Alert archive / Utah / Red Flag Warnings in 2020
Red Flag Warning 36, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this red flag warning at Sep 16, 2020, 2:49 PM MDT for 26 counties in Utah. It took effect at Sep 17, 2020, 2:00 PM MDT. It was in force for 55 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Sep 16, 2020, 2:49 PM MDT (20:49 UTC)
- In effect from
- Sep 17, 2020, 2:00 PM MDT
- Expired
- Sep 19, 2020, 9:00 PM MDT
- In force
- 55 hr
- Issued by
- NWS Salt Lake City, UT
All 26 counties
Beaver County, UT, Box Elder County, UT, Cache County, UT, Carbon County, UT, Davis County, UT, Duchesne County, UT, Emery County, UT, Garfield County, UT, Iron County, UT, Juab County, UT, Kane County, UT, Millard County, UT, Morgan County, UT, Piute County, UT, Rich County, UT, Salt Lake County, UT, San Juan County, UT, Sanpete County, UT, Sevier County, UT, Summit County, UT, Tooele County, UT, Utah County, UT, Wasatch County, UT, Washington County, UT, Wayne County, UT, Weber County, UT
The radar
The Salt Lake City radar (KMTX), 193 km from the middle of the area, began a volume at 20:46 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
Salt Lake City I, UT (KSLC), launched 12:00Z, 8.8 hours before the alert went out and 132 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
- 3910 m above ground
- 0-6 km bulk shear
- 3 kt
- 0-1 km storm-relative helicity
- -6 m²/s²
- 0-3 km storm-relative helicity
- 6 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
976 WWUS85 KSLC 162049 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 249 PM MDT Wed Sep 16 2020 UTZ492-495-171300- /O.UPG.KSLC.FW.A.0022.200917T2000Z-200919T0300Z/ /O.NEW.KSLC.FW.W.0036.200917T2000Z-200919T0300Z/ Central Utah West Desert-Color Country West Desert- 249 PM MDT Wed Sep 16 2020 ...RED FLAG WARNING IN EFFECT FROM 2 PM THURSDAY TO 9 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 492 AND 495... The National Weather Service in Salt Lake City has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 2 PM Thursday to 9 PM MDT Friday. The Fire Weather Watch is no longer in effect. * AFFECTED AREA...Fire Weather Zone 492 Central Utah West Desert and Fire Weather Zone 495 Color Country West Desert. * WINDS...South winds 10 to 20 mph with occasional gusts to 30 mph Thursday afternoon. South winds increasing to 20 to 25 mph with gusts to 35 mph on Friday. * RELATIVE HUMIDITY...8 to 10 percent Thursday and between 10 to 15 percent on Friday. Poor overnight recovery Thursday night. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ478-479-484-488-493-496-497-171300- /O.UPG.KSLC.FW.A.0022.200918T1500Z-200919T0300Z/ /O.NEW.KSLC.FW.W.0036.200918T1500Z-200919T0300Z/ Salt Lake Desert-Wasatch Mountains-Tavaputs Plateau- Manti National Forest-Central Utah Mountains- Color Country Mountains-Mojave Desert- 249 PM MDT Wed Sep 16 2020 ...RED FLAG WARNING IN EFFECT FROM 9 AM TO 9 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478...479... 484...488...493...496 AND 497... The National Weather Service in Salt Lake City has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 9 AM to 9 PM MDT Friday. The Fire Weather Watch is no longer in effect. * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert...Fire Weather Zone 479 Wasatch Mountains...Fire Weather Zone 484 Tavaputs Plateau...Fire Weather Zone 488 Manti National Forest...Fire Weather Zone 493 Central Utah Mountains...Fire Weather Zone 496 Color Country Mountains and Fire Weather Zone 497 Mojave Desert. * WINDS...South winds 15 to 25 mph with gusts to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ483-171300- /O.NEW.KSLC.FW.W.0036.200918T1500Z-200919T0300Z/ Southern Ashley National Forest- 249 PM MDT Wed Sep 16 2020 ...RED FLAG WARNING IN EFFECT FROM 9 AM TO 9 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE 483... The National Weather Service in Salt Lake City has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 9 AM to 9 PM MDT Friday. * AFFECTED AREA...Fire Weather Zone 483 Southern Ashley National Forest. * WINDS...Southwest winds 10 to 20 mph with gusts in the 25 to 30 mph range. * RELATIVE HUMIDITY...10 to 15 percent. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ489-494-498-171300- /O.EXT.KSLC.FW.A.0022.200918T1500Z-200920T0300Z/ San Rafael Swell-Henry Mountains-Grand Staircase- 249 PM MDT Wed Sep 16 2020 ...FIRE WEATHER WATCH NOW IN EFFECT FROM FRIDAY MORNING THROUGH SATURDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489...494 AND 498... * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 494 Henry Mountains and Fire Weather Zone 498 Grand Staircase. * WINDS...On Friday, south winds 10 to 20 mph with gusts between 25 to 30 mph. On Saturday, southwest winds 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. * IMPACTS...Critical fire weather conditions are possible. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Fire Weather Watch means that there is a potential for critical fire weather conditions. Continue to monitor for the latest forecasts and for possible Red Flag Warnings. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
