Alert archive / Arizona / Red Flag Warnings in 2021

Red Flag Warning 13, NWS Tucson, AZ

April 21, 20216 counties in Arizona

NWS Tucson, AZ issued this red flag warning at Apr 21, 2021, 2:37 PM MST for 6 counties in Arizona. It took effect at Apr 22, 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
Apr 21, 2021, 2:37 PM MST (21:37 UTC)
In effect from
Apr 22, 2021, 12:00 PM MST
Expired
Apr 22, 2021, 8:00 PM MST
In force
8 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 21:40 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

Tuscon, AZ (KTUS), launched 12:00Z, 9.6 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 12:00Z on 2021-04-21Temperature 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 12:00Z on 2021-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 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
3916 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

143 
WWUS85 KTWC 212137
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
237 PM MST Wed Apr 21 2021

AZZ153-220300-
/O.CAN.KTWC.FW.A.0009.210422T1900Z-210423T0300Z/
/O.CON.KTWC.FW.W.0012.000000T0000Z-210422T0300Z/
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-
237 PM MST Wed Apr 21 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR STRONG AND GUSTY WINDS, LOW HUMIDITY AND A VERY HIGH FIRE 
DANGER RATING FOR FIRE WEATHER ZONE 153... 
...FIRE WEATHER WATCH IS CANCELLED FOR THURSDAY FOR FIRE WEATHER 
ZONE 153...

The National Weather Service in Tucson has cancelled the Fire
Weather Watch on Thursday. 

* AFFECTED AREA...All of Fire Weather Zone 153.

* TIMING...Until 8 PM MST this evening.

* WINDS...South to southwest winds of 20 to 30 mph with gusts to
  45 mph. 

* RELATIVE HUMIDITY...Minimum relative humidity values 5 to 15
  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.

&&

$$

AZZ151-152-154-220545-
/O.UPG.KTWC.FW.A.0009.210422T1900Z-210423T0300Z/
/O.NEW.KTWC.FW.W.0013.210422T1900Z-210423T0300Z/
/O.CON.KTWC.FW.W.0012.000000T0000Z-210422T0300Z/
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 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
237 PM MST Wed Apr 21 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR STRONG AND GUSTY WINDS, LOW HUMIDITY AND A VERY HIGH FIRE 
DANGER RATING FOR FIRE WEATHER ZONES 151, 152 AND 154... 
...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MST THURSDAY FOR 
STRONG AND GUSTY WINDS, LOW HUMIDITY AND A VERY HIGH FIRE DANGER 
RATING FOR PORTIONS OF FIRE WEATHER ZONES 151, 152 AND 154...

The National Weather Service in Tucson has issued a Red Flag
Warning, which is in effect from noon to 8 PM MST Thursday. The
Fire Weather Watch is no longer in effect Thursday. 

* AFFECTED AREA...All of Fire Weather Zones 151, 152 and 154
  through 8 PM MST this evening and portions of Fire Weather Zones
  151, 152 and 154 Thursday.

* TIMING...Until 8 PM MST this evening and Noon to 8 PM MST
  Thursday. 

* WINDS...South to southwest winds of 20 to 30 mph with gusts to 
  45 mph today. Southwest winds of 15 to 30 mph with gusts to 35 
  to 40 mph on Thursday.

* RELATIVE HUMIDITY...Minimum relative humidity values 5 to 10 
  percent in the valleys and 10 to 15 percent over the higher 
  terrain both today and Thursday.

* 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.

&&

$$

AZZ150-220300-
/O.CON.KTWC.FW.W.0012.000000T0000Z-210422T0300Z/
Arizona Fire Weather Zone 150
Sonoran FDRA-Most of Pima County-South Central Pinal County-
Tohono O'odham Nation-Tucson Metropolitan area-TDC-
237 PM MST Wed Apr 21 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR STRONG AND GUSTY WINDS, LOW HUMIDITY AND A VERY HIGH FIRE 
DANGER RATING FOR FIRE WEATHER ZONE 150...

* AFFECTED AREA...Fire Weather Zone 150.

* TIMING...Until 8 PM MST this evening.

* WINDS...South to southwest winds of 20 to 30 mph with gusts to 
  45 mph.

* RELATIVE HUMIDITY...Minimum relative humidity values 5 to 10 
  percent in the valleys and 10 to 15 percent over the higher 
  terrain.

