Alert archive / Arizona / Red Flag Warnings in 2021

Red Flag Warning 19, NWS Tucson, AZ

May 21, 20216 counties in Arizona

NWS Tucson, AZ issued this red flag warning at May 21, 2021, 2:27 AM MST for 6 counties in Arizona. It took effect at May 22, 2021, 10:00 AM MST. 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 21, 2021, 2:27 AM MST (09:27 UTC)
In effect from
May 22, 2021, 10:00 AM MST
Expired
May 22, 2021, 8:00 PM MST
In force
10 hr
Issued by
NWS Tucson, AZ

Counties Cochise County, AZ, Graham County, AZ, Greenlee County, AZ, Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 61 km from the middle of the area, began a volume at 09:29 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

Tuscon, AZ (KTUS), launched 00:00Z, 9.5 hours before the alert went out and 49 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, Tuscon, AZ at 00:00Z on 2021-05-21Temperature 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, Tuscon, AZ at 00:00Z on 2021-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939587897Sfc1 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
4494 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

309 
WWUS85 KTWC 210927
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
227 AM MST Fri May 21 2021

AZZ150>154-212200-
/O.UPG.KTWC.FW.A.0013.210522T1700Z-210523T0300Z/
/O.NEW.KTWC.FW.W.0019.210522T1700Z-210523T0300Z/
/O.EXT.KTWC.FW.W.0018.210521T1700Z-210522T0200Z/
Arizona Fire Weather Zone 150
Sonoran FDRA-Most of Pima County-South Central Pinal County-
Tohono O'odham Nation-Tucson Metropolitan area-TDC-
Arizona Fire Weather Zone 151
Western half Desert Grasslands FDRA including elevations up to
5500 feet in Southeast corner of Pinal County-
Extreme Eastern Pima County-Western third of Cochise County-
Santa Cruz County-TDC-Arizona Fire Weather Zone 152
Eastern half Desert Grasslands FDRA including elevations up to
5500 feet in Southwest Graham County and Eastern two thirds of
Cochise County-Southern San Carlos Reservation-
Southern Greenlee County below 5000 feet-TDC-
Arizona Fire Weather Zone 153
Northern Graham County-Northern Greenlee County-
White and Gila Mountains-Apache Sitgreaves NF-
Southern San Carlos Reservation above 5000 feet-SDC-
Arizona Fire Weather Zone 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
227 AM MST Fri May 21 2021

...RED FLAG WARNING NOW IN EFFECT FROM 10 AM THIS MORNING TO 7 PM
MST THIS EVENING FOR GUSTY WINDS, LOW RH AND VERY HIGH FIRE DANGER
RATING FOR THE EASTERN HALF OF FIRE WEATHER ZONE 150, ALL OF 151, 
NORTHERN HALF OF 152, ALL OF 153, AND 154 EXCLUDING THE 
CHIRICAHUAS... 

...RED FLAG WARNING IS IN EFFECT FROM 10 AM TO 8 PM MST SATURDAY FOR
STRONG GUSTY WINDS, LOW RH AND VERY HIGH FIRE DANGER RATING FOR 
EASTERN ZONE 150 AND ALL OF ZONES 151, 152, 153 AND 154......

The start time of the Red Flag Warning for today was adjusted and is
now in effect from 10 am to 7 pm today. The adjustment was made to 
account for current and expected wind and RH conditions. 

The National Weather Service in Tucson has upgraded the Saturday 
Fire Weather Watch to a Red Flag Warning, which is in effect from 10
AM to 8 PM MST Saturday. 

* AFFECTED AREA...For today, most of southeast Arizona except western
  Pima county, eastern two-thirds of Cochise county and the southeast
  parts of Graham and Greenlee counties. For Saturday the warning is
  in effect everywhere from the Baboquivari Mountains eastward. 

* TIMING...For Today, from 10 am through 7 pm which should be the
  windiest time period. For Saturday, the warning is in effect from
  10 am through 8 pm in the evening. 

* WINDS...For today, southwest 15 to 25 mph, with gusts around 35 
  mph. Local gusty and erratic outflow wind gusts of 35 to 45 mph are
  possible around virga shafts or dry thunderstorms which are most 
  likely from the Safford area North and East. For Saturday, winds 
  are expected to be stronger at southwest 15 to 30 mph, with gusts 
  to 40 mph.

* RELATIVE HUMIDITY...8-15 percent today and generally 5-10 percent 
  on Saturday.

* IMPACTS...Any fires that develop or are ongoing will have the
  potential to spread rapidly and be resistant to control efforts.

* FOR A DETAILED VIEW OF THE HAZARD AREA...Visit weather.gov/Tucson
  and click on the Detailed Hazards Icon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now...or are expected to develop. A
combination of strong winds...low relative humidity...and dry
vegetation will create the potential for rapid and erratic fire
growth.

