Alert archive / Colorado / Flash Flood Warnings in 2021
Flash Flood Warning 69, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this flash flood warning at Aug 13, 2021, 2:27 PM MDT for Grand 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 13, 2021, 2:27 PM MDT (20:27 UTC)
- Expired
- Aug 13, 2021, 4:44 PM MDT
- In force
- 2 hr
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Flood severity
- None
County Grand County, CO
The radar
The Denver radar (KFTG), 118 km from the middle of the area, began a volume at 20:31 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, 8.5 hours before the alert went out and 221 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
- 18 J/kg
- Mixed-layer CIN
- -415 J/kg
- Mixed-layer LCL
- 1285 m above ground
- 0-6 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- -31 m²/s²
- 0-3 km storm-relative helicity
- 13 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
247
WGUS55 KBOU 132027
FFWBOU
COC049-132330-
/O.NEW.KBOU.FF.W.0069.210813T2027Z-210813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Denver CO
227 PM MDT Fri Aug 13 2021
The National Weather Service in Denver has issued a
* Flash Flood Warning for...
Northeastern Grand County in north central Colorado...
* Until 530 PM MDT.
* At 227 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area, just northeast of Grand Lake.
Between 0.3 and 0.7 inches of rain have fallen. Additional
rainfall amounts of 0.1 to 0.2 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...
the eastern portions of the East Troublesome Burn Area, and Grand
Lake.
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 East Troublesome burn area. Some areas affected
include the North Inlet in the town of Grand Lake, and Tonahutu
Creek. Rock slides or debris flows can also be expected across rural
roads.
The heavy rains could also trigger rock slides or debris flows in
steep terrain.
&&
LAT...LON 4030 10577 4030 10575 4027 10574 4025 10576
4025 10580 4024 10580 4026 10582 4029 10580
FLASH FLOOD...RADAR INDICATED
$$
Barjenbruch3 follow-up statements
423
WGUS75 KBOU 132102
FFSBOU
Flash Flood Statement
National Weather Service Denver CO
302 PM MDT Fri Aug 13 2021
COC049-132330-
/O.CON.KBOU.FF.W.0069.000000T0000Z-210813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand CO-
302 PM MDT Fri Aug 13 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MDT THIS
AFTERNOON FOR NORTHEASTERN GRAND COUNTY...
At 302 PM MDT, Doppler radar indicated thunderstorms with heavy rain
had moved out of the flash flood warning area. producing heavy rain
across the warned area. Between 0.3 and 0.8 inches of rain have
fallen on the far east side of the East Troublesome Burn area, in
the upper reaches of North Inlet.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, gulches,
roads, and poor drainage and low-lying areas.
Some locations that will experience flash flooding include...
the North Inlet, down into the northeast side of Grand Lake.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to higher ground now. Act quickly to protect your life.
Heavy Rainfall will cause flash flooding of small creeks, streams,
and ditches in the East Troublesome burn area. Some areas affected
include the North Inlet into the town of Grand Lake, and Tonahutu
Creek. Rock slides or debris flows can also be expected across rural
roads and trails.
The heavy rains could also trigger rock slides or debris flows in
steep terrain.
&&
LAT...LON 4030 10577 4030 10575 4027 10574 4025 10576
4025 10580 4024 10580 4026 10582 4029 10580
FLASH FLOOD...RADAR INDICATED
$$
Barjenbruch893
WGUS75 KBOU 132113
FFSBOU
Flash Flood Statement
National Weather Service Denver CO
313 PM MDT Fri Aug 13 2021
COC049-132330-
/O.CON.KBOU.FF.W.0069.000000T0000Z-210813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand CO-
313 PM MDT Fri Aug 13 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MDT THIS
AFTERNOON FOR THE FAR EASTERN PORTIONS OF THE EAST TROUBLESOME FIRE
NEAR GRAND LAKE IN GRAND COUNTY...
At 313 PM MDT, Doppler radar indicated thunderstorms producing heavy
rain near the warned area. Between 0.3 and 0.8 inches of rain have
fallen. Additional rainfall is possible across the 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...
the North Inlet, down into the northeast side of Grand Lake.
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 East Troublesome burn area. Some areas affected
include the North Inlet into the town of Grand Lake, and Tonahutu
Creek. Rock slides or debris flows can also be expected across rural
roads and trails.
The heavy rains could also trigger rock slides or debris flows in
steep terrain.
&&
LAT...LON 4030 10577 4030 10575 4027 10574 4025 10576
4025 10580 4024 10580 4026 10582 4029 10580
FLASH FLOOD...RADAR INDICATED
$$
Barjenbruch660
WGUS75 KBOU 132244
FFSBOU
Flash Flood Statement
National Weather Service Denver CO
444 PM MDT Fri Aug 13 2021
COC049-132254-
/O.CAN.KBOU.FF.W.0069.000000T0000Z-210813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand CO-
444 PM MDT Fri Aug 13 2021
...FLASH FLOOD WARNING IS CANCELLED FOR THE EAST TROUBLESOME BURN
AREA IN NORTHEASTERN GRAND COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose an
immediate threat. Mainly light showers will still be possible
through the evening.
LAT...LON 4030 10577 4030 10575 4027 10574 4025 10576
4025 10580 4024 10580 4026 10582 4029 10580
$$
BarjenbruchThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 6:10 PM MDT | Special Weather Statement | BOU | Elbert | 50 min |
| Aug 12, 7:01 PM MDT | Special Weather Statement | BOU | Elbert | 29 min |
| Aug 12, 7:49 PM MDT | Severe Thunderstorm Warning | BOU | Elbert | 26 min |
| Aug 12, 10:51 PM MDT | Areal Flood Advisory | BOU | Washington | 84 min |
| Aug 12, 11:09 PM MDT | Special Weather Statement | BOU | Douglas | 36 min |
| Aug 12, 11:21 PM MDT | Areal Flood Advisory | BOU | Douglas | 20 min |
| Aug 12, 11:41 PM MDT | Flash Flood Warning | BOU | Douglas | 94 min |
| Aug 13, 12:38 AM MDT | Areal Flood Advisory | BOU | Douglas, Jefferson | 82 min |
| Aug 13, 1:20 PM MDT | Areal Flood Advisory | BOU | Grand | 85 min |
| Aug 13, 1:42 PM MDT | Areal Flood Advisory | BOU | Grand | 2 hr |
| Aug 13, 3:36 PM MDT | Areal Flood Advisory | BOU | Grand | 69 min |
| Aug 13, 3:53 PM MDT | Areal Flood Advisory | BOU | Larimer | 2 hr |
| Aug 13, 5:39 PM MDT | Flash Flood Warning | BOU | Grand | 2 hr |
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.