Snow looks increasingly likely for Clark County, including Vancouver, over the weekend.
A special weather statement issued by the National Weather Service at 11 a.m. Thursday forecasts a cold front dropping south from Alaska beginning late Saturday, then settling into place at the same time showers move into the area.
The result: a few inches of snow on the Hockinson Hills and higher-level elevations, and snow in varying amounts in lower elevations.
Steve Pierce, The Columbian's weather blogger, said that Sunday will be a raw day, with temperatures near or slightly above freezing. It will be cold enough to snow, he said, but the question will be how much moisture is in the area.
Pierce also said that there is a "pretty decent" chance of more snow on Monday or perhaps Tuesday, adding that long-term weather models are not yet developed enough to make it a solid forecast. Look for a return to seasonal weather, i.e. rain, after that.
He updated his blog this afternoon. Here is an excerpt:
After six weeks of mundane weather, the coldest air mass so far this winter is scheduled to arrive Saturday night across much of the Pacific Northwest, just in time time for the holiday weekend. The system in question will be arriving from the Gulf of Alaska and will push snow levels to the valley floor at times beginning Saturday night and lasting though at least Monday. This system has its origins in Alaska where temperatures have been well below normal as of late. At this point it does not appear as though this will qualify as a true Pacific Northwest "arctic blast" (temperatures at or below 32 degrees for daytime highs west of the Cascades) but overnight lows will likely fall below freezing across many locations Saturday night through Monday.
Temperatures will fall quickly after sunset on Saturday and any precipitation associated with this system will likely fall as snow or a rain/snow mix all the way down to the valley floor. Sunday and Monday will feel raw outside, with high temperatures in the upper 30s west of the Cascades and snow showers likely. The big question remains, how much snow will fall and where? A pattern like this is difficult to predict, as precipitation amounts will be showery in nature and thus hit-and-miss. The hills above 500 ft are likely to see the best chances for accumulating snow along with other snow prone locations. If a more consolidated line of precipitation moves across the area Saturday night, nearly everyone could see accumulating snow, albeit light.
All eyes then turn to early next week. With plenty of cold air in place, another system will likely arrive Monday and Tuesday from the west. This system has the potential to bring a more widespread snow event to the valley floor for a period of time before changing over to rain. Models are up in the air right now on which scenario will play out early next week....