Alert archive / Colorado / Flash Flood Warnings in 2021
Flash Flood Warning 67, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this flash flood warning at Aug 6, 2021, 6:53 PM MDT for Larimer 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 6, 2021, 6:53 PM MDT (00:53 UTC)
- Expired
- Aug 6, 2021, 9:15 PM MDT
- In force
- 2 hr
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Flood severity
- None
County Larimer County, CO
The radar
The Cheyenne radar (KCYS), 100 km from the middle of the area, began a volume at 00:54 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, 0.9 hours before the alert went out and 230 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.
- Mixed-layer CAPE
- 4 J/kg
- Mixed-layer CIN
- -256 J/kg
- Mixed-layer LCL
- 3329 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- -32 m²/s²
- 0-3 km storm-relative helicity
- 94 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
531
WGUS55 KBOU 070053
FFWBOU
COC069-070315-
/O.NEW.KBOU.FF.W.0067.210807T0053Z-210807T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Denver CO
653 PM MDT Fri Aug 6 2021
The National Weather Service in Denver has issued a
* Flash Flood Warning for...
Central Larimer County in north central Colorado...
* Until 915 PM MDT.
* At 653 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, gulches,
roads, and poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Kinikinik, Rustic, Pingree Park, Chambers Lake, Red Feather Lakes
and Pennock Pass.
This includes the following additional locations...
Monument Gulch, Jacks Gulch, Upper Pingree Park Road, Lower Pingree
Park Road, Sky Ranch, Gulches along Highway 14 near and above
Rustic, Rising water and large debris in the Poudre River, Pingree
Hill, Goodell Corner, Bellaire Lake, Crown Point Road, The Upper
Poudre Canyon, The Laramie River Road near Chambers Lake, Long Draw
Road and Remote areas in the Cameron Peak Wilderness.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to higher ground now. Act quickly to protect your life.
Heavy Rainfall will cause flash flooding of small creeks, streams,
and ditches in the affected part of the Cameron Peak burn area. Rock
slides or debris flows can also be expected across rural roads.
&&
LAT...LON 4052 10588 4072 10596 4084 10553 4059 10543
4052 10587
FLASH FLOOD...RADAR INDICATED
$$1 follow-up statement
736
WGUS75 KBOU 070311
FFSBOU
Flash Flood Statement
National Weather Service Denver CO
911 PM MDT Fri Aug 6 2021
COC069-070321-
/O.EXP.KBOU.FF.W.0067.000000T0000Z-210807T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Larimer CO-
911 PM MDT Fri Aug 6 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 915 PM MDT THIS EVENING FOR
CENTRAL LARIMER COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4052 10588 4072 10596 4084 10553 4059 10543
4052 10587
$$
CooperThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 6, 6:15 PM MDT | Special Weather Statement | BOU | Logan | 45 min |
| Aug 6, 6:24 PM MDT | Special Weather Statement | BOU | Jackson | 36 min |
| Aug 6, 7:36 PM MDT | Special Weather Statement | BOU | Larimer | 24 min |
| Aug 6, 7:58 PM MDT | Areal Flood Advisory | BOU | Larimer | 2 hr |
| Aug 6, 10:06 PM MDT | Areal Flood Advisory | BOU | Larimer | 84 min |
| Aug 7, 1:08 PM MDT | Special Weather Statement | BOU | Lincoln | 52 min |
| Aug 7, 1:48 PM MDT | Severe Thunderstorm Warning | BOU | Elbert, Lincoln | 42 min |
| Aug 7, 2:29 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 33 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.