Alert archive / Utah / Flash Flood Warnings in 2021
Flash Flood Warning 28, NWS Grand Junction, CO
NWS Grand Junction, CO issued this flash flood warning at Jul 24, 2021, 3:42 PM MDT for San Juan County, Utah. 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
- Jul 24, 2021, 3:42 PM MDT (21:42 UTC)
- Expired
- Jul 24, 2021, 5:51 PM MDT
- In force
- 2 hr
- Issued by
- NWS Grand Junction, CO
- Area
- Storm-based polygon
- Flood severity
- None
County San Juan County, UT
The radar
The Grand Junction radar (KGJX), 98 km from the middle of the area, began a volume at 21:46 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, 9.7 hours before the alert went out and 87 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
- 19 J/kg
- Mixed-layer CIN
- -266 J/kg
- Mixed-layer LCL
- 1844 m above ground
- 0-6 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- 40 m²/s²
- 0-3 km storm-relative helicity
- 94 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
741
WGUS55 KGJT 242142
FFWGJT
UTC037-250045-
/O.NEW.KGJT.FF.W.0028.210724T2142Z-210725T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
342 PM MDT Sat Jul 24 2021
The National Weather Service in Grand Junction has issued a
* Flash Flood Warning for...
Northeastern San Juan County in southeastern Utah...
* Until 645 PM MDT.
* At 342 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1 inch of rain
has fallen. Additional rainfall amounts of 0.5 to 1 inch 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, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
mainly rural areas of Northeastern San Juan County
This includes the following streams and drainages...
West Paradox Creek and Roc Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 3847 10907 3850 10907 3850 10906 3849 10906
3846 10906
FLASH FLOOD...RADAR INDICATED
$$
JDC2 follow-up statements
138
WGUS75 KGJT 242243
FFSGJT
Flash Flood Statement
National Weather Service Grand Junction CO
443 PM MDT Sat Jul 24 2021
UTC037-250045-
/O.CON.KGJT.FF.W.0028.000000T0000Z-210725T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Juan UT-
443 PM MDT Sat Jul 24 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MDT THIS
EVENING FOR NORTHEASTERN SAN JUAN COUNTY...
At 443 PM MDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 0.5 and 1 inch of rain has
fallen. Additional rainfall amounts of 0.5 to 1 inch are possible in
the warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
mainly rural areas of Northeastern San Juan County
This includes the following streams and drainages...
West Paradox Creek and Roc Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 3847 10907 3850 10907 3850 10906 3849 10906
3846 10906
FLASH FLOOD...RADAR INDICATED
$$
JDC550
WGUS75 KGJT 242351
FFSGJT
Flash Flood Statement
National Weather Service Grand Junction CO
551 PM MDT Sat Jul 24 2021
UTC037-250001-
/O.CAN.KGJT.FF.W.0028.000000T0000Z-210725T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Juan UT-
551 PM MDT Sat Jul 24 2021
...FLASH FLOOD WARNING IS CANCELLED FOR NORTHEASTERN SAN JUAN
COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
A Flash Flood Watch remains in effect until 900 PM MDT for portions
of Colorado and southeast Utah.
LAT...LON 3847 10907 3850 10907 3850 10906 3849 10906
3846 10906
$$
JDCThe office that day
Everything else NWS Grand Junction, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 6:04 PM MDT | Areal Flood Advisory | GJT | Uintah | 116 min |
| Jul 23, 7:24 PM MDT | Areal Flood Advisory | GJT | Grand, San Juan | 3 hr |
| Jul 24, 3:51 AM MDT | Flash Flood Watch | GJT | Grand, San Juan | 17 hr |
| Jul 24, 1:26 PM MDT | Areal Flood Advisory | GJT | San Juan | 3 hr |
| Jul 24, 3:35 PM MDT | Flash Flood Warning | GJT | San Juan | 3 hr |
| Jul 24, 3:47 PM MDT | Flash Flood Warning | GJT | San Juan | 3 hr |
Nearby
Flash Flood Warnings in Utah, 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.