Standing closed canopy timber is producing active fire behavior and spotting, adjacent fuels become less continuous with scattered timber, brush, grass, and exposed granite hillsides.

Red fir fuel type with montane shrub and brush understory interspersed with pockets of nonburnable fuels in granitite rock outcrops. Fir trees are large diameter and over 100 ft tall and suffer from insect and disease mortality, leading to significant snag component and 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 dad and down with standing snags, increasing spotting potential. 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 below 10%. Active burning in recent days illustrates a fuel complex that is generally available across all types and size classes.

Active Fire Behavior was observed with isolated torching, flanking and creeping.

Fire has continued to spread to the north and northeast via surface spread in heavy fuels and short to medium range spotting (between ¼ to ½ of a mile). The red fir fuel type has a significant dead and down component and is highly conducive to both ember production as well as ember reception, leading to frequent spotting. Wind alignments from the south and west increase spotting to the north and northeast, with a noteworthy large spot fire established east of Tanner meadow on the SW facing slope. The heavy fuel loading presents resistance to control issues for ground resources, reducing line production rates, though numerous granite outcroppings and bare areas provide some opportunities for using natural barriers. To the north, fire growth is expected to slow as it encounters the footprint of the 2017 Empire Fire. Threats to values at risk and potential fire behavior are greatest as the fire moves downslope to the west and southwest, where heavier mixed conifer fuels increase potential for fire behavior that would challenge ground resources. The fire remains wholly within the wilderness area of Yosemite National Park and is expected to stay that way through the forecast period.

Construct direct handline where topography and fire behavior permit. Establish secondary and contingency lines. Employ rotary-wing aviation assets to check fire spread, moderate flame lengths to thresholds suitable for direct attack. Continue to identify and construct helispots and sling sites to support operational mission. Establish Badger Camp within 48 hours.

12 hours: The current fire footprint lies on the margin of a predicted afternoon precipitation event. Should the system materialize, fire behavior will decrease as fine fuel moisture values recover. A forecasted easterly wind shift will accompany the system. Without a wetting rain, wind alignment will accelerate growth westward along the main perimeter and eastward across active spot fires where continuous, unburned fuels remain highly receptive. 

24 hours: A return to a warm and dry pattern will resume a backing fire progression, with spot fire spread driven by ridge-top winds. Even moderate to light winds have resulted in frequent spotting. Growth from spots to the north and east will continue as fire establishes in isolated timber stringers. Potential for short uphill runs and continued spotting in red fir fuels remains as fire in drainages responds to the warming and drying trend. Northwestern flank of the fire will continue to back downslope driven by rollout and shortrange spotting. In the south, fire is likely to remain in the Chilnualna drainage along the creek. If it crosses the creek, it will enter the footprint of the 2017 South Fork Fire, where it will be in alignment with slope but out of wind alignment and in an area with less fuel than the current perimeter. Successful suppression efforts make crossing Chilnualna Creek lower probability than previously. 

48 hours: Steady northward progression in the 2017 Empire fire footprint will likely bring the fire in the vicinity of Empire Meadow and the northern reach of Alder Creek. Northeastern spread will reach and could cross Bridalveil Creek in the absence of suppression actions. Eastern spread will be confined to timber stringers and meadows between patches of unburnable rock 

72 hours: Fire growth will continue along uncontained segments of the fire perimeter. Spread is expected to remain minimal unless the fire establishes in continuous timber stringers along the northern and eastern flanks under favorable wind and slope alignment. If suppression efforts along the west flank are not successful, fire will also likely back down to the main stem of Alder Creek west of current perimeter. 

Anticipated after 72 hours: Continuing warm and dry weather will be conducive to fire spread with no significant change in weather pattern in the current forecast. Area of the fire unchecked by suppression action will make uphill runs and produce frequent spotting when fuels and slope align with wind direction. Diurnal patterns of west and south winds in the afternoon will push fire to the north and east while downcanyon/downslope winds overnight contribute to west and southwest spread when unchecked by suppression actions.

Observed: An area of low pressure moving through California brought a few showers and isolated thunderstorms to the Sierra. Rainfall amounts in and around the fire are expected to remain around a tenth of an inch or less. This will lead to higher humidity and cooler temperatures. West winds will shift to the northeast around 8-10 mph late this afternoon and evening. 

12-Hour Overnight: Mostly cloudy skies will dissipate overnight with mostly clear skies expected by morning. There could be a few isolated light showers in the evening, but most of the precipitation will have ended after sunset. Relative humidity will recover into the 60-70% range. Temperatures will cool into the upper 40s to lower-50s, with light drainage winds of 2-5 mph.

24-Hour: The system responsible for the unsettled weather will move east Tuesday, with less cloud cover and no precipitation expected. Temperatures will remain rather cool, with highs in the mid to upper 50s, while minimum humidity will remain elevated in the 40s. Southwest to west winds will be 4-7 mph, with occasional gusts to 10 mph. 

48-Hour: Warmer and drier conditions will develop Wednesday, with highs in the 60s and humidity falling into the 30s. High pressure will build back into the region. Winds will follow a typical diurnal pattern with just a few gusts to around 10 mph in the afternoon. 

72-Hour: Similar conditions expected Thursday with temperatures in the mid-60s, humidity falling into the mid-30s and typical diurnal winds. 

Extended (After 72 Hours): High pressure will weaken by the end of the week as an area of low pressure approaches the west coast. This will bring slightly cooler temperatures and a slight increase in afternoon winds. No precipitation is expected through the weekend.