AgWeatherNet Weekly Weather Outlook Monday Update for April 12 to April 18, 2021

A dry week ahead for Washington with breezy conditions in some areas

Mark Ingalls, AgWeatherNet Intern
Craig Oswald, AgWeatherNet Field Meteorologist

Synopsis:

Mostly sunny skies are expected across most of Washington through the week as the region lies under the influence of competing dry weather systems. East-northeasterly winds are expected statewide with breezy conditions daily and rather windy conditions in the Columbia Basin through Thursday. Otherwise, a warming trend is in the forecast, lasting Monday through Saturday west of the Cascades and Wednesday through the weekend in the eastern half of the state.

Discussion:

Dry conditions will be in place across Washington for most of the week with flow generally coming from the interior of the continent through about Friday. A ridge of high pressure is building across British Columbia and Alberta. Meanwhile an upper feature over the Canadian Prairies is expected to spin up into a cutoff low that should be in place over the Great Basin by Tuesday. There is a chance of some upslope showers near the crest of the Cascades and Blues as the low's center moves toward Nevada, but that is about all the precipitation that can be expected, and even this is a long shot given how dry conditions have been recently and continue to be.

Daytime heating and cooler temperatures aloft will promote vertical mixing to mix stronger winds aloft down to the surface through Thursday in the Columbia Basin. The windiest day should be Tuesday, when gusts may reach 45+ mph in some spots with a stiff breeze spreading into adjacent areas.

Typically, winds would trend lighter during the overnight hours with the loss of daytime heating. This is not expected to be the case this week as cold air fills into the Canadian Prairies causing a large area of high pressure to build. At the same time, a surface trough of low pressure (separate from the larger low in the Great Basin) is forecasted to build along the Washington and Oregon Coast. Under this setup, wind will flow from Alberta toward the coast, keeping things breezy in the Columbia Basin overnight with light to breezy winds in places like Western Washington, the Yakima Valley, and Okanogan. As Alberta, Saskatchewan, and Manitoba warm this week the high pressure will weaken, slowly decreasing winds with nearly calm conditions possible Thursday night.

Starting Friday, the low over the Great Basin is forecast to move eastward, allowing the ridge to build south into the Western United States. This should lessen winds further and allow warmer temperatures to spread into the region. The Puget Sound Region may see temperatures above 70 degrees Saturday. By Sunday, the warmest parts of the Columbia Basin may exceed 80 Sunday.

Looking forward beyond the forecast period, models are indicating a return to unsettled weather midweek as the ridge breaks down. Look for more details on that in the outlook on Friday. Drought conditions have once again expanded in the Columbia Basin following a dry couple of weeks. There has been no expansion to the severe drought (D2/5) area, which covers a small area including George, Prosser, Plymouth, and Maryhill. Moderate drought (D1/5) now includes Ritzville and Goldendale, along with locations that were already covered such as the Tri-Cities, Moses Lake, and Yakima. Drought conditions do not presently exist in mountain regions of Washington, Idaho, and British Columbia, which should help to mitigate effects in irrigated regions of the Yakima Valley and Columbia Basin for the time being.


Important Points About Next Week's Weather

South Central Washington
Remainder of the Week
  • Wind: Out of the NE, breezy through Thu.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 60s Tue, mid 60s Wed, upper 60s Thu, mid 70s Fri.
  • Low Temps: Upper 30s Mon-Fri nights.
  • Sky Cover: Clear.
Weekend
  • Wind: Generally light and variable.
  • Precipitation: Dry conditions expected.
  • High Temps: Upper 70s Sat, low 80s Sun.
  • Low Temps: Mid 40s Sat & Sun nights.
  • Sky Cover: Clear.

North Central Washington
Remainder of the Week
  • Wind: Generally N to NE, widespread breezy Tue, breezy in the Basin through Thu.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 60s Tue, mid 60s Wed, upper 60s Thu, low 70s Fri. Cooler in higher terrain.
  • Low Temps: Mid 30s Mon-Tue nights, upper 30s Wed-Fri nights. Cooler in higher terrain and sheltered valleys.
  • Sky Cover: Clear.
Weekend
  • Wind: Generally light and variable.
  • Precipitation: Dry conditions expected.
  • High Temps: Upper 70s Sat & Sun. Cooler in higher terrain.
  • Low Temps: Mid 40s Sat & Sun nights. Cooler in higher terrain and sheltered valleys.
  • Sky Cover: Clear.

Eastern Washington
Remainder of the Week
  • Wind: Generally NE, breezy areas through Thu.
  • Precipitation: Dry conditions expected.
  • High Temps: Upper 50s Tue, low 60s Wed, mid 60s Thu, upper 60s Fri. Warmer in the Lewis & Clark Valley.
  • Low Temps: Low 30s Mon-Wed nights, mid 30s Thu-Fri nights. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Clear.
Weekend
  • Wind: Generally light and variable.
  • Precipitation: Dry conditions expected.
  • High Temps: Mid 70s Sat & Sun. Warmer in the Lewis & Clark Valley.
  • Low Temps: Low 40s Sat & Sun nights. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Clear.

Western Washington
Remainder of the Week
  • Wind: E with breezy areas along the coast and mountain gaps through Thu.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 60s Tue, mid 60s Wed-Thu, low 70s Fri. Cooler in higher terrain and along the coast.
  • Low Temps: Near 40 Mon-Wed nights, mid 40s Thu night, upper 40s Fri night. Cooler in higher terrain.
  • Sky Cover: Clear.
Weekend
  • Wind: E with breezy areas Sat, light and variable Sun.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 70s Sat & Sun. Cooler in higher terrain and along the coast.
  • Low Temps: Upper 40s Sat & Sun nights. Cooler in higher terrain.
  • Sky Cover: Clear.

Washington State University