AgWeatherNet Weekly Weather Outlook for December 20 to December 26, 2014

Active Weather Through Early Next Week; Cooler By Christmas Day

Nic Loyd, Meteorologist, 509-786-9357
Gerrit Hoogenboom, Director, 509-786-9371

A diverse spectrum of weather concerns awaits Washington in the coming days, as we enter an active and changeable regime during the home stretch of the Holiday Season. The two main issues facing us are stormy weather this weekend, and then a potential pattern change to cooler weather around Christmas Day.

The operative words for this weekend are wet, windy, and warm. A powerful 170 knot jet stream will take aim at Washington, and should propel an atmospheric river of moisture toward the Northwest. Rain is expected across most of the state on Saturday, with heavy totals possible in the mountains. Flooding could become a concern on some area rivers. Another worry will be sudden strong winds near the east slopes of the Cascades sometime around Sunday. Aside from the generally strong winds aloft, there are indications that a mountain wave event could induce isolated pockets of damaging winds later in the weekend. Finally, any sunny and windy areas in central Washington may climb into the 50s to mid 60s on Sunday. There will also be a large temperature gradient, with much warmer weather in southern parts of eastern Washington.

Conditions should calm somewhat early next week, although rain and breezes are likely to continue in some areas. Starting around Christmas Eve or Christmas Day, a trough dropping down from the north is expected to usher in cooler and drier weather. The pattern thereafter is highly uncertain, as a blocking pattern may develop over the North Pacific. These setups sometimes allow cold air to pour into Washington.

Unfortunately, warm antecedent conditions diminish the likelihood of a White Christmas, although we can hold out hope for a Christmas miracle.

Please stay tuned to AgWeatherNet for updates on the winter weather, and look for the next outlook on Tuesday, December 23rd.

Temperatures
  • Becoming much milder on Sunday and into next week.
  • Cooler by Christmas Day.

Precipitation
  • Rain developing statewide on Saturday, with heavy totals in the mountains.
  • Rain continuing in many areas on Sunday and into early next week, except in central areas.
  • Possibly drier later next week.

Wind
  • Potentially windy on Sunday, especially in south central Washington.
  • Breezy at times next week.

Frost Risk Summary
  • This Weekend: Low to moderate risk in the east on Saturday morning, and low risk on Sunday morning.
  • Next Week: Low risk early, and possibly increasing later in the week.

8 to 14 Day Outlook - December 27, 2014 to January 2, 2015
  • Overall, near average temperatures and near to below average precipitation are expected during the 8 to 14 day time frame.

Important Points about Next Week's Weather

South Central Washington
  • Normal conditions for this time of the year would be highs in the upper 30s to low 40s and lows in the mid to upper 20s.
Weekend
  • Rain on Saturday, with strong winds possible on Sunday.
  • Highs in the 40s to around 50 on Saturday, and 50s to low 60s on Sunday.
  • Lows in the 30s on Saturday morning, and upper 30s to 40s on Sunday morning.
Next Week
  • Mostly dry. A chance of rain at times early in the week, and then a slight chance of rain or snow later in the week.
  • Highs in the 50s early, and cooler later in the week.
  • Lows in the mid 30s to 40s early, and cooler later in the week.

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

Eastern Washington
  • Normal conditions for this time of the year would be highs in the mid to upper 30s and lows in the mid 20s.
Weekend
  • Rain and becoming windy.
  • Highs in the 40s on Saturday, and upper 40s to 50s on Sunday.
  • Lows in the 30s on Saturday morning, and upper 30s to mid 40s on Sunday morning.
Next Week
  • A chance of rain early in the week, and then a slight chance of rain or snow later in the week.
  • Highs in the upper 40s to mid 50s early, and cooler later in the week.
  • Lows in the mid 30s to mid 40s early, and cooler later in the week.

Western Washington
  • Normal conditions for this time of the year would be highs in the mid to upper 40s and lows in the mid to upper 30s.
Weekend
  • Rain, heavy at times.
  • Highs in the upper 40s to 50s on Saturday, and 50s on Sunday.
  • Lows in the 40s on Saturday morning, and mid 40s to mid 50s on Sunday morning.
Next Week
  • Rain likely around mid week.
  • Highs in the upper 40s to 50s early, and cooler later in the week.
  • Lows in the upper 30s to 40s early, and cooler later in the week.

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