AgWeatherNet Weekly Weather Outlook for June 12 to June 18, 2020

A few more days of unsettled weather with dry conditions likely by mid week

Craig Oswald, Field Meteorologist, 509-786-9256
Mark Ingalls, AgWeatherNet Intern

Discussion:

A few days of unsettled and cool weather look to impact Washington state before conditions trend warmer and mostly dry by the end of next week.

The brief window of dry and warm weather we had earlier this week has given way to another trough and upper low moving into the region from the west/northwest. This will continue to provide unsettled weather through the weekend and into next week with varying chances for precipitation across the state. Generally speaking, interior and south central Washington will trend drier than elsewhere with only a few scattered and isolated rain showers expected. Western Washington will trend wetter, per usual, with scattered rain showers and widespread rain expected through early next week and more consistent and heavier rain showers through the Cascades and Olympics. Eastern and north central Washington are generally expected to see scattered rain showers through the beginning of next week, with more consistent activity over the Blue Mountains, and upland and mountain regions of northern Washington.

A few isolated thunderstorms are also possible through eastern Washington by late afternoon Friday. The threat of thunderstorms is expected to linger into the first part of the overnight. These storms are not anticipated to be overly strong with the main concerns being localized heavy rain fall and gusty winds. There is also a chance for some small hail. No notable thunderstorm activity is expected beyond Friday night with only garden variety scattered rain showers anticipated.

While unsettled conditions are expected to prevail through the weekend as well as the beginning of next week as indicated, there looks to be a period where rain shower activity is likely to decrease as the trough currently situated over the west coast, mentioned at the beginning of the outlook, continues east. Specifically, Sunday night will likely see a down turn in shower activity with a widespread increase around the Monday night timeframe (there is some model disagreement on the exact timing) as a renewed round of widespread rain showers moves into the state form the west/southwest thanks to another upper low and modest surface cycle anticipated to be poised off the coast of British Columbia.

Conditions are likely to trend dry through Wednesday state wide as a zonal flow pattern sets up over Washington State. There is however some disagreement between models at this time as there is some indication of a passing shortwave embedded in the mean flow. This could provide enough dynamics for a few scattered showers, likely to be relegated to western Washington and the Cascades. This will be monitored and touched upon in Mondays update.

Cooler than average temperatures are also in store by Saturday as the upper trough moves inland. Well below average temperatures can be expected through the weekend with a slow warming trend beginning around Tuesday as the zonal flow pattern sets up over the state. Temperatures are expected to return to near seasonable by weeks end. With temperatures aloft again cooling thanks to the passage of a robust upper low over Washington, a brief discussion is warranted for overnight low temperatures. Temperatures look to begin cooling through Friday night with cooler than average conditions in store by Saturday. Temperatures aloft look to remain cool though Monday night before warming for Tuesday night, with Saturday night anticipated to be the coldest. Based on model derived temperatures aloft, the potential low temperature for Saturday night would be around 32-33 degrees given a clear, dry, and calm night through south central Washington, with slightly warmer temperatures elsewhere. HOWEVER, it appears that all three factors will be swinging in the favor of growers. It is anticipated that there will be plenty of cloud cover through the state with partly cloudy skies expected at worst during the overnights. Respectable surface pressure gradients also look to keep winds generally light to breezy through the period. And with a decent, moist, southwest flow and scattered rain shower activity, dewpoints look to hover in the upper 30s. All this combined indicates that overnight lows in the coldest locations may reach near 40. Particularly wind sheltered areas that mange to find a few breaks in the clouds Saturday night stand a chance to reach upper 30s, but this is expected to be rare.


8 to 14 Day Outlook  June 19, 2020 to June 25, 2020
  • Above average temperatures and slightly below 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 Sat-Sun with gusts to 30 mph.
  • Precipitation: Chance for a rain shower or two Friday night and Saturday. Any showers to move in from the W/SW. Conditions to turn mostly dry Saturday night and remain so for the weekend with only a low chance for a stray rain shower or two through the weekend.
  • High Temps: Low 80s Fri, near 70 Sat, low 70s Sun.
  • Low Temps: Mid 50s Fri night, near 50 Sat night, low 50s Sun night.
  • Sky Cover: Mostly cloudy to overcast Fri-Sat, mostly sunny Sun.
Next Week
  • Wind: SW winds remaining with breezy conditions possible Tuesday. Becoming light and variable Wednesday.
  • Precipitation: Brief low chance for a rain shower or two Monday with any showers moving in from the W/SW before turning mostly dry again Tuesday. Likely to remain dry through the week.
  • High Temps: Low 70s Mon-Tue, mid 70s Wed, near 80 Thu.
  • Low Temps: Low 50s 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: Generally W flow. Breezy at times through the weekend along I-90 and US 2 with gusts to 30 mph.
  • Precipitation: Scattered rain showers Friday moving from 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: Near 80 Fri, near 70 Sat-Sun. Cooler in high terrain.
  • Low Temps: Mid 50s Fri night, upper 40s Sat night, near 50 Sun night. Cooler in high terrain.
  • Sky Cover: Mostly cloudy to cloudy Fri-Sat. Partly to mostly cloudy Sun.
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: Near 70 Mon, low 70s Tue, mid 70s Wed, upper 70s Thu. Cooler in high terrain.
  • Low Temps: Upper 40s Mon night, mid 40s Tue night, low 50s Wed night, mid 50s Thu night. Cooler in high terrain.
  • Sky Cover: Sunny to mostly cloudy.

Eastern Washington
Weekend
  • Wind: Generally SW flow. Breezy Saturday and Sunday with gusts to 30 mph. T-storms may produce higher gusts.
  • Precipitation: Periodic rain showers through the weekend. Best chance is Fri night and Sat. Some showers might have lightning strikes.
  • High Temps: Mid 70s Fri, upper 50s Sat, near 60 Sun.
  • Low Temps: Mid 40s Fri night, low 40s Sat night, mid 40s Sun night.
  • Sky Cover: Mostly cloudy to overcast Fri-Sun.
Next Week
  • Wind: SW to W flow Monday-Tuesday, becoming light and variable Wednesday-Thursday. Breezy conditions possible Tuesday.
  • Precipitation: Isolated showers Mon and Wed. Likely dry for the latter part of the week.
  • High Temps: Low to mid 60s Mon-Wed, upper 60s to low 70s Thu.
  • Low Temps: Low to mid 40s Mon night-Wed night, upper 40s to low 50s Thu night.
  • Sky Cover: Partly to mostly cloudy Mon-Thu.

Western Washington
Weekend
  • Wind: Light with generally W flow through the weekend. Topography may affect wind direction locally.
  • Precipitation: Rain Fri and Sat, showers possible Sun.
  • High Temps: Mid 60s Fri, low 60s Sat, mid 60s Sun. Cooler in the Cascades and Olympics.
  • Low Temps: Low 50s Fri night, near 50 Sat night, low 50s Sun night. Cooler in the Cascades and Olympics.
  • Sky Cover: Mostly cloudy to overcast Fri-Sun.
Next Week
  • Wind: Flow generally out of the W and NW. Breezy on the coast Mon-Tue and Thu. Breezy in the Puget Sound Region Mon where topography will point winds to out of the S.
  • Precipitation: Rain likely Mon-Tue, rain showers Wed, trending dry Thu.
  • High Temps: Low to mid 60s Mon-Tue, mid to upper 60s Wed, near 70 Thu. Cooler in the Cascades and Olympics.
  • Low Temps: Low to mid 50s Mon night-Thu night. Cooler in the Cascades and Olympics.
  • Sky Cover: Partly cloudy to overcast Mon-Thu.

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