7 follow-up statements
230 WWUS85 KSLC 170925 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 325 AM MDT Thu Sep 17 2020 UTZ492-495-172200- /O.CON.KSLC.FW.W.0036.200917T2000Z-200919T0300Z/ Central Utah West Desert-Color Country West Desert- 325 AM MDT Thu Sep 17 2020 ...RED FLAG WARNING REMAINS IN EFFECT FROM 2 PM THIS AFTERNOON TO 9 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 492 AND 495... * AFFECTED AREA...Fire Weather Zone 492 Central Utah West Desert and Fire Weather Zone 495 Color Country West Desert. * WINDS...South winds 10 to 20 mph with occasional gusts to 30 mph Thursday afternoon. South winds increasing to 20 to 25 mph with gusts to 35 mph on Friday. * RELATIVE HUMIDITY...8 to 10 percent this afternoon and between 9 to 14 percent on Friday. Poor overnight recovery tonight. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ478-479-483-484-488-493-496-497-172200- /O.CON.KSLC.FW.W.0036.200918T1500Z-200919T0300Z/ Salt Lake Desert-Wasatch Mountains- Southern Ashley National Forest-Tavaputs Plateau- Manti National Forest-Central Utah Mountains- Color Country Mountains-Mojave Desert- 325 AM MDT Thu Sep 17 2020 ...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM TO 9 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478...479...483...484...488...493...496 AND 497... * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert...Fire Weather Zone 479 Wasatch Mountains...Fire Weather Zone 483 Southern Ashley National Forest...Fire Weather Zone 484 Tavaputs Plateau...Fire Weather Zone 488 Manti National Forest...Fire Weather Zone 493 Central Utah Mountains...Fire Weather Zone 496 Color Country Mountains and Fire Weather Zone 497 Mojave Desert. * WINDS...Southwest winds 10 to 20 mph with gusts in the 25 to 30 mph range. * RELATIVE HUMIDITY...9 to 15 percent. Poor overnight recovery tonight. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ489-494-498-172200- /O.CON.KSLC.FW.A.0022.200918T1500Z-200920T0300Z/ San Rafael Swell-Henry Mountains-Grand Staircase- 325 AM MDT Thu Sep 17 2020 ...FIRE WEATHER WATCH REMAINS IN EFFECT FROM FRIDAY MORNING THROUGH SATURDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489...494 AND 498... * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 494 Henry Mountains and Fire Weather Zone 498 Grand Staircase. * WINDS...On Friday, south winds 10 to 20 mph with gusts between 25 to 30 mph. On Saturday, southwest winds 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. * IMPACTS...Critical fire weather conditions are possible. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Fire Weather Watch means that there is a potential for critical fire weather conditions. Continue to monitor for the latest forecasts and for possible Red Flag Warnings. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
068 WWUS85 KSLC 172025 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 225 PM MDT Thu Sep 17 2020 UTZ489-494-498-181200- /O.UPG.KSLC.FW.A.0022.200918T1500Z-200920T0300Z/ /O.EXB.KSLC.FW.W.0036.200918T1800Z-200920T0300Z/ San Rafael Swell-Henry Mountains-Grand Staircase- 225 PM MDT Thu Sep 17 2020 ...RED FLAG WARNING IN EFFECT FROM NOON FRIDAY TO 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489...494 AND 498... The National Weather Service in Salt Lake City has issued a Red Flag Warning for wind and low relative humidity, which is in effect from noon Friday to 9 PM MDT Saturday. The Fire Weather Watch is no longer in effect. * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 494 Henry Mountains and Fire Weather Zone 498 Grand Staircase. * WINDS...On Friday, south winds 10 to 20 mph with gusts between 25 to 30 mph. On Saturday, southwest winds 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ492-495-181200- /O.CON.KSLC.FW.W.0036.000000T0000Z-200919T0300Z/ Central Utah West Desert-Color Country West Desert- 225 PM MDT Thu Sep 17 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 492 AND 495... * AFFECTED AREA...Fire Weather Zone 492 Central Utah West Desert and Fire Weather Zone 495 Color Country West Desert. * WINDS...South winds 10 to 20 mph with occasional gusts to 30 mph this afternoon and evening, mainly western portions. South winds increasing to 20 to 25 mph with gusts to 40 mph on Friday. * RELATIVE HUMIDITY...8 to 10 percent this afternoon and between 9 to 14 percent on Friday. Poor overnight recovery tonight. