Alert archive / Utah / Red Flag Warnings in 2021
Red Flag Warning 23, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this red flag warning at Aug 16, 2021, 11:45 AM MDT for 14 counties in Utah. It took effect at Aug 17, 2021, 12:00 PM MDT. It was in force for 9 hr. 19 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Aug 16, 2021, 11:45 AM MDT (17:45 UTC)
- In effect from
- Aug 17, 2021, 12:00 PM MDT
- Expired
- Aug 17, 2021, 9:00 PM MDT
- In force
- 9 hr
- Issued by
- NWS Salt Lake City, UT
Counties Box Elder County, UT, Cache County, UT, Davis County, UT, Juab County, UT, Millard County, UT, Morgan County, UT, Rich County, UT, Salt Lake County, UT, Sanpete County, UT, Summit County, UT, Tooele County, UT, Utah County, UT, Wasatch County, UT, Weber County, UT
The radar
The Salt Lake City radar (KMTX), 80 km from the middle of the area, began a volume at 17:48 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, 3:58 PM MDT | TSTM WND GST 62 | 6 Sse Clive, UT | TSTORM WIND GUST TO 62 MPH |
| Aug 17, 4:15 PM MDT | TSTM WND GST 58 | 16 Wnw Dugway, UT | UPPER CEDAR MTN MESONET SENSOR |
| Aug 17, 4:20 PM MDT | TSTM WND GST 63 | Delle, UT | MESONET SITE NEAR DELLE |
| Aug 17, 4:20 PM MDT | TSTM WND GST 64 | 1 W Delle, UT | I-80 AT WEST DELLE |
| Aug 17, 4:53 PM MDT | TSTM WND GST 64 | 5 Ne Black Rock, UT | TSTORM WIND GUST TO 64 MPH AT BLACK ROCK |
| Aug 17, 4:55 PM MDT | TSTM WND GST 62 | 25 W Dugway, UT | |
| Aug 17, 5:15 PM MDT | TSTM WND GST 61 | 16 Wnw Dugway, UT | |
| Aug 17, 5:15 PM MDT | TSTM WND GST 62 | 12 W Dugway, UT | |
| Aug 17, 5:19 PM MDT | TSTM WND GST 65 | Ne Lake Pt, UT | THUNDERSTORM WIND GUST MEASURED AT THE MARINA STATION. |
| Aug 17, 5:19 PM MDT | TSTM WND GST 65 | Ne Lake Pt, UT | THUNDERSTORM WIND GUST MEASURED AT THE MARINA STATION. |
| Aug 17, 5:23 PM MDT | TSTM WND GST 68 | 4 Nw Magna, UT | THUNDERSTORM WIND GUST OF 68 MPH MEASURED AT THE CENTER TAILINGS STATION. |
| Aug 17, 5:23 PM MDT | TSTM WND GST 68 | 4 Nw Magna, UT | THUNDERSTORM WIND GUST OF 68 MPH MEASURED AT THE CENTER TAILINGS STATION. |
| Aug 17, 5:45 PM MDT | TSTM WND GST 78 | 14 Sw Dugway, UT | |
| Aug 17, 5:55 PM MDT | TSTM WND DMG | Midvale, UT | PHOTO OF A LARGE TREE DOWN ON CAR AT APARTMENT COMPLEX PARKING LOT. TIME ESTIMATED FROM RADAR. |
| Aug 17, 6:00 PM MDT | TSTM WND DMG | Draper, UT | FOUR TREES FELL ON A HOME IN DRAPER. TIME ESTIMATED BY RADAR. |
| Aug 17, 6:57 PM MDT | TSTM WND GST 73 | 6 Ene Orem, UT | THUNDERSTORM WIND GUST RECORDED AT THE PROVO CANYON STATION. |
| Aug 17, 7:00 PM MDT | TSTM WND GST 69 | 3 Ne Sundance, UT | THUNDERSTORM WIND GUST OF 69 MPH RECORDED AT THE DEER CREEK DAM STATION. |
| Aug 17, 7:58 PM MDT | NON-TSTM WND GST 66 | 2 N Layton, UT | HILL AFB ASOS MEASURED A WIND GUST OF 66MPH. |
| Aug 17, 8:36 PM MDT | TSTM WND GST 69 | 16 Wnw Dugway, UT | UPPER CEDAR MOUNTAIN MESONET RECORDED A 69 MPH WIND GUST. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Salt Lake City I, UT (KSLC), launched 12:00Z, 5.8 hours before the alert went out and 19 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
- 3298 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 40 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
053 WWUS85 KSLC 161745 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 1145 AM MDT Mon Aug 16 2021 UTZ478-479-492-171200- /O.NEW.KSLC.FW.W.0023.210817T1800Z-210818T0300Z/ Salt Lake Desert-Wasatch Mountains-Central Utah West Desert- 1145 AM MDT Mon Aug 16 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT TUESDAY FOR LIGHTNING AFTER AN EXTENDED DRY PERIOD, MICROBURSTS, GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478, 479, AND 492... The National Weather Service in Salt Lake City has issued a Red Flag Warning for lightning after an extended dry period, microbursts, gusty wind and low relative humidity, which is in effect from noon to 9 PM