AgWeatherNet Christmas Week Weather Outlook for December 22 to December 28, 2012

Snowfall on Christmas Day Could Bring White Christmas to Parts of Eastern Washington

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

As a frontal system approaches the state on Tuesday, dreams of a White Christmas may become reality, at least for northern areas of eastern Washington. While the strength and available moisture of the storm remain uncertain, it is possible that snow will develop in eastern Washington later on Christmas Day. Whether or not Christmas snowfall materializes, some of these areas that currently have significant snow cover should still have some remaining on Christmas morning. However, presently snow-free areas are unlikely to see any accumulating snowfall before Tuesday.

Weak weather systems moving across Washington in a moist southwesterly flow will maintain a chance of rain or snow showers this weekend, although precipitation amounts will be light. The upper low responsible for the inclement weather will finally move inland later on Sunday, as drier air begins to enter the region. The one exception will be in southeastern Washington, where a chance of rain or snow will occur on Monday morning. A brief ridge of high pressure will translate through the state on Monday for drier but cool weather on Christmas Eve. The next storm will approach the coast on late on Christmas Eve. Although the timing and other details are subject to change, it appears that rain will develop on Christmas morning in western Washington, with snow or rain developing east of the Cascades later in the day. The low pressure area will affect the state through Wednesday. While the storm may weaken or split as it moves inland, the potential exists for moderate precipitation amounts. It is possible, however, that this storm will be the last storm for quite some time. The end of next week may see a return to quieter and dry weather, which could last into early January 2013, as a ridge of high pressure builds over the region.

Temperatures
  • Near seasonal levels on average.
  • Relatively mild this weekend, especially east of the Cascades.
  • Cooler next week.

Rainfall
  • Light precipitation possible at times statewide this weekend.
  • Rain most likely in western and southeastern Washington, with snow most likely in the northern part of eastern Washington and the mountains.
  • Drier on Monday, except a chance of rain or snow in southeastern Washington in the morning.
  • Rain developing in western Washington on Christmas morning, with rain or snow developing east of the Cascades by afternoon or evening. Snow likely for the mountains.
  • Drier late in the week.

Wind
  • Light breezes this weekend.
  • Breezy conditions possible around Tuesday.

Frost Risk Summary
  • This weekend through next week: Generally moderate risk early, becoming high by Monday.

8 to 14 Day Outlook - December 29 to January 4
  • The large scale pattern will feature a change next weekend, as a ridge of high pressure builds over the Northwest. Drier and less active conditions are possible as 2013 begins, while temperatures may be near to slightly above normal.

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
  • A chance of rain at times, except possibly a mix near the Cascades.
  • Highs in the mid 30s to mid 40s.
  • Lows in the upper 20s to mid 30s on Saturday morning, and mid 20s to low 30s on Sunday morning.
Next Week
  • Dry early, with a chance of rain or snow by Christmas Day.
  • Highs in the 30s to low 40s.
  • Lows in the 20s to low 30s.

North Central Washington
  • Normal conditions for this time of the year would be highs in the mid 30s and lows in the low to mid 20s.
Weekend
  • Light snow or rain at times.
  • Highs in the 30s.
  • Lows in the mid 20s to around 30.
Next Week
  • Dry early, with a chance of snow or mix by Christmas Day.
  • Highs in the mid 20s to mid 30s.
  • Lows in the upper teens to 20s.

Eastern Washington
  • Normal conditions for this time of the year would be highs in the mid to upper 30s and lows in the mid to upper 20s.
Weekend
  • Light rain at times, except possibly a mix in the north.
  • Highs in the upper 30s to mid 40s on Saturday, and mid to upper 30s on Sunday.
  • Lows in the low to mid 30s on Saturday morning, and mid 20s to around 30 on Sunday morning.
Next Week
  • Dry early, with a chance of snow or rain by late on Christmas Day.
  • Highs in the upper 20s to mid 30s.
  • Lows in the 20s.

Western Washington
  • Normal conditions for this time of the year would be highs in the upper 40s and lows in the mid to upper 30s.
Weekend
  • Light rain or showers at times.
  • Light snow showers in the mountains.
  • Highs in the 40s.
  • Lows in the 30s to around 40.
Next Week
  • Mostly dry on Christmas Eve Day, with rain developing by Christmas morning.
  • A chance of showers later in the week.
  • Highs in the 40s.
  • Lows in the 30s to around 40.

Washington State University