On Sunday afternoon, the National Weather Service in Pendleton issued an excessive heat warning for the Tri-Cities, Yakima, Walla Walla, Hermiston, and surrounding areas. This replaces the excessive heat watch issued for the region on Saturday. The warning goes into effect Monday at 11:00 and runs until 23:00 Friday.
As I noted in my blog post on Saturday, hot temperatures are likely to continue past Friday, but that far out is too far for the National Weather Service to reasonably issue an alert for. I expect the warning timeframe to be extended as time goes on.
The entire seven-day forecast calls for highs above 100° for the Tri-Cities. The hottest temperatures begin Thursday, which may be the beginning of a several day stretch with highs above 110°. I expect the hottest temperatures to be found in the Tri-Cities and Hermiston areas, possibly reaching 115°.
Not only is it possible for daily records to be broken in the Columbia Basin, but this heat wave may also challenge the record for consecutive days above 100°, 105°, and 110°. At the Tri-Cities, these records are 10, 6, and 5 days in a row respectively.
Several nights in a row with lows in the 70s are going to limit overnight relief. While most folks in the Columbia Basin have air conditioning in their homes, there are some who don’t. Check on neighbors and friends, especially the elderly and those in older homes.
Charlie Phillips, a meteorologist in Seattle and fellow WeatherTogether blogger pointed out that unlike the 2021 heat wave, this event is not what some might call a heat dome. In 2021, an area of high pressure in the upper levels broke off from the general flow and creating a literal dome over the Pacific Northwest. The heat wave this week will result from high pressure, but is not separated from the rest of the flow over North America.
It is starting to look like a system during the first week of August will be the Pacific Northwest’s next chance at temperatures closer to average. For the Lower Columbia Basin, that’s highs in the low to mid 90s.
This post is mainly meant to focus on the excessive heat warning and forecast for the Lower Columbia Basin. For a broader look at the weather pattern causing this heat wave, see Charlie’s excellent blog post from Sunday morning or mine from Friday afternoon.
