Alert archive / Colorado / Flash Flood Warnings in 2011
Flash Flood Warning 7, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this flash flood warning at Jul 7, 2011, 6:18 PM MDT for Boulder County, Colorado. It was in force for 3 hr. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 7, 2011, 6:18 PM MDT (00:18 UTC)
- Expired
- Jul 7, 2011, 9:15 PM 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 00:18 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 7, 7:00 PM MDT | FLASH FLOOD | 2 Sse Gold Hill, CO | LARGE DEBRIS FLOWS ON FOURMILE CANYON DRIVE, WEST OF WALLSTREET. BIGGEST FLOW WAS WEST OF EMERSON GULCH,100 YARDS WIDE AND FOUR FEET DEEP. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Denver, CO (KDNR), launched 00:00Z, 0.3 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.
- Mixed-layer CAPE
- 259 J/kg
- Mixed-layer CIN
- -60 J/kg
- Mixed-layer LCL
- 1195 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 58 m²/s²
- 0-3 km storm-relative helicity
- 88 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
224 WGUS55 KBOU 080018 FFWBOU COC013-080315- /O.NEW.KBOU.FF.W.0007.110708T0018Z-110708T0315Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE DENVER CO 618 PM MDT THU JUL 7 2011 THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A * FLASH FLOOD WARNING FOR... CENTRAL BOULDER COUNTY IN NORTHEAST COLORADO * UNTIL 915 PM MDT * AT 618 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN FROM A THUNDERSTORM OVER SUNSHINE...OR 32 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...4 MILE BURN SCAR. 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. THIS IS A LIFE THREATENING SITUATION. HEAVY RAINFALL WILL CAUSE EXTENSIVE AND SEVERE FLASH FLOODING OF CREEKS...STREAMS...AND DITCHES IN THE FOURMILE BURN AREA. SOME DRAINAGE BASINS IMPACTED INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE CANYON CREEK. SEVERE DEBRIS FLOWS CAN ALSO BE ANTICIPATED ACROSS ROADS. ROADS AND DRIVEWAYS MAY BE WASHED AWAY IN PLACES. IF YOU ENCOUNTER FLOOD WATERS...CLIMB TO SAFETY. && LAT...LON 4003 10541 4007 10540 4009 10529 4003 10530 $$
3 follow-up statements
743 WGUS75 KBOU 080052 FFSBOU FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE DENVER CO 652 PM MDT THU JUL 7 2011 COC013-080315- /O.CON.KBOU.FF.W.0007.000000T0000Z-110708T0315Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BOULDER CO- 652 PM MDT THU JUL 7 2011 ...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT FOR CENTRAL BOULDER COUNTY... AT 648 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN FROM A THUNDERSTORM NEAR SUMMERVILLE...OR ABOUT 32 MILES NORTHWEST OF DENVER. THIS STORM WAS MOVING EAST AT 15 MPH. LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WALLSTREET...SUNSHINE...SUMMERVILLE...SALINA...CRISMAN AND NORTHWESTERN BOULDER. AFTER A BRIEF RESPITE OF RAINFALL OVER THE EASTERN SECTIONS OF THE FOUR MILE BURN AREA...ANOTHER ROUND OF THUNDERSTORMS WILL BE MOVING OVER THE FOUR MILE BURN SCAR THROUGH 8 PM. RAINFALL RATES COULD BE UP TO A HALF INCH IN 15 MINUTES. SPOTTERS WITHIN THE BURN AREA REPORTED RAINFALL ABOUT HALF INCH OF RAIN IN 20 MINUTES...HOWEVER NO FLOODING WAS REPORTED. WITH ADDITIONAL RAINFALL ON THE WAY THE THREAT OF FLASH FLOODING IS STILL VERY HIGH. PRECAUTIONARY/PREPAREDNESS ACTIONS... THIS IS A LIFE THREATENING SITUATION. HEAVY RAINFALL WILL CAUSE EXTENSIVE AND SEVERE FLASH FLOODING OF CREEKS...STREAMS...AND DITCHES IN THE FOURMILE BURN AREA. SOME DRAINAGE BASINS IMPACTED INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE CANYON CREEK. SEVERE DEBRIS FLOWS CAN ALSO BE ANTICIPATED ACROSS ROADS. ROADS AND DRIVEWAYS MAY BE WASHED AWAY IN PLACES. IF YOU ENCOUNTER FLOOD WATERS...CLIMB TO SAFETY. && LAT...LON 4003 10541 4007 10540 4009 10529 4003 10530 $$
