AgWeatherNet Weekly Weather Outlook Monday Update for May 18 to May 24, 2020

Unsettled weather through the week and briefly dry over the weekend

Craig Oswald, Field Meteorologist, 509-786-9256

Discussion:

Weather conditions this week continue to look quite unsettled. An upper level low looks to continue to move south along the west coast and into the Great Basin. Relatively moist southwesterly/southerly flow and instability through the atmosphere are expected to continue to bring mostly scattered rain showers as well as a thunderstorm or two (with the aid of surface heating) through much of the state early in the week. Daily rain totals are expected to be highly variable with zero or a couple hundredths of an inch in spots to over a quarter inch in localized spots impacted by strong shower or thunderstorm activity. However, as the upper trough and jet streak continue to move east, atmospheric dynamics look to become less favorable for thunderstorms by mid-week. Pockets of nighttime fog are also likely early in the week through wind sheltered areas as winds look to remain mostly light and dew points high.

The unsettled weather for the latter half of the week still looks to be a product of another upper disturbance moving in from the northwest paired with the previous upper low moving north into Idaho from the Great Basin. Showers throughout eastern Washington look to generally move in from the east mid-week, with showers throughout western Washington moving in from the west/northwest. By weeks end, the disturbance from the northwest is expected to make its way across the state with weather remaining unsettled. However, while a few scattered rain showers are expected, it is anticipated that there will be a lower chance showers than what there was earlier in the week.

A brief ridge looks to pass over the Pacific Northwest Saturday bringing a quick reprieve from any precipitation. Sunday is expected to bring a return of rain showers as a band of frontal type rain, aided by moisture from the tropics, looks to begin moving into the state form the west on Sunday. The westerly nature of the flow will likely leave south central Washington mostly dry with western and far eastern Washington picking up most of the rain. It is likely north central Washington will see mostly upland rain showers.

Temperatures are expected to drop below seasonable mid-week with Wednesday, Thursday, and Friday nights looking to be the coldest as the disturbance from the northwest and its associated cold pool begin to pass through the state. With this being said, elevated dewpoints, ample cloud cover, and breezier conditions will all help to prevent drastic surface cooling. Temperatures in the coldest areas of north and south central Washington will likely be in the upper 30s. This will continue to be monitored through the week.


Important Points about Next Week's Weather

South Central Washington
Remainder of the Week
  • Wind: Generally SW and light. Gusts 40+ mph possible under any thunderstorm activity. Becoming windier on Wednesday with some gusts near 35 mph possible. Winds remaining elevated through Friday.
  • Precipitation: Continuation of passing rain showers along with a thunderstorm or two through the first part of the week. Lower chance for showers by Thursday and Friday yet remaining unsettled. Greater shower activity expected throughout eastern portions of the region and during the day with any daytime surface heating.
  • High Temps: Low 70s Tue, low 70s Wed, mid 60s Thu, upper 60s Fri.
  • Low Temps: Upper 40s Mon night, upper 40s Tue night, mid 40s Wed night, low 40s Thu night.
  • Sky Cover: Mostly cloudy Mon night, mostly cloudy Tue, mostly cloudy Tue night, mostly sunny Wed, partly cloudy Wed night, partly sunny Thu, partly cloudy Thu night, partly sunny Fri.

Weekend
  • Wind: Trending light Friday night. Remaining light and generally SW yet variable through the weekend.
  • Precipitation: Trending dry Friday night. Chance for scattered rain showers returns Sunday.
  • High Temps: Low 70s Sat, upper 70s Sun.
  • Low Temps: Low 40s Fri night, mid 40s Sat night, upper 40s Sun night.
  • Sky Cover: Mostly sunny to partly cloudy.

