Early Monday morning, the National Weather Service issued a heat advisory for the Columbia Basin. That advisory will still start at 11:00 Tuesday but now extends to 20:00 Thursday. It includes the Tri-Cities, Yakima, Walla Walla, Hermiston, and surrounding areas.
FORECAST
This heatwave comes just in time for the start of meteorological summer, which begins June 1. A ridge of high pressure is passing over the region to provide clear skies and hot temperatures. Wednesday is still forecast to be the hottest day, with highs likely nearing 105 for the Tri-Cities and Hermiston. This may break daily records for June 2. The daily record in the Tri-Cities, for example, is 103 set in 1986. The Columbia Basin should not get close to monthly records, however, which are around 110.
A cool down begins Thursday as the ridge axis moves to the east. While highs may be five to ten degrees cooler in some spots, this still places them within heat advisory criteria. A more active pattern is expected into the weekend as the ridge keeps moving on and an upper level trough takes it’s place. The trough will allow temperatures to continue to cool and as small disturbances move through the trough the region may experience breezy conditions and a few rain showers (though it looks like the rain will be mainly confined to mountain regions). Fine details on this pattern will become clearer in the coming days.
SAFETY TIPS
While the air will be hot, the water will not. On Sunday, Ice Harbor Dam recorded an average water temperature of 59 degrees. While water temperature will vary based on the time of day, water depth, and flow pattern, it is important to keep this in mind when recreating on area water bodies. Without proper gear, a person can become hypothermic in these temperatures in one to two hours.
On the other side of the spectrum, be sure to watch for signs of heat related illnesses. Try to limit your time outdoors to the morning and evening hours and drink plenty of fluids. Children and the elderly are especially vulnerable to these illnesses as their body temperature can rise three to five times faster than a typical adult’s. Remember that heat stroke is deadly and warrants medical attention.
Never leave children or pets unattended in vehicles. In 2020 alone, 25 children were reported as being killed by being left in a vehicle in the United States. This was well below the annual average, but each of these deaths was preventable.
The information in this post is accurate as of 11:45 May 31, 2021. You can check updated forecast info 24/7 by using my Forecast Map tool.
