The 11th Conference on Applied Climatology

5.5
EL NINO AND ITS IMPACT ON FIRE WEATHER IN ALASKA

Jason Hess, NOAA/NWS, Anchorage, AK; and C. Scott and G. Hufford

Examining the relationship of El Nino to weather patterns in Alaska shows wide climate variations that depend on the teleconnection between the tropics and the northern latitudes. However, the weather patterns exhibited in Alaska during and just after moderate to strong
El Nino episodes are generally consistent: above normal temperature and precipitation along the Alaska coast, and above normal temperature and below normal precipitation in the interior. The warm, dry conditions in the interior increase wild fire potential. Statistics on the amount of acreage burned since 1940 show that fifteen out of seventeen biggest fire years occurred during a moderate to strong El Nino episode. The average amount of acreage burned during these fifteen events was 966,328 hectares, compared to 340,002 hectares during normal years. The El Nino years account for nearly 63% of the total acreage burned over the last 58 years. Evidence points to increased dry thunderstorms and associated lightning activity during an El Nino episode in the interior; the percent of total acreage burned by lightning caused fires increases from a normal of less than 40% to greater than 96%.

The 11th Conference on Applied Climatology