Arizona, 2020

Wildfire in Arizona, July 1 to 23, 2020

July 1 to 23, 2020 · NWS TWC · 4 events in 4 counties and zones

Lightning ignited the Bighorn Fire on the west side of the Santa Catalina Mountains during the evening of June 5th. The fire spread rapidly over the subsequent days and weeks, driven by multiple days of strong winds before becoming fully contained on July 23rd.

Where it happened

Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
2
Property damage
None recorded
Crop damage
None recorded
Events
4

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS TWC wrote it up.

Lightning ignited the Bighorn Fire on the west side of the Santa Catalina Mountains during the evening of June 5th. The fire spread rapidly over the subsequent days and weeks, driven by multiple days of strong winds before becoming fully contained on July 23rd. The fire consumed a total of 119,987 acres. Residents were evacuated at times and a total of nine firefighters sustained minor injuries while fighting the fire. While no property damage occurred, the cost of fighting the fire was estimated at $44 million.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tucson, AZ wrote its last area forecast discussion before the first event at Jun 30, 2:52 PM MST, 9 hours 8 minutes earlier.

Area forecast discussion, Jun 30, 2:52 PM MST, 9 hours 8 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
252 PM MST Tue Jun 30 2020

.SYNOPSIS...Dry conditions today with some afternoon breeziness.
Isolated to scattered afternoon and evening thunderstorms will then
prevail Wednesday through the weekend. Below normal temperatures
through Thursday followed by hotter temperatures Friday into early
next week.

&&

.DISCUSSION...Scattered flat cumulus clouds were across the
eastern half of the forecast area this afternoon otherwise it was
sunny. At the surface, the dewpoints have mixed out into the 30's
to lower 40's. Another day of gusty winds, but nothing like what
occurred Sunday and Monday.

Precipitable water values this afternoon ranged from 0.40" to
0.70" morning with values over 1" south of the border across
Sonora MX. With high pressure to the east and a weak trof off the
nrn Baja coast, the flow aloft turns southerly on Wednesday
pushing PW values over 1" across southern half of the forecast
area. Still some timing differences per the latest CAMS on this
transition day with isolated showers/thunderstorms moving north
across the area Wednesday afternoon into Wednesday night with a
few showers possible into the overnight hours. Main threat from
storms will be gusty winds and lightning, which hopefully doesn't
start any new fires. Can't rule out blowing dust between Tucson
and Phoenix late tomorrow afternoon into tomorrow evening. A few
showers lingering into the overnight hours.

Better chance of storms on Thursday with a bit more moisture
across the area. Drying out a bit on Friday for less storm
activity.

Slight chance of storms over the weekend, mainly mountain huggers,
as we hold on to limited moisture. Main concern over the weekend
will be how hot will it get as strong high pressure centers itself
over the area. Upped temps a degree each weekend day from previous
forecast.

Low grade monsoon forecast to start the first full week of July.

&&

.AVIATION...Valid through 02/00Z. SKC-FEW clouds 10k-15k ft MSL.
SFC wind southwest to west 13-20 kts with gusts 25-30 kts until
01/03Z. SFC winds then diminish to less than 12 kts after 01/03Z.
Isold -SHRA/TS after 01/19z, mainly SE of KTUS. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Dry conditions today with afternoon breezes,
though remaining below critical Red Flag thresholds. Increased
moisture starting on Wednesday will result in isolated to scattered
showers and thunderstorms mainly in the afternoon and evening each
day through the weekend for most of southeast Arizona with the
exception of Western Pima County where dry conditions will prevail.
Minimum humidity levels will be in the 15-30 percent range starting
Wednesday onward. Overnight recoveries will be very good.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...None.

&&

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

4 wildfire. Local standard time, as filed.

Wildfire, Tucson Metro Area

When
July 1, 12:00 AM MST to July 23, 12:00 PM MST
Where
Tucson Metro Area forecast zone
Reported by
Park/Forest Service
Coordinates
32.097, -111.790 (the zone’s center; the record gives no point)

Lightning started the Bighorn Fire on the west side of the Santa Catalina Mountains during the evening of June 5th. The fire spread rapidly over the subsequent days and weeks, driven by multiple days of strong winds. Residents of Summerhaven, nearby mountain communities and those on the periphery of the mountains from the Catalina Foothills to southern Pinal County and near Redington Road were evacuated at times, but no structures were damaged by the fire. Two firefighters sustained minor injuries battling the fire during July, bringing the total number of injured personnel fighting the fire to nine. The fire became fully contained on July 23rd after a total of 119,978 acres burned.

Wildfire, Southeast Pinal County

When
July 1, 12:00 AM MST to July 23, 12:00 PM MST
Where
Southeast Pinal County forecast zone
Reported by
Park/Forest Service
Coordinates
32.904, -111.345 (the zone’s center; the record gives no point)

Lightning started the Bighorn Fire on the west side of the Santa Catalina Mountains during the evening of June 5th. The fire spread rapidly over the subsequent days and weeks, driven by multiple days of strong winds. Residents of Summerhaven, nearby mountain communities and those on the periphery of the mountains from the Catalina Foothills to southern Pinal County and near Redington Road were evacuated at times, but no structures were damaged by the fire. Two firefighters sustained minor injuries battling the fire during July, bringing the total number of injured personnel fighting the fire to nine. The fire became fully contained on July 23rd after a total of 119,978 acres burned.

Wildfire, Upper San Pedro River Valley

When
July 1, 12:00 AM MST to July 23, 12:00 PM MST
Where
Upper San Pedro River Valley forecast zone
Reported by
Park/Forest Service
Coordinates
32.109, -110.569 (the zone’s center; the record gives no point)

Lightning started the Bighorn Fire on the west side of the Santa Catalina Mountains during the evening of June 5th. The fire spread rapidly over the subsequent days and weeks, driven by multiple days of strong winds. Residents of Summerhaven, nearby mountain communities and those on the periphery of the mountains from the Catalina Foothills to southern Pinal County and near Redington Road were evacuated at times, but no structures were damaged by the fire. Two firefighters sustained minor injuries battling the fire during July, bringing the total number of injured personnel fighting the fire to nine. The fire became fully contained on July 23rd after a total of 119,978 acres burned.

Wildfire, Santa Catalina and Rincon Mountains

When
July 1, 12:00 AM MST to July 23, 12:00 PM MST
Where
Santa Catalina and Rincon Mountains forecast zone
Injuries
0 direct, 2 indirect
Reported by
Park/Forest Service
Coordinates
32.501, -111.567 (the zone’s center; the record gives no point)

Lightning started the Bighorn Fire on the west side of the Santa Catalina Mountains during the evening of June 5th. The fire spread rapidly over the subsequent days and weeks, driven by multiple days of strong winds. Residents of Summerhaven, nearby mountain communities and those on the periphery of the mountains from the Catalina Foothills to southern Pinal County and near Redington Road were evacuated at times, but no structures were damaged by the fire. Two firefighters sustained minor injuries battling the fire during July, bringing the total number of injured personnel fighting the fire to nine. The fire became fully contained on July 23rd after a total of 119,978 acres burned.

What these are

Wildfire
A fire burning in wildland vegetation, with its acreage and damage where known.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Arizona in 2020Every state in 2020This day in weather historyWarnings in Arizona, July 2020

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 912335, 912336, 912337, 912338.