PORTLAND, Ore. (KOIN) – First off, a new year with new records to break! Well that might be difficult, 2015 brought some active weather to the Pacific Northwest and that might be hard to top especially those hot summer days from 2015. The first couple of days of January has brought cold and sunny weather to the Pacific Northwest. So I will ask you this, would you rather have the cold sunny weather or the warmer wet weather? Most people I ask are split, after being out in the bitter cold with the wind chill, many resort back to the warm wet weather. I’ll take the sunny crisp cold winter for at least a few more weeks before I start leaning back to some mild weather. It’s winter!
Well the atmosphere is always trying to balance itself out, so of course the shift to a wetter warmer pattern returns this week. Before we get there though our second half of the weekend will bring a tricky forecast. The ground is cold and temperatures have been falling and falling the last couple of days as cold air from the Gorge pools to the PDX neighborhoods. A relatively weak system will pull in from the south and drag a small amount of moisture on in and this will eventually push to PDX by the morning and will taper off by night. Here is where the forecast gets tough, temperatures at the surface are cold (cold air has been sinking in the valleys for days), but warmer air will be moving in aloft.There are a ton of elements and questions:
Will we warm up? How thick of a warm sector will move in (that’s important between a decision of rain/sleet/freezing rain/snow)? Just how warm will it get? How much will upslope flow from the mountains hold a cold gap of air? How long will it take the system to move? Is it too dry in PDX for much to fall to the surface? How long until saturation occurs? …
This list goes on. But, I love a forecast like this. I love diving into every element and dissecting weather models and obsessing over what the atmosphere is doing. This isn’t a typical bluebird day forecast (which I also love), but it this forecast takes time and it builds experience.
That being said, tonight’s forecast is important. Roads can get iced over and slick, snow can add some trouble, all while many are getting back at it after the holiday. Snow is likely and freezing rain is definitely likely. Just where, when, and how long will it last. More questions to ask.
Right now my forecast calls for a wintry mix for the greater Portland area, with the potential for light snow early to mid-day (~1″), but eventually turning over to freezing rain/rain by the early afternoon. It’s going to be pretty close because temperatures aren’t going to warm much with clouds and cold dense air stuck at the surface.
You will want to keep up with our weather app and join in to KOIN 6 with all the updates. The main areas of concern will be the Columbia River Gorge (I-84) and the Central/Southern Willamette Valley (I-5). The National Weather Service has those areas under a Winter Weather Advisory.
To a wonderful 2016- Joseph