AgWeatherNet Weekly Weather Outlook for Apr 24 to Apr 30, 2020

A wet period for Western Washington and unsettled weather for Eastern Washington

Craig Oswald, Field Meteorologist, 509-786-9256
Joe Zagrodnik, Postdoctoral Research Associate

Discussion:

This outlook period can best be defined as wet weather for western Washington and a few chances for very light precipitation throughout eastern Washington. This more active period looks to be courtesy of an upper level trough that has taken residence over Alaska and the north Pacific in place of the robust ridge that had provided our recent stretch of dry weather prior to this week. This looks to place the storm track in a position to allow multiple surface cyclones to move generally southwest to northeast and enter northern British Columbia. The broad precipitation band associated with the cold front of each of these systems are what look to bring rain to the state, generally from the west.

Showers look to me mostly widespread and light to moderate through western Washington for most of the period. There will be times of decreased shower activity between systems, but showers are expected to remain active through much of the week before trending drier Thursday with only a few lingering scattered showers likely. Showers will remain more consistent through the Cascades and Olympics, and snow levels look to be around 5000ft. A few snowflakes may mix in with the rain at pass levels, but little to no accumulation is expected.

Since the source of much of the precipitation is due to decaying frontal boundaries, eastern Washington is anticipated to receive only periods of light and scattered rain. As precipitation makes its way east and over the Cascades, much of the moisture is expected to be squeezed out over the mountains before reaching the east side of the state. With a general lack of other mechanisms in the atmosphere to help produce precipitation, eastern Washington will simply be left to receive whatever moisture is able to make it over the Cascades.

Temperatures generally look to be seasonable for the first half of the period, turn warmer than average for eastern Washington around mid week, and remain so through the end of the week. With that being said, minimum temperatures throughout north central and south central Washington look to generally remain above freezing through the period. However, Saturday night looks to bring some concern for temperatures to dip just below freezing in the typical cold spots, especially for north central Washington. Dew points look to lower to the mid 20s for the Okanogan area Saturday night. Partly cloudy skies paired with winds trending light to calm through the over night could put overnight low temperatures near 30 in cold locations. Cold locations through south central Washington look to be in the low 30s Saturday night.


8 to 14 Day Outlook  May 1, 2020 to May 7, 2020
  • Near average temperatures and near 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 SW and light. Becoming breezy on Saturday with some gusts around 25-30mph possible. Trending light Saturday night.
  • Precipitation: A few passing light rain showers from the W/SW Saturday with some areas likely to remain dry. Trending dry Saturday night.
  • High Temps: Mid 60s Friday, low 70s Saturday, low 70s Sunday.
  • Low Temps: Low 40s Friday night, upper 30s Saturday night, mid 40s Sunday night.
  • Sky Cover: Mostly sunny Friday, partly cloudy Friday night, mostly cloudy Saturday, partly cloudy Saturday night, partly sunny Sunday, partly cloudy Sunday night.
Next Week
  • Wind: Light W/SW wind becoming windy Monday with some gusts 40+mph likely. Trending light and variable Monday night. Remaining light and variable through the week with periods of increased breeziness from the SW.
  • Precipitation: Chance for a few scattered rain showers moving through from the W early Monday. Trending dry Monday night. More consistent scattered rain showers likely to move through from the SW Friday.
  • High Temps: Low 70s Monday, mid 70s Tuesday, near 80 Wednesday, mid 70s Thursday.
  • Low Temps: Low 40s Monday night, upper 40s Tuesday night, upper 40s Wednesday night, mid 40s Thursday night.
  • Sky Cover: Mostly sunny to mostly cloudy.

