Dangerous northwestern U.S. heat will soon ease but only slightly
Temperatures in some locations have been rivaling the highest mark on record for any date this week.
"A northward bulge in the jet stream, an area of high pressure at the surface, intense sunshine and dry soil conditions are responsible for the extreme heat," according to AccuWeather Senior Meteorologist Brett Anderson.
The jet stream is a fast river of air at the level which aircraft cruises. The jet stream separates heat to the south from cool air to the north.
High pressure is a large area of sinking, dry air that spins in a slow clockwise direction.
The sinking air heats up as it descends through the atmosphere. The stronger the area of high pressure, the greater the amount of heat is produced.
It will still be hot this weekend but not as extreme.
"By this weekend, the jet stream will straighten out, and the area of high pressure will weaken," Anderson said. ■