Alert archive / Colorado / Flash Flood Warnings in 2021
Flash Flood Warning 72, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this flash flood warning at Aug 16, 2021, 3:53 PM MDT for Jackson County, Larimer County, Colorado. It was in force for 112 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 16, 2021, 3:53 PM MDT (21:53 UTC)
- Expired
- Aug 16, 2021, 5:45 PM MDT
- In force
- 112 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Flood severity
- None
Counties Jackson County, CO, Larimer County, CO
The radar
The Cheyenne radar (KCYS), 111 km from the middle of the area, began a volume at 21:55 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, 9.9 hours before the alert went out and 240 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
- 1 J/kg
- Mixed-layer CIN
- -425 J/kg
- Mixed-layer LCL
- 2615 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 28 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
315
WGUS55 KBOU 162153
FFWBOU
COC057-069-162345-
/O.NEW.KBOU.FF.W.0072.210816T2153Z-210816T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Denver CO
353 PM MDT Mon Aug 16 2021
The National Weather Service in Denver has issued a
* Flash Flood Warning for...
Eastern Jackson County in north central Colorado...
Western Larimer County in north central Colorado...
* Until 545 PM MDT.
* At 353 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Up to 0.5 inches of rain have
fallen. Additional rainfall amounts up to 0.5 inches are possible
in 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...
mainly rural areas of Eastern Jackson and Western Larimer Counties
This includes the following streams and drainages...
Two and One Half Creek, Joe Wright Creek, North Fork Joe Wright
Creek, Laramie River and North Fork West Branch Laramie River.
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 10591 4059 10591 4064 10590 4064 10586
4054 10586 4053 10591
FLASH FLOOD...RADAR INDICATED
$$
RPK1 follow-up statement
613
WGUS75 KBOU 162342
FFSBOU
Flash Flood Statement
National Weather Service Denver CO
542 PM MDT Mon Aug 16 2021
COC057-069-162352-
/O.EXP.KBOU.FF.W.0072.000000T0000Z-210816T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jackson CO-Larimer CO-
542 PM MDT Mon Aug 16 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 545 PM MDT THIS AFTERNOON FOR
EASTERN JACKSON AND WESTERN LARIMER COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4057 10591 4059 10591 4064 10590 4064 10586
4054 10586 4053 10591
$$
RPKThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 15, 6:16 PM MDT | Special Weather Statement | BOU | Lincoln | 59 min |
| Aug 16, 4:06 PM MDT | Areal Flood Advisory | BOU | Grand | 18 min |
| Aug 16, 4:24 PM MDT | Flash Flood Warning | BOU | Grand | 111 min |
| Aug 16, 4:32 PM MDT | Flash Flood Warning | BOU | Larimer | 118 min |
| Aug 16, 5:02 PM MDT | Areal Flood Advisory | BOU | Grand | 88 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.