AgWeatherNet Weekly Weather Outlook for Jan 31 to Feb 6, 2020

Cooler air and a dry/clear period sandwiched between widespread precipitation

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

Discussion:

The state of Washington is slated to see a wet Friday evening and Saturday with fairly widespread precipitation expected due in part to a strong atmospheric river following along a baroclinic boundary into the Pacific Northwest. Much of this precipitation looks to be in the form of rain (heavy at times in western Washington) aside from some of the higher ranges through the Cascades. This is expected to change however as a strong cold front, associated with a surface low pressure system moving into British Columbia, looks to begin sweeping across the state of Washington from the northwest early afternoon Saturday. This will help to intensify ongoing precipitation as well as begin lowering the snow level Saturday evening. Snow will mostly occur throughout mountain and upland areas with rain remaining through lowland areas. Snow accumulation in most areas is expected to remain generally modest except for the high Cascades which look to pick up over a foot of new snow.

A few hazards associated with the Friday and Saturday event include landslide and flood hazard throughout western Washington. 1-3 inches of rain are likely for lowland areas and 5-10 inches likely through the Olympics and Cascades. The Seattle NWS office has already issued flood watches for many rivers including the Snoqualmie, Stillaguamish, Skagit, Skokomish, Chehalis, and Elwha. Also, as snow levels lower throughout mountain regions, it is anticipated that they will reach pass levels Saturday night. A couple of inches of accumulation are likely at pass levels. Windy conditions are also expected through Saturday with winds from a south/southwest direction, turning westerly after the passage of the cold front. Gusts 50+ mph are likely in some locales, especially the Basin/Palouse and the Puget Sound region.

Sunday through Tuesday will be defined by much cooler temperatures as a pocket of cold air is expected to settle over Washington after the passing of the cold front. Weather conditions are anticipated to remain dry/mostly dry during this time except for some scattered rain showers through the western part of the state. In fact, a stray snow shower or two may be even be seen thorough the Puget Sound lowlands Sunday evening as over night temperatures are expected to dip just below freezing. Mostly sunny to clear skies are expected for eastern Washington during this time while western Washington remains under mostly broken cloud cover with just a few peeks of sunshine likely.

The Tuesday night time frame will see the return of widespread precipitation. Rain can be expected in western Washington as temperatures look to begin warming again late Tuesday and through the end of the period. Eastern Washington however still looks to remain cooler and is anticipated to see light snow in most areas with south central Washington and lowland areas generally trending more toward rain. Any snow accumulations are expected to be modest. The threat for some showery type precipitation is expected to linger through the state until the end of the period, with an uptick in precipitation anticipated to return in the Thursday/Friday time frame. It is also worth mentioning that as this disturbance moves through the state, a stronger surface pressure gradient will accompany it, meaning breezy conditions throughout much of the state with winds again generally from the southwest.

Of interest, it is noted that it rained everyday in the month of January in Hoquiam and Quillayute. The Quillayute rain streak currently sits at 45 days (as of Friday, 31 January) which is two days away from the record. With a drying trend expected for Sunday and only a few scattered showers likely for Monday, we may fall just short of upsetting the current record.

Looking further ahead, some models are hinting at an arctic air outbreak during the second week of February. Details will become clearer as we approach this time frame, but winter still has a few tricks up her sleeve!


Key Points:

  • Below seasonal temps Sunday through Tuesday.
  • Rainy/snowy first part of the weekend, mostly dry Sunday and into next next week, return of widespread precip around Tuesday night.

Temperatures
  • Temps dropping Saturday night.
  • Below seasonal temps Sunday and early next week.
  • Warming back to around normal by week's end.

Precipitation
  • Widespread rain, some upland snow, and mountain snow Saturday. Snow lowering to pass level Saturday night.
  • A few scattered rain showers lingering through western Washington Sunday-Tuesday. Dry/mostly dry east of the Cascades.
  • Return of widespread rain/upland snow/heavy mountain snow around Tuesday night. Precip becoming more scattered again through week's end.

