Cloudy and cold this morning with light snow shower over the Yakima/Kittitas Valleys until 10 AM. Rain/Snow mix developing late this evening from the Tri-Cities to foothills. Morning temperatures in the teens-20s (40s foothills), near 30 by noon and afternoon highs in the low-mid 30s.
Lingering snow showers will continue this morning in the Yakima/Kittitas Valley where they could see another 1-3"(Winter Weather Advisory). A Winter Storm Warning remains in effect for the East Slopes and Cascades as moderate to heavy snow is expect to fall through this evening (East Slopes: 3-7"; Passes: Up to 1 ft.)
A complicated weather pattern is setting up a very challenging forecast for the rest of the week. The warm front that brought us the snow yesterday and overnight has lifted north allowing warm air advection to push into the region. This warm air will have the greatest impact on the Tri-Cities and east into the foothills. Highs today should climb into the mid 30s and even warmer into the foothills were down slope winds have them in the low-mid 40s already. Theses warming temperatures will lead to some snow melt and slushy roads in the foothills. We could even see some street flooding in the Walla Walla and Pendleton area with snow/ice blocking storm drains.
A rain or rain/snow mix will develop late afternoon/evening from the Tri-Cities into the foothills as a cold front moves east. This winter mix should change to snow overnight, maybe a few pockets of freezing rain. It should remain all snow for the Yakima/Kittitas Valleys. At this time snowfall accumulation looks light at 1-2". A brief break in between systems Wedneday afternoon-Thursday morning.
The next winter storm arrives Thursday afternoon-early Friday morning with a wintry mix of freezing rain, sleet and rain/snow mix from the Tri-Cities and east into the foothills. Accumulating snow west into the Yakima/Kittitas Valleys (1-4") and Cascades will be likely.
Saturday looks dry and maybe a little sun if we're lucky with highs in the low-mid 30s. A weak system will produce of few snow showers late Sunday-early Monday morning. Highs mid-upper 20s and lows in the teens.