873 WGUS75 KBOU 080132 FFSBOU FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE DENVER CO 732 PM MDT THU JUL 7 2011 COC013-080315- /O.CON.KBOU.FF.W.0007.000000T0000Z-110708T0315Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BOULDER CO- 732 PM MDT THU JUL 7 2011 ...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT FOR CENTRAL BOULDER COUNTY... THE HEAVIEST RAIN HAS ENDED OVER THE FOUR MILE BURN AREA WITH ONLY LIGHT TO MODERATE RAINFALL REMAINING OVER THE BURN. ADDITIONAL RAINFALL WILL BE UP TO A QUARTER INCH IN ONE HOUR WITH ADDITIONAL LIGHTER RAIN SHOWERS EXPECTED THROUGH MIDNIGHT. LOCAL LAW ENFORCEMENT OFFICIALS REPORTED 2 FEET OF DEBRIS AT 4 MILE AND EMERSON ROAD. A MUD SLIDE WAS ALSO REPORTED AT THE 8000 MILE MARKER ON FOUR MILE ROAD...WHICH WAS 100 YARDS WIDE AND FOUR FEET DEEP WITH DEBRIS. LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WALLSTREET...SUNSHINE...SUMMERVILLE...SALINA AND CRISMAN. 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. && LAT...LON 4003 10541 4007 10540 4009 10529 4003 10530 $$
035 WGUS75 KBOU 080317 FFSBOU FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE DENVER CO 917 PM MDT THU JUL 7 2011 COC013-080323- /O.EXP.KBOU.FF.W.0007.000000T0000Z-110708T0315Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BOULDER CO- 917 PM MDT THU JUL 7 2011 ...THE FLASH FLOOD WARNING WILL EXPIRE AT 915 PM MDT FOR CENTRAL BOULDER COUNTY... BOULDER COUNTY EMERGENCY MANAGEMENT REPORTED NO ADDITONAL FLASH FLOODING OVER THE 4 MILE BURN SCAR...BUT ARE STILL WORKING ON DEBRIS FLOWS ON FOUR MILE ROAD. FLOOD WATERS HAVE SUBSIDED AND FLASH FLOODING IS NO LONGER EXPECTED. THERE ARE STILL SOME SCATTERED SHOWERS AND THUNDERSTORMS THAT MAY MOVE INTO PORTIONS OF THE FOUR MILE BURN THROUGH MIDNIGHT...BUT ADDITIONAL RAINFALL RATES ARE EXPECTED TO BE UP TO A THIRD OF AN INCH OR LESS THAN AN HOUR. LAT...LON 4003 10541 4007 10540 4009 10529 4003 10530 $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 7, 6:07 PM MDT | Areal Flood Advisory | BOU | Boulder, Gilpin, Jefferson | 83 min |
| Jul 7, 6:27 PM MDT | Flash Flood Warning | BOU | Boulder, Gilpin, Jefferson | 3 hr |
| Jul 7, 6:35 PM MDT | Areal Flood Advisory | BOU | Larimer | 85 min |
| Jul 7, 7:28 PM MDT | Areal Flood Advisory | BOU | Boulder | 2 hr |
| Jul 7, 7:38 PM MDT | Areal Flood Advisory | BOU | Adams, Arapahoe, Denver | 2 hr |
| Jul 7, 8:02 PM MDT | Flash Flood Warning | BOU | Clear Creek, Gilpin | 97 min |
| Jul 7, 10:05 PM MDT | Areal Flood Advisory | BOU | Adams, Arapahoe, Denver | 4 hr |
| Jul 7, 10:27 PM MDT | River Flood Advisory | BOU | Adams | 14 hr |
| Jul 8, 1:21 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Broomfield, Denver, Jefferson | 39 min |
| Jul 8, 1:46 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver | 44 min |
| Jul 8, 2:07 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe, Denver | 34 min |
| Jul 8, 4:11 PM MDT | Severe Thunderstorm Warning | BOU | Elbert, Lincoln | 49 min |
| Jul 8, 4:39 PM MDT | Severe Thunderstorm Warning | BOU | Larimer, Weld | 24 min |
| Jul 8, 4:57 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 16 min |
| Jul 8, 5:11 PM MDT | Severe Thunderstorm Warning | BOU | Elbert | 21 min |
| Jul 8, 5:20 PM MDT | Areal Flood Advisory | BOU | Summit | 4 days |
Nearby
Flash Flood Warnings in Colorado, 2011Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.