Alert archive / Colorado / Flash Flood Warnings in 2021
Flash Flood Warning 1, NWS Grand Junction, CO
NWS Grand Junction, CO issued this flash flood warning at May 31, 2021, 11:45 AM MDT for La Plata County, Colorado. It was in force for 3 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
- May 31, 2021, 11:45 AM MDT (17:45 UTC)
- Expired
- May 31, 2021, 2:45 PM MDT
- In force
- 3 hr
- Issued by
- NWS Grand Junction, CO
- Area
- Storm-based polygon
- Flood severity
- None
County La Plata County, CO
The radar
The Grand Junction radar (KGJX), 183 km from the middle of the area, began a volume at 17:47 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
Grand Junction, CO (KGJT), launched 12:00Z, 5.8 hours before the alert went out and 197 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1713 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 20 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
675
WGUS55 KGJT 311745
FFWGJT
COC067-312045-
/O.NEW.KGJT.FF.W.0001.210531T1745Z-210531T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
1145 AM MDT Mon May 31 2021
The National Weather Service in Grand Junction has issued a
* Flash Flood Warning for...
The 416 Burn Area in...
North Central La Plata County in southwestern Colorado...
* Until 245 PM MDT.
* At 1145 AM MDT, Doppler radar indicated thunderstorms producing
heavy rain over the 416 Burn Area. Between 0.5 and 0.75 inches of
rain have fallen. The expected rainfall rate is 0.3 to 0.6 inches
in 1 hour. Flash flooding is ongoing or expected to begin shortly.
Excessive rainfall over the burn scar will result in debris flow
moving through the Hermosa Creek Drainage and Tripp Gulch. This
includes areas along Highway 550. The debris flow can consist of
rock, mud, vegetation and other loose materials.
HAZARD...Flash flooding caused by thunderstorms in and around
the 416 Burn Area.
SOURCE...Radar.
IMPACT...Flooding of areas in and around the 416 Burn Area.
* Some locations that will experience flash flooding include...
Hermosa and Trimble.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Heavy rainfall will cause extensive and severe flash flooding of
creeks...streams...and ditches in the 416 Burn Area. Severe debris
flows can also be anticipated across roads. Roads and driveways may
be washed away in places. If you encounter flood waters...climb to
safety.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.
&&
LAT...LON 3743 10779 3737 10788 3744 10796 3752 10781
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.3-0.6 INCHES IN 1 HOUR
$$
KJS2 follow-up statements
594
WGUS75 KGJT 311918
FFSGJT
Flash Flood Statement
National Weather Service Grand Junction CO
118 PM MDT Mon May 31 2021
COC067-312045-
/O.CON.KGJT.FF.W.0001.000000T0000Z-210531T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Plata CO-
118 PM MDT Mon May 31 2021
...FLASH FLOOD WARNING FOR THE 416 BURN AREA REMAINS IN EFFECT UNTIL
245 PM MDT THIS AFTERNOON FOR NORTH CENTRAL LA PLATA COUNTY...
At 118 PM MDT, Doppler radar indicated light rain continuing over
the 416 Burn Area. Between 0.5 and 1 inch of rain has fallen.
Additional heavy rainfall is not expected at this time. There have
been no reports of flash flooding but the threat still remains due
to previous rainfall.
Excessive rainfall over the burn scar will result in debris flow
moving through the Hermosa Creek Drainage and Tripp Gulch. This
includes areas along Highway 550. The debris flow can consist of
rock, mud, vegetation and other loose materials.
HAZARD...Flash flooding caused by thunderstorms in and around the
416 Burn Area.
SOURCE...Radar.
IMPACT...Flooding of areas in and around the 416 Burn Area.
Some locations that will experience flash flooding include...
Hermosa and Trimble.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Moderate to heavy rainfall will cause extensive and severe flash
flooding of creeks...streams...and ditches in the 416 Burn Area.
Severe debris flows can also be anticipated across roads. Roads and
driveways may be washed away in places. If you encounter flood
waters...climb to safety.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.
&&
LAT...LON 3743 10779 3737 10788 3744 10796 3752 10781
FLASH FLOOD...RADAR INDICATED
$$
MMS825 WGUS75 KGJT 312042 FFSGJT Flash Flood Statement National Weather Service Grand Junction CO 242 PM MDT Mon May 31 2021 COC067-312052- /O.EXP.KGJT.FF.W.0001.000000T0000Z-210531T2045Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ La Plata CO- 242 PM MDT Mon May 31 2021 ...FLASH FLOOD WARNING FOR THE 416 BURN AREA WILL EXPIRE AT 245 PM MDT THIS AFTERNOON FOR NORTH CENTRAL LA PLATA COUNTY... Some light showers will continue over the burn scar but heavy rain has ended. Flooding is no longer expected to pose a threat. LAT...LON 3743 10779 3737 10788 3744 10796 3752 10781 $$ TGR
The office that day
Everything else NWS Grand Junction, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 30, 7:16 PM MDT | Special Weather Statement | GJT | Garfield | 44 min |
| May 31, 12:07 PM MDT | Severe Thunderstorm Warning | GJT | La Plata | 23 min |
| May 31, 12:31 PM MDT | Special Weather Statement | GJT | La Plata | 29 min |
| May 31, 12:34 PM MDT | Severe Thunderstorm Warning | GJT | La Plata | 12 min |
| May 31, 1:00 PM MDT | Special Weather Statement | GJT | La Plata | 45 min |
| May 31, 1:14 PM MDT | Special Weather Statement | GJT | La Plata | 46 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.