Please advise the appropriate officials or fire crews in the
field of the Red Flag Warning for portions of Southeast Arizona.

&&

$$

Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
5 follow-up statements
251 
WWUS85 KTWC 212142
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
242 PM MST Fri May 21 2021

AZZ150>154-221330-
/O.CON.KTWC.FW.W.0018.000000T0000Z-210522T0200Z/
/O.CON.KTWC.FW.W.0019.210522T1700Z-210523T0300Z/
Arizona Fire Weather Zone 150
Sonoran FDRA-Most of Pima County-South Central Pinal County-
Tohono O'odham Nation-Tucson Metropolitan area-TDC-
Arizona Fire Weather Zone 151
Western half Desert Grasslands FDRA including elevations up to
5500 feet in Southeast corner of Pinal County-
Extreme Eastern Pima County-Western third of Cochise County-
Santa Cruz County-TDC-Arizona Fire Weather Zone 152
Eastern half Desert Grasslands FDRA including elevations up to
5500 feet in Southwest Graham County and Eastern two thirds of
Cochise County-Southern San Carlos Reservation-
Southern Greenlee County below 5000 feet-TDC-
Arizona Fire Weather Zone 153
Northern Graham County-Northern Greenlee County-
White and Gila Mountains-Apache Sitgreaves NF-
Southern San Carlos Reservation above 5000 feet-SDC-
Arizona Fire Weather Zone 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
242 PM MST Fri May 21 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM MST THIS EVENING
FOR GUSTY WINDS, LOW RH AND VERY HIGH FIRE DANGER RATING FOR THE
EASTERN HALF OF FIRE WEATHER ZONE 150, ALL OF 151, NORTHERN HALF
OF 152, ALL OF 153, AND 154 EXCLUDING THE CHIRICAHUAS...

...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MST
SATURDAY FOR GUSTY WINDS, LOW RH AND VERY HIGH FIRE DANGER RATING
FOR THE EASTERN HALF OF FIRE WEATHER ZONE 150, ALL OF 151,
NORTHERN HALF OF 152, ALL OF 153, AND 154 EXCLUDING THE
CHIRICAHUAS...

The start time of the Red Flag Warning for today was adjusted and
is now in effect from 10 am to 7 pm today. The adjustment was
made to account for current and expected wind and RH conditions.

The National Weather Service in Tucson has upgraded the Saturday
Fire Weather Watch to a Red Flag Warning, which is in effect from
10 AM to 8 PM MST Saturday.

* AFFECTED AREA...For today, most of southeast Arizona except 
  western Pima county, eastern two-thirds of Cochise county and 
  the southeast parts of Graham and Greenlee counties. For 
  Saturday the warning is in effect everywhere from the 
  Baboquivari Mountains eastward. 

* TIMING...For Today, from 10 am through 7 pm which should be 
  the windiest time period. For Saturday, the warning is in 
  effect from 10 am through 8 pm in the evening. 

* WINDS...For today, southwest 15 to 25 mph, with gusts around
  35 mph. Local gusty and erratic outflow wind gusts of 35 to 
  45 mph are possible around virga shafts or dry thunderstorms 
  which are most likely from the Safford area North and East. 
  For Saturday, winds are expected to be stronger at southwest 
  15 to 30 mph, with gusts to 40 mph. 

* RELATIVE HUMIDITY...8-15 percent rest of today and generally 
  5-10 percent on Saturday. 

* IMPACTS...Any fires that develop or are ongoing will have the 
  potential to spread rapidly and be resistant to control 
  efforts.

* FOR A DETAILED VIEW OF THE HAZARD AREA...Visit
  weather.gov/Tucson and click on the Detailed Hazards Icon. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now...or are expected to develop. A
combination of strong winds...low relative humidity...and dry
vegetation will create the potential for rapid and erratic fire
growth.

Please advise the appropriate officials or fire crews in the
field of the Red Flag Warning for portions of Southeast Arizona.

