National Significant Wildland Fire Potential Outlook (July 2020)
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Significant Wildland Fire Potential Outlook
July 2020
Significant Wildland Fire Potential Outlook
August 2020
Significant Wildland Fire Potential Outlook
September 2020
Significant Wildland Fire Potential Outlook
October 2020
National Significant Wildland Fire Potential Outlook
Predicted by, National Interagency Fire Center
Issued: July 1, 2020
Outlook Period: July, August, September, and October 2020
Executive Summary
The significant wildland fire potential forecasts included in this outlook represent the cumulative forecasts of the ten Geographic Area Predictive Services units and the National Predictive Services unit.
A significant increase in fire activity was observed in June as fine fuels became critically dry across most of the southern half of the West. Persistent hot and dry conditions along with periodic wind events allowed for the development of large fires across the Southwest, Colorado, and Southern California. In Alaska, dry fuels became receptive to fire early in the month. A persistent, month-long convective pattern developed and started numerous fires. However, most storms were wet, and the cumulative effects of the precipitation eventually reduced the large fire potential across much of the state. A three day lighting event led to an increase in fire activity during third week of the month across the Great Basin and California.
Precipitation was below average in June across most of the country except across the Pacific Northwest where amounts were generally 150% of average or greater. Areas of concern emerged across California, the Great Basin, and Arizona where less than 5% of monthly precipitation was received. Temperatures were generally a few degrees above normal along the Pacific Coast and a few degrees below normal across the Interior West. In the East, temperatures were generally near normal in June.
July is the entry point into the core of the Western Fire Season. As the season sequentially expands west and north across California, the Great Basin and the Central Rockies into the Northern Rockies and the Pacific Northwest, it will encounter areas of intensifying and expanding drought. This will lead to Above Normal significant large fire potential across large portions of the Great Basin and Northern California that will expand further north into the Pacific Northwest and Northern Rockies in August and September. The elevated potential in southwestern areas will begin to diminish with the arrival of the monsoon in early July. Activity will linger into mid-September in northern areas until the seasonal transition begins and begins to bring the season to a close. In Alaska, significant large fire activity will become less frequent in late July as returning moisture events gradually reduce the fire potential.
October will mark the beginning of a period of activity for Southern California as the fall wind season begins. With a transition to a La Niña episode expected, drier than average conditions are forecasted to occur. The factors that favor the development of Foehn wind events may be more frequent in occurrence. Given the heavy loading of fine fuels, this is a concern.