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Some Relief From the Heat is Ahead in the Northwest, California This Weekend Into Early Next Week
Published: August 11, 2018
A brief break from the very hot temperatures that have prevailed across the Northwest and much of California recently is expected this weekend and into early next week.
A strong and persistent upper-level ridge of high pressure has been in place over the West once again over the past week. This brought a stretch of well above-average temperatures to portions of the West Coast and Northwest.
Highs in the 90s and 100s have dominated the region, and several daily record highs have been set. Baker City, Oregon, set a new all-time record high on Thursday with 108 degrees, its hottest temperature in more than 90 years of recordkeeping.
Even in locations where records were not broken, temperatures were 10 to 20 degrees warmer than average for this time of year.
The stubborn heat in the West has even resulted in Reno, Nevada, setting an all-time record for the number of days that temperatures have climbed to at least 100 degrees in a year: 19 days in 2018 as of Aug. 11. The previous record was 16 days, set just last year.
A pattern shift is beginning to take shape, which is good news for those looking for a break from the excessive heat.
An upper-level trough, or southward dip in the jet stream, and a cold front will slide through the Pacific Northwest this weekend.
This will result in cooler temperatures spreading from west to east across the region.
High temperatures were near or slightly below average on Saturday from California into Washington and Oregon. Sunday and Monday, temperatures closer to average will reach into the interior Northwest, as well.
Onshore flow and cloud cover will also mean cooler temperatures in portions of California.
(MAPS: 10-Day Forecast)
Most of the West will experience temperatures a few degrees within average on Monday, although parts of the Northwest coast will begin to see increasing temperatures again.
Seattle will see temperatures near average for mid-August this weekend and 20 degrees cooler than this past week, when highs reached the mid-90s. The average high in Portland, Oregon, is in the lower 80s, and highs held in the 70s on Saturday, though temperatures will warm to near-average on Sunday.
Temperatures will still top out in the 90s in places like Boise, Idaho, and Reno, Nevada, but this will feel cooler than the recent hot stretch of highs above the century mark and will be near average for mid-August.
In addition to the cooler temperatures, western Washington and northwestern Oregon will see the chance for a few showers or thunderstorms into early Sunday. Rainfall accumulations will generally be light.
Portland measured 0.01 inches of rain just after noon Saturday, ending a 39-day streak with no measurable precipitation.
High pressure will build back into the Northwest next week, bringing warmer weather once again. However, current indications are that it will not be quite as hot as this past week.
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