North Central Washington
Weekend
  • Wind: Generally SW and light. Becoming breezy on Saturday with some gusts around 25-30mph possible, especially through the Basin. Trending light Saturday night.
  • Precipitation: Some light rain showers moving through from the W Saturday. Greater shower activity in upland areas expected. Trending dry Saturday night.
  • High Temps: Mid 60s Friday, mid 60s Saturday, low 60s Sunday. Cooler through higher terrain.
  • Low Temps: Mid 40s Friday night, upper 30s Saturday night, mid 40s Sunday night. Cooler through higher terrain.
  • Sky Cover: Sunny Friday, partly cloudy Friday night, cloudy Saturday, partly cloudy Saturday night, mostly cloudy Sunday, mostly cloudy Sunday night.
Next Week
  • Wind: Light W/SW wind becoming windy Monday with some gusts 40+mph likely, particularly through the Basin. Trending light and variable Monday night. Remaining light and variable through the week with periods of increased breeziness from the SW.
  • Precipitation: Chance for a few scattered rain showers moving through from the W early Monday. A greater chance for shower activity through upland areas. Trending dry Monday night. Low chance for a scattered rain shower or two Wednesday and Wednesday night. Dry expected Thursday. More consistent scattered rain showers likely to move through from the S/SW Friday.
  • High Temps: Mid 60s Monday, upper 60s Tuesday, low 70s Wednesday, near 70 Thursday. Cooler through higher terrain.
  • Low Temps: Near 40 Monday night, mid 40s Tuesday night, mid 40s Wednesday night, mid 40s Thursday night. Cooler through higher terrain.
  • Sky Cover: Partly sunny to mostly cloudy.

Eastern Washington
Weekend
  • Wind: Generally SW and light. Becoming breezy on Saturday with some gusts around 25-30mph possible. Trending light Saturday night.
  • Precipitation: Some light rain showers moving through from the W Saturday with some areas likely to remain dry. Trending dry Saturday night.
  • High Temps: Upper 50s Friday, upper 50s Saturday, low 60s Sunday.
  • Low Temps: Mid 40s Friday night, upper 30s Saturday night, mid 40s Sunday night.
  • Sky Cover: Partly sunny Friday, partly cloudy Friday night, mostly cloudy Saturday, mostly cloudy Saturday night, mostly cloudy Sunday, cloudy Sunday night.
Next Week
  • Wind: Light W/SW wind becoming windy Monday with some gusts 45+mph likely. Trending light and variable Monday night. Remaining light and variable through the week with periods of increased breeziness from the SW.
  • Precipitation: Scattered rain showers likely to move through from the W early Monday. Trending dry Monday night. Likely dry through the middle of the week. More consistent scattered rain showers likely to move through from the SW Friday.
  • High Temps: Low 60s Monday, mid 60s Tuesday, low 70s Wednesday, mid 60s Thursday.
  • Low Temps: Near 40 Monday night, mid 40s Tuesday night, mid 40s Wednesday night, mid 40s Thursday night.
  • Sky Cover: Partly sunny to mostly cloudy.

Western Washington
Weekend
  • Wind: Generally SW and light. Becoming breezy on Saturday with some gusts around 25-30mph possible. Trending light Saturday night.
  • Precipitation: Light to moderate widespread rain moving in from the W on Saturday. Rain becoming more scattered in nature Saturday night and remaining through Sunday. Scattered rain showers to increase Sunday night.
  • High Temps: Low 60s Friday, near 60 Saturday, low 60s Sunday. Much cooler through the Cascades and Olympics.
  • Low Temps: Mid 40s Friday night, low 40 Saturday night, mid 40s Sunday night. Much cooler through the Cascades and Olympics.
  • Sky Cover: Partly sunny Friday, mostly cloudy Friday night, cloudy Saturday, mostly cloudy Saturday night, cloudy Sunday, cloudy Sunday night. Areas of fog likely during the overnights.
Next Week
  • Wind: Light S/SW wind becoming windy Monday with some gusts around 35mph likely. Trending light and generally SW yet variable Monday night. Remaining light and SW/variable through the week.
  • Precipitation: Rain Showers Monday. Showers remaining on/off through mid week. Trending drier Thursday with a few stray rain showers likely to linger through weeks end. Greater shower activity through the mountains.
  • High Temps: Low 60s Monday, mid 60s Tuesday, upper 60s 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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Washington State University