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ478-479-483-484-488-493-496-497-181200- /O.CON.KSLC.FW.W.0036.200918T1500Z-200919T0300Z/ Salt Lake Desert-Wasatch Mountains- Southern Ashley National Forest-Tavaputs Plateau- Manti National Forest-Central Utah Mountains- Color Country Mountains-Mojave Desert- 225 PM MDT Thu Sep 17 2020 ...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM TO 9 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478...479...483...484...488...493...496 AND 497... * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert...Fire Weather Zone 479 Wasatch Mountains...Fire Weather Zone 483 Southern Ashley National Forest...Fire Weather Zone 484 Tavaputs Plateau...Fire Weather Zone 488 Manti National Forest...Fire Weather Zone 493 Central Utah Mountains...Fire Weather Zone 496 Color Country Mountains and Fire Weather Zone 497 Mojave Desert. * WINDS...Southwest winds 10 to 20 mph with gusts in the 25 to 30 mph range. * RELATIVE HUMIDITY...9 to 15 percent. Poor overnight recovery tonight. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
949 WWUS85 KSLC 180850 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 250 AM MDT Fri Sep 18 2020 UTZ492-495-182200- /O.CON.KSLC.FW.W.0036.000000T0000Z-200919T0300Z/ Central Utah West Desert-Color Country West Desert- 250 AM MDT Fri Sep 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 492 AND 495... * AFFECTED AREA...Fire Weather Zone 492 Central Utah West Desert and Fire Weather Zone 495 Color Country West Desert. * WINDS...South winds 20 to 25 mph with gusts to 40 mph. * RELATIVE HUMIDITY...9 to 14 percent. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ478-479-483-484-488-493-496-497-182200- /O.CON.KSLC.FW.W.0036.200918T1500Z-200919T0300Z/ Salt Lake Desert-Wasatch Mountains- Southern Ashley National Forest-Tavaputs Plateau- Manti National Forest-Central Utah Mountains- Color Country Mountains-Mojave Desert- 250 AM MDT Fri Sep 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM THIS MORNING TO 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478...479...483...484...488...493...496 AND 497... * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert...Fire Weather Zone 479 Wasatch Mountains...Fire Weather Zone 483 Southern Ashley National Forest...Fire Weather Zone 484 Tavaputs Plateau...Fire Weather Zone 488 Manti National Forest...Fire Weather Zone 493 Central Utah Mountains...Fire Weather Zone 496 Color Country Mountains and Fire Weather Zone 497 Mojave Desert. * WINDS...Southwest winds 10 to 20 mph with gusts in the 25 to 30 mph range. * RELATIVE HUMIDITY...9 to 15 percent. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ489-494-498-182200- /O.CON.KSLC.FW.W.0036.200918T1800Z-200920T0300Z/ San Rafael Swell-Henry Mountains-Grand Staircase- 250 AM MDT Fri Sep 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489...494 AND 498... * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 494 Henry Mountains and Fire Weather Zone 498 Grand Staircase. * WINDS...On Friday, south winds 10 to 20 mph with gusts between 25 to 30 mph. On Saturday, southwest winds 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. Poor humidity recovery at night. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
333 WWUS85 KSLC 182045 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 245 PM MDT Fri Sep 18 2020 UTZ492-495-190300- /O.CON.KSLC.FW.W.0036.000000T0000Z-200919T0300Z/ Central Utah West Desert-Color Country West Desert- 245 PM MDT Fri Sep 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 492 AND 495... * AFFECTED AREA...Fire Weather Zone 492 Central Utah West Desert and Fire Weather Zone 495 Color Country West Desert. * WINDS...South winds will continue to increase to 20 to 25 mph with gusts to 40 mph this afternoon, then persist through this evening. * RELATIVE HUMIDITY...9 to 14 percent. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ478-479-483-484-488-493-496-497-190300- /O.CON.KSLC.FW.W.0036.000000T0000Z-200919T0300Z/ Salt Lake Desert-Wasatch Mountains- Southern Ashley National Forest-Tavaputs Plateau- Manti National Forest-Central Utah Mountains- Color Country Mountains-Mojave Desert- 245 PM MDT Fri Sep 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478... 