AgWeatherNet Weekly Weather Outlook for July 19 to July 25, 2021

Mainly dry this week with highs near average for many

Mark Ingalls, AgWeatherNet Intern

Synopsis:

A cool down is slated to begin Tuesday as an upper level trough begins to work its way across British Columbia. Precipitation is forecast to be limited with some drizzle possible along the Coast and low precipitation thunderstorms in mainly mountainous regions near the Idaho border. Low clouds are likely to be observed through much of Western Washington's lowlands with dry and mostly sunny conditions east of the Cascades. Friday through Sunday should remain dry with temperatures reaching a few degrees higher.

Discussion:

An area of low pressure and associated upper level trough located in the Pacific Ocean off British Columbia are forecast to begin passing over the province Tuesday. This will result in a cooling trend for Washington with enhanced onshore flow. West of the Cascades, some drizzle is possible along the coast with low clouds spreading into inland lowland areas through Wednesday. East of the Cascades, very little cloud cover is expected. Isolated dry thunderstorms are possible in mountainous areas near the Idaho border through Wednesday morning.

Wednesday is likely to be the coolest day of the week in Western and North-Central Washington with Thursday being the coolest in South-Central and Eastern Washington. Friday, the region warms under the influence of a ridge building on the High Plains. Since the Pacific Northwest will be well removed from the ridge axis, temperatures are only forecast to raise by a few degrees. Most of the lowlands west of the Cascades will remain below 80 degrees through the weekend, with highs in the eastern half of the state generally in the upper 80s to mid 90s.

Throughout the week, haze and smoke will contribute to local weather conditions. With the position of current major fires and the upper level flow pattern, most of the smoke should be limited to areas generally east of the Tri-Cities and Moses Lake. Locations with heavy smoke may see lower afternoon temperatures.

The drought gripping the American West continues to worsen in Washington. In last week's update of the National Drought Monitor, exceptional drought was noted, generally within about thirty miles of Othello, with a small area reaching in from Idaho to also include Clarkston. Exceptional is the worst of the four drought categories used for the National Drought Monitor and this represents the first time conditions this bad have been noted anywhere in Washington since the drought monitor began to be issued in 2000.

Most of the rest of Eastern Washington remains in extreme drought (level 3/4). West of the Cascades, Clark County continues to have severe drought (level 2/4). Moderate drought (level 1/4) conditions have now spread up the I-5 corridor to around Tacoma. The northwestern portion of the Olympic Peninsula, San Juan Islands, northern Island County, and lowland portions of both Whatcom and Skagit Counties. With little if any precipitation in the forecast, the drought is likely to continue slowly worsening for the foreseeable future.


8 to 14 Day Outlook, July 26 to August 01, 2021
  • Above average temperatures and below average precipitation are favored for the period.

Important Points About Next Week's Weather

South Central Washington
Remainder of the Week
  • Wind: W to SW Tue-Wed with breezy areas, generally light Thu-Fri.
  • Precipitation: Dry conditions expected.
  • High Temps: Mid 90s Tue, low 90s Wed, near 90 Thu, mid 90s Fri.
  • Low Temps: Upper 60s Mon night, low 60s Tue night, upper 50s Wed night, near 60 Thu night, low 60s Fri night.
  • Sky Cover: Mostly clear with areas of smoke and haze.
Weekend
  • Wind: Generally W, breezy Sun.
  • Precipitation: Dry conditions expected.
  • High Temps: Mid 90s Sat & Sun.
  • Low Temps: Mid 60s Sat & Sun nights.
  • Sky Cover: Mostly clear with areas of smoke and haze.

North Central Washington
Remainder of the Week
  • Wind: W to SW Tue-Wed with breezy areas, generally light Thu-Fri.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 90s Tue, upper 80s Wed, near 90 Thu, low 90s Fri. Cooler in higher terrain.
  • Low Temps: Upper 60s Mon night, low 60s Tue night, near 60 Wed night, low 60s Thu night, mid 60s Fri night. Cooler in higher terrain.
  • Sky Cover: Mostly clear with areas of smoke and haze.
Weekend
  • Wind: Generally W, breezy Sun.
  • Precipitation: Dry conditions expected.
  • High Temps: Mid 90s Sat & Sun. Cooler in higher terrain.
  • Low Temps: Mid 60s Sat & Sun nights. Cooler in higher terrain.
  • Sky Cover: Mostly clear with areas of smoke and haze.

Eastern Washington
Remainder of the Week
  • Wind: W to SW Tue-Wed with breezy areas, generally light Thu, W with breezy areas Wed.
  • Precipitation: Dry thunderstorms possible Tue-Wed, mainly in higher terrain.
  • High Temps: Low 90s Tue, upper 80s Wed-Thu, low 90s Fri. Warmer in the Lewis & Clark Valley.
  • Low Temps: Mid 60s Mon night, near 60 Tue night, mid 50s Wed-Thu nights, upper 50s Fri night. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Mostly clear with areas of smoke and haze.
Weekend
  • Wind: Generally W, breezy Sun.
  • Precipitation: Dry conditions expected.
  • High Temps: Mid 90s Sat & Sun. Warmer in the Lewis & Clark Valley.
  • Low Temps: Near 60 Sat & Sun nights. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Mostly clear with areas of smoke and haze.

Western Washington
Remainder of the Week
  • Wind: Generally W with breezy areas (mainly along the coast) Tue-Fri.
  • Precipitation: Some drizzle along the coast Tue-Wed, otherwise dry.
  • High Temps: Low 70s Tue, near 70 Wed, mid 70s Thu-Fri. Cooler in higher terrain and along the coast.
  • Low Temps: Upper 50s Mon night, mid 50s Tue-Fri nights. Cooler in higher terrain.
  • Sky Cover: Mostly cloudy Tue-Wed, mostly clear Thu-Fri.
Weekend
  • Wind: Generally W with breezy areas.
  • Precipitation: Dry conditions expected.
  • High Temps: Upper 70s Sat-Sun. Cooler in higher terrain and along the coast.
  • Low Temps: Upper 50s Sat-Sun nights. Cooler in higher terrain.
  • Sky Cover: Mostly clear.

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