Running out the door to head to my energy trading shift, but thought I’d post a quick update regarding the historic arctic blast and our accompanying lowland snow chances before then. Hope to have more tomorrow when there’s a bit more time!
Arctic blast: Our extended/extremely strong arctic blast is still on tap, and there weren’t too many changes in the models over the past two days. The arctic air will arrive Sunday morning, Monday – Wednesday may be the coldest days, and we may moderate a bit towards the end of the week. Current forecasts have temperatures staying *below freezing* from Sunday all the way through Thursday. Overnight lows should be in the teens in the city and single digits in the suburbs. I’m hoping Lake Washington will freeze enough for me to go ice skating by Foster Island.
Christmas Weekend Snow: As I mentioned in my previous blog – temperatures appear to be marginal for a White Christmas here in Seattle. Temperatures will be cool (highs of upper 30s), but the real cold arctic air won’t arrive until Sunday. I think there’s a chance of some snowflakes in the air on Christmas but I don’t see much accumulation in the cities. The exception is further north in Whatcom County, where temperatures *should* be cold enough for accumulating snow.
Sunday looks more favorable for snow in Seattle. The true arctic air will be making its way south then, and we’ll still have some moisture around from the system that came through Saturday. The precipitation will be showery in nature, so snowfall amounts on Sunday should be highly variable with both elevation and location… places with higher elevation and where the showers are heaviest will see the most snowfall. This doesn’t look like a major event for Seattle, but there could be significant travel impacts since temps will be cold enough for snow to stick to the roads – or worse – melt initially, and then freeze into ice as even colder air filters in Sunday night.
Monday – Wednesday look mostly dry. There’s the chance of some light snow on Thursday, but that’s still pretty far out.
Extended forecast: Temperatures have warmed a bit the far extended forecast (first week of January), but the forecast has also trended a bit wetter. It’s looking more likely that the Cascades could see substantial amounts of snow during this time. For the lowlands – time will tell… the forecast has a lot of time to change… but I have a feeling we’ll at least have another chance of lowland snow sometime in the first week of January. Stay tuned!
Below images show the predicted snowfall and temps for Seattle and Portland for the next two weeks from the 12z ECMWF ensemble. Portland looks a little snowier overall due to storms having a more southern track. Though the main story with this event is historic cold, both cities should have multiple chances to see at least a little snow over the next two weeks.
