Timber (Litter and Understory) Brush (2 feet) Medium Logging Slash

Red fir fuel type with montane shrub and brush understory interspersed with pockets of non-burnable fuels in granite rock outcrops. Fir trees are large diameter, over 100 ft. tall, and suffer from insect and disease mortality, leading to a significant snag component with large amounts of heavy dead and down coarse woody debris. Most active fire behavior has come from the dense, closed canopy red fir stands, where torching and isolated crown fire pockets have also contributed to spotting. Fuels in 2017 fire footprints have less closed canopy but contain significant dead and down with standing snags, increasing spotting potential. Surface spread rates are lower in the Empire Fire (2017) Footprint, but spotting continues to drive spread. Montane shrubs and brush in the understory are generally available to burn but are not at critical fuel moisture levels. Heavy dead and down fuels are dry, with fuel moisture in 1,000 hr. fuel around 12%.

Moderate, Spotting, Creeping, Single Tree Torching

Creeping fire behavior observed in the unburned fuels within the fire perimeter. The heavy fuel accumulations of dead and down continue to readily consume, deep root systems continue to smolder. Slash and blowdown in the previous burn scars continue to burn freely within the current fire perimeter near Horizon Ridge and H-17. Fuels adjacent to the fire perimeter remain receptive to spot fires. This has been the primary factor to fire’s spread.

Strengthen primary and contingency lines. Employ rotary-wing aviation assets to check fire spread, moderate flame lengths to thresholds suitable for direct attack. Crews may conduct firing operations as appropriate to bring fire to containment line from Division M/Q break to the east and south toward Division T. In Branch 5 continue with patrol and mop up in Division A. In Division Z crews will be constructing direct line to Division T/Z break and patrolling completed primary lines from the A/Z break north towards the Z/T break. In Division T will be scouting and/or constructing direct/indirect fire lines along the eastern portion of the fire to the T/Q break.

12 hours: Overnight heavy interior fuels will continue to consume. With lack of pronounced overnight winds conditions are not favorable for fire spread. Any potential spread is further suppressed by the presence of an overnight inversion.

24 hours: Fire spread will generally be terrain driven if ember cast establishes a spot fire outside the current perimeter. Continued spread eastward toward Ostrander Lake and east from H-17 are possible on the eastern flank. Fire will continue to back down toward Alder Creek on the western flank.

48 hours: Fire spread will generally be terrain driven if ember cast establishes a spot fire outside the current perimeter. Continued spread eastward toward Ostrander Lake and east from H-17 are possible on the eastern flank. Fire will continue to back down toward Alder Creek on the western flank.

72 hours: Fire spread will generally be terrain driven if ember cast establishes a spot fire outside the current perimeter. Continued spread eastward toward Ostrander Lake and east from H-17 are possible on the eastern flank. Fire will continue to back down toward Alder Creek on the western flank.

Anticipated after 72 hours: Slight decrease in temperatures, however wind values increase slightly and revert to a southwest direction, in alignment with earlier spread. Elevated spotting potential continues. Fire spread that has reached alignment with uphill slopes may lead to areas of active growth. Challenge to existing indirect control lines should be anticipated if reached by fire spread.

Observed: Mostly sunny conditions with some fair weather cumulus are occurring today across the fire area today. Very warm temperatures in the 60s and 70s and minimum relative humidity in the 20-30% range are occurring. Terrain driven winds from the west up to 8 mph with gusts 10-18 mph are being observed. 

12-Hour Overnight: Clear with typical drainage winds, mostly from the east. Relative humidity recoveries are likely to be 40-60% with low ranging from the upper 40s to near 60. Smoke will again settle into the drainages in and around the fire area.

24-72 Hour Forecast: Warm and dry conditions with similar temperatures, relative humidities, and winds to the short term are expected to continue Tuesday thru Thursday as high pressure across the area strengthens a bit. 

Extended (After 72 Hours): There is high confidence in a significant weather change to cooler weather beginning Friday into this weekend. Temperatures are likely to decrease by 10-20 degrees from Thursday to Sunday. A period of increased mixing and gusty winds are likely with a slight chance of measurable precipitation.