Alert archive / Arizona / Red Flag Warnings in 2021

Red Flag Warning 3, NWS Phoenix, AZ

May 19, 2021La Paz County, Yuma County, Arizona; Imperial County, Riverside County, California

NWS Phoenix, AZ issued this red flag warning at May 19, 2021, 2:47 AM MST for La Paz County, Yuma County, Arizona; Imperial County, Riverside County, California. It took effect at May 20, 2021, 12:00 PM MST. 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: May 19, 2021, 2:47 AM MST (09:47 UTC)
In effect from: May 20, 2021, 12:00 PM MST
Expired: May 20, 2021, 8:00 PM MST
In force: 8 hr
Issued by: NWS Phoenix, AZ

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

The radar

The Yuma radar (KYUX), 93 km from the middle of the area, began a volume at 09:52 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

Yuma Prvg Ground, AZ (K1Y7), launched 00:00Z, 9.8 hours before the alert went out and 99 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3169 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: 58 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

076 
WWUS85 KPSR 190947
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
247 AM MST Wed May 19 2021

AZZ131-CAZ231-192300-
/O.NEW.KPSR.FW.W.0003.210520T1900Z-210521T0300Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Lower Colorado River Valley CA-
247 AM MST Wed May 19 2021 /247 AM PDT Wed May 19 2021/

...RED FLAG WARNING IN EFFECT FROM NOON MST /NOON PDT/ TO 8 PM
MST /8 PM PDT/ THURSDAY FOR STRONG WINDS, LOW RELATIVE HUMIDITY
AND HIGH 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 high fire
danger, which is in effect from noon MST /noon PDT/ to 8 PM MST 
/8 PM PDT/ Thursday.

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

* TIMING...Thursday afternoon and evening.

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

* RELATIVE HUMIDITY...As low as 10 percent.

* IMPACTS...Fuels are dry and fire danger is high. 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

4 follow-up statements

762 
WWUS85 KPSR 192006
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
106 PM MST Wed May 19 2021

AZZ131-CAZ231-201145-
/O.CON.KPSR.FW.W.0003.210520T1900Z-210521T0300Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Lower Colorado River Valley CA-
106 PM MST Wed May 19 2021 /106 PM PDT Wed May 19 2021/

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON MST /NOON PDT/ TO
8 PM MST /8 PM PDT/ THURSDAY FOR STRONG WINDS, LOW RELATIVE
HUMIDITY AND HIGH 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.

* TIMING...Thursday afternoon and evening.

* WINDS...Southwest 15 to 25 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 9 percent.

* IMPACTS...Fuels are dry and fire danger is high. 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

221 
WWUS85 KPSR 200900
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
200 AM MST Thu May 20 2021

AZZ131-CAZ231-202300-
/O.CON.KPSR.FW.W.0003.210520T1900Z-210521T0300Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Lower Colorado River Valley CA-
200 AM MST Thu May 20 2021 /200 AM PDT Thu May 20 2021/

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON MST/ NOON PDT/ 
TODAY TO 8 PM MST/ 8 PM PDT/ THIS EVENING FOR STRONG WINDS, LOW 
RELATIVE HUMIDITY AND HIGH 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.

* TIMING...This afternoon and evening.

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

* RELATIVE HUMIDITY...As low as 9 percent.

* IMPACTS...Fuels are dry and fire danger is high. 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

998 
WWUS85 KPSR 202059
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
159 PM MST Thu May 20 2021

AZZ131-CAZ231-210300-
/O.CON.KPSR.FW.W.0003.000000T0000Z-210521T0300Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Lower Colorado River Valley CA-
159 PM MST Thu May 20 2021 /159 PM PDT Thu May 20 2021/

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MST /8 PM PDT/
THIS EVENING FOR STRONG WINDS, LOW RELATIVE HUMIDITY AND HIGH
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.

* TIMING...This afternoon and evening.

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

* RELATIVE HUMIDITY...As low as 9 percent.

* IMPACTS...Fuels are dry and fire danger is high. 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

161 
WWUS85 KPSR 210302
RFWPSR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Phoenix AZ
802 PM MST Thu May 20 2021

AZZ131-CAZ231-210415-
/O.EXP.KPSR.FW.W.0003.000000T0000Z-210521T0300Z/
Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ-
Lower Colorado River Valley CA-
802 PM MST Thu May 20 2021 /802 PM PDT Thu May 20 2021/

...RED FLAG WARNING HAS EXPIRED FOR STRONG WINDS, LOW RELATIVE
HUMIDITY AND HIGH FIRE DANGER FOR THE LOWER COLORADO RIVER 
VALLEY...

Winds have weakened below Red Flag thresholds and will continue to
do so. In addition, humidities have begun to increase and are
expected to improve as the night progresses.

$$

National Weather Service Phoenix is on the internet at

weather.gov/phoenix

Nearby

Red Flag Warnings in Arizona, 2021 Red Flag Warnings in California, 2021 Every red flag warning in 2021

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.