North Central Washington
Remainder of the Week
  • Wind: Generally W yet variable and light. Gusts 40+ mph possible under any thunderstorm activity. Becoming windier on Wednesday with some gusts near 35 mph possible through the Basin. Winds remaining elevated through Friday.
  • Precipitation: Continuation of rain showers along with a thunderstorm or two through the first part of the week. Slightly less shower activity expected by Thursday and Friday yet remaining unsettled with scattered showers likely. Greater shower activity expected through upland areas and during the day with any daytime surface heating.
  • High Temps: Low 70s Tue, low 70s Wed, mid 60s Thu, mid 60s Fri. Cooler through high terrain.
  • Low Temps: Upper 40s Mon night, near 50 Tue night, mid 40s Wed night, mid 40s Thu night. Cooler through high terrain.
  • Sky Cover: Mostly cloudy Mon night, partly sunny Tue, mostly cloudy Tue night, mostly cloudy Wed, partly cloudy Wed night, partly sunny Thu, mostly cloudy Thu night, mostly cloudy Fri.

Weekend
  • Wind: Trending light Friday night. Remaining light and turning S yet variable through the weekend.
  • Precipitation: Trending dry Friday night with a few upland rain showers likely to linger into Saturday. Scattered rain showers return Sunday, mostly through upland areas.
  • High Temps: Near 70 Sat, mid 70s Sun. Cooler through high terrain.
  • Low Temps: Low 40s Fri night, mid 40s Sat night, mid 40s Sunday night. Cooler through high terrain.
  • Sky Cover: Mostly sunny to mostly cloudy.

Eastern Washington
Remainder of the Week
  • Wind: Generally SW and light. Gusts 40+ mph possible under any thunderstorm activity. Becoming windier on Wednesday with some gusts near 35 mph possible, especially through the Palouse. Winds remaining elevated through Friday.
  • Precipitation: Continuation of passing rain showers and prolonged periods of rain fall along with a thunderstorm or two through the first part of the week. Slightly less shower activity expected by Thursday and Friday yet remaining unsettled with scattered showers likely. Greater shower activity expected during the day with any daytime surface heating.
  • High Temps: Near 60 Tue, mid 50s Wed, mid 50s Thu, mid 50s Friday.
  • Low Temps: Mid 40s Mon night, mid 40s Tue night, low 40s Wed night, upper 30s Thu night.
  • Sky Cover: Mostly cloudy Mon night, mostly cloudy Tue, mostly cloudy Tue night, cloudy Wed, mostly cloudy Wed night, mostly cloudy Thu, mostly cloudy Thu night, mostly cloudy Fri.

Weekend
  • Wind: Trending light Friday night. Remaining light and generally SW yet variable through the weekend.
  • Precipitation: Trending dry Friday night. Scattered rain showers return Sunday.
  • High Temps: Low 60s Sat, mid 60s Sun.
  • Low Temps: Upper 30s Fri night, low 40s Sat night, mid 40s Sun night.
  • Sky Cover: Partly sunny to mostly cloudy.

Western Washington
Remainder of the Week
  • Wind: Generally W and light. Becoming breezy on Wednesday and remaining so through the week. Windier near the coast and sound.
  • Precipitation: Rain showers and scattered rain showers through the week. More consistent showers through the Cascades and Olympics.
  • High Temps: Mid 60s Tue, low 60s Wed, upper 50s Thu, low 60s Fri. Much cooler through the Cascades and Olympics.
  • Low Temps: Upper 40s Mon night, mid 40s Tue night, mid 40s Wed night, low 40s Thu night. Much cooler through the Cascades and Olympics.
  • Sky Cover: Mostly cloudy Mon night, mostly cloudy Tue, mostly cloudy Tue night, mostly cloudy Wed, mostly cloudy Wed night, cloudy Thu, mostly cloudy Thu night, mostly cloudy Fri.

Weekend
  • Wind: Trending light Friday night and becoming mostly variable. Turning SW and becoming breezy again Sunday.
  • Precipitation: Briefly trending dry Saturday and Saturday night. Widespread rain showers return Sunday.
  • High Temps: Mid 60s Sat, upper 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: Partly sunny to mostly cloudy.

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