* 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
4 follow-up statements
093 
WWUS85 KTWC 220258
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
758 PM MST Wed Apr 21 2021

AZZ151-152-154-221100-
/O.EXP.KTWC.FW.W.0012.000000T0000Z-210422T0300Z/
/O.CON.KTWC.FW.W.0013.210422T1900Z-210423T0300Z/
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 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
758 PM MST Wed Apr 21 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TO 8 PM MST
THURSDAY FOR STRONG AND GUSTY WINDS, LOW HUMIDITY AND A VERY HIGH
FIRE DANGER RATING FOR FIRE WEATHER ZONES 151, 152, AND 154... 

...RED FLAG WARNING WILL EXPIRE AT 8 PM MST THIS EVENING FOR FOR 
FIRE WEATHER ZONES 151, 152, AND 154...

* AFFECTED AREA...Fire weather zone 151, 152 and 154.

* TIMING...Noon to 8 PM MST on Thursday.

* WINDS...Southwest winds of 15 to 30 mph with gusts to 35 to 40 
  mph on Thursday.

* RELATIVE HUMIDITY...Minimum relative humidity values 5 to 10
  percent in the valleys and 10 to 15 percent over the higher
  terrain on Thursday.

* 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.

&&

$$

AZZ150-153-220400-
/O.EXP.KTWC.FW.W.0012.000000T0000Z-210422T0300Z/
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 153
Northern Graham County-Northern Greenlee County-
White and Gila Mountains-Apache Sitgreaves NF-
Southern San Carlos Reservation above 5000 feet-SDC-
758 PM MST Wed Apr 21 2021

...RED FLAG WARNING WILL EXPIRE AT 8 PM MST THIS EVENING FOR FIRE
WEATHER ZONES 150 AND 153...

Winds continued to diminish in speed along with the relative
humidity starting to increase. Thus, the warning will expire at 8
PM MST.

$$


Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
502 
WWUS85 KTWC 221017
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
317 AM MST Thu Apr 22 2021

AZZ151-152-154-222300-
/O.CON.KTWC.FW.W.0013.210422T1900Z-210423T0300Z/
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 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
317 AM MST Thu Apr 22 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 8 PM MST
THIS EVENING FOR STRONG AND GUSTY WINDS, LOW HUMIDITY AND A VERY
HIGH FIRE DANGER RATING FOR FIRE WEATHER ZONES 151, 152, AND
154...

* AFFECTED AREA...Fire weather zone 151, 152 and 154, south and
  east of a Nogales to Benson to Safford line.

* TIMING...Noon to 8 PM MST today.

* WINDS...Southwest winds of 15 to 30 mph with gusts to 40 mph. 
  Stronger gusts possible over higher ridges. 

* RELATIVE HUMIDITY...Minimum relative humidity values around 10 
  percent in the valleys and 10 to 18 percent over the higher 
  terrain.

* 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 very 
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
439 
WWUS85 KTWC 222032
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
132 PM MST Thu Apr 22 2021

AZZ151-152-154-230300-
/O.CON.KTWC.FW.W.0013.000000T0000Z-210423T0300Z/
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 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
132 PM MST Thu Apr 22 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MST THIS EVENING
FOR STRONG AND GUSTY WINDS, LOW HUMIDITY AND A VERY HIGH FIRE
DANGER RATING FOR FIRE WEATHER ZONES 151, 152, AND 154...

* AFFECTED AREA...Fire weather zone 151, 152 and 154, south and 
  east of a Nogales to Benson to Safford line. 

* TIMING...Until 8 PM MST this evening.

* WINDS...Southwest winds of 15 to 30 mph with gusts to 40 mph. 
  Stronger gusts possible over higher ridges.

* RELATIVE HUMIDITY...Minimum relative humidity values around 
  10 percent in the valleys and 10 to 18 percent over the 
  higher terrain.

* 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 very
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
634 
WWUS85 KTWC 230306
RFWTWC

URGENT - FIRE WEATHER MESSAGE
National Weather Service Tucson AZ
806 PM MST Thu Apr 22 2021

AZZ151-152-154-230415-
/O.EXP.KTWC.FW.W.0013.000000T0000Z-210423T0300Z/
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 154
Forest Woodlands FDRA including the Sky Islands of Southeast
Arizona above 5500 feet-Coronado NF-TDC-
806 PM MST Thu Apr 22 2021

...RED FLAG WARNING HAS EXPIRED FOR FIRE WEATHER ZONES 151, 152, 
AND 154...

Winds continued to diminish in speed along with the relative
humidity starting to increase. Thus, the warning expired at 8 PM 
MST.

$$

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The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 10:21 AM MSTBlowing Dust AdvisoryTWCPima, Pinal10 hr

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.