Alert archive / California / Red Flag Warnings in 2017

Red Flag Warning 9, NWS Phoenix, AZ

December 14, 2017Imperial County, Riverside County, San Bernardino County, California; La Paz County, Yuma County, Arizona

NWS Phoenix, AZ issued this red flag warning at Dec 14, 2017, 1:41 AM PST for Imperial County, Riverside County, San Bernardino County, California; La Paz County, Yuma County, Arizona. It took effect at Dec 14, 2017, 8:00 AM PST. It was in force for 8 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
Dec 14, 2017, 1:41 AM PST (09:41 UTC)
In effect from
Dec 14, 2017, 8:00 AM PST
Expired
Dec 14, 2017, 4:00 PM PST
In force
8 hr
Issued by
NWS Phoenix, AZ

Counties La Paz County, AZ, Yuma County, AZ, Imperial County, CA, Riverside County, CA, San Bernardino County, CA

The radar

The Yuma radar (KYUX), 132 km from the middle of the area, began a volume at 09:40 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

San Diego, CA (KNKX), launched 00:00Z, 9.7 hours before the alert went out and 217 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, San Diego, CA at 00:00Z on 2017-12-14Temperature 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, San Diego, CA at 00:00Z on 2017-12-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.193958Sfc1 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
5029 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

288 
WWUS85 KPSR 140941
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
241 AM MST Thu Dec 14 2017

CAZ230-232-142200-
/O.NEW.KPSR.FW.W.0009.171214T1600Z-171215T0000Z/
Joshua Tree National Park-
Imperial County And Eastern Riverside County-
141 AM PST Thu Dec 14 2017

...RED FLAG WARNING IN EFFECT FROM 8 AM THIS MORNING TO 4 PM PST
THIS AFTERNOON FOR STRONG WINDS, LOW RELATIVE HUMIDITY AND VERY 
HIGH TO EXTREME FIRE DANGER FOR SOUTHEAST CALIFORNIA...

The National Weather Service in Phoenix has issued a Red Flag
Warning for strong winds, low relative humidity and very high to
extreme fire danger, which is in effect from 8 AM this morning to
4 PM PST this afternoon.

* AFFECTED AREA...Joshua Tree National Park, eastern Riverside 
  County and portions of Imperial County.

* WINDS...North 20 to 30 mph with gusts up to 45 mph.

* TIMING...Today from mid-morning through late afternoon.

* RELATIVE HUMIDITY...As low as 8 percent.

* IMPACTS...Fuels are very dry and fire danger is very high to
  extreme. These conditions combined with low relative humidity 
  and strong winds will lead to widespread hazardous fire weather 
  conditions. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Please advise the appropriate officials and fire crews in the
field of this red flag warning.

&&

$$

AZZ131-CAZ231-142200-
/O.NEW.KPSR.FW.W.0009.171214T1800Z-171215T0000Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Lower Colorado River Valley CA-
241 AM MST Thu Dec 14 2017 /141 AM PST Thu Dec 14 2017/

...RED FLAG WARNING IN EFFECT FROM 11 AM MST /10 AM PST/ THIS
MORNING TO 5 PM MST /4 PM PST/ THIS AFTERNOON FOR STRONG WINDS,
LOW RELATIVE HUMIDITY AND VERY HIGH TO EXTREME FIRE DANGER FOR THE
LOWER COLORADO RIVER VALLEY...

The National Weather Service in Phoenix has issued a Red Flag
Warning for strong winds, low relative humidity and very high to
extreme fire danger, which is in effect from 11 AM MST /10 AM 
PST/ this morning to 5 PM MST /4 PM PST/ this afternoon.

* AFFECTED AREA...Yuma/Martinez Lake and Vicinity/Lower Colorado 
  River Valley AZ and Lower Colorado River Valley CA.

* WINDS...North 20 to 30 mph with gusts up to 45 mph.

* TIMING...Today from mid-morning through late afternoon.

* RELATIVE HUMIDITY...As low as 12 percent.

* IMPACTS...Fuels are very dry and fire danger is very high to
  extreme. These conditions combined with low relative humidity 
  and strong winds will lead to widespread hazardous fire weather 
  conditions. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Please advise the appropriate officials and fire crews in the
field of this red flag warning.

&&

$$

National Weather Service Phoenix is on the internet at

weather.gov/phoenix
2 follow-up statements
790 
WWUS85 KPSR 142058
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
158 PM MST Thu Dec 14 2017

CAZ230-232-150000-
/O.CON.KPSR.FW.W.0009.000000T0000Z-171215T0000Z/
Joshua Tree National Park-
Imperial County And Eastern Riverside County-
1258 PM PST Thu Dec 14 2017

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PST THIS
AFTERNOON FOR STRONG WINDS, LOW RELATIVE HUMIDITY AND VERY HIGH
TO EXTREME FIRE DANGER FOR SOUTHEAST CALIFORNIA...

* AFFECTED AREA...Joshua Tree National Park and Imperial County 
  And Eastern Riverside County.

* WINDS...North 20 to 30 mph with gusts up to 45 mph.

* TIMING...Today from mid-morning through late afternoon.

* RELATIVE HUMIDITY...As low as 8 percent.

* IMPACTS...Fuels are very dry and fire danger is very high to 
  extreme. These conditions combined with low relative humidity 
  and strong winds will lead to widespread hazardous fire 
  weather conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Please advise the appropriate officials and fire crews in the
field of this red flag warning.

&&

$$

AZZ131-CAZ231-150000-
/O.CON.KPSR.FW.W.0009.000000T0000Z-171215T0000Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Lower Colorado River Valley CA-
158 PM MST Thu Dec 14 2017 /1258 PM PST Thu Dec 14 2017/

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM MST /4 PM PST/
THIS AFTERNOON FOR STRONG WINDS, LOW RELATIVE HUMIDITY AND VERY
HIGH TO EXTREME FIRE DANGER FOR THE LOWER COLORADO RIVER VALLEY...

* AFFECTED AREA...Yuma/Martinez Lake and Vicinity/Lower Colorado 
  River Valley AZ and Lower Colorado River Valley CA.

* WINDS...North 15 to 25 mph with gusts up to 40 mph.

* TIMING...Today from mid-morning through late afternoon.

* RELATIVE HUMIDITY...As low as 12 percent.

* IMPACTS...Fuels are very dry and fire danger is very high to 
  extreme. These conditions combined with low relative humidity 
  and strong winds will lead to widespread hazardous fire 
  weather conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Please advise the appropriate officials and fire crews in the
field of this red flag warning.

&&

$$

National Weather Service Phoenix is on the internet at

weather.gov/phoenix
955 
WWUS85 KPSR 150013
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
513 PM MST Thu Dec 14 2017

AZZ131-CAZ230>232-150115-
/O.EXP.KPSR.FW.W.0009.000000T0000Z-171215T0000Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Joshua Tree National Park-Lower Colorado River Valley CA-
Imperial County And Eastern Riverside County-
513 PM MST Thu Dec 14 2017 /413 PM PST Thu Dec 14 2017/

...RED FLAG WARNING HAS EXPIRED FOR STRONG WINDS, LOW RELATIVE
HUMIDITY AND VERY HIGH FIRE DANGER FOR SOUTHEAST CALIFORNIA...

Winds have now dropped below criteria this evening allowing the 
warning to expire.

$$

National Weather Service Phoenix is on the internet at

weather.gov/phoenix

The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 14, 1:29 AM PSTWind AdvisoryPSRImperial, Riverside, San Bernardino15 hr

Nearby

Red Flag Warnings in California, 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.