Summer brings fire weather season
The Panhandle has seen some much needed rainfall and cooler temperatures during the past week, which have helped bring the year-to-date rain totals close to normal. As of May 23, 1.51 inches of rain had fallen across Coeur d’Alene, bringing our year-to-date total to 11.08 inches. Though near normal, this spring probably seems much drier compared with last year’s soggy season, when nearly 17 inches of rain had fallen in the same time period.
The summer season starts next month and with it will come fire weather season as temperatures start to warm up. In addition to rainfall, temperatures, relative humidity and wind will become important factors to keep an eye on. Fire weather season runs from mid-June to October and usually peaks in July. Though it seems like the Western United States is plagued with more than its fair share of wildfire woes each summer, Florida and Georgia are the areas currently being hit hard. Nearly 500 fires have been reported in Florida during the first two weeks of May, burning more than 170,000 acres.
Severe to extreme drought is affecting the region, where some locations are seeing rainfall amounts as much as 16 inches below normal for the year. Though the Idaho Panhandle is experiencing near-normal conditions, according to the drought severity index put out by the Climate Prediction Center, areas from western Wyoming into Southern Idaho and much of the desert Southwest are experiencing extreme drought conditions. This does not bode well ahead of a summer season that is expected to be hotter and drier than normal, especially in the already drought-parched regions.
Weather conditions may be responsible not only for starting fires but for either aiding or hindering their growth as well. Locally, dry lightning is the leading cause of wildfires. In 2006, of 196 large wildfire incidents in Idaho, 149 were caused by lightning.
Once fires get going, the humidity and wind play a crucial role in fire growth. Obviously, the most dangerous conditions consist of low humidities coupled with strong winds. The passage of cold fronts during fire weather season often present the most troublesome scenarios. Storms ahead of the front may produce lightning which can ignite wildfires. Behind the front, strong winds worsen the situation for fires that are already burning.
Just as weather can affect a fire, the opposite is true as well. Large, violent wildfires can create their own strong winds called fire whirls. The rapidly rising hot air begins to rotate, much like a tornado, and debris can be hurled considerable distances.
When dangerous fire weather conditions are forecast, a fire weather watch is issued by the National Weather Service. The watch is upgraded to a “red flag warning” when critical fire weather conditions, which could lead to explosive fire growth, are occurring or are expected shortly.
Memorial day weather
In this part of the country, most folks don’t expect scorching weather for the Memorial holiday weekend. Average highs hover right around 70 degrees. Last year, after temperatures soared into the 90s during the middle of the month, a long stretch of wet weather cooled temperatures back down into the 50s and 60s through May 31. In the previous five years, high temperatures for Memorial Day ranged from the low 60s to the upper 70s. This year temperatures are expected to be close to normal.