AgWeatherNet Weekly Outlook for May 21 to May 27, 2021

Generally unsettled weather continues with low precipitation values

Mark Ingalls, AgWeatherNet Intern

Synopsis:

An area of low pressure centered near Reno will begin lifting northeastward on Saturday to bring another chance of rain showers and isolated thunderstorms to Eastern Washington. By Sunday the low will be far enough north to allow for showers west of the Cascades, but these should be light. Weak troughing for the first half of next week keep rain chances in place for Western Washington with dry and breezy conditions to the east. Flow becomes more zonal for the second half of the week which may allow for winds to ease but shortwave disturbances may allow for continued showers outside of arid portions of the state.

Discussion:

The strong upper level low responsible for the showers and thunderstorms seen over the last couple of days was centered near Reno. This southerly position gives a much lower chance for precipitation during the day Friday in Eastern Washington with the bulk of the moisture not making it this far north. The low begins moving northeastward Saturday to inject another chance at lowland showers and thunderstorms in the eastern half of the state but current indications are that these will not be as widespread as what was observed Thursday. With Washington lying on the north side of the low’s counterclockwise flow, most of Western Washington will remain dry as they are shadowed by the Cascade Mountains.

The center of the low moves far enough north Sunday that upper level flow is expected to shift back to being out of the east, bringing in a chance of rain showers for Western Washington and cutting off much of the east side of the state through Monday. Tightening pressure gradients look to cause breezy conditions most afternoons in Eastern Washington through Tuesday with the strongest winds expected near the mountain gaps.

A weak upper level trough passes through on Tuesday to increase rain chances in the west and expand them back into the eastern half of the state. Otherwise, zonal flow remains the dominant weather pattern. Rain showers continue to be possible through the end of the forecast period in the mountains and west of the Cascades with lower chances also possible along the Palouse. Over the next week, rainfall rates are expected to be fairly light and not be enough to make a significant impact on drought conditions that much of the region is experiencing.


8 to 14 Day Outlook, May 07 to May 13, 2021
  • Above average temperatures and below average precipitation are favored for the period.

Important Points About Next Week's Weather

South Central Washington
Weekend
  • Wind: NE with breezy areas Sat, W and breezy Sun.
  • Precipitation: Chance of rain Sat.
  • High Temps: Mid 60s Sat, mid 70s Sun.
  • Low Temps: Mid 40s Fri-Sat nights, near 50 Sun night.
  • Sky Cover: Mostly cloudy Sat, partly cloudy Sun.
Next Week
  • Wind: Generally W through the week. Breezy Mon-Tue, light Wed, breezy Thu.
  • Precipitation: Chance of showers Tue.
  • High Temps: Near 80 Mon-Tue, mid 70s Wed, upper 70s Thu.
  • Low Temps: Low 50s Mon night, near 50 Tue night, upper 40s Wed night, near 50 Thu night.
  • Sky Cover: Partly cloudy.

North Central Washington
Weekend
  • Wind: NE with breezy areas Sat, W and breezy Sun.
  • Precipitation: Chance of upslope showers Sat.
  • High Temps: Mid 70s Sat, upper 70s Sun. Cooler in higher terrain.
  • Low Temps: Near 50 Fri night, low 50s Sat-Sun nights. Cooler in higher terrain.
  • Sky Cover: Partly cloudy.
Next Week
  • Wind: Generally W through the week. Breezy Mon-Tue, light Wed, breezy Thu.
  • Precipitation: Chance of upslope showers through the week. Chance of lowland showers Tue.
  • High Temps: Mid 70s Mon-Thu, cooler in higher terrain.
  • Low Temps: Low 50s Mon-Thu nights. Cooler in higher terrain.
  • Sky Cover: Partly cloudy.

Eastern Washington
Weekend
  • Wind: NE with breezy areas Sat, W and breezy Sun.
  • Precipitation: Chance of showers Sat.
  • High Temps: Near 70 Sat & Sun. Warmer in the Lewis & Clark Valley.
  • Low Temps: Mid 40s Fri-Sat, upper 40s Sun. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Mostly cloudy Sat, partly cloudy Sun.
Next Week
  • Wind: Generally W through the week. Breezy Mon-Tue, light Wed, breezy Thu.
  • Precipitation: Low chance of rain Tue-Thu.
  • High Temps: Low 70s Mon-Tue, near 70 Wed, upper 60s Thu. Warmer in the Lewis & Clark Valley.
  • Low Temps: Mid 40s Mon-Thu nights. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Partly cloudy.

Western Washington
Weekend
  • Wind: W & breezy on the coast/through the straight Sat-Sun. Widespread breezy Sun.
  • Precipitation: Rain showers beginning Sun.
  • High Temps: Near 70 Sat, mid 60s Sun. Cooler in higher terrain.
  • Low Temps: Upper 40s Fri night, mid 50s Sat night, near 50 Sun night. Cooler in higher terrain.
  • Sky Cover: Partly cloudy Sat, mostly cloudy Sun.
Next Week
  • Wind: S & light Mon, W and breezy through the Strait Tue-Wed, S with breezy areas Thu.
  • Precipitation: Rain showers through the week.
  • High Temps: Low 60s Mon, mid 60s Tue-Thu. Cooler in higher terrain.
  • Low Temps: Low 50s Mon-Thu nights. Cooler in higher terrain.
  • Sky Cover: Mostly cloudy to overcast.

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