Alert archive / Colorado / Flash Flood Warnings in 2021

Flash Flood Warning 31, NWS Goodland, KS

July 16, 2021Cheyenne County, Colorado

NWS Goodland, KS issued this flash flood warning at Jul 16, 2021, 5:39 PM MDT for Cheyenne County, Colorado. It was in force for 58 min. 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 16, 2021, 5:39 PM MDT (23:39 UTC)
Expired
Jul 16, 2021, 6:37 PM MDT
In force
58 min
Issued by
NWS Goodland, KS
Area
Storm-based polygon
Flood severity
None

County Cheyenne County, CO

The radar

The Pueblo radar (KPUX), 107 km from the middle of the area, began a volume at 23:43 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, 11.7 hours before the alert went out and 102 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 2021-07-16Temperature 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 2021-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.19395878Sfc1 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
2659 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

358 
WGUS53 KGLD 162339
FFWGLD
COC017-170145-
/O.NEW.KGLD.FF.W.0031.210716T2339Z-210717T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Goodland KS
539 PM MDT Fri Jul 16 2021

The National Weather Service in Goodland has issued a

* Flash Flood Warning for...
  Northwestern Cheyenne County in east central Colorado...

* Until 745 PM MDT.

* At 539 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  mainly rural areas of Northwestern Cheyenne County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3902 10316 3903 10297 3887 10295 3886 10316
      3888 10316 3889 10316 3893 10316 3894 10316
      3897 10316 3898 10316 3900 10316 3901 10316

FLASH FLOOD...RADAR INDICATED

$$

JN
2 follow-up statements
522 
WGUS73 KGLD 170000
FFSGLD

Flash Flood Statement
National Weather Service Goodland KS
600 PM MDT Fri Jul 16 2021

COC017-170145-
/O.CON.KGLD.FF.W.0031.000000T0000Z-210717T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cheyenne CO-
600 PM MDT Fri Jul 16 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM MDT THIS 
EVENING FOR NORTHWESTERN CHEYENNE COUNTY...

At 600 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Flash flooding is ongoing or expected 
to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  mainly rural areas of Northwestern Cheyenne County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3902 10316 3903 10297 3887 10295 3886 10316
      3888 10316 3889 10316 3893 10316 3894 10316
      3897 10316 3898 10316 3900 10316 3901 10316

FLASH FLOOD...RADAR INDICATED

$$

JN
487 
WGUS73 KGLD 170037
FFSGLD

Flash Flood Statement
National Weather Service Goodland KS
637 PM MDT Fri Jul 16 2021

COC017-170047-
/O.CAN.KGLD.FF.W.0031.000000T0000Z-210717T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cheyenne CO-
637 PM MDT Fri Jul 16 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN CHEYENNE 
COUNTY...

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

LAT...LON 3902 10316 3903 10297 3887 10295 3886 10316
      3888 10316 3889 10316 3893 10316 3894 10316
      3897 10316 3898 10316 3900 10316 3901 10316

$$

JN

The office that day

Everything else NWS Goodland, KS issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 15, 10:20 PM MDTDense Fog AdvisoryGLDKit Carson, Yuma11 hr
Jul 16, 4:15 PM MDTSpecial Weather StatementGLDKit Carson30 min
Jul 16, 4:44 PM MDTSpecial Weather StatementGLDYuma46 min
Jul 16, 5:02 PM MDTSpecial Weather StatementGLDCheyenne28 min
Jul 16, 5:29 PM MDTFlash Flood WarningGLDKit Carson87 min
Jul 16, 5:34 PM MDTSevere Thunderstorm WarningGLDKit Carson56 min
Jul 16, 5:37 PM MDTSpecial Weather StatementGLDCheyenne23 min
Jul 16, 5:42 PM MDTSevere Thunderstorm WarningGLDCheyenne14 min

Nearby

Flash Flood Warnings in Colorado, 2021Every flash flood warning in 2021

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.