AgWeatherNet Weekly Weather Outlook for June 5 to June 11, 2020

A cool and unsettled weekend with more rain showers next week

Craig Oswald, Field Meteorologist, 509-786-9256
Mark Ingalls, AgWeatherNet Intern
Joe Zagrodnik, Postdoctoral Research Associate

Discussion:

Cooler temperatures look to continue with unsettled weather on the horizon for this outlook period, making this discussion a somewhat lengthy and challenging one. A brief overview is as follows.

The first disturbance to impact the Pacific northwest is an upper low that is currently making its way south along the British Columbia coast. This, paired with a weaker upper low moving northeast from the southern California coast will help to elongate the upper trough and position it ideally over Washington state to provide an ideal synoptic set up for active weather. Rain showers will start to move in from the southwest Friday night in eastern Washington and from the west in western Washington. Generally unsettled and rainy conditions will dominate the weekend statewide with the Columbia Basin and south central Washington expected to see a much lower chance for showers however after Friday night. The cold core nature, typical of these upper lows, will also provide a rejuvenating shot of cooler temperatures across the state with temperatures expected to bottom out Sunday and slowly warm through next week. Temperatures are expected to be near seasonable again by the end of next week. West/southwest winds also look to become quite breezy Saturday and even windier through much of the state by Sunday. Winds are expected to remain elevated through Monday before trending lighter.

A brief shortwave ridge looks to pass through the Pacific Northwest Monday, providing a brief reprieve from rain showers for much of eastern Washington and a substantial down tick in shower activity for western Washington, even though a few scattered and isolated rain showers will likely linger here.

Another upper low and its associate trough are anticipated to move into the state from the west Tuesday. A modest surface cyclone associated with this disturbance will also help provide widespread rain showers through western Washington and mostly isolated and scattered rain through eastern Washington as a weak cold front passes from the west. The central Basin and south central Washington will again likely remain mostly dry due to the westerly nature of this system. As the front passes through the state. Temperatures are anticipated to dip a few degrees, but the general warming trend through the course of the week looks to remain intact.

The upper trough associated with the passing system Tuesday is indicated by models to further deepen and take a few days residence off the west coast. This will keep the Pacific Northwest in a synoptic pattern conducive for the continuation of unsettled weather. Mostly cloudy skies and passing scattered rain showers from the southwest are expected to continue to impact parts of the state through the end of the week.

As alluded to in Mondays outlook and above, the upper low moving south into the Pacific northwest from the Gulf of Alaska this weekend still looks to bring a shot of cooler air into the region. Overnight temperatures are likely to remain safe for growers Saturday, Sunday, and Monday nights, but please watch overnight temperatures closely into early next week. Temperatures will generally remain in the mid 40s while near 40 is likely in locations that typically trend colder than surrounding areas. Partly cloudy skies, light winds, and dew points in the mid to upper 30s are expected all three nights, helping to bolster surface temperatures as well. Temperatures aloft look to be coldest Sunday night, with the Wenatchee area and upper Yakima Valley expected to be slightly cooler aloft than elsewhere. For this reason, don't be surprised if a few more locations in these regions manage to dip just into the upper 30s Sunday night, especially the upper Yakima Valley.

Last Saturday (May 30), the Inland Northwest experienced the region's largest severe weather outbreak since May 2006. The Storm Prediction Center in Oklahoma issued an enhanced risk for severe thunderstorms for portions of Eastern Oregon and Eastern Washington  a first for the Pacific Northwest since that category was introduced in 2014. The day started early with non-severe thunderstorms in parts of Washington. By 8 am, the Richland Airport had recorded 0.54 inches of precipitation. These storms were isolated in nature, and the Tri-Cities Airport in Pasco only received 0.01" from that storm despite being only about nine miles away.

Individual supercells formed in Southern Oregon and progressed north, dropping hail the size of eggs and producing straight-line winds up to 115 mph. As these storms progressed into Washington the hail threat decreased but the strong winds continued, bringing down numerous trees in the Yakima Valley, Columbia Basin, and on the Palouse. Peak wind gusts observed by AgWeatherNet were generally in the 60-70 mph range. A non-AgWeatherNet station near Vantage recorded a gust of 97 mph. In Washtucna, a firefighter was tragically killed cutting trees during storm cleanup.


8 to 14 Day Outlook  June 12, 2020 to June 18, 2020
  • Slightly below average temperatures and slightly above average precipitation are expected during the 8 to 14 day time frame.

