Alert archive / Colorado / Flash Flood Warnings in 2012

Flash Flood Warning 21, NWS Denver/Boulder, CO

July 16, 2012Boulder County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 16, 2012, 4:34 PM MDT for Boulder County, Colorado. It was in force for 49 min. 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 16, 2012, 4:34 PM MDT (22:34 UTC)
Expired
Jul 16, 2012, 5:23 PM MDT
In force
49 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

County Boulder County, CO

The radar

The Denver radar (KFTG), 78 km from the middle of the area, began a volume at 22:37 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 12:00Z, 10.6 hours before the alert went out and 185 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 2012-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 2012-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
1 J/kg
Mixed-layer CIN
-362 J/kg
Mixed-layer LCL
2158 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
50 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.

940 
WGUS55 KBOU 162234
FFWBOU
COC013-170030-
/O.NEW.KBOU.FF.W.0021.120716T2234Z-120717T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
434 PM MDT MON JUL 16 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...THE FOUR MILE BURN AREA OF CENTRAL
  BOULDER COUNTY IN NORTHEAST COLORADO

* UNTIL 630 PM MDT

* AT 431 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 6 MILES SOUTHEAST OF CRISMAN...
  OR 25 MILES NORTHWEST OF DENVER. THIS STORM WAS MOVING NORTHWEST AT
  15 MPH.  SOME RAINFALL GAUGES IN THE BOULDER AREA HAVE REPORTED UP 
  TO 0.50 INCHES IN 15 MINUTES.  THESE THUNDERSTORMS WAS MOVING INTO 
  THE FOUR MILE BURN AREA. 

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

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.

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.

&&

LAT...LON 4006 10544 4009 10535 4004 10531 4000 10540

$$



RJK
1 follow-up statement
452 
WGUS75 KBOU 162323
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
523 PM MDT MON JUL 16 2012

COC013-162327-
/O.CAN.KBOU.FF.W.0021.000000T0000Z-120717T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
523 PM MDT MON JUL 16 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR THE FOUR MILE BURN 
AREA IN CENTRAL BOULDER COUNTY...

THE STORM THAT PROMPTED THE WARNING HAS WEAKENED.

THE STORM THAT PROMPTED THE WARNING FELL APART QUICKLY AS IS 
APPROACHED THE FOUR MILE BURN AREA.  RAINFALL GAUGES IN THE FOUR 
MILE BURN AREA RECORDED 0.20 TO 0.50 INCHES OF RAINFALL IN AROUND 30 
MINUTES TIME.  THE BOULDER COUNTY EMERGENCY MANAGEMENT REPORTED NO 
FLOODING ISSUES IN THE FOUR MILE BURN AREA WITH THIS STORM.  

LAT...LON 4006 10544 4009 10535 4004 10531 4000 10540

$$



RJK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 1:43 PM MDTFlash Flood WarningBOULarimer3 hr
Jul 16, 2:31 PM MDTFlash Flood WarningBOUJefferson, Park51 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.