479...483...484...488...493...496 AND 497... * AFFECTED AREA...Fire Weather Zone 478 Salt Lake Desert...Fire Weather Zone 479 Wasatch Mountains...Fire Weather Zone 483 Southern Ashley National Forest...Fire Weather Zone 484 Tavaputs Plateau...Fire Weather Zone 488 Manti National Forest...Fire Weather Zone 493 Central Utah Mountains...Fire Weather Zone 496 Color Country Mountains and Fire Weather Zone 497 Mojave Desert. * WINDS...Southwest winds will continue to increase to 10 to 20 mph with gusts in the 25 to 30 mph range this afternoon, then persist through this evening. * RELATIVE HUMIDITY...9 to 15 percent. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ489-494-498-191300- /O.CON.KSLC.FW.W.0036.000000T0000Z-200920T0300Z/ San Rafael Swell-Henry Mountains-Grand Staircase- 245 PM MDT Fri Sep 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489... 494 AND 498... * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 494 Henry Mountains and Fire Weather Zone 498 Grand Staircase. * WINDS...For the rest of today, south winds will continue to increase to 10 to 20 mph with gusts between 25 to 30 mph. On Saturday, southwest winds 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. Poor humidity recovery at night. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
790 WWUS85 KSLC 190317 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 917 PM MDT Fri Sep 18 2020 UTZ478-479-483-484-488-492-493-495>497-190430- /O.EXP.KSLC.FW.W.0036.000000T0000Z-200919T0300Z/ Salt Lake Desert-Wasatch Mountains- Southern Ashley National Forest-Tavaputs Plateau- Manti National Forest-Central Utah West Desert- Central Utah Mountains-Color Country West Desert- Color Country Mountains-Mojave Desert- 917 PM MDT Fri Sep 18 2020 ...RED FLAG WARNING HAS EXPIRED FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 478...479...483...484...488... 492...493...495...496 AND 497... Winds have decreased this evening for much of northern and western Utah and humidities will trend higher tonight into tomorrow. $$ UTZ489-494-498-191200- /O.CON.KSLC.FW.W.0036.000000T0000Z-200920T0300Z/ San Rafael Swell-Henry Mountains-Grand Staircase- 917 PM MDT Fri Sep 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489... 494 AND 498... * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 494 Henry Mountains and Fire Weather Zone 498 Grand Staircase. * WINDS...Southwest winds 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. Poor humidity recovery at night. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
536 WWUS85 KSLC 190642 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 1242 AM MDT Sat Sep 19 2020 UTZ492-493-495>497-191445- /O.EXA.KSLC.FW.W.0036.000000T0000Z-200920T0300Z/ Central Utah West Desert-Central Utah Mountains- Color Country West Desert-Color Country Mountains-Mojave Desert- 1242 AM MDT Sat Sep 19 2020 ...RED FLAG WARNING IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 492...493... 495...496 AND 497... The National Weather Service in Salt Lake City has issued a Red Flag Warning for wind and low relative humidity, which is in effect until 9 PM MDT this evening. * AFFECTED AREA...Fire Weather Zone 492 Central Utah West Desert...Fire Weather Zone 493 Central Utah Mountains...Fire Weather Zone 495 Color Country West Desert...Fire Weather Zone 496 Color Country Mountains and Fire Weather Zone 497 Mojave Desert. * WINDS...Southwest 15 to 25 mph with gusts 30 to 40 mph. * RELATIVE HUMIDITY...As low as 14 percent. Poor humidity recovery at night. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ UTZ489-494-498-191445- /O.CON.KSLC.FW.W.0036.000000T0000Z-200920T0300Z/ San Rafael Swell-Henry Mountains-Grand Staircase- 1242 AM MDT Sat Sep 19 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489... 494 AND 498... * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 494 Henry Mountains and Fire Weather Zone 498 Grand Staircase. * WINDS...Southwest 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. Poor humidity recovery at night. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or are imminent. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
