Alert archive / Colorado / Flash Flood Warnings in 2011

Flash Flood Warning 11, NWS Denver/Boulder, CO

July 8, 2011Washington County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Jul 8, 2011, 10:33 PM MDT for Washington County, Colorado. It was in force for 4 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 8, 2011, 10:33 PM MDT (04:33 UTC)
Expired
Jul 9, 2011, 2:30 AM MDT
In force
4 hr
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

County Washington County, CO

The radar

The Goodland radar (KGLD), 106 km from the middle of the area, began a volume at 04:35 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, 4.6 hours before the alert went out and 39 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 00:00Z on 2011-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 112 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2011-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -124 square meters per square second.193958Sfc1 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
112 J/kg
Mixed-layer CIN
-123 J/kg
Mixed-layer LCL
2514 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-124 m²/s²
0-3 km storm-relative helicity
12 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

824 
WGUS55 KBOU 090433
FFWBOU
COC121-090830-
/O.NEW.KBOU.FF.W.0011.110709T0433Z-110709T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
1033 PM MDT FRI JUL 8 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN WASHINGTON COUNTY IN NORTHEAST COLORADO

* UNTIL 230 AM MDT

* AT 1032 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 5 MILES SOUTHWEST OF COPE...OR
  40 MILES SOUTH OF AKRON. THIS STORM WAS MOVING NORTHEAST AT 15 MPH.

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

DOPPLER RADAR ESTIMATES THAT AROUND 4 INCHES OF RAIN HAS FALLEN OVER 
EXTREME SOUTHEASTERN WASHINGTON COUNTY NEAR COPE THE PAST 90 MINUTES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND
ARROYOS...AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY AS THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY. DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A
FEW INCHES OF RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR
VEHICLE. TURN AROUND...DO NOT DROWN.


&&

LAT...LON 3971 10280 3957 10281 3957 10300 3968 10297

$$
3 follow-up statements
324 
WGUS75 KBOU 090512
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1112 PM MDT FRI JUL 8 2011

COC121-090830-
/O.CON.KBOU.FF.W.0011.000000T0000Z-110709T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON CO-
1112 PM MDT FRI JUL 8 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM MDT FOR
SOUTHEASTERN WASHINGTON COUNTY...

AT 1108 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
HEAVY RAIN FROM A THUNDERSTORM NEAR COPE...OR ABOUT 38 MILES 
SOUTHEAST OF AKRON. THIS STORM WAS MOVING NORTHEAST AT 15 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
COPE.

DOPPLER RADAR ESTIMATES THAT OVER 6 INCHES OF RAIN MAY HAVE FALLEN 
OVER EXTREME SOUTHEASTERN WASHINGTON COUNTY SINCE 9 PM NEAR COPE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING ALONG THE 
ARIKAREE RIVER...HIGHWAY 36...SMALL CREEKS AND STREAMS...COUNTRY 
ROADS...NORMALLY DRY WASHES AND ARROYOS...AS WELL AS FARMLAND ALONG 
THE BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY AS THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY. DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A
FEW INCHES OF RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR
VEHICLE. TURN AROUND...DO NOT DROWN.

&&

LAT...LON 3971 10280 3957 10281 3957 10300 3968 10297

$$
031 
WGUS75 KBOU 090643
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
1243 AM MDT SAT JUL 9 2011

COC121-090830-
/O.CON.KBOU.FF.W.0011.000000T0000Z-110709T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON CO-
1243 AM MDT SAT JUL 9 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM MDT FOR
SOUTHEASTERN WASHINGTON COUNTY...

AT 1240 AM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
SCATTERED THUNDERSTORMS MOVING EASTWARDS TOWARDS COPE.  THESE 
THUNDERSTORMS COULD PRODUCE ADDITIONAL HEAVY RAIN OVER SOUTHEAST 
WASHINGTON COUNTY THROUGH 2 AM.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
COPE.

DOPPLER RADAR ESTIMATES THAT OVER 6 INCHES OF RAIN MAY HAVE FALLEN 
EARLIER TONIGHT OVER SOUTHEAST WASHINGTON COUNTY NEAR COPE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM PREVIOUS HEAVY RAINS WILL CAUSE FLASH FLOODING 
ALONG THE ARIKAREE RIVER...HIGHWAY 36...SMALL CREEKS AND 
STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND ARROYOS...AS WELL 
AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY AS THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY. DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A
FEW INCHES OF RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR
VEHICLE. TURN AROUND...DO NOT DROWN.

&&

LAT...LON 3971 10280 3957 10281 3957 10300 3968 10297

$$
192 
WGUS75 KBOU 090838
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
238 AM MDT SAT JUL 9 2011

COC121-090848-
/O.EXP.KBOU.FF.W.0011.000000T0000Z-110709T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON CO-
238 AM MDT SAT JUL 9 2011

...THE FLASH FLOOD WARNING HAS EXPIRED FOR SOUTHEASTERN WASHINGTON 
COUNTY...HOWEVER A FLOOD ADVISORY HAS BEEN ISSUED UNTIL 530 AM MDT.


LAT...LON 3971 10280 3957 10281 3957 10300 3968 10297

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 6:04 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick56 min
Jul 8, 6:10 PM MDTSevere Thunderstorm WarningBOULincoln31 min
Jul 8, 6:42 PM MDTAreal Flood AdvisoryBOUPhillips, Sedgwick93 min
Jul 8, 7:04 PM MDTSevere Thunderstorm WarningBOUAdams, Broomfield, Denver, Jefferson45 min
Jul 8, 7:18 PM MDTAreal Flood AdvisoryBOUAdams, Boulder, Broomfield, Jefferson, Weld3 hr
Jul 8, 8:11 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick34 min
Jul 8, 9:03 PM MDTAreal Flood AdvisoryBOUPhillips, Sedgwick61 min
Jul 8, 10:02 PM MDTFlash Flood WarningBOUPhillips, Sedgwick6 hr
Jul 8, 11:49 PM MDTRiver Flood AdvisoryBOUWeld5 hr
Jul 9, 12:02 AM MDTAreal Flood AdvisoryBOULarimer66 hr
Jul 9, 2:34 AM MDTAreal Flood AdvisoryBOUWashington3 hr
Jul 9, 4:12 PM MDTSpecial Weather StatementBOUBoulder63 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.