Wind
  • Windy Friday night through Saturday state wide with winds from the S/SW and turning W. Winds becoming light Sunday and remaining so into the first part of the week. Breezier conditions likely at times near the end of the period.

8 to 14 Day Outlook – Feb 7, 2020 to Feb 13, 2020
  • Below average temperatures and near to 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
  • A few light rain showers, clearing through Saturday night with some patchy fog. Dry Sunday. Sunny to overcast.
  • Highs in the low 60s Friday, near 60 Saturday, and upper 40s Sunday.
  • Lows in the upper 40s Saturday morning, and mid 30s Sunday morning.
Next Week
  • Dry early in the week. Return of rain showers and rain/snow showers in upland areas in the Tuesday night time frame followed by a low chance of scattered rain through Thursday. Sunny to overcast.
  • Highs in the mid 40s Monday and Tuesday. Low 50s Wednesday, and upper 50s Thursday.
  • Lows near 30 Monday and Tuesday mornings. Upper 30s Wednesday morning, and low 40s Thursday morning.

North Central Washington
Weekend
  • Light rain showers and upland snow with modest accumulations, clearing through Saturday night with some patchy fog. Mostly dry Sunday. Mostly sunny to overcast.
  • Highs in the low 40s Friday, upper 40s Saturday, and mid 30s Sunday. Cooler throughout higher terrain.
  • Lows in the upper 30s Saturday morning, and mid 20s Sunday morning. Cooler throughout higher terrain.
Next Week
  • Dry early in the week. Return of rain/snow showers and upland snow showers in the Tuesday night time frame followed by more scattered rain/snow through Thursday. Mostly sunny to overcast.
  • Highs in the low 30s Monday and Tuesday. Upper 30s Wednesday, and low 40s Thursday. Cooler throughout higher terrain.
  • Lows in the low 30s Monday morning, dropping to near 20 Tuesday morning. Upper 20s Wednesday morning, and low 30s Thursday morning. Cooler throughout higher terrain.

Eastern Washington
Weekend
  • Light rain showers with some snow mixed in Saturday night, clearing through Saturday night with some patchy fog. No significant snow accumulations. Mostly dry Sunday. Sunny to overcast.
  • Highs in the low 50s Friday, near 50 Saturday, and upper 30s Sunday.
  • Lows in the low 40s Saturday morning, and upper 20s Sunday morning.
Next Week
  • Dry early in the week. Return of rain/snow showers in the Tuesday night time frame followed by more scattered rain through Thursday. Sunny to overcast.
  • Highs in the mid 30s Monday and Tuesday. Low 40s Wednesday, and upper 40s Thursday.
  • Lows in the mid 20s Monday morning, and low 20s Tuesday morning. Upper 20s Wednesday morning, and upper 30s Thursday morning.

Western Washington
Weekend
  • Periods of light to heavy lowland rain and mountain snow, tapering off to scattered showers Sunday. Rain expected to change over to snow at pass levels Saturday night with a couple of inches of accumulation. Patchy fog at times. Partly sunny to overcast.
  • Highs in the mid 50s Friday, low 50s Saturday, and low 40s Sunday. Much cooler throughout the Cascades/Olympics.
  • Lows in the upper 40s Saturday morning, and low 40s Sunday morning. Much cooler throughout the Cascades/Olympics.
Next Week
  • A few scattered rain showers and scattered mountain snow showers early in the week. Return of light to moderate rain and more substantial mountain snow in the Tuesday afternoon time frame. Extended periods of precip to continue through Thursday. Partly sunny to overcast.
  • Highs in the low 40s Monday, and mid 40s Tuesday. Near 50 Wednesday, and low 50s Thursday. Much cooler throughout the Cascades/Olympics.
  • Lows in the upper 20s Monday morning, and low 30s Tuesday morning. Near 40 Wednesday morning, and mid 40s Thursday morning. Much cooler throughout the Cascades/Olympics.

  • Like us on Facebook at https://www.facebook.com/AgWeatherNet
    Follow us on Twitter at https://www.twitter.com/AgWeatherNet
Washington State University