MDT Tuesday. * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert, Fire Weather Zone 479 Wasatch Mountains and Fire Weather Zone 492 Central Utah West Desert. * THUNDERSTORMS...Isolated to widely scattered thunderstorms will develop Tuesday afternoon and shift eastward across the area through evening. * OUTFLOW WINDS...Any thunderstorms will bring the threat of strong and erratic outflow winds. * WINDS...South 10 to 20 mph with gusts up to 35 mph. * RELATIVE HUMIDITY...As low as 10 percent. * IMPACTS...Critical fire weather conditions are expected. Any new fire starts could spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of lightning...dry fuel conditions...gusty microburst winds...strong winds...low relative humidity...and warm temperatures will create favorable conditions for new fire starts and extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
2 follow-up statements
591 WWUS85 KSLC 170927 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 327 AM MDT Tue Aug 17 2021 UTZ478-479-492-172200- /O.CON.KSLC.FW.W.0023.210817T1800Z-210818T0300Z/ Salt Lake Desert-Wasatch Mountains-Central Utah West Desert- 327 AM MDT Tue Aug 17 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR LIGHTNING AFTER AN EXTENDED DRY PERIOD, MICROBURSTS, GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478, 479, AND 492... * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert, Fire Weather Zone 479 Wasatch Mountains and Fire Weather Zone 492 Central Utah West Desert. * THUNDERSTORMS...Isolated to widely scattered thunderstorms will develop this afternoon and shift eastward across the area through this evening. * OUTFLOW WINDS...Any thunderstorms will bring the threat of strong and erratic outflow winds. * WINDS...South 10 to 20 mph with gusts up to 35 mph. * RELATIVE HUMIDITY...As low as 10 percent. * IMPACTS...Critical fire weather conditions are expected. Any new fire starts could spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now, or are imminent. A combination of lightning, dry fuel conditions, gusty microburst winds, strong winds, low relative humidity, and warm temperatures will create favorable conditions for new fire starts and extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
819 WWUS85 KSLC 172032 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 232 PM MDT Tue Aug 17 2021 UTZ478-479-492-180300- /O.CON.KSLC.FW.W.0023.000000T0000Z-210818T0300Z/ Salt Lake Desert-Wasatch Mountains-Central Utah West Desert- 232 PM MDT Tue Aug 17 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR LIGHTNING AFTER AN EXTENDED DRY PERIOD, MICROBURSTS, GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478, 479, AND 492... * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert, Fire Weather Zone 479 Wasatch Mountains and Fire Weather Zone 492 Central Utah West Desert. * THUNDERSTORMS...Isolated to widely scattered thunderstorms will develop this afternoon and shift eastward across the area through this evening. * OUTFLOW WINDS...Any thunderstorms will bring the threat of strong and erratic outflow winds. * WINDS...South 10 to 20 mph with gusts up to 35 mph. * RELATIVE HUMIDITY...As low as 10 percent. * IMPACTS...Critical fire weather conditions are expected. Any new fire starts could spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now, or are imminent. A combination of lightning, dry fuel conditions, gusty microburst winds, strong winds, low relative humidity, and warm temperatures will create favorable conditions for new fire starts and extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
The office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 2:18 PM MDT | Flash Flood Watch | SLC | Beaver, Carbon, Duchesne, Emery, Garfield, Iron and 13 more | 64 hr |
Nearby
Red Flag Warnings in Utah, 2021Every red flag 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.