin, Jefferson	2 hr
Aug 30, 9:34 PM MDT	Areal Flood Advisory	BOU	Arapahoe	116 min

Nearby

Flash Flood Warnings in Colorado, 2016 Every flash flood warning in 2016

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.