Heating up early in the West, Southwest
Our weather here across the Inland Northwest has literally been the envy of those living in California, the Desert Southwest and the Southeast last week. While temperatures in Coeur d’Alene and surrounding regions have been in the pleasant 70s and 80s, record-smashing heat has been reported in places like Sacramento, Palm Springs, Las Vegas and Phoenix, just to name a few areas. In the Southeast, tropical moisture drenched that part of the country.
Many of us heard about the dangerous heat that developed over California and the Desert Southwest last week, which continues across the southwestern portions of the country early this week. For example, for three days in a row, Phoenix brought record high temperatures. On June 19, the mercury hit 118 degrees. The hottest day was on Tuesday, June 20 with an extremely hot 119 degrees, the fourth hottest day on record. It was 117 degrees on June 21. Phoenix also broke the record for the warmest low temperature on June 21 with a low was 90 degrees. It’s hard to believe that their midnight temperature on that date was about 100 degrees.
In other parts of the Desert Southwest, highs were at or above 120 degrees. Yuma, Ariz., topped out at 120 degrees last week and Palm Springs, Calif., hit 122 degrees last Tuesday.
Also on June 20, it was extremely and dangerously hot in the desert areas. Death Valley, Calif., set a new record for the date with a high of an incredible 127 degrees. Despite the high heat, tourists were flocking to Death Valley to get a picture next to the digital thermometer next to the visitor center, which in direct sunlight measured 130 degrees. People using their smartphones were only able to use them for less than 10 minutes before the devices would shut down from the heat. By the way, Death Valley’s official 127 temperature last week was only 7 degrees below their all-time world record high of 134 degrees set back in 1913.
My friends and relatives who live in the Sacramento, Calif., area were also having great difficulty in dealing with the oppressive heat last week. Reports of temperatures of over 110 degrees were common and the ones with pools measured water temperatures in the 90s. It was like bath water and too warm to swim.
Last week’s heat was so intense that there were reports of widespread power outages as the power grids were overwhelmed with most people using their air conditioners to keep cool. This weather also led to dozens of flights being canceled because, for some planes, it was too dangerous to fly.
Most of the flights that were affected leaving the Phoenix Sky Harbor International Airport last week were the smaller Bombardier CRJ airlines, not the bigger planes like the Boeing 747 and others. The reason is that hot air is much less dense and more shallow than cold air so aircrafts need more power from their engines to take off. In very hot temperatures near 120 degrees, some of the smaller planes have a more difficult time generating the “lift” required to get the plane in the air, resulting in potential safety issues. Also, aircraft components may overheat and become damaged due to the high temperatures.
Experienced pilots and other airline personnel will check on what is known as the “density altitude.” This is the pressure altitude corrected for temperature. The air density decreases as the temperature and altitude increase. According to aopa.org, it’s essentially the altitude at which the airplane “feels” its flying. On those hot and humid days, the airplane moves slower and needs more engine power to create the same lift.
By contrast, airplanes usually perform very well when the air is very cold, assuming there’s no ice or snow. The colder air is more dense and provides more lift. On Jan. 15, 2009, the U.S. Airways Flight 1549 was hit from bird strikes, which disabled the engines and forced the pilots to land in the Hudson River in New York. In that case, the plane able to stay airborne longer due to the remarkable skill of its pilots and the dense air. The aircraft was able to glide long enough to land in the water and miss the George Washington Bridge. If this incident occurred with much warmer temperatures, the outcome may have been more serious.
In terms of our local weather, after the chance of an isolated shower or thunderstorm today, it looks like lots of sunshine and very warm afternoons into July. The Fourth of July looks dry and warm. The rest of the summer season should be quite nice, but we’ll see some afternoons with highs into the 90s, especially toward the end of next month. August should have close to “normal” precipitation and temperatures. Moisture should start increasing later in the fall to above normal levels, especially if sea-surface temperatures don’t warm up.
Contact Randy Mann at randy@longrangeweather.com