With high temperatures in the forecast, it's time for another summer branch drop advisory. Summer branch drop is a widely-observed, poorly-understood phenomenon where large horizontal or leaning limbs or stems suddenly break and fall. It seems to occur more on hot, calm afternoons of late summer, and may be associated with heavy foliage and/or heavy seed crops. Recommendations on hot, still, late summer afternoons include: do practice situational awareness; don't leave immobile people (infants, elderly, etc.) directly under large oak trees; do run away if you hear a sharp crack in an overhead oak tree; do report witnessed tree failures. Residents and workers who are under oaks daily may have a higher exposure to risk of tree failure than visitors. For additional information about tree hazards and tree hazard management in Yosemite National Park go to:
http://www.nps.gov/yose/planyourvisit/yoursafety.htm