Alert archive / Colorado / Flash Flood Warnings in 2021
Flash Flood Warning 71, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this flash flood warning at Aug 14, 2021, 6:48 PM MDT for Larimer County, Colorado. It was in force for 115 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
- Aug 14, 2021, 6:48 PM MDT (00:48 UTC)
- Expired
- Aug 14, 2021, 8:43 PM MDT
- In force
- 115 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Flood severity
- None
County Larimer County, CO
The radar
The Cheyenne radar (KCYS), 98 km from the middle of the area, began a volume at 00:47 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, 0.8 hours before the alert went out and 227 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
- 666 J/kg
- Mixed-layer CIN
- -45 J/kg
- Mixed-layer LCL
- 3335 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -22 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
The text
As transmitted.
520
WGUS55 KBOU 150048
FFWBOU
COC069-150400-
/O.NEW.KBOU.FF.W.0071.210815T0048Z-210815T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Denver CO
648 PM MDT Sat Aug 14 2021
The National Weather Service in Denver has issued a
* Flash Flood Warning for...
Central Larimer County in north central Colorado...
* Until 1000 PM MDT.
* At 648 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Flash flooding is ongoing or
expected to begin shortly. Rainfall rates up to 0.50 inch in 20
minutes can be expected.
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...
Pingree Park, Rustic, Kinikinik, Pennock Pass and Chambers Lake.
This includes the following additional locations...
Box Prairie, Upper Buckhorn along County Road 44H, Crystal Mountain,
Poudre Springs, 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, Remote areas in the Cameron Peak Wilderness
and Hague Creek.
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 4057 10592 4063 10593 4073 10581 4080 10567
4075 10553 4068 10550 4059 10536 4047 10542
4046 10565 4055 10583 4053 10591 4057 10591
FLASH FLOOD...RADAR INDICATED
$$
RJK2 follow-up statements
972
WGUS75 KBOU 150122
FFSBOU
Flash Flood Statement
National Weather Service Denver CO
722 PM MDT Sat Aug 14 2021
COC069-150400-
/O.CON.KBOU.FF.W.0071.000000T0000Z-210815T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Larimer CO-
722 PM MDT Sat Aug 14 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 10 PM MDT THIS
EVENING FOR CENTRAL LARIMER COUNTY...
At 722 PM MDT, Doppler radar indicated showers and thunderstorms
producing moderate heavy rain across the warned area. Flash flooding
is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, gulches,
roads, and poor drainage and low-lying areas.
Some locations that will experience flash flooding include...
Pingree Park, Rustic, Kinikinik, Pennock Pass and Chambers Lake.
This includes the following additional locations...
Box Prairie, Upper Buckhorn along County Road 44H, Crystal Mountain,
Poudre Springs, Monument Gulch, Jacks Gulch, Upper Pingree Park
Road, Lower Pingree Park Road, Sky Ranch, Gulches along Highway 14
near and above Rustic, Rising water and large debris in the Poudre
River, Pingree Hill, Goodell Corner, Bellaire Lake, Crown Point
Road, The Upper Poudre Canyon, The Laramie River Road near Chambers
Lake, Long Draw Road, Remote areas in the Cameron Peak Wilderness
and Hague Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to higher ground now. Act quickly to protect your life.
Heavy Rainfall will cause flash flooding of small creeks, streams,
and ditches in the affected part of the Cameron Peak burn area. Rock
slides or debris flows can also be expected across rural roads.
&&
LAT...LON 4057 10592 4063 10593 4073 10581 4080 10567
4075 10553 4068 10550 4059 10536 4047 10542
4046 10565 4055 10583 4053 10591 4057 10591
FLASH FLOOD...RADAR INDICATED
$$
RJK649
WGUS75 KBOU 150243
FFSBOU
Flash Flood Statement
National Weather Service Denver CO
843 PM MDT Sat Aug 14 2021
COC069-150253-
/O.CAN.KBOU.FF.W.0071.000000T0000Z-210815T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Larimer CO-
843 PM MDT Sat Aug 14 2021
...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL LARIMER COUNTY...
There may be a few light rain showers over the Cameron Peak burn
area the of rest of this evening but the heavy rainfall is over.
Flooding is no longer expected to pose a threat. Please continue to
heed remaining road closures.
LAT...LON 4057 10592 4063 10593 4073 10581 4080 10567
4075 10553 4068 10550 4059 10536 4047 10542
4046 10565 4055 10583 4053 10591 4057 10591
$$
RJKThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 14, 7:15 PM MDT | Special Weather Statement | BOU | Summit | 30 min |
| Aug 14, 7:38 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 52 min |
| Aug 14, 8:01 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 44 min |
| Aug 14, 8:28 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 47 min |
| Aug 14, 8:29 PM MDT | Severe Thunderstorm Warning | BOU | Sedgwick | 46 min |
| Aug 14, 8:43 PM MDT | Severe Thunderstorm Warning | BOU | Logan, Washington | 47 min |
| Aug 14, 9:15 PM MDT | Severe Thunderstorm Warning | BOU | Phillips, Sedgwick | 14 min |
| Aug 14, 9:28 PM MDT | Severe Thunderstorm Warning | BOU | Logan, Washington | 47 min |
| Aug 14, 9:31 PM MDT | Special Weather Statement | BOU | Weld | 44 min |
| Aug 15, 2:32 PM MDT | Areal Flood Advisory | BOU | Grand | 88 min |
| Aug 15, 5:19 PM MDT | Special Weather Statement | BOU | Lincoln | 41 min |
| Aug 15, 5:25 PM MDT | Special Weather Statement | BOU | Teller | 65 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.