Alert archive / Utah / Flash Flood Warnings in 2021
Flash Flood Warning 118, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this flash flood warning at Aug 18, 2021, 9:53 PM MDT for Iron County, Utah. 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
- Aug 18, 2021, 9:53 PM MDT (03:53 UTC)
- Expired
- Aug 19, 2021, 1:00 AM MDT
- In force
- 3 hr
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Iron County, UT
The radar
The Cedar City radar (KICX), 22 km from the middle of the area, began a volume at 03:54 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
Las Vegas, NV (KVEF), launched 00:00Z, 3.9 hours before the alert went out and 271 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
- 3543 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 11 m²/s²
- 0-3 km storm-relative helicity
- 14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
637
WGUS55 KSLC 190353
FFWSLC
UTC021-190700-
/O.NEW.KSLC.FF.W.0118.210819T0353Z-210819T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
953 PM MDT Wed Aug 18 2021
The National Weather Service in Salt Lake City has issued a
* Flash Flood Warning for...
South Central Iron County in southern Utah...
* Until 100 AM MDT.
* At 953 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.25 and 0.5 inches of
rain have fallen. Additional rainfall amounts of 0.75 to 1.5
inches are possible in the warned area. 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...
Cedar City, Enoch and Summit.
Emergency management reported flooding developing along most
drainages coming into the area from the east. This is expected to
result in life threatening flash flooding.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3781 11301 3783 11297 3782 11293 3774 11292
3763 11298 3761 11313 3773 11311
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
MPS2 follow-up statements
129
WGUS75 KSLC 190527
FFSSLC
Flash Flood Statement
National Weather Service Salt Lake City UT
1127 PM MDT Wed Aug 18 2021
UTC021-190700-
/O.CON.KSLC.FF.W.0118.000000T0000Z-210819T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-
1127 PM MDT Wed Aug 18 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 AM MDT THURSDAY FOR
SOUTH CENTRAL IRON COUNTY...
At 1127 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1 inch of rain
has fallen. Additional rainfall amounts of 0.25 to 0.5 inches are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Cedar City, Enoch and Summit.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3781 11301 3783 11297 3782 11293 3774 11292
3763 11298 3761 11313 3773 11311
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
MPS826
WGUS75 KSLC 190659
FFSSLC
Flash Flood Statement
National Weather Service Salt Lake City UT
1259 AM MDT Thu Aug 19 2021
UTC021-190709-
/O.EXP.KSLC.FF.W.0118.000000T0000Z-210819T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-
1259 AM MDT Thu Aug 19 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 1 AM MDT EARLY THIS MORNING
FOR SOUTH CENTRAL IRON COUNTY...
Heavy rain has decreased over south-central Iron County. Flooding is
no longer expected to pose an immediate threat. Runoff from earlier
heavy rain will continue to gradually diminish, although light to
occasionally moderate rain will continue through late tonight.
Please continue to heed any remaining road closures.
A Flash Flood Watch remains in effect until 600 AM MDT.
LAT...LON 3781 11301 3783 11297 3782 11293 3774 11292
3763 11298 3761 11313 3773 11311
$$
LCThe office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 7:43 PM MDT | Flash Flood Warning | SLC | Kane | 4 hr |
| Aug 18, 8:01 PM MDT | Flash Flood Warning | SLC | Garfield | 3 hr |
| Aug 18, 8:46 PM MDT | Special Weather Statement | SLC | Iron | 44 min |
| Aug 18, 9:39 PM MDT | Flash Flood Warning | SLC | Iron, Washington | 3 hr |
| Aug 18, 9:48 PM MDT | Areal Flood Advisory | SLC | Iron | 5 min |
| Aug 18, 10:07 PM MDT | Flash Flood Warning | SLC | Iron | 3 hr |
| Aug 18, 11:11 PM MDT | Flash Flood Warning | SLC | Kane, Washington | 5 hr |
| Aug 19, 1:43 AM MDT | Flash Flood Warning | SLC | Garfield, Wayne | 3 hr |
| Aug 19, 2:03 AM MDT | Flash Flood Warning | SLC | Garfield, Kane, San Juan | 6 hr |
| Aug 19, 2:31 AM MDT | Flash Flood Warning | SLC | Kane | 3 hr |
| Aug 19, 3:50 AM MDT | Special Weather Statement | SLC | 25 min | |
| Aug 19, 9:39 AM MDT | Special Weather Statement | SLC | Kane | 36 min |
| Aug 19, 10:16 AM MDT | River Flood Warning | SLC | Duchesne | 4 hr |
| Aug 19, 10:54 AM MDT | Special Weather Statement | SLC | Juab | 51 min |
| Aug 19, 11:15 AM MDT | Areal Flood Advisory | SLC | Millard | 2 hr |
| Aug 19, 11:42 AM MDT | Special Weather Statement | SLC | Sanpete | 48 min |
| Aug 19, 12:29 PM MDT | Special Weather Statement | SLC | Sanpete | 46 min |
| Aug 19, 12:49 PM MDT | Flash Flood Warning | SLC | Garfield, Wayne | 3 hr |
| Aug 19, 1:04 PM MDT | Special Weather Statement | SLC | Utah | 56 min |
| Aug 19, 1:25 PM MDT | Special Weather Statement | SLC | Carbon | 50 min |
| Aug 19, 2:12 PM MDT | Special Weather Statement | SLC | Carbon, Duchesne | 63 min |
| Aug 19, 2:59 PM MDT | Special Weather Statement | SLC | Duchesne | 61 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.