PORTLAND, Ore. (AP) - The National Weather Service in Portland has issued an excessive heat warning.
The warning issued Monday runs from noon Tuesday until late Friday. Forecasters say the high temperatures Wednesday and Thursday might reach Portland's all-time record of 107 degrees.
Triple-digit highs are already present in some parts of the state, with Medford expected to hit 105 degrees on Monday afternoon and exceed 110 on Wednesday and Thursday.
The weather service warns that the elderly will be particularly vulnerable during the heat wave. It has also warned people to reschedule strenuous activities to early morning or evening hours, and not leave pets or children in hot vehicles.
An excessive heat warning also is set to go into effect for much of the interior of Western Washington this week.
The warning begins 2 p.m. Tuesday and remains in effect until 9 p.m. Friday.
KOMO reports ( http://bit.ly/2vbywzd ) a huge ridge of high pressure is building over the Pacific Coast this week, bringing in a hot air mass from the Desert Southwest. Meanwhile, a strong thermal trough will build along the coast by midweek, which will draw in a gusty east wind.
Highs Tuesday will get well into the 80s, with low- to mid-90s likely on Wednesday. On Thursday, there's the potential the potential for areas from Seattle south and east to reach 100 degrees or more.
The National Weather Service says the hottest day in Seattle since the 1890s was 103 degrees on July 29, 2009.