AgWeatherNet Weekly Weather Outlook Monday Update for April 26 to May 2, 2021

Warm week followed by a cooler weekend

Mark Ingalls, AgWeatherNet Intern

Synopsis:

A ridge building over the west coast is expected to keep most of the state dry through at least Thursday aside from a few possible showers generally north of Mount Vernon and west of the Cascades resulting from a weak disturbance forecasted to transit British Columbia Tuesday and Wednesday. A warming trend is expected, with parts of Eastern Washington getting close to 90 on Thursday. Friday, the ridge begins to break down with an incoming frontal boundary to bring cooler temperatures and a chance of showers over the weekend.

Discussion:

The trough the brought unsettled conditions to Washington over the weekend is on its way out. Behind it, a ridge is building over the region. This will result in drier conditions through Thursday west of the Cascades and through Friday to the east. A warming trend is forecasted, with temperatures along the I-5 corridor reaching into the 70s and close to 90 in the Columbia Basin by Thursday. Despite dry conditions from the ridge, westerly flow should keep mostly cloudy skies in place through the week west of the Cascades. Skies will be mostly clear in Eastern Washington Tuesday and Wednesday, but mostly cloudy skies are likely there on Thursday and Friday. A weak disturbance crossing British Columbia Tuesday and Wednesday may bring a few rain showers to Whatcom, San Juan, and Skagit Counties, but the chance of precipitation is low.

Rain chances return to Western Washington on Friday as a cold front approaches the coast. Moisture spreads east of the Cascades Saturday, but in both locations the chance of rain is pretty low except in the Cascades and the windward side of the Olympics. Most noticeable will be the decrease in temperatures behind the front, with highs forecasted to drop to around 60 in the Puget Sound Region on Saturday and to the mid 70s or cooler over the weekend in Eastern Washington lowlands. Unsettled weather behind the front keeps rain chances in place for Western Washington through the weekend, but Sunday should be dry for much of the Columbia Basin.


Important Points About Next Week's Weather

South Central Washington
Remainder of the Week
  • Wind: Generally W to SW with breezy areas in the afternoon through Thu, W and breezy Fri.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 70s Tue, upper 70s Wed, upper 80s Thu, low 80s Fri.
  • Low Temps: Mid 30s Mon night, mid 40s Tue night, low 50s Wed night, mid 50s Thu-Fri nights. Cooler in sheltered areas.
  • Sky Cover: Clear Tue, partly cloudy Wed, mostly cloudy Thu-Fri.
Weekend
  • Wind: W and breezy Sat, S Sun.
  • Precipitation: Low chance of rain Sat.
  • High Temps: Mid 70s Sat, low 70s Sun.
  • Low Temps: Upper 40s Sat night, near 40 Sun night.
  • Sky Cover: Clear to partly cloudy.

North Central Washington
Remainder of the Week
  • Wind: Generally W to SW with breezy areas in the afternoon through Thu, W and breezy Fri.
  • Precipitation: Dry conditions expected.
  • High Temps: Near 70 Tue, mid 70s Wed, low 80s Thu, upper 70s Fri. Cooler in higher terrain.
  • Low Temps: Near 40 Mon night, mid 40s Tue night, near 50 Wed night, low 50s Thu night, near 50 Fri night. Cooler in higher terrain.
  • Sky Cover: Partly cloudy Tue & Wed, mostly cloudy Thu & Fri.
Weekend
  • Wind: W and breezy Sat & Sun.
  • Precipitation: Low chance of rain Sat.
  • High Temps: Near 70 Sat & Sun. Cooler in higher terrain.
  • Low Temps: Mid 40s Sat night, upper 30s Sun night. Cooler in higher terrain.
  • Sky Cover: Clear to partly cloudy.

Eastern Washington
Remainder of the Week
  • Wind: Generally W to SW with breezy areas in the afternoon through Thu, W and breezy Fri.
  • Precipitation: Dry conditions expected.
  • High Temps: Mid 60s Tue, near 70 Wed, upper 70s Thu, mid 70s Fri. Warmer in the Lewis & Clark Valley.
  • Low Temps: Mid 30s Mon night, near 40 Tue night, mid 40s Wed night, low 50s Thu night, near 50 Fri night. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Clear to partly cloudy Tue-Wed, mostly cloudy Thu-Fri.
Weekend
  • Wind: W and breezy Sat & Sun.
  • Precipitation: Low chance of rain Sat.
  • High Temps: Near 70 Sat, mid 60s Sun. Warmer in the Lewis & Clark Valley.
  • Low Temps: Low 40s Sat night, mid 30s Sun night. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Partly cloudy.

Western Washington
Remainder of the Week
  • Wind: Generally W and light Tue-Thu, SW with breezy areas Fri.
  • Precipitation: Low chance of rain N Tue-Wed (see discussion). Chance of rain area-wide Fri.
  • High Temps: Near 60 Tue, mid 60s Wed, near 70 Thu, mid 60s Fri. Cooler in higher terrain and on the coast.
  • Low Temps: Mid 40s Mon night, upper 40s Tue night, near 50 Wed night, low 50s Thu night, near 50 Fri night. Cooler in higher terrain.
  • Sky Cover: Mostly cloudy.
Weekend
  • Wind: Generally W, breezy along the Coast and Strait.
  • Precipitation: Chance of rain.
  • High Temps: Near 60 Sat & Sun. Cooler in higher terrain.
  • Low Temps: Mid 40s Sat night, low 40s Sun night. Cooler in higher terrain.
  • Sky Cover: Mostly cloudy to overcast.

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