Alert archive / Colorado / Flash Flood Warnings in 2013

Flash Flood Warning 21, NWS Denver/Boulder, CO

August 22, 2013Douglas County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 22, 2013, 4:12 PM MDT for Douglas 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 22, 2013, 4:12 PM MDT (22:12 UTC)
Expired
Aug 22, 2013, 6:45 PM MDT
In force
3 hr
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

County Douglas County, CO

The radar

The Denver radar (KFTG), 58 km from the middle of the area, began a volume at 22:15 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 12:00Z, 10.2 hours before the alert went out and 152 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 2013-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 994 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 12:00Z on 2013-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
994 J/kg
Mixed-layer CIN
-200 J/kg
Mixed-layer LCL
831 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
-4 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.

167 
WGUS55 KBOU 222212
FFWBOU
COC035-230045-
/O.NEW.KBOU.FF.W.0021.130822T2212Z-130823T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
412 PM MDT THU AUG 22 2013

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN DOUGLAS COUNTY IN NORTHEAST COLORADO...

* UNTIL 645 PM MDT

* AT 408 PM MDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING 
  HEAVY RAIN ACROSS THE WARNED AREA. TWO TO 3 INCHES OF RAIN HAS 
  FALLEN IN THIS AREA. IF IT HAS NOT DEVELOPED YET...FLASH FLOODING 
  IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CASTLE ROCK...LARKSPUR AND THE PINERY. 

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 1.5 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

PLUM CREEK IN CENTRAL DOUGLAS COUNTY WILL BE MOST PRONE TO FLASH 
FLOODING. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE. DO NOT 
DRIVE THROUGH HIGH WATER. TURN AROUND AND DON'T DROWN.  

&&

LAT...LON 3923 10494 3934 10494 3945 10488 3945 10478
      3931 10474 3923 10478

$$
BAKER
2 follow-up statements
138 
WGUS75 KBOU 222325
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
525 PM MDT THU AUG 22 2013

COC035-230045-
/O.CON.KBOU.FF.W.0021.000000T0000Z-130823T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DOUGLAS CO-
525 PM MDT THU AUG 22 2013

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MDT FOR
EASTERN DOUGLAS COUNTY...

AT 517 PM MDT...LOCAL LAW ENFORCEMENT REPORTED FLOOD WATERS COVERING 
MANY ROADS IN CENTRAL DOUGLAS COUNTY. EARLIER THIS AFTERNOON 
INTERSTATE 25 NEAR THE TOMAH EXIT SOUTH OF CASTLE ROCK CLOSED DUE TO 
FLOOD WATERS.  
 
HEAVY RAINFALL HAS GENERALLY ENDED IN THE AREA COVERED BY THIS 
WARNING AND THUNDERSTORMS PRODUCING THE TORRENTIAL RAINFALL EARLIER 
THIS AFTERNOON HAVE MOVED OUT OF THE AREA. 

DOPPLER RADAR ESTIMATES THAT 2 TO 3 INCHES OF RAIN FELL ON PORTIONS 
OF CENTRAL DOUGLAS COUNTY CENTERED ALONG PLUM CREEK BETWEEN 345 PM 
AND 5 PM MDT THIS AFTERNOON. 

SOME LOCATIONS THAT MAY STILL BE EXPERIENCING FLOODING INCLUDE... 
CASTLE ROCK AND SURROUNDING AREAS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES.  ADDITIONALLY...
COUNTRY ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND
OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 3923 10494 3934 10494 3945 10488 3945 10478
      3931 10474 3923 10478

$$
BAKER
113 
WGUS75 KBOU 230045
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
645 PM MDT THU AUG 22 2013

COC035-230045-
/O.CON.KBOU.FF.W.0021.000000T0000Z-130823T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DOUGLAS CO-
645 PM MDT THU AUG 22 2013

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MDT FOR
EASTERN DOUGLAS COUNTY...

AT 632 PM MDT...DOPPLER RADAR WAS NO LONGER INDICATING HEAVY RAIN IN 
THE AREA COVERED BY THIS WARNING. FURTHERMORE THERE HAS BEEN NO 
RECENT REPORTS OF FLASH FLOODING IN THE WARNING AREA DUE TO 
TORRENTIAL RAINFALL EARLIER THIS AFTERNOON. THEREFORE THIS WARNING 
WILL BE ALLOWED TO EXPIRE AT 645 PM MDT.  
 
EARLIER THIS AFTERNOON LOCAL LAW ENFORCEMENT REPORTED A NUMBER OF 
CAR FLOATING IN FLOOD WATERS NEAR THE INTERSECTION OF CHATFIELD 
AVENUE AND SHAFFER PARKWAY IN SOUTH CENTRAL JEFFERSON COUNTY. PUBLIC 
ALSO REPORTED VEHICLES FLOATING IN HIGH WATER AND DEEP HAIL NEAR KEN 
CARYL RANCH IN SOUTHEAST JEFFERSON COUNTY.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU 
CAN DO SO SAFELY.

&&

LAT...LON 3923 10494 3934 10494 3945 10488 3945 10478
      3931 10474 3923 10478

$$

BAKER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 6:14 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick31 min
Aug 21, 6:40 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick50 min
Aug 21, 7:26 PM MDTSpecial Weather StatementBOUAdams64 min
Aug 22, 2:44 PM MDTSpecial Weather StatementBOUDouglas46 min
Aug 22, 3:09 PM MDTSpecial Weather StatementBOUDouglas36 min
Aug 22, 3:29 PM MDTSpecial Weather StatementBOUDouglas46 min
Aug 22, 3:56 PM MDTAreal Flood AdvisoryBOUDouglas, Elbert2 hr
Aug 22, 4:06 PM MDTSevere Thunderstorm WarningBOUDouglas54 min
Aug 22, 4:34 PM MDTSevere Thunderstorm WarningBOUDouglas41 min
Aug 22, 5:05 PM MDTSevere Thunderstorm WarningBOUDouglas25 min
Aug 22, 5:45 PM MDTAreal Flood AdvisoryBOUArapahoe, Denver, Douglas, Jefferson3 hr
Aug 22, 5:45 PM MDTAreal Flood AdvisoryBOUJefferson3 hr
Aug 22, 5:45 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver, Jefferson30 min

Nearby

Flash Flood Warnings in Colorado, 2013Every flash flood warning in 2013

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.