Important Points about Next Week's Weather

South Central Washington
Weekend
  • Wind: Light and variable winds turning SW and increasing through Friday night. Remaining SW and breezy Saturday. Becoming windier Sunday with some gusts near 40 mph possible.
  • Precipitation: Chance for a rain shower or two Friday night. Any showers to move in from the W/SW. Conditions to turn mostly dry Saturday and remain so for the weekend with only a low chance for a stray rain shower or two through the weekend.
  • High Temps: Mid 70s Fri, low 70s Sat, near 70 Sun.
  • Low Temps: Upper 40s Fri night, upper 40s Sat night, mid 40s Sun night.
  • Sky Cover: Cloudy Fri, cloudy Fri night, partly sunny Sat, mostly cloudy Sat night, mostly cloudy Sun, mostly cloudy Sun night.
Next Week
  • Wind: SW winds remaining windy Monday with some gusts near 40 mph possible. Winds to ease slightly Monday night. Generally SW and light to breezy conditions expected for the remainder of the week.
  • Precipitation: Mostly dry conditions continue Monday. Brief low chance for a rain shower or two again Tuesday with any showers moving in from the W/SW before turning mostly dry again Wednesday. Better chance for scattered rain showers on Thursday and Friday.
  • High Temps: Low 70s Mon, near 70 Tue, near 80 Wed, mid 80s Thu.
  • Low Temps: Mid 40s Mon night, near 50 Tue night, low 50s Wed night, mid 50s Thu night.
  • Sky Cover: Partly sunny to mostly cloudy.

North Central Washington
Weekend
  • Wind: Light and variable Friday. Becoming breezy Friday night with W winds, especially along I-90 and US 2. Windier Sunday with some gusts to 40 mph, particularly through the Basin.
  • Precipitation: Scattered rain showers to begin moving in Friday night form the SW with the greatest shower activity through upland areas. Showers to linger on and off through the weekend. Generally a low chance for showers through the Basin after Friday night.
  • High Temps: Mid 70s Fri, near 70 Sat, upper 60s Sun. Cooler in high terrain.
  • Low Temps: Low 50s Fri night, mid 40s Sat night, mid 40s Sun night. Cooler in high terrain.
  • Sky Cover: Cloudy Fri, cloudy Fri night, mostly cloudy Sat, mostly cloudy Sat night, mostly cloudy Sun, mostly cloudy Sun night.
Next Week
  • Wind: Breezy to windy conditions continue Monday with W winds. Winds to ease slightly Monday night. Generally light and variable expected for the remainder of the week.
  • Precipitation: Isolated to scattered upland and mountain rain showers through the week. Better chance for a few lowland showers Tuesday and again Thursday and Friday. Less shower activity through the Basin.
  • High Temps: Upper 60s Mon, mid 60s Tue, mid 70s Wed, upper 70s Thu. Cooler in high terrain.
  • Low Temps: Low 40s Mon night, upper 40s Tue night, low 50s Wed night, mid 50s Thu night. Cooler in high terrain.
  • Sky Cover: Partly sunny to cloudy.

Eastern Washington
Weekend
  • Wind: Light and variable winds turning SW and increasing through Friday night. Remaining SW and breezy Saturday. Becoming windier Sunday with some gusts near 40 mph possible, especially through the Palouse.
  • Precipitation: Rain showers to begin moving in Friday night. Showers to linger on and off through the weekend while remaining more consistent through the Blue Mtns.
  • High Temps: Low 70s Fri, Near 60 Sat, mid 50s Sun.
  • Low Temps: Upper 40s Fri night, low 40s Sat night, low 40s Sun night.
  • Sky Cover: Cloudy Fri, cloudy Fri night, cloudy Sat, mostly cloudy Sat night, mostly cloudy Sun, mostly cloudy Sun night.
Next Week
  • Wind: SW winds remaining windy Monday with some gusts near 40 mph possible. Winds to ease slightly Monday night. Generally SW and light to breezy conditions expected for the remainder of the week.
  • Precipitation: Rain showers trending dry Monday. A good chance for scattered rain showers again Tuesday with showers moving in from the W/SW before turning mostly dry again Wednesday. Another good chance for scattered rain showers again on Thursday and Friday.
  • High Temps: Upper 50s Mon, low 60s Tue, upper 60s Wed, mid 70s Thu.
  • Low Temps: Upper 30s Mon night, mid 40s Tue night, upper 40s Wed night, low 50s Thu night.
  • Sky Cover: Partly sunny to cloudy.

Western Washington
Weekend
  • Wind: Breezy W winds along the coast and the Strait of Juan de Fuca Friday and Saturday, generally light winds inland. W winds becoming windy along the coast and Strait Sunday, breezy conditions inland.
  • Precipitation: Widespread scattered rain showers beginning Friday night and persisting through the weekend.
  • High Temps: Upper 60s Fri, low 60s Sat, low 60s Sun. Much cooler through the Cascades and Olympics.
  • Low Temps: Mid 40s Fri night, mid 40s Sat night, mid 40s Sun night. Much cooler through the Cascades and Olympics.
  • Sky Cover: Mostly cloudy to overcast.
Next Week
  • Wind: Continued windy conditions along the coast and Strait of Juan de Fuca until Tuesday with breezy conditions inland. Winds easing Tuesday night and becoming generally SW yet variable and light.
  • Precipitation: Scattered rain showers becoming widespread Tuesday. Showers expected to again turn more scattered in nature Wednesday and linger through the week.
  • High Temps: Low 60s Mon, low 60s Tue, upper 60s Wed, low 70s Thu. Much cooler through the Cascades and Olympics.
  • Low Temps: Mid 40s Mon night, low 50s Tue night, near 50 Wed night, low 50s Thu night. Much cooler through the Cascades and Olympics.
  • Sky Cover: Mostly cloudy to overcast. Patchy fog likely by mid week and through weeks end as winds turn lighter after Tuesday.

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