Weather 12-19-19


The well-advertised winter storm is upon us. As mentioned earlier this storm will come through in two phases. The first, a warm front, moved across the Cascades last night and is slowly pushing across the forecast area this morning bringing light snow and some freezing rain. Expect a short break in the precipitation late this morning from west to east as that first warm front moves out of the area. This will be a short lived break as the next warm front will be close on the heels of the firs by early this afternoon. This weather system has a deeper moisture tap and lift and is also quite a bit stronger and longer-lasting. So, expect an 80% chance of snow then snow mixed with rain late this afternoon with high temperatures today around 32 degrees. A Winter Storm Warning goes into effect at Noon through early Friday morning for the Wenatchee Valley with 2-5 inches of snow expected along with possible freezing rain. Precipitation amounts today will be from a tenth to two tenths in the lowlands and a quarter inch or higher for the Panhandle mountains.

For tonight and Friday precipitation amounts will be much, much higher, with the Columbia Basin and Wenatchee Valley receiving from a tenth to a quarter inch and the mountains inches of precipitation as a fire hose of subtropical moisture remains aimed into the Pacific Northwest ahead of an elongated trough limping across the Eastern Pacific. There is a 100% chance of precipitation tonight. Northcentral Washington weather for Friday calling for cloudy skies with an 80% chance for rain and rain mixed with snow, much warmer too, with afternoon highs tomorrow in the lower 40’s.

By Friday night and Saturday, a deeper area of low pressure approaches the California Coast then rapidly tracks northward toward Northcentral Washington with an 80% chance of rain Friday night and a 60% chance of morning showers on Saturday with highs near 40 degrees. The air mass will continue to be warm and very wet which will push snow levels higher. It looks to be a mild night for many locations in the Columbia Basin and Wenatchee Valley where overnight lows will be warmer than what is considered normal for afternoon highs this time of year.

Snow amounts for most of the mountains will be measured in feet by then end of this weekend. Impacts will be any travel across the region the next 2-3 days.

One last weak weather disturbance will swing through Sunday and will keep a slight threat for snow showers but confidence is low exactly how this last band of precipitation will play out and could lead to light snow for some during the Monday morning commute. High temperatures on Sunday still mild into the upper 30’s. Monday through Christmas Day look to be dry.

The Wenatchee Valley can expect mostly sunny to partly cloudy skies on Monday and on Christmas Eve with mostly cloudy ski8es on Christmas Day Wednesday with afternoon highs in the mid 30’s.