Alert archive / Utah / Flash Flood Warnings in 2021
Flash Flood Warning 97, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this flash flood warning at Aug 17, 2021, 5:10 PM MDT for Kane County, Utah. It was in force for 4 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 17, 2021, 5:10 PM MDT (23:10 UTC)
- Expired
- Aug 17, 2021, 9:00 PM MDT
- In force
- 4 hr
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Kane County, UT
The radar
The Cedar City radar (KICX), 112 km from the middle of the area, began a volume at 23:13 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
Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 11.2 hours before the alert went out and 217 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
- 984 J/kg
- Mixed-layer CIN
- -55 J/kg
- Mixed-layer LCL
- 829 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 135 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.8
The text
As transmitted.
280
WGUS55 KSLC 172310
FFWSLC
UTC025-180300-
/O.NEW.KSLC.FF.W.0097.210817T2310Z-210818T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
510 PM MDT Tue Aug 17 2021
The National Weather Service in Salt Lake City has issued a
* Flash Flood Warning for...
Central Kane County in southern Utah...
* Until 900 PM MDT.
* At 510 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across portions of Wahweep Creek and the headwaters of
Tommy Smith Creek. Between 1.25 and 2 inches of rain have fallen.
Flash flooding is ongoing or expected to begin shortly. Additional
heavy rainfall will continue southward along the Wahweep Creek
drainage.
HAZARD...Life threatening flash flooding. Thunderstorms
producing flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Big Water.
This includes the following highways...
US Route 89 between mile markers 4 and 7.
This includes the following streams and drainages...
Tommy Smith Creek and Wahweap Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3719 11185 3723 11188 3730 11189 3740 11182
3746 11172 3741 11168 3732 11171 3720 11168
3710 11164 3705 11159 3702 11148 3700 11146
3700 11150 3704 11163 3709 11168 3715 11181
3716 11184
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SW2 follow-up statements
734
WGUS75 KSLC 180142
FFSSLC
Flash Flood Statement
National Weather Service Salt Lake City UT
742 PM MDT Tue Aug 17 2021
UTC025-180300-
/O.CON.KSLC.FF.W.0097.000000T0000Z-210818T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
742 PM MDT Tue Aug 17 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING
FOR CENTRAL KANE COUNTY...
At 742 PM MDT, Doppler radar indicated thunderstorms producing heavy
rain across portions of Wahweep Creek and the headwaters of Tommy
Smith Creek. Between 1.5 and 2.5 inches of rain have fallen. Flash
flooding is ongoing or expected to begin shortly. Additional heavy
rainfall is anticipated to move into the northern portion of the
warned area shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Big Water.
This includes the following highways...
US Route 89 between mile markers 4 and 7.
This includes the following streams and drainages...
Tommy Smith Creek and Wahweap Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3719 11185 3723 11188 3730 11189 3740 11182
3746 11172 3741 11168 3732 11171 3720 11168
3710 11164 3705 11159 3702 11148 3700 11146
3700 11150 3704 11163 3709 11168 3715 11181
3716 11184
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SW068
WGUS75 KSLC 180258
FFSSLC
Flash Flood Statement
National Weather Service Salt Lake City UT
858 PM MDT Tue Aug 17 2021
UTC025-180308-
/O.EXP.KSLC.FF.W.0097.000000T0000Z-210818T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
858 PM MDT Tue Aug 17 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR
CENTRAL KANE COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Runoff from earlier heavy rainfall will continue to diminish
through the evening hours. Additional light flows will be possible
along Wahweep Creek as isolated showers continue upstream. Please
continue to heed any road closures.
A Flash Flood Watch remains in effect until 1200 AM MDT Thursday for
portions of central Utah, northern Utah and southern Utah.
LAT...LON 3719 11185 3723 11188 3730 11189 3740 11182
3746 11172 3741 11168 3732 11171 3720 11168
3710 11164 3705 11159 3702 11148 3700 11146
3700 11150 3704 11163 3709 11168 3715 11181
3716 11184
$$
SWThe office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 17, 1:31 PM MDT | Special Weather Statement | SLC | Kane | 44 min |
| Aug 17, 1:50 PM MDT | Severe Thunderstorm Warning | SLC | Garfield, Kane | 20 min |
| Aug 17, 2:23 PM MDT | Severe Thunderstorm Warning | SLC | Beaver, Garfield, Piute | 52 min |
| Aug 17, 2:50 PM MDT | Flash Flood Warning | SLC | Garfield | 3 hr |
| Aug 17, 3:14 PM MDT | Special Weather Statement | SLC | Juab | 31 min |
| Aug 17, 3:20 PM MDT | Special Weather Statement | SLC | Tooele | 25 min |
| Aug 17, 3:29 PM MDT | Severe Thunderstorm Warning | SLC | Sevier | 46 min |
| Aug 17, 3:51 PM MDT | Severe Thunderstorm Warning | SLC | Tooele | 24 min |
| Aug 17, 4:12 PM MDT | Severe Thunderstorm Warning | SLC | Tooele | 48 min |
| Aug 17, 4:18 PM MDT | Flash Flood Warning | SLC | Emery, Wayne | 3 hr |
| Aug 17, 4:29 PM MDT | Severe Thunderstorm Warning | SLC | Tooele | 46 min |
| Aug 17, 4:39 PM MDT | Severe Thunderstorm Warning | SLC | Millard | 66 min |
| Aug 17, 4:53 PM MDT | Flash Flood Warning | SLC | Garfield | 3 hr |
| Aug 17, 4:56 PM MDT | Severe Thunderstorm Warning | SLC | Garfield | 24 min |
| Aug 17, 5:00 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Salt Lake, Tooele | 30 min |
| Aug 17, 5:12 PM MDT | Severe Thunderstorm Warning | SLC | Tooele | 63 min |
| Aug 17, 5:30 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Salt Lake | 45 min |
| Aug 17, 5:37 PM MDT | Flash Flood Warning | SLC | Garfield, Kane | 6 hr |
| Aug 17, 5:40 PM MDT | Severe Thunderstorm Warning | SLC | Millard | 50 min |
| Aug 17, 5:48 PM MDT | Special Weather Statement | SLC | Sanpete | 27 min |
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.