Alert archive / Utah / Red Flag Warnings in 2017

Red Flag Warning 1, NWS Salt Lake City, UT

May 5, 2017Washington County, Utah

NWS Salt Lake City, UT issued this red flag warning at May 5, 2017, 12:22 PM MDT for Washington County, Utah. It took effect at May 6, 2017, 10:00 AM MDT. It was in force for 10 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
May 5, 2017, 12:22 PM MDT (18:22 UTC)
In effect from
May 6, 2017, 10:00 AM MDT
Expired
May 6, 2017, 8:00 PM MDT
In force
10 hr
Issued by
NWS Salt Lake City, UT

County Washington County, UT

The radar

The Cedar City radar (KICX), 66 km from the middle of the area, began a volume at 18:28 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 12:00Z, 6.4 hours before the alert went out and 207 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, Las Vegas, NV at 12:00Z on 2017-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2017-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3911 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
1 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

614 
WWUS85 KSLC 051822
RFWSLC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Salt Lake City UT
1222 PM MDT Fri May 5 2017

UTZ497-061300-
/O.NEW.KSLC.FW.W.0001.170506T1600Z-170507T0200Z/
Mojave Desert-
1222 PM MDT Fri May 5 2017

...RED FLAG WARNING IN EFFECT FROM 10 AM TO 8 PM MDT SATURDAY FOR
WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE 497 BELOW
3500 FEET...

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 to 8 PM MDT Saturday.

* AFFECTED AREA...Fire Weather Zone 497 Mojave Desert below 3500
  feet which includes St George and surrounding areas.

* WINDS...Southwest 20 to 30 mph with gusts to 40 mph.

* RELATIVE HUMIDITY...Lowering to near 10 percent.

* IMPACTS...A combination of gusty winds and low humidity will
  create the potential for rapid fire growth.

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.

&&

$$

Rogowski

For more information from NOAA/National Weather Service visit...
http://weather.gov/saltlakecity
2 follow-up statements
043 
WWUS85 KSLC 060945
RFWSLC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Salt Lake City UT
345 AM MDT Sat May 6 2017

UTZ497-062130-
/O.CON.KSLC.FW.W.0001.170506T1600Z-170507T0200Z/
Mojave Desert-
345 AM MDT Sat May 6 2017

...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 497 BELOW 3500 FEET...

* AFFECTED AREA...Fire Weather Zone 497 Mojave Desert.

* WINDS...Southwest 20 to 30 mph with gusts to 40 mph.

* RELATIVE HUMIDITY...Lowering to near 10 percent.

* IMPACTS...A combination of gusty winds and low humidity will 
  create the potential for rapid fire growth.

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
814 
WWUS85 KSLC 061925
RFWSLC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Salt Lake City UT
125 PM MDT Sat May 6 2017

UTZ497-070200-
/O.CON.KSLC.FW.W.0001.000000T0000Z-170507T0200Z/
Mojave Desert-
125 PM MDT Sat May 6 2017

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE
497 BELOW 3500 FEET...

* AFFECTED AREA...Fire Weather Zone 497 Mojave Desert.

* WINDS...Southwest 20 to 30 mph with gusts to 40 mph.

* RELATIVE HUMIDITY...Lowering to near 10 percent.

* IMPACTS...A combination of gusty winds and low humidity will 
  create the potential for rapid fire growth.

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.

&&

$$

Rogowski

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
May 5, 1:47 PM MDTFlash Flood WatchSLC14 min
May 5, 2:01 PM MDTFlood WatchSLC21 hr
May 5, 2:05 PM MDTWind AdvisorySLC30 hr

Nearby

Red Flag Warnings in Utah, 2017Every red flag warning in 2017

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.