Alert archive / Colorado / Flash Flood Warnings in 2012

Flash Flood Warning 10, NWS Denver/Boulder, CO

July 6, 2012Larimer County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 6, 2012, 1:06 PM MDT for Larimer 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 6, 2012, 1:06 PM MDT (19:06 UTC)
Expired
Jul 6, 2012, 3:40 PM MDT
In force
3 hr
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

County Larimer County, CO

The radar

The Cheyenne radar (KCYS), 77 km from the middle of the area, began a volume at 19:07 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, 7.1 hours before the alert went out and 219 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 2012-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2053 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
28 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.

058 
WGUS55 KBOU 061906
FFWBOU
COC069-062200-
/O.NEW.KBOU.FF.W.0010.120706T1906Z-120706T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
106 PM MDT FRI JUL 6 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL LARIMER COUNTY IN NORTH CENTRAL COLORADO

* UNTIL 400 PM MDT

* AT 104 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR RUSTIC...OR 26 MILES WEST
  OF FORT COLLINS. THIS STORM WAS NEARLY STATIONARY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RUSTIC.

DOPPLER RADAR ESTIMATES THAT 1.5 TO 2.5 INCHES OF RAIN HAS FALLEN 
FROM A SERIES OF STORMS MOVING OVER THE AREA SINCE 1130 AM MDT.

THE HIGH PARK BURN SCAR IS NOT INCLUDED IN THE WARNING AT THIS 
TIME...BUT RESIDENTS IN THE BURN AREA SHOULD REMAIN ALERT TO 
CHANGING WEATHER CONDITIONS.

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 CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO
TRIGGER ROCK SLIDES OR DEBRIS FLOWS IN STEEP TERRAIN.

&&

LAT...LON 4081 10557 4080 10542 4063 10555 4063 10562

$$
2 follow-up statements
747 
WGUS75 KBOU 061940
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
140 PM MDT FRI JUL 6 2012

COC069-062200-
/O.CON.KBOU.FF.W.0010.000000T0000Z-120706T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LARIMER CO-
140 PM MDT FRI JUL 6 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM MDT FOR
CENTRAL LARIMER COUNTY...

AT 135 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY
HEAVY RAIN HAD FALLEN FROM A SERIES OF THUNDERSTORMS IN THE VICINITY 
OF RUSTIC...OR ABOUT 27 MILES WEST OF FORT COLLINS.  THE STORMS WERE 
MOVING TO THE NORTH AT 10 MPH.  

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
RUSTIC.  RIVER BASINS AFFECTED BY THE HEAVY RAIN INCLUDE THE CACHE 
LA POUDRE RIVER AND MANHATTAN CREEK...BETWEEN RUSTIC TO JUST 
SOUTHEAST OF RED FEATHER LAKES.

DOPPLER RADAR ESTIMATES THAT 2 TO 3 INCHES OF RAIN HAS  FALLEN FROM 
THESE STORM SINCE 1130 AM MDT.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THESE STORMS 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.

IT IS IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS...RIVERS...
OR CREEKS...WHICH CAN BECOME KILLERS IN HEAVY RAINS. CAMPERS SHOULD
AVOID CAMPING ALONG STREAMS OR CREEKS DURING THREATENING RAINS.

&&

LAT...LON 4081 10557 4080 10542 4063 10555 4063 10562

$$
294 
WGUS75 KBOU 062140
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
340 PM MDT FRI JUL 6 2012

COC069-062150-
/O.CAN.KBOU.FF.W.0010.000000T0000Z-120706T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LARIMER CO-
340 PM MDT FRI JUL 6 2012

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

THE STORM THAT PROMPTED THE WARNING HAS EXITED THE AREA.

LAT...LON 4081 10557 4080 10542 4063 10555 4063 10562

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 12:45 PM MDTAreal Flood AdvisoryBOULarimer90 min
Jul 6, 1:55 PM MDTAreal Flood AdvisoryBOUJefferson, Park80 min
Jul 6, 2:12 PM MDTAreal Flood AdvisoryBOULarimer93 min
Jul 6, 3:23 PM MDTAreal Flood AdvisoryBOUDouglas82 min
Jul 6, 3:36 PM MDTFlash Flood WarningBOUDouglas2 hr
Jul 6, 4:22 PM MDTAreal Flood AdvisoryBOULarimer83 min
Jul 6, 4:36 PM MDTAreal Flood AdvisoryBOUBoulder63 min
Jul 6, 4:52 PM MDTAreal Flood AdvisoryBOUDouglas83 min
Jul 6, 5:38 PM MDTFlash Flood WarningBOULarimer103 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.