AgWeatherNet Weekly Weather Outlook for May 1 to May 7, 2020

A few chilly nights over the weekend and early next week followed by a warming trend

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

Discussion:

A strong jet stream and the broad trough associated with it continue to reside over the north Pacific. This looks to keep the Pacific Northwest in an active weather pattern for the weekend. Yet another low pressure system looks to continue to move toward the coast of British Columbia with its broad band of frontal precipitation to begin bringing rain showers to western Washington Friday evening. A greater chance for precipitation is expected throughout eastern Washington beginning Saturday due to the southwesterly nature of the flow. The westerly flow experienced over the past week had been responsible for keeping much of interior Washington dry with earlier frontal passages due to the rain shadow effect of the Cascades. Conditions look to trend dry through eastern Washington Saturday night and Sunday with western Washington not turning dry until Sunday night.

Dryer and colder air is expected to move into the state from the west through Saturday night with the passing cold front. This will bring frost concerns for growers in north central and south central Washington primarily Saturday and Sunday nights. With cold air aloft and dew points in the mid 20s at the surface likely, the potential for upper 20s in the usual cold locations looks to be possible, especially with winds expected to trend light to calm during the overnights.

A weak upper level disturbance embedded in the mean flow looks to produce enough instability to bring more rain showers into the state from the southwest Monday night. Western Washington is expected to see widespread showers while far eastern and northern Washington will see a lower chance for scattered showers. Interior portions of the state will likely remain dry. However, the increase in clouds look to keep overnight low temperatures above freezing for growers throughout north central and south central Washington.

Western Washington will likely not completely dry out before another round of rain moves into the state form the southwest Tuesday night. South central and low elevation portions of north central Washington will likely remain dry again due to the weak nature of the passing disturbance. Far eastern Washington and upland areas of northern Washington stand to see a renewed chance for scattered rain showers. Conditions look to remain unsettled through Wednesday before trending dry Wednesday night. Growers can again expect to see temperatures remain above freezing during the overnight throughout north central and south central Washington.

Mid week will see a hearty warming trend through the state as the robust zonal jet across the north Pacific continues to break down and a high amplitude ridge builds over the west coast. Along with warmer weather, dry conditions, mostly clear to sunny skies, and light winds are also expected statewide Thursday and Friday to finish out the week.


8 to 14 Day Outlook  May 8, 2020 to May 17, 2020
  • Warmer than 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: Generally W and SW with windy conditions Saturday and Sunday. Gusts exceeding 45 mph in areas.
  • Precipitation: Scattered rain showers with possible thunder during the day and evening Saturday, with the best chance east of Toppenish. Isolated leftover showers Sunday.
  • High Temps: Mid 70s Friday, near 70 Saturday, mid 60s Sunday.
  • Low Temps: Upper 40s Friday night, lower 40s Saturday night, near 40 Sunday night.
  • Sky Cover: Partly cloudy Friday, mostly cloudy Friday night and Saturday, partly cloudy Saturday night through Sunday night.
Next Week
  • Wind: Breezy Monday with some gusts 30+mph from the SW likely. Trending light and variable Monday night into Tuesday. Another round of windy conditions likely Wednesday before calming again Thursday. Flow switches from S/SW to N Thursday.
  • Precipitation: Chance for a few scattered rain showers moving through Monday night into Tuesday. Otherwise dry.
  • High Temps: Low 70s Monday, mid 70s Tuesday, mid 70s Wednesday, upper 70s Thursday.
  • Low Temps: Mid 40s Monday night, mid 40s Tuesday night, low 50s Wednesday night, low 50s Thursday night.
  • Sky Cover: Sunny to partly cloudy.

North Central Washington
Weekend
  • Wind: Generally S/SW and light. Becoming breezy on Saturday with some gusts around 25-30mph possible, especially through the Basin. Trending light Sunday.
  • Precipitation: Scattered rain showers with upland snow Saturday. Isolated lingering rain/upland snow showers Sunday.
  • High Temps: Mid 60s Friday, mid to upper 50s Saturday, upper 50s Sunday. Cooler through higher terrain.
  • Low Temps: Low 40s Friday night, mid 30s Saturday night, low 30s Sunday night. Cooler through higher terrain and in protected valleys.
  • Sky Cover: Mostly cloudy Friday, partly cloudy Friday night, mostly cloudy Saturday, partly cloudy Saturday night through Sunday night.
Next Week
  • Wind: Light W/SW with periodic breezy conditions in some Basin locations. Switching to N flow Thursday.
  • Precipitation: Isolated rain showers Monday, primarily in the Okanogan region. Otherwise dry.
  • High Temps: Low 60s Monday, upper 60s Tuesday, mid 60s Wednesday, upper 60s Thursday. Cooler through higher terrain.
  • Low Temps: Mid 30s Monday night, low 40s Tuesday night, low 40s Wednesday night, upper 40s Thursday night. Cooler through higher terrain and protected valleys.
  • Sky Cover: Sunny to partly cloudy.

Eastern Washington
Weekend
  • Wind: Generally SW and light. Becoming breezy on Saturday with some gusts around 35 mph possible. Letting up some Saturday night with gusts to 25 mph lingering into Sunday.
  • Precipitation: Rain showers and thunderstorms Saturday with isolated leftover showers Sunday.
  • High Temps: Mid 60s Friday, mid 60s Saturday, upper 50s Sunday.
  • Low Temps: Near 40 Friday night, mid 30s Saturday night, mid 30s Sunday night.
  • Sky Cover: Switching between partly and mostly cloudy through the weekend.
Next Week
  • Wind: SW flow switching to N Thursday. Breezy Monday with some gusts to 30 mph. Trending light and variable Monday night into Tuesday with another shot of breezy conditions Wednesday. Returning to light Thursday.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 60s Monday, mid 60s Tuesday, mid 60s Wednesday, mid 60s Thursday.
  • Low Temps: Low 40s Monday night, near 40 Tuesday night, mid 40s Wednesday night, near 50 Thursday night.
  • Sky Cover: Sunny to partly cloudy.

Western Washington
Weekend
  • Wind: Generally S and light except intermittent breezy conditions on the Coast and around the San Juan Islands/Strait of Juan de Fuca.
  • Precipitation: Light to moderate rain showers moving in from the W Friday night and lasting through Sunday night.
  • High Temps: Near 60 Friday, near 50 Saturday, mid 50s Sunday. Much cooler through the Cascades and Olympics.
  • Low Temps: Upper 40s Friday night, low 40 Saturday night, low 40s Sunday night. Much cooler through the Cascades and Olympics.
  • Sky Cover: Partly to mostly cloudy through the weekend.
Next Week
  • Wind: S flow switching to N on Thursday. Localized on and off breezy conditions through the week.
  • Precipitation: Rain Showers Monday night into Tuesday. Isolated light showers remaining on and off through the rest of the week. Greater shower activity through the mountains.
  • High Temps: Upper 50s Monday, low 60s Tuesday, upper 50s Wednesday, mid 60s Thursday. Much cooler through the Cascades and Olympics.
  • Low Temps: Low 40s Monday night, mid 40s Tuesday night, mid 40s Wednesday night, mid 40s Thursday night. Much cooler through the Cascades and Olympics.
  • Sky Cover: Partly sunny to cloudy.

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