Alert archive / Colorado / Flash Flood Warnings in 2018

Flash Flood Warning 49, NWS Pueblo, CO

September 6, 2018Custer County, Fremont County, Colorado

NWS Pueblo, CO issued this flash flood warning at Sep 6, 2018, 4:12 PM MDT for Custer County, Fremont 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: Sep 6, 2018, 4:12 PM MDT (22:12 UTC)
Expired: Sep 6, 2018, 7:15 PM MDT
In force: 3 hr
Issued by: NWS Pueblo, CO
Area: Storm-based polygon
Flood severity: None

Counties Custer County, CO, Fremont County, CO

What was reported inside it

Time	Report	Where	Remark
Sep 6, 5:41 PM MDT	FLASH FLOOD	3 S Coaldale, CO	MAJOR FLASH FLOODING REPORTED AT BUTTER CREEK.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 10.2 hours before the alert went out and 254 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1824 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 206 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

545 
WGUS55 KPUB 062212
FFWPUB
COC027-043-070115-
/O.NEW.KPUB.FF.W.0049.180906T2212Z-180907T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pueblo CO
412 PM MDT THU SEP 6 2018

The National Weather Service in Pueblo has issued a

* Flash Flood Warning for...
  Southwestern Fremont County in central Colorado...
  Northwestern Custer County in southeastern Colorado...

* Until 715 PM MDT.

* At 411 PM MDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to 
  begin for the Hayden Pass Burn scar area. The drainages affected 
  will be Cottonwood Creek, Butter Creek, and Little Cottonwood 
  Creek.

* Flash flooding will remain over mainly rural areas of southwestern
  Fremont and northwestern Custer Counties.
  Excessive rainfall over the burn scar will result in debris flow 
  moving through the Cottonwood Creek, Butter Creek, and Little 
  Cottonwood Creek. The debris flow can consist of rock, mud, 
  vegetation and other loose materials.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. Life-threatening flooding of
creeks, roads and normally dry arroyos is likely. The heavy rains
will likely trigger rockslides, mudslides and debris flows in steep
terrain, especially in and around these areas.

&&

LAT...LON 3835 10567 3824 10568 3825 10579 3827 10581
      3827 10582 3829 10584 3829 10585 3830 10586
      3836 10579

$$

KTS

4 follow-up statements

857 
WGUS75 KPUB 062243
FFSPUB

Flash Flood Statement
National Weather Service Pueblo CO
443 PM MDT THU SEP 6 2018

COC027-043-070115-
/O.CON.KPUB.FF.W.0049.000000T0000Z-180907T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fremont CO-Custer CO-
443 PM MDT THU SEP 6 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM MDT FOR
SOUTHWESTERN FREMONT AND NORTHWESTERN CUSTER COUNTIES...

At 438 PM MDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to one inch of rain has already 
fallen over portions of the Hayden Pass burn scar. Flash flooding is 
expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Cottonwood Creek, Butter Creek, Little Cottonwood 
Creek, Mosher Creek, Oak Creek, and Sullivan Creek river basins. The 
debris flow can consist of rock, mud, vegetation and other loose 
materials.

Flash flooding will remain over mainly rural areas of southwestern
Fremont and northwestern Custer Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. Life-threatening flooding of
creeks, roads and normally dry arroyos is likely. The heavy rains
will likely trigger rockslides, mudslides and debris flows in steep
terrain, especially in and around these areas.

&&

LAT...LON 3835 10567 3824 10568 3825 10579 3827 10581
      3827 10582 3829 10584 3829 10585 3830 10586
      3836 10579

$$

BL

734 
WGUS75 KPUB 062332
FFSPUB

Flash Flood Statement
National Weather Service Pueblo CO
532 PM MDT THU SEP 6 2018

COC027-043-070115-
/O.CON.KPUB.FF.W.0049.000000T0000Z-180907T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fremont CO-Custer CO-
532 PM MDT THU SEP 6 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM MDT FOR
SOUTHWESTERN FREMONT AND NORTHWESTERN CUSTER COUNTIES...

At 528 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Up to one and a half to two inches of 
rain has already fallen across eastern portions of the Hayden Pass 
burn scar. Flash flooding is expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Cottonwood Creek, Butter Creek, Little Cottonwood 
Creek, Mosher Creek, Oak Creek, and Sullivan Creek river basins. The 
debris flow can consist of rock, mud, vegetation and other loose 
materials.

Flash flooding will remain over mainly rural areas of southwestern 
Fremont and northwestern Custer Counties over and near the Hayden 
Pass burn scar.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. Life-threatening flooding of
creeks, roads and normally dry arroyos is likely. The heavy rains
will likely trigger rockslides, mudslides and debris flows in steep
terrain, especially in and around these areas.

&&

LAT...LON 3835 10567 3824 10568 3825 10579 3827 10581
      3827 10582 3829 10584 3829 10585 3830 10586
      3836 10579

$$

BL

870 
WGUS75 KPUB 062353
FFSPUB

Flash Flood Statement
National Weather Service Pueblo CO
553 PM MDT THU SEP 6 2018

COC027-043-070115-
/O.CON.KPUB.FF.W.0049.000000T0000Z-180907T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fremont CO-Custer CO-
553 PM MDT THU SEP 6 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM MDT FOR
SOUTHWESTERN FREMONT AND NORTHWESTERN CUSTER COUNTIES...

At 546 PM MDT, Doppler radar indicated heavy rain has ended across 
the warned area but the flash flood risk persists. Up to two inches 
of rain has fallen over eastern portions of the Hayden Pass burn 
scar. Major flash flooding has been reported in Butter Creek, and 
elevated flows in Cottonwood Creek and Little Cottonwood Creek.

Excessive rainfall over the burn scar will, and in some cases 
already has, result in debris flow moving through the Cottonwood 
Creek, Butter Creek, Little Cottonwood Creek, Mosher Creek, Oak 
Creek, and Sullivan Creek river basins. The debris flow can consist 
of rock, mud, vegetation and other loose materials.

Flash flooding will remain over mainly rural areas of southwestern 
Fremont and northwestern Custer Counties in and near the Hayden Pass 
burn scar.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. Life-threatening flooding of
creeks, roads and normally dry arroyos is likely. The heavy rains
will likely trigger rockslides, mudslides and debris flows in steep
terrain, especially in and around these areas.

&&

LAT...LON 3835 10567 3824 10568 3825 10579 3827 10581
      3827 10582 3829 10584 3829 10585 3830 10586
      3836 10579

$$

BL

999 
WGUS75 KPUB 070110
FFSPUB

Flash Flood Statement
National Weather Service Pueblo CO
710 PM MDT THU SEP 6 2018

COC027-043-070116-
/O.EXP.KPUB.FF.W.0049.000000T0000Z-180907T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fremont CO-Custer CO-
710 PM MDT THU SEP 6 2018

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN FREMONT AND NORTHWESTERN
CUSTER COUNTIES WILL EXPIRE AT 715 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 3835 10567 3824 10568 3825 10579 3827 10581
      3827 10582 3829 10584 3829 10585 3830 10586
      3836 10579

$$

BL

The office that day

Everything else NWS Pueblo, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 6, 2:51 PM MDT	Special Weather Statement	PUB	Teller	39 min
Sep 6, 4:08 PM MDT	Areal Flood Advisory	PUB	Custer, Fremont	112 min

Nearby

Flash Flood Warnings in Colorado, 2018 Every flash flood warning in 2018

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.