Alert archive / Colorado / Flash Flood Warnings in 2019

Flash Flood Warning 13, NWS Denver/Boulder, CO

August 20, 2019Adams County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at Aug 20, 2019, 7:10 PM MDT for Adams County, Colorado. It was in force for 2 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 20, 2019, 7:10 PM MDT (01:10 UTC)
Expired
Aug 20, 2019, 9:15 PM MDT
In force
2 hr
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Flood severity
None

County Adams County, CO

The radar

The Denver radar (KFTG), 24 km from the middle of the area, began a volume at 01:13 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, 1.2 hours before the alert went out and 92 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 2019-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 358 joules per kilogram.LCLEL10008507005003002001001 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 2019-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -51 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
358 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
3844 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-51 m²/s²
0-3 km storm-relative helicity
-24 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

As transmitted.

689 
WGUS55 KBOU 210110
FFWBOU
COC001-210315-
/O.NEW.KBOU.FF.W.0013.190821T0110Z-190821T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Denver CO
710 PM MDT Tue Aug 20 2019

The National Weather Service in Denver Colorado has issued a

* Flash Flood Warning for...
  Central Adams County in northeastern Colorado...

* Until 915 PM MDT.

* At 708 PM MDT, Doppler radar indicated thunderstorms producing 
  torrential rain across the warned area, centered about 12 miles 
  north of Strasburg.  Up to three inches of rain have already 
  fallen. Flash flooding is expected to begin shortly.

* Flash flooding will remain over mainly rural areas of central Adams
  County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3986 10435 3996 10433 3996 10425 3987 10425

$$

BARJENBRUCH
2 follow-up statements
565 
WGUS75 KBOU 210154
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
754 PM MDT Tue Aug 20 2019

COC001-210315-
/O.CON.KBOU.FF.W.0013.000000T0000Z-190821T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams CO-
754 PM MDT Tue Aug 20 2019

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT FOR
CENTRAL ADAMS COUNTY...

At 753 PM MDT, Doppler radar indicated that heavy rain had ended. 
Radar estimated between 2 and 3.5 inches of rain had fallen in a 
short period of time earlier this evening. Flash flooding is 
expected to be ongoing. 

Flash flooding will remain over mainly rural areas of central Adams
County.

This includes the following streams and drainages...
Comanche Creek, Wolf Creek, Kiowa Creek, Lost Creek and Mule Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3986 10435 3996 10433 3996 10425 3987 10425

$$

BARJENBRUCH
139 
WGUS75 KBOU 210316
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
916 PM MDT Tue Aug 20 2019

COC001-210323-
/O.EXP.KBOU.FF.W.0013.000000T0000Z-190821T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams CO-
916 PM MDT Tue Aug 20 2019

...THE FLASH FLOOD WARNING FOR CENTRAL ADAMS COUNTY WILL EXPIRE AT
915 PM MDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3986 10435 3996 10433 3996 10425 3987 10425

$$

RJK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 6:30 PM MDTSevere Thunderstorm WarningBOUAdams45 min
Aug 21, 12:04 AM MDTSpecial Weather StatementBOULogan, Phillips, Sedgwick, Weld41 min
Aug 21, 4:50 PM MDTAreal Flood AdvisoryBOUBoulder115 min

Nearby

Flash Flood Warnings in Colorado, 2019Every flash flood warning in 2019

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.