AgWeatherNet Weekly Outlook for March 05 to March 11, 2021

Active weekend followed by cooler and drier conditions

Mark Ingalls, AgWeatherNet Intern
Craig Oswald, AgWeatherNet Field Meteorologist
Joe Boomgard-Zagrodnik, AgWeatherNet Postorctoral Research Associate

Synopsis:

Two frontal passages over the weekend are expected to bring light rain and mountain snow showers to part of the state along with breezy conditions in the typical windy spots. By next week, a deep cutoff low slides south toward San Francisco, shifting the general storm track south into California and placing Washington on the north side of the jet stream. This will allow for cooler temperatures compared to the last couple days with dry conditions expected statewide for the work week.

Discussion:

The cold front currently over Western Washington will slowly move into the Cascades and Eastern Washington overnight to spread rain and mountain snow showers into those areas. Snow levels in the Cascades will be starting around 5000 feet, lowering to around 2500 feet behind the cold front to allow for some snow at pass level. Breezy conditions in the North Sound region should taper off overnight while continuing along the Coast. Saturday, winds pick up modestly in the Columbia Basin and toward Spokane. The cold front is expected to weaken as it passes eastward, limiting precipitation values in arid portions of Washington.

A brief gap in the action is expected ahead of a weak frontal boundary that should cross the state Saturday night into Sunday. Areas that see precipitation Friday into Saturday can expect similar conditions on Sunday, though snow levels may drop another couple hundred feet. Winds behind this front will be a bit higher and more widespread than Friday and Saturday. Most lowland areas should see breezy conditions, with gusts possibly reaching near 40 mph along I-90 from Ritzville to Spokane.

A strong upper low sliding south toward San Francisco Monday into Tuesday is expected to take the general storm track southward with it. As it does so, a few shortwave disturbances embedded within the flow may produce some light rain and mountain snow showers in southwest Washington and the Blue Mountains. Otherwise, expect mainly dry conditions statewide.

Temperatures over the next week will be cooler than observed the last couple days thanks to the Pacific Northwest's position within the cold sector north of the jet stream. Look for temperatures to be near average across the state, with below freezing overnight temperatures possible for much of Eastern Washington Monday through Thursday. Low-lying areas prone to nocturnal surface inversions such as around Naches, the upper Kittitas Valley, and the Methow Valley may experience hard freeze conditions with temperatures potentially dropping to just above 20.

Temperatures in some of the particularly cold locations have already observed overnight lows in the mid 20s at times this past week. Light freeze conditions may also be observed in agricultural areas of Western Washington. However, expectant cloud cover will likely limit the extent of freezing temperatures across the state. Most tree fruits remain mostly dormant with some pit fruits such as Apricots beginning to bud in far southern Washington with some near bud stage two, giving a 10% kill threshold of roughly 20 degrees. Cherries look to remain much more dormant.


8 to 14 Day Outlook, March 12 to March 18, 2021
  • Below average temperatures and near average precipitation are favored for the period.

Important Points About Next Week's Weather

South Central Washington
Weekend
  • Wind: Generally SW. Breezy areas Sat, widespread breezy Sun. Gusts to 30 mph.
  • Precipitation: Low chance of rain Fri night.
  • High Temps: Mid 50s Sat & Sun.
  • Low Temps: Low 40s Fri night, upper 30s Sat night, low 30s Sun night.
  • Sky Cover: Mostly cloudy Sat & Sun.
Next Week
  • Wind: Light & variable Mon-Wed. W & breezy Thu.
  • Precipitation: Dry conditions expected.
  • High Temps: Mid 50s Mon-Thu.
  • Low Temps: Low 30s Mon night-Thu night.
  • Sky Cover: Mostly cloudy Mon-Tue, partly cloudy Wed-Thu.

North Central Washington
Weekend
  • Wind: Generally SW. Breezy areas Sat & Sun. Gusts to 30 mph. Strongest in the Basin.
  • Precipitation: Low chance of rain and mountain snow Fri night & Sun.
  • High Temps: Near 50 Sat, upper 40s Sun. Cooler in higher terrain.
  • Low Temps: Mid 30s Fri night, low 30s Sat night, upper 20s Sun night. Cooler in higher terrain.
  • Sky Cover: Mostly cloudy.
Next Week
  • Wind: Light & variable Mon-Wed. W & breezy Thu.
  • Precipitation: Dry conditions expected.
  • High Temps: Near 50 Mon-Thu. Cooler in higher terrain.
  • Low Temps: Near 30 Mon night-Thu night. Cooler in higher terrain.
  • Sky Cover: Partly cloudy.

Eastern Washington
Weekend
  • Wind: Generally SW. Breezy Sat, windy areas Sun. Gusts to 40 mph Sun.
  • Precipitation: Low chance of rain Sat & Sun.
  • High Temps: Upper 40s Sat & Sun. Warmer in the Lewis & Clark Valley.
  • Low Temps: Mid 30s Fri night, low 30s Sat night, upper 20s Sun night. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Mostly cloudy.
Next Week
  • Wind: Light & variable Mon-Wed. W & breezy Thu.
  • Precipitation: Dry conditions expected.
  • High Temps: Near 50 Mon-Thu. Warmer in the Lewis & Clark Valley.
  • Low Temps: Near 30 Mon night-Thu night. Warmer in the Lewis & Clark Valley.
  • Sky Cover: Mostly cloudy Mon-Tue, partly cloudy Wed-Thu.

Western Washington
Weekend
  • Wind: Generally S. Breezy on the coast Sat. Widespread breezy Sun.
  • Precipitation: Rain and mountain snow showers through Sun.
  • High Temps: Near 50 Sat & Sun. Cooler in higher terrain.
  • Low Temps: Low 40s Fri night, near 40 Sat night, upper 30s Sun night. Cooler in higher terrain.
  • Sky Cover: Mostly cloudy to overcast.
Next Week
  • Wind: Generally E Mon-Wed. Switching to W with breezy areas Thu.
  • Precipitation: Low chance of rain SW Mon & Tue.
  • High Temps: Low 50s Mon-Thu. Cooler in higher terrain.
  • Low Temps: Mid 30s Mon night-Thu night. Cooler in higher terrain.
  • Sky Cover: Partly to mostly cloudy.

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Washington State University