Alert archive / California / Red Flag Warnings in 2017

Red Flag Warning 19, NWS Las Vegas, NV

October 20, 2017San Bernardino County, California; Clark County, Nevada; Mohave County, Arizona

NWS Las Vegas, NV issued this red flag warning at Oct 20, 2017, 3:08 PM PDT for San Bernardino County, California; Clark County, Nevada; Mohave County, Arizona. It took effect at Oct 21, 2017, 12:00 PM PDT. It was in force for 2 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
Oct 20, 2017, 3:08 PM PDT (22:08 UTC)
In effect from
Oct 21, 2017, 12:00 PM PDT
Expired
Oct 21, 2017, 2:21 PM PDT
In force
2 hr
Issued by
NWS Las Vegas, NV

Counties Mohave County, AZ, San Bernardino County, CA, Clark County, NV

The radar

The Las Vegas radar (KESX), 15 km from the middle of the area, began a volume at 22:13 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, 10.1 hours before the alert went out and 101 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 2017-10-20Temperature 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 2017-10-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2559 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
259 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

993 
WWUS85 KVEF 202208
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
308 PM PDT Fri Oct 20 2017

AZZ101-CAZ229-NVZ466-211200-
/O.NEW.KVEF.FW.W.0019.171021T1900Z-171022T0100Z/
Lake Mead NRA/Colorado River-AZ side-Lower Colorado River Valley-
Lake Mead NRA/Colorado River-NV side-
308 PM PDT Fri Oct 20 2017 /308 PM MST Fri Oct 20 2017/

...RED FLAG WARNING IN EFFECT FROM NOON PDT /NOON MST/ TO 6 PM
PDT /6 PM MST/ SATURDAY FOR STRONG WINDS AND LOW RH FOR FIRE
WEATHER ZONES 101, 229, AND 466...

The National Weather Service in Las Vegas has issued a Red Flag
Warning, which is in effect from noon PDT /noon MST/ to 6 PM PDT
/6 PM MST/ Saturday. 

* AFFECTED AREA...In Arizona...Fire weather zone 101. In 
  California...Fire weather zone 229. In Nevada...Fire weather 
  zone 466. 

* TIMING...Winds will increase overnight out of the north and
  continue through much of Saturday before decreasing late. 

* WIND...North 15 to 25 mph with gusts to 35 mph. 

* HUMIDITY...Minimum values 5 to 10 percent from late morning
  through late afternoon Saturday. 

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now....or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

weather.gov/lasvegas
3 follow-up statements
867 
WWUS85 KVEF 210941
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
241 AM PDT Sat Oct 21 2017


AZZ101-CAZ229-NVZ466-211930-
/O.CON.KVEF.FW.W.0019.171021T1900Z-171022T0100Z/
Lake Mead NRA/Colorado River-AZ side-Lower Colorado River Valley-
Lake Mead NRA/Colorado River-NV side-
241 AM PDT Sat Oct 21 2017 /241 AM MST Sat Oct 21 2017/

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON PDT /NOON MST/
TODAY TO 6 PM PDT /6 PM MST/ THIS EVENING FOR STRONG WINDS AND
LOW RH FOR FIRE WEATHER ZONES 101, 229, AND 466...

* AFFECTED AREA...In Arizona...Fire weather zone 101. In 
  California...Fire weather zone 229. In Nevada...Fire weather 
  zone 466. 

* TIMING...Winds will increase out of the north and continue
  through much of the day before decreasing late this evening.

* WIND...North 15 to 25 mph with gusts to 35 mph.

* HUMIDITY...Minimum values 5 to 10 percent from late morning 
  through late afternoon Saturday.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now....or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$


weather.gov/lasvegas
747 
WWUS85 KVEF 211919
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
1219 PM PDT Sat Oct 21 2017

AZZ101-CAZ229-NVZ466-220100-
/O.CON.KVEF.FW.W.0019.000000T0000Z-171022T0100Z/
Lake Mead NRA/Colorado River-AZ side-Lower Colorado River Valley-
Lake Mead NRA/Colorado River-NV side-
1219 PM PDT Sat Oct 21 2017 /1219 PM MST Sat Oct 21 2017/

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 PM PDT /6 PM MST/
THIS EVENING FOR STRONG WINDS AND LOW RH FOR FIRE WEATHER ZONES
101, 229, AND 466...

* AFFECTED AREA...In Arizona...Fire weather zone 101. In 
  California...Fire weather zone 229. In Nevada...Fire weather 
  zone 466. 

* TIMING...Winds will increase out of the north and continue 
  through much of the day before decreasing late this evening.

* WIND...North 15 to 25 mph with gusts to 35 mph.

* HUMIDITY...Minimum values 5 to 10 percent.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now....or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$


weather.gov/lasvegas
983 
WWUS85 KVEF 212121
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
221 PM PDT Sat Oct 21 2017

AZZ101-CAZ229-NVZ466-212230-
/O.CAN.KVEF.FW.W.0019.000000T0000Z-171022T0100Z/
Lake Mead NRA/Colorado River-AZ side-Lower Colorado River Valley-
Lake Mead NRA/Colorado River-NV side-
221 PM PDT Sat Oct 21 2017 /221 PM MST Sat Oct 21 2017/

...RED FLAG WARNING IS CANCELLED FOR STRONG WINDS AND LOW RH FOR
FIRE WEATHER ZONES 101, 229, AND 466...

The National Weather Service in Las Vegas has cancelled the Red
Flag Warning. 

Winds have diminished across the region this afternoon. Therefore
the Red Flag Warning has been cancelled. 

$$


weather.gov/lasvegas

The office that day

Everything else NWS Las Vegas, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 20, 8:03 AM PDTLake Wind AdvisoryVEFSan Bernardino30 hr
Oct 20, 10:21 AM PDTHigh Wind WarningVEFInyo3 hr
Oct 20, 10:21 AM PDTWind AdvisoryVEFInyo10 hr

Nearby

Red Flag Warnings in California, 2017Red Flag Warnings in Nevada, 2017Red Flag Warnings in Arizona, 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.