&&

$$


Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
530 
WWUS85 KTWC 220208
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
708 PM MST Fri May 21 2021

AZZ150>154-221100-
/O.EXP.KTWC.FW.W.0018.000000T0000Z-210522T0200Z/
/O.CON.KTWC.FW.W.0019.210522T1700Z-210523T0300Z/
Arizona Fire Weather Zone 150
Sonoran FDRA-Most of Pima County-South Central Pinal County-
Tohono O'odham Nation-Tucson Metropolitan area-TDC-
Arizona Fire Weather Zone 151
Western half Desert Grasslands FDRA including elevations up to
5500 feet in Southeast corner of Pinal County-
Extreme Eastern Pima County-Western third of Cochise County-
Santa Cruz County-TDC-Arizona Fire Weather Zone 152
Eastern half Desert Grasslands FDRA including elevations up to
5500 feet in Southwest Graham County and Eastern two thirds of
Cochise County-Southern San Carlos Reservation-
Southern Greenlee County below 5000 feet-TDC-
Arizona Fire Weather Zone 153
Northern Graham County-Northern Greenlee County-
White and Gila Mountains-Apache Sitgreaves NF-
Southern San Carlos Reservation above 5000 feet-SDC-
Arizona Fire Weather Zone 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
708 PM MST Fri May 21 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MST
SATURDAY FOR GUSTY WINDS, LOW RH AND VERY HIGH FIRE DANGER RATING
FOR THE EASTERN HALF OF FIRE WEATHER ZONE 150, ALL OF 151,
NORTHERN HALF OF 152, ALL OF 153, AND 154 EXCLUDING THE
CHIRICAHUAS...

...RED FLAG WARNING HAS EXPIRED TODAY FOR GUSTY WINDS, LOW RH AND
VERY HIGH FIRE DANGER RATING FOR THE EASTERN HALF OF FIRE WEATHER
ZONE 150, ALL OF 151, NORTHERN HALF OF 152, ALL OF 153, AND 154 
EXCLUDING THE CHIRICAHUAS...

The National Weather Service in Tucson continues the Saturday 
Red Flag Warning, which is in effect from 10 AM to 8 PM MST 
Saturday.

* AFFECTED AREA...Most of southeast Arizona, including everywhere
  from the Baboquivari Mountains eastward.

* TIMING...Saturday, 10 am through 8 pm in the evening.

* WINDS...Winds are expected to be stronger Saturday, from the 
  southwest at 15 to 30 mph, with gusts to 40 mph.

* RELATIVE HUMIDITY...5-10 percent.

* IMPACTS...Any fires that develop or are ongoing will have the 
  potential to spread rapidly and be resistant to control 
  efforts.

* FOR A DETAILED VIEW OF THE HAZARD AREA...Visit
  weather.gov/Tucson and click on the Detailed Hazards Icon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now...or are expected to develop. A
combination of strong winds...low relative humidity...and dry
vegetation will create the potential for rapid and erratic fire
growth.

Please advise the appropriate officials or fire crews in the
field of the Red Flag Warning for portions of Southeast Arizona.

&&

$$


Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
466 
WWUS85 KTWC 221002
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
302 AM MST Sat May 22 2021

AZZ150>154-222215-
/O.CON.KTWC.FW.W.0019.210522T1700Z-210523T0300Z/
Arizona Fire Weather Zone 150
Sonoran FDRA-Most of Pima County-South Central Pinal County-
Tohono O'odham Nation-Tucson Metropolitan area-TDC-
Arizona Fire Weather Zone 151
Western half Desert Grasslands FDRA including elevations up to
5500 feet in Southeast corner of Pinal County-
Extreme Eastern Pima County-Western third of Cochise County-
Santa Cruz County-TDC-Arizona Fire Weather Zone 152
Eastern half Desert Grasslands FDRA including elevations up to
5500 feet in Southwest Graham County and Eastern two thirds of
Cochise County-Southern San Carlos Reservation-
Southern Greenlee County below 5000 feet-TDC-
Arizona Fire Weather Zone 153
Northern Graham County-Northern Greenlee County-
White and Gila Mountains-Apache Sitgreaves NF-
Southern San Carlos Reservation above 5000 feet-SDC-
Arizona Fire Weather Zone 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
302 AM MST Sat May 22 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
8 PM MST THIS EVENING FOR STRONG GUSTY WINDS, LOW RH AND A VERY 
HIGH TO EXTREME FIRE DANGER RATING FOR THE EASTERN HALF OF FIRE 
WEATHER ZONE 150 AND ALL OF ZONES 151, 152, 153 AND 154...

The National Weather Service in Tucson continues the Red Flag 
Warning, which is in effect from 10 AM to 8 PM MST today.

* AFFECTED AREA...Most of southeast Arizona, including 
  everywhere from the Baboquivari Mountains eastward. 

* TIMING...10 AM through 8 PM in this evening.

* WINDS...Southwest winds will increase to 15 to 30 mph, with
  gusts to 45 mph. Winds will be slow to diminish this evening. 

* RELATIVE HUMIDITY...Dropping to 6-13 percent followed by very 
  poor overnight recoveries. 

* IMPACTS...Any fires that develop or are ongoing will have the 
  potential to spread rapidly and be resistant to control 
  efforts.