486 WWUS85 KSLC 192121 RFWSLC URGENT - FIRE WEATHER MESSAGE National Weather Service Salt Lake City UT 321 PM MDT Sat Sep 19 2020 UTZ489-492>498-200300- /O.CON.KSLC.FW.W.0036.000000T0000Z-200920T0300Z/ San Rafael Swell-Central Utah West Desert-Central Utah Mountains- Henry Mountains-Color Country West Desert-Color Country Mountains- Mojave Desert-Grand Staircase- 321 PM MDT Sat Sep 19 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 489... 492...493...494...495...496...497 AND 498... * AFFECTED AREA...Fire Weather Zone 489 San Rafael Swell...Fire Weather Zone 492 Central Utah West Desert...Fire Weather Zone 493 Central Utah Mountains...Fire Weather Zone 494 Henry Mountains...Fire Weather Zone 495 Color Country West Desert... Fire Weather Zone 496 Color Country Mountains...Fire Weather Zone 497 Mojave Desert and Fire Weather Zone 498 Grand Staircase. * WINDS...Southwest 15 to 25 mph with gusts between 30 to 35 mph. * RELATIVE HUMIDITY...10 to 15 percent. Poor humidity recovery at night. * IMPACTS...Critical fire weather conditions are expected. Any fire starts may 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 strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ For more information from NOAA/National Weather Service visit... http://weather.gov/saltlakecity
What forecasters said that day
The local office's own words before this red flag warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Salt Lake City, UT wrote its last area forecast discussion before this red flag warning went out at Sep 16, 9:26 AM MDT, 5 hours 23 minutes earlier.
Area forecast discussion, Sep 16, 9:26 AM MDT, 5 hours 23 minutes before
Area Forecast Discussion
National Weather Service Salt Lake City UT
926 AM MDT Wed Sep 16 2020
.SYNOPSIS...High pressure aloft will maintain above normal
temperatures and dry conditions through the end of the week. An
upper level trough moving east through the northern Rockies will
bring a chance for showers and thunderstorms to northern Utah late
Friday evening through Saturday, with cooler temperatures across
the state this weekend.
&&
.DISCUSSION...Morning satellite and H5 analysis place the axis of
a broad upper ridge oriented along the UT/NV border, with
northern extension stretching to southern BritCol attm. Upstream
of this a deep closed low nearly cut-off from the mean northern
branch flow remains spinning off the PacNW coast.
Due to the orientation of the upper ridge, the local area will
once again remain dry and stable today, with resultant
temperatures remaining near 10 degrees above climatological norms.
The bulk of the western wildfire smoke remains upstream of the
ridge axis and to our west, but enough resides aloft for locally
hazy skies today.
Current forecast captures this well, and have not made any updates
to the going forecast. Previous discussion below.
.PREVIOUS DISCUSSION...The mid-latitude upper trough centered
on 135W this morning will slowly drift east into the Pacific
Northwest by Friday, then accelerate east and weaken as it moves
through the northern Rockies/northern Great Basin this weekend.
Ahead of this trough a surface cold front will advance into
northwest Utah Friday afternoon, then continue into
central/eastern Utah early Saturday. Strong and gusty southerly
winds are expected ahead of the front across mainly southern and
western Utah, with temperatures remaining well above normal ahead
of the front Friday.
Convective precipitation will likely remain confined to the
northern third of the state Friday night through at least Saturday
morning. The latest deterministic models do show some increase in
PWAT values advecting in from the southwest ahead of the trough
on Friday. The initial convection will likely form in an area of
low-level convergence behind the surface front late Friday
afternoon/evening, with the best organized convection developing
and expanding east as the upper trough moves into the area late
Friday night/early Saturday. This increasing synoptic-scale lift
along with adequate moisture should finally produce some
measurable rain across northern Utah by late Friday evening
through early Saturday.
.LONG TERM (After 12Z Saturday)...The Pacific Northwest trough will
graze northern Utah Friday night into Saturday, bringing noticeably
cooler temperatures for the weekend. Maxes are expected to run up to
5F below seasonal normals over northern Utah and near climo for
southern Utah. The best moisture and instability with the trough
look to remain north of the area, but there is a threat of precip,
primarily along the front during the day Saturday. Overall, global
models and ensembles continue to come into better agreement with
regard to the evolution of the system so confidence is increasing in
the forecast and associated impacts.
