The Grasshopper Fire has grown slightly and now covers nearly 93,800 acres.  Containment remains at 76 percent.  Fire officials say crews were prepared for another challenging day on the fireline, with rising temperatures, lower humidity and gusty winds in the forecast.  Similar conditions Monday increased fire activity in two areas — the Boulder Creek area in the southwest corner of the fire, and the northwest corner east of Highway 35.  Tethered logging operations are continuing to remove heavy fuels in steep terrain, while other logging crews are clearing wood and slash piles near Highway 35.  On the eastern and southern portions of the fire, where containment lines have held, crews are planning rehabilitation work to reduce the risk of erosion and other environmental damage.  Fire managers are watching for critically dry fuels to become more volatile today.  Officials say tree torching is possible, and people may see more smoke than in recent days.  Communities east of the Grasshopper Fire could also see worsening air quality today, with some areas reaching unhealthy levels.