* FOR A DETAILED VIEW OF THE HAZARD AREA...Visit 
  weather.gov/Tucson and click on the Detailed Hazards Icon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions 
are either occurring now, or are expected to develop. A 
combination of strong winds, low relative humidity and dry 
vegetation will create the potential for rapid, erratic fire 
growth and extreme fire behavior.

Please advise the appropriate officials or fire crews in the
field of the Red Flag Warning for portions of Southeast Arizona.

&&

$$

Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
418 
WWUS85 KTWC 222116
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
216 PM MST Sat May 22 2021

AZZ150>154-230300-
/O.CON.KTWC.FW.W.0019.000000T0000Z-210523T0300Z/
Arizona Fire Weather Zone 150
Sonoran FDRA-Most of Pima County-South Central Pinal County-
Tohono O'odham Nation-Tucson Metropolitan area-TDC-
Arizona Fire Weather Zone 151
Western half Desert Grasslands FDRA including elevations up to
5500 feet in Southeast corner of Pinal County-
Extreme Eastern Pima County-Western third of Cochise County-
Santa Cruz County-TDC-Arizona Fire Weather Zone 152
Eastern half Desert Grasslands FDRA including elevations up to
5500 feet in Southwest Graham County and Eastern two thirds of
Cochise County-Southern San Carlos Reservation-
Southern Greenlee County below 5000 feet-TDC-
Arizona Fire Weather Zone 153
Northern Graham County-Northern Greenlee County-
White and Gila Mountains-Apache Sitgreaves NF-
Southern San Carlos Reservation above 5000 feet-SDC-
Arizona Fire Weather Zone 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
216 PM MST Sat May 22 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR STRONG GUSTY WINDS, LOW RH, AND A VERY HIGH TO EXTREME FIRE
DANGER RATING FOR THE EASTERN HALF OF FIRE WEATHER ZONE 150 AND
ALL OF ZONES 151, 152, 153 AND 154...

* AFFECTED AREA...Most of southeast Arizona, including 
  everywhere from the Baboquivari Mountains eastward. 

* TIMING...Through 8 PM this evening.

* WINDS...Out of the southwest at 15 to 30 mph, with gusts to 45 
  mph. Winds will be slow to diminish this evening.

* RELATIVE HUMIDITY...Expect values between 6-13 percent followed
  by very poor overnight recoveries.

* IMPACTS...Any fires that develop or are ongoing will have the 
  potential to spread rapidly and be resistant to control 
  efforts.

* FOR A DETAILED VIEW OF THE HAZARD AREA...Visit 
  weather.gov/Tucson and click on the Detailed Hazards Icon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or are expected to develop. A
combination of strong winds, low relative humidity and dry
vegetation will create the potential for rapid, erratic fire
growth and extreme fire behavior.

Please advise the appropriate officials or fire crews in the
field of the Red Flag Warning for portions of Southeast Arizona.

&&

$$


Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
116 
WWUS85 KTWC 230259
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
759 PM MST Sat May 22 2021


AZZ150>154-230400-
/O.EXP.KTWC.FW.W.0019.000000T0000Z-210523T0300Z/
Arizona Fire Weather Zone 150
Sonoran FDRA-Most of Pima County-South Central Pinal County-
Tohono O'odham Nation-Tucson Metropolitan area-TDC-
Arizona Fire Weather Zone 151
Western half Desert Grasslands FDRA including elevations up to
5500 feet in Southeast corner of Pinal County-
Extreme Eastern Pima County-Western third of Cochise County-
Santa Cruz County-TDC-Arizona Fire Weather Zone 152
Eastern half Desert Grasslands FDRA including elevations up to
5500 feet in Southwest Graham County and Eastern two thirds of
Cochise County-Southern San Carlos Reservation-
Southern Greenlee County below 5000 feet-TDC-
Arizona Fire Weather Zone 153
Northern Graham County-Northern Greenlee County-
White and Gila Mountains-Apache Sitgreaves NF-
Southern San Carlos Reservation above 5000 feet-SDC-
Arizona Fire Weather Zone 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
759 PM MST Sat May 22 2021

...RED FLAG WARNING WILL EXPIRE AT 8 PM MST THIS EVENING FOR
STRONG GUSTY WINDS, LOW RH, AND A VERY HIGH TO EXTREME FIRE
DANGER RATING FOR THE EASTERN HALF OF FIRE WEATHER ZONE 150 AND
ALL OF ZONES 151, 152, 153 AND 154...

Winds are diminishing across the area, while temperatures cool
down for the evening. As a result, relative humidities will
gradually increase. This will end critical fire conditions across
southern and southeast Arizona. Thus the Red Flag warning will be
allowed to expire. 

$$


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Nearby

Red Flag Warnings in Arizona, 2021Every 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.