Behind the trough, weak ridging is expected to return for early next
week, resulting in a warming trend into Monday as conditions remain
dry. Spread in the guidance increases as day seven approaches, but
there is some indication of the ridge weakening by midweek, cooling
temperatures slightly and allowing for some increase in
instability.
&&
.AVIATION...VFR conditions will continue at KSLC through the valid
TAF period. Expect southeast winds to transition to the northwest
between 19Z-20Z. Southeast flow should return around 03Z.
&&
.FIRE WEATHER...High pressure aloft will remain centered over the
interior west through Friday. Temperatures will remain above
normal with dry conditions expected through the end of the week.
The upper level trough currently off the Pacific Northwest coast
will work slowly east the next couple of days. This trough will
finally move inland on Friday, then accelerate east and gradually
weaken as it tracks across the northern Rockies/northern Great
Basin this weekend.
Increasing southerly winds ahead of the advancing trough will
reach into western Utah by Thursday afternoon. Already low
humidity values combined with the increasing winds could bring
critical fire weather conditions into west-central and southwest
Utah Thursday afternoon and evening. Stronger and more widespread
southerly winds and continued low humidity will result in critical
fire weather conditions across much of the state Friday.
Fire weather watches are in effect for portions of western Utah
beginning Thursday afternoon, with most of the state under watches
on Friday. Thursday looks to be a marginal event at this time,
with more certainty for the Friday event due to the expected
elevated and widespread southerly winds and low humidity.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Fire Weather Watch from Friday morning through Friday evening
for UTZ478-479-484-488-489-493-494-496>498.
Fire Weather Watch from Thursday afternoon through Friday
evening for UTZ492-495.
WY...None.
&&
DISCUSSION/AVIATION...Merrill/Billingsley
PREVIOUS DISCUSSION...Conger/Traphagan
For more information from NOAA's National Weather Service visit...
http://weather.gov/saltlakecity
For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.phpHazardous weather outlook, Sep 16, 5:50 AM MDT, 8 hours 59 minutes before
Hazardous Weather Outlook National Weather Service Salt Lake City UT 550 AM MDT Wed Sep 16 2020 UTZ001>016-019>021-517-518-WYZ021-171200- Cache Valley/Utah Portion-Northern Wasatch Front- Salt Lake and Tooele Valleys-Southern Wasatch Front- Great Salt Lake Desert and Mountains-Wasatch Mountain Valleys- Wasatch Mountains I-80 North-Wasatch Mountains South of I-80- Western Uinta Mountains-Wasatch Plateau/Book Cliffs- Western Uinta Basin-Castle Country-San Rafael Swell- Sanpete/Sevier Valleys-West Central Utah-Southwest Utah- Utahs Dixie and Zion National Park-South Central Utah- Glen Canyon Recreation Area/Lake Powell-Central Mountains- Southern Mountains-Southwest Wyoming- 550 AM MDT Wed Sep 16 2020 This Hazardous Weather Outlook is for the western two thirds of Utah and southwest Wyoming. .DAY ONE...Today and Tonight High pressure aloft across the outlook area will bring another day of unseasonably warm and dry conditions to the outlook area. Smoke from regional wildfires will produce hazy skies along with poor air quality across mainly northern Utah and southwest Wyoming. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Above normal temperatures and dry conditions will persist through Friday. Smoke from regional wildfires will persist across mainly northern and western Utah along with southwest Wyoming through the end of the week. Increasing southerly winds beginning Thursday afternoon along with low humidity values will bring the potential for critical fire weather conditions across portions of western Utah Thursday, then over much of the outlook area on Friday. An upper level trough moving east through the northern Rockies will push a cold front south across the area Friday night through Saturday. Significantly cooler temperatures are expected this weekend. Any precipitation associated with the passing trough will primarily remain over northern Utah and southwest Wyoming Friday night through Saturday. A return to high pressure aloft across the region will bring about a gradual warming tend early next week. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. For more information from NOAA/s National Weather Service visit... http://weather.gov/saltlakecity For information on potential road travel impacts visit... http://www.udottraffic.utah.gov/roadweatherforecast.aspx
Nearby
Red Flag Warnings in Utah, 2020Every red flag warning in 2020
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.