Alert archive / Utah / Red Flag Warnings in 2019

Red Flag Warning 21, NWS Salt Lake City, UT

September 17, 20195 counties in Utah

NWS Salt Lake City, UT issued this red flag warning at Sep 17, 2019, 3:36 AM MDT for 5 counties in Utah. It took effect at Sep 17, 2019, 10:00 AM MDT. It was in force for 11 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 17, 2019, 3:36 AM MDT (09:36 UTC)
In effect from
Sep 17, 2019, 10:00 AM MDT
Expired
Sep 17, 2019, 9:00 PM MDT
In force
11 hr
Issued by
NWS Salt Lake City, UT

Counties Garfield County, UT, Kane County, UT, San Juan County, UT, Washington County, UT, Wayne County, UT

The radar

The Cedar City radar (KICX), 120 km from the middle of the area, began a volume at 09:37 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 00:00Z, 9.6 hours before the alert went out and 273 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.

Skew-T log-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 00:00Z on 2019-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 410 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 00:00Z on 2019-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
410 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
1616 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
29 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

294 
WWUS85 KSLC 170936
RFWSLC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Salt Lake City UT
336 AM MDT Tue Sep 17 2019

UTZ494-498-172200-
/O.CAN.KSLC.FW.W.0020.000000T0000Z-190917T1000Z/
/O.NEW.KSLC.FW.W.0021.190917T1600Z-190918T0300Z/
Henry Mountains-Grand Staircase-
336 AM MDT Tue Sep 17 2019

...RED FLAG WARNING IN EFFECT FROM 10 AM THIS MORNING TO 9 PM MDT
THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER
ZONES 494 AND 498...
...RED FLAG WARNING IS CANCELLED FOR DRY THUNDERSTORMS AND GUSTY
OUTFLOW WINDS FOR FIRE WEATHER ZONES 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 10 AM this morning to 9 PM MDT this evening. 

* AFFECTED AREA...Fire Weather Zone 494 Henry Mountains and Fire 
  Weather Zone 498 Grand Staircase.

* WINDS...West to southwest with gusts up to 30 mph are expected.

* RELATIVE HUMIDITY...As low as 11 to 15 percent.

* IMPACTS...The combination of gusty winds and low humidity will
  lead to rapid spread of fires.

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.

&&

$$

UTZ478-482-489-492-493-495>497-171045-
/O.CAN.KSLC.FW.W.0020.000000T0000Z-190917T1000Z/
Salt Lake Desert-Western Uintah Basin-San Rafael Swell-
Central Utah West Desert-Central Utah Mountains-
Color Country West Desert-Color Country Mountains-Mojave Desert-
336 AM MDT Tue Sep 17 2019

...RED FLAG WARNING IS CANCELLED FOR WIND AND LOW RELATIVE
HUMIDITY FOR FIRE WEATHER ZONES 478...482...489...492...493...
495...496 AND 497...

The National Weather Service in Salt Lake City has cancelled the
Red Flag Warning.

$$

For more information from NOAA/National Weather Service visit...
http://weather.gov/saltlakecity
1 follow-up statement
248 
WWUS85 KSLC 172107
RFWSLC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Salt Lake City UT
307 PM MDT Tue Sep 17 2019

UTZ494-498-180300-
/O.CON.KSLC.FW.W.0021.000000T0000Z-190918T0300Z/
Henry Mountains-Grand Staircase-
307 PM MDT Tue Sep 17 2019

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 494 AND
498...

* AFFECTED AREA...Fire Weather Zone 494 Henry Mountains and Fire 
  Weather Zone 498 Grand Staircase.

* WINDS...West to southwest with gusts up to 30 mph are expected.

* RELATIVE HUMIDITY...As low as 11 to 15 percent.

* IMPACTS...The combination of gusty winds and low humidity will 
  lead to rapid spread of fires.

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.

&&

$$

UTZ495-181200-
/O.NEW.KSLC.FW.A.0011.190918T1800Z-190920T0400Z/
Color Country West Desert-
307 PM MDT Tue Sep 17 2019

...FIRE WEATHER WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THURSDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 495...

The National Weather Service in Salt Lake City has issued a Fire
Weather Watch for wind and low relative humidity, which is in
effect from Wednesday afternoon through Thursday evening.

* AFFECTED AREA...Fire Weather Zone 495 Color Country West 
  Desert.

* WINDS...Southwest 20 to 25 mph with gusts near 40 mph. 

* RELATIVE HUMIDITY...10 to 15% with fair recoveries at night. 

* IMPACTS...The combination of low humidity and very strong winds
  is forecast. These conditions may lead to rapid spread of fires,
  especially during the afternoon and early evening hours.

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

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 16, 6:17 PM MDTSpecial Weather StatementSLCWasatch43 min
Sep 16, 6:29 PM MDTSpecial Weather StatementSLCWasatch46 min
Sep 16, 7:18 PM MDTSpecial Weather StatementSLCWasatch42 min
Sep 17, 3:07 PM MDTFire Weather WatchSLCBeaver, Iron, Washington13 hr

Nearby

Red Flag Warnings in Utah, 2019Every red flag warning in 2019

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.