Snow, Snizzle, What Is it Falling From The Sky Today?

A lot of people across the region are reporting some light snow on their lawns  this morning. A very cold and damp air mass is changing drizzle into ‘snizzle’.
Monday 'snizzle' covers the side of the road in SE Portland.
Typically in a setup like this, we get an inversion – meaning that the air aloft (above the ground) is warmer. This allows the cold air to sink to the lowest elevations. Cold air actually weighs more than warm air. We call this stable air.

An airmass is considered unstable, when lifted air continues to rise on its own because it’s warmer than the air above. Think about the old adage: warm air rises.

Since the air today above the surface is cooler, the surface air is rising, cooling and condensing out this moisture in the form of snizzle and sometimes light snow.

Science aside, as we make our way through the later half of today and especially all week-long, the air above will warm-up. This means that we return to a ‘typical’ set-up where the coldest air will remain along the valley floors with a lot of fog.

Air in the mountains and along the coast will be warmer and much sunnier.


Another shot – albeit a slight one for Valley snow

If you are a snow lover and hoping to see some more Valley snow, I have some good news and some bad news.

It’s been feeling very springlike lately with highs in the mid 50s. Now that’s warm for January standards; but enough of that, if one thing is certain, it’s that much colder air is moving in.

Rain will get going late tonight and through much of Wednesday. As the rain moves through a potent cold front also moves through. But as every north-westerner knows, how much moisture is available as the coldest air moves-in?

So here’s the good news: any precipitation that falls overnight on Wednesday and into Thursday should be in the form of snow. This means that all of us have a chance to see snow flying.

The bad news: it appears as though the brunt of the precipitation is in the form of rain when temperatures are too warm, so sticking snows are unlikely along the Valley floor.

Here is the latest 72 hour forecast from our in house RPM model.SnowCast_72hr

So it doesn’t look too promising for Valley snow to accumulate. But keep in mind, if any moisture hangs on for a longer period of time and the cold air (which can be pulled down quickly by intense precipitation rates) sets in, we may have to adjust our forecasts.

Right now I’d say anyone, even along the Valley floor, could see at least a dusting.

Most Of Oregon Had A White Christmas and A Dry 2013?

Unless you live along the Coast or in the Willamette Valley, chances are good you had a white Christmas.
From the Coast Range to the Gorge, to the Cascades and points east –

snow was in the air. Check out some of these snow totals. Christmas2012

Back in Portland Christmas was a wet day with cool temperatures in the upper 30s to lower 40s.
The front that brought the rain and snow is lifting out and behind it is cool showery weather.

So weatherwise, prepare for scattered showers for the remainder of the night with temperatures falling slowly into the upper 30s. If you are headed out to a movie, grab an umbrella and the rain gear, but overall the heaviest rain has ended.

Tomorrow some scattered showers will roll-in as the next weather maker moves to our south. Highs will be in the mid 40s.

Get ready for this breaking news: Thursday through next year – that’s right I said next year – should be mainly dry! Morning fog, followed by partly sunny skies is the forecast from Friday and beyond – courtesy of a dry east wind.

On A Final And Personal Note,although I was unable to be with my family today, I am grateful that we will all celebrate tomorrow in San Diego. Working with my wife Kacey is always fun, and my in-laws near Dallas, Texas had a wonderful Christmas surprise – A White Christmas. They sent me this beautiful picture which I showed on the 6pm news tonight. Dallas

Merry Christmas to all, and all a goodnight,

First Snow, Now Floods

After a snowy, cold start to our work-week mother nature has delivered a fire hose of moisture. Heavy rains and massive snow melt due to warmer temperatures have rivers and streams on the rise.
Here are some areas flooding right now:
South Yamhill River at McMinnville Pudding River at Aurora Clackamas River at Estacada Clackamas River at Oregon City Johnson Creek at Sycamore
Meanwhile the central Willamette Valley has seen the worst flooding from Salem and Turner.
As always, turn around if you see flooded intersections and roadways.
The other story over the past couple of days is the tremendous amount of snowfall in the Cascades. Here are some 48 hour snow totals:
Ski Bowl 25″ Timberline Lodge 21″ Mt. Hood Meadows 44″
a warm front slowly lifts through the region today, the heaviest rains will taper off by late afternoon. This will give the smaller rivers and creeks some time to subside, however, another storm will move through the region Friday with more rain expected.
Stay with us here at KOIN Local 6 for updates.
Matt Brode

It WILL Snow in Portland

It seems like Portland is always on the bubble when it come to snow. We have so many near hits but so few home-runs. I am about 100% sure that snow will fall in the lowest elevations of downtown Portland and the airport.

We, Meteorologists, use a lot of tools to predict the weather. Current analysis, experience and serious computer models. Let’s review the models.

The NAM is probably our best short range (out to 84 hours) model. It shows plenty of cold air and enough moisture to drop snow to the valley floor.

The GFS is a longer range model and it agrees completely with the NAM

The Canadian and European models are also used (the EURO more frequently) and they are actually even colder than our “domestic” models.

I could really geek out even more and go into more detail but here’s my assurance. At some point in time from Sunday-Tuesday if you live in the City of Portland you will see snow. In my two years of forecasting in the City of Portland, this is the first time I’ve been so convinced.


I think the limiting factors, for the lowest elevations will be some onshore flow, the rain shadow effect (where the Coast Range steals our moisture) and the fact that temperatures will mainly be above freezing, so not more than 1-2″ in the valley but with any elevation a good 2-4″ could stick.

Get ready for a major pattern change by Wednesday – mild weather should return with potentially heavy rains. There may be a narrow window where the cold air is in place that we could see some ice issues but more on that later.

Let it snow!