Drought — Chiricahua Mountains, Arizona

2020-09-29 to 2020-09-30 · Chiricahua Mountains, Arizona

Event narrative

The extreme drought (D3) category, which began in late August, continued throughout September across the same sections of southeast Arizona from Tucson north and east, and expanded southward to encompass all of Graham and Greenlee counties along with all but the southwest quarter of Cochise County. The area included the San Carlos Apache Tribe lands, the White Mountains, Pinaleno Mountains, Santa Catalina Mountains and the Chiricahua Mountains.

Aside from isolated thunderstorms that produced heavy rain near the Pima/Cochise county line on the 8th and in northeast Cochise County on the 9th, most of the area received less than 0.25 of rainfall during September, and record breaking heat continued. While the heavy rain on the 8th doused the relatively small Spud Rock Fire in the Rincon Mountains, several other lightning caused wildfires that started in August continued into September due to the lack of monsoon rainfall. This included the Cow Canyon Fire in Greenlee County, which grew to over 1500 acres toward the end of the month in hot, dry and breezy conditions. Soil moisture readings were well below normal and fell below the 10th percentile ranking and levels at San Carlos Reservoir fell to less than 5 percent of storage capacity by the end of the month.

Wider weather episode

The extreme drought (D3) category, which began in late August, continued throughout September across the same sections of southeast Arizona from Tucson north and east, and expanded southward to encompass all of Graham and Greenlee counties along with all but the southwest quarter of Cochise County. Aside from isolated thunderstorms that produced heavy rain near the Pima/Cochise county line on the 8th and in northeast Cochise County on the 9th, most of the area received less than 0.25 of rainfall during September, and record breaking heat continued. While the heavy rain on the 8th doused the relatively small Spud Rock Fire in the Rincon Mountains, several other lightning caused wildfires that started in August continued into September due to the lack of monsoon rainfall. This included the Cow Canyon Fire in Greenlee County, which grew to over 1500 acres toward the end of the month in hot, dry and breezy conditions. Soil moisture readings were well below normal and fell below the 10th percentile ranking. Levels at San Carlos Reservoir fell to less than 5 percent of storage capacity by the end of the month.

Source: NOAA Storm Events Database, event_id 917550. Narrative written by the NWS forecast office that issued the report.