Alert archive / Utah / Flash Flood Warnings in 2021
Flash Flood Warning 98, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this flash flood warning at Aug 17, 2021, 5:37 PM MDT for Garfield County, Kane County, Utah. It was in force for 6 hr. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 17, 2021, 5:37 PM MDT (23:37 UTC)
- Expired
- Aug 17, 2021, 11:30 PM MDT
- In force
- 6 hr
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
Counties Garfield County, UT, Kane County, UT
The radar
The Cedar City radar (KICX), 79 km from the middle of the area, began a volume at 23:41 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 17, 11:00 PM MDT | FLASH FLOOD | 14 Wnw Big Water, UT | PARIA RIVER GAGE AT US 89 ROSE 3.3 FEET WITH AN INCREASE IN FLOW FROM 4 CFS TO 1790 CFS. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 11.6 hours before the alert went out and 236 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.
756
WGUS55 KSLC 172337
FFWSLC
UTC017-025-180530-
/O.NEW.KSLC.FF.W.0098.210817T2337Z-210818T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
537 PM MDT Tue Aug 17 2021
The National Weather Service in Salt Lake City has issued a
* Flash Flood Warning for...
Southwestern Garfield County in southern Utah...
Central Kane County in southern Utah...
* Until 1130 PM MDT.
* At 537 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the upper headwaters of the Paria River. Between
0.5 and 1.25 inches of rain have fallen. Flash flooding is ongoing
or expected to begin 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...
the Paria River drainage.
This includes the following highways...
US Route 89 between mile markers 20 and 23.
This includes the following streams and drainages...
Willis Creek, Squaw Creek, Hogeye Creek, Bull Valley Gorge, and
the Paria River through the Arizona border.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3754 11205 3755 11203 3743 11199 3734 11192
3717 11190 3700 11184 3700 11188 3712 11194
3721 11195 3730 11201 3743 11213 3745 11219
3750 11225 3753 11223
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SW2 follow-up statements
240
WGUS75 KSLC 180403
FFSSLC
Flash Flood Statement
National Weather Service Salt Lake City UT
1003 PM MDT Tue Aug 17 2021
UTC017-025-180530-
/O.CON.KSLC.FF.W.0098.000000T0000Z-210818T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
1003 PM MDT Tue Aug 17 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1130 PM MDT THIS
EVENING FOR SOUTHWESTERN GARFIELD AND CENTRAL KANE COUNTIES...
At 1003 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the upper headwaters of the Paria River. Between 2
and 4 inches of rain have fallen. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
the Paria River drainage.
This includes the following highways...
US Route 89 between mile markers 20 and 23.
This includes the following streams and drainages...
Willis Creek, Squaw Creek, Hogeye Creek, Bull Valley Gorge, and
the Paria River through the Arizona border.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3754 11205 3755 11203 3743 11199 3734 11192
3717 11190 3700 11184 3700 11188 3712 11194
3721 11195 3730 11201 3743 11213 3745 11219
3750 11225 3753 11223
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SW973
WGUS75 KSLC 180528
FFSSLC
Flash Flood Statement
National Weather Service Salt Lake City UT
1128 PM MDT Tue Aug 17 2021
UTC017-025-180538-
/O.EXP.KSLC.FF.W.0098.000000T0000Z-210818T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
1128 PM MDT Tue Aug 17 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 1130 PM MDT THIS EVENING FOR
SOUTHWESTERN GARFIELD AND CENTRAL KANE COUNTIES...
The heavy rain has ended over the Paria River drainage. Although
light to occasionally moderate rain will continue through late
tonight, the threat of additional flash flooding has decreased.
Runoff from earlier flash flooding will continue to diminish
overnight. Please continue to heed any remaining 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 3754 11205 3755 11203 3743 11199 3734 11192
3717 11190 3700 11184 3700 11188 3712 11194
3721 11195 3730 11201 3743 11213 3745 11219
3750 11225 3753 11223
$$
LCThe 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, 5:10 PM MDT | Flash Flood Warning | SLC | Kane | 4 hr |
| 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, 5:40 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.