AgWeatherNet Weekly Weather Outlook for October 14 to October 20, 2017

Cold on Saturday Morning, Then Warmer and Drier; Becoming Active Next Week

Nic Loyd, Meteorologist, 509-786-9357

Temperatures should be near or below freezing for many sites east of the Cascades on Saturday morning, as building high pressure brings increasingly stable conditions back to the region. However, the main story for later this weekend will be the warmer, drier, and calmer weather. The benign respite is expected to be short lived, however, as an active jet stream could direct a couple of moist systems into the state starting around Tuesday. There may be significant rain at times in western areas, along with periodically windy conditions. Central Washington looks to be rain shadowed for much of the time by southwesterly air flow, although a slight chance of rain is still in order given the dynamic nature of the disturbances.

High temperatures are likely to decrease later in the period in rainy areas, but appreciable atmospheric mixing and some sunshine are likely to keep conditions fairly mild for a while in central Washington. Low temperatures are anticipated to remain rather mild, at least through mid week, due to the clouds and winds. Overall, variable weather is forecast in the coming days, which is consistent with this typically changeable time of year.

Here are the key points:

  • Widespread frost east of the Cascades on Saturday morning
  • Pleasant weather for Saturday afternoon to Monday
  • Significant western rainfall, heavy mountain rain or snow, and statewide strong winds possible by the middle of next week

    • Temperatures
      • Cold on Saturday morning, and then becoming warmer.
      • Cooler western afternoons by mid next week, and then additional cooling late in the period.

      Precipitation
      • Mostly dry through early next week.
      • Rain likely at times in western Washington starting around Tuesday.
      • A chance of rain east of the Cascades later in the week.

      Wind
      • Generally light this weekend.
      • Breezy to windy at times starting around Tuesday.

      8 to 14 Day Outlook - October 21, 2017 to October 27, 2017
      • Overall, near to above average temperatures and near to above average precipitation are expected during the 8 to 14 day time frame.

      Frost Risk Summary
      • This Weekend: High risk on Saturday morning, except moderate for western WA, and moderate risk on Sunday morning.
      • Next Week: Low to moderate risk on Monday morning, and then low risk, and moderate risk late in the week.

      Long Range Discussion / Seasonal (Winter) Outlook

      The potential late-autumn development of a weak La Niña event and recent decadal trends are prominent factors in this winter’s outlook. While winters are generally becoming warmer over time, a weak La Niña would suggest the possibility of relatively colder temperatures. Certain dynamical forecast models are also indicating enhanced odds of above normal precipitation. Given the conflicting signals, probabilities are currently favoring near normal temperatures, and near to slightly above normal precipitation for the 2017/2018 winter season.


      Important Points about Next Week’s Weather

      South Central Washington
      • Normal conditions for this time of the year would be highs in the mid to upper 60s and lows in the mid 30s to mid 40s.
      Weekend
      • Mostly dry.
      • Highs in the mid 50s to mid 60s on Saturday, and low to mid 60s on Sunday.
      • Lows in the mid 20s to mid 30s on Saturday morning, and upper 20s to 30s on Sunday morning.
      Next Week
      • Mostly dry early. A slight chance of rain later in the week.
      • Highs in the mid 60s to low 70s early, and possibly cooler later in the week.
      • Lows in the mid 30s to low 40s on Monday morning, and then warmer, and possibly cooler later in the week.

      North Central Washington
      • Normal conditions for this time of the year would be highs in the upper 50s to mid 60s and lows in the mid 30s to low 40s.
      Weekend
      • Mostly dry.
      • Highs in the 50s on Saturday, and mid 50s to mid 60s on Sunday.
      • Lows in the upper 20s to mid 30s on Saturday morning, and 30s on Sunday morning.
      Next Week
      • A slight chance of rain later in the week.
      • Highs in the mid to upper 60s early, and possibly cooler later in the week.
      • Lows in the mid 30s to mid 40s on Monday morning, and then warmer, and possibly cooler later in the week.

      Eastern Washington
      • Normal conditions for this time of the year would be highs in the upper 50s to mid 60s and lows in the mid 30s to low 40s.
      Weekend
      • Mostly dry.
      • Highs in the low to mid 50s on Saturday, and upper 50s to mid 60s on Sunday.
      • Lows in the upper 20s to mid 30s on Saturday morning, and 30s on Sunday morning.
      Next Week
      • A chance of rain later in the week.
      • Highs in the 60s to around 70 early, and cooler later in the week.
      • Lows in the mid 30s to low 40s on Monday morning, and then warmer, and possibly cooler later in the week.

      Western Washington
      • Normal conditions for this time of the year would be highs in the upper 50s to mid 60s and lows in the low to mid 40s.
      Weekend
      • Mostly dry. A slight chance of rain later on Saturday in the north.
      • Areas of morning fog.
      • Highs in the 50s to low 60s on Saturday, and upper 50s to 60s on Sunday.
      • Lows in the mid 30s to low 40s on Saturday morning, and upper 30s to mid 40s on Sunday morning.
      Next Week
      • A slight chance of rain later on Monday in the north, and then rain likely at times region-wide starting on Tuesday.
      • Highs in the 60s to low 70s on Monday, and cooler later in the week.
      • Lows in the 40s on Monday morning, and then warmer, and possibly cooler later in the week.


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