Bring On The Snow!
Wednesday Morning Update
Good morning. Check out the picture above taken by the ODOT camera in Seaside, Oregon just after 11am. Perhaps a sign of just how cold the air is that will be over us in a few hours? If they can see snow on the beaches, it will only be a matter of time before it makes its way inland. I just got done looking at the latest data that just came in this morning and so far everything looks on track for snow down to sea level later this afternoon. Both the NAM and the WRF show a nice healthy band of snow showers moving into the metro area anytime after 3pm today and lasting through the evening. This morning’s 12z model soundings and 4km meteograms support snow to the valley floor from Seattle to Salem. I was watching the Weather Channel this morning and noticed they were sending crews to Seattle today to report on what is supposed to be 4-6″ up there. They also commented about getting 4-6″ in Portland as well. I hate to rain on their parade, but I just don’t see enough moisture to put up those kinds of numbers in either city. Maybe in the hills around the metro area, but not in the city itself. In fact, both the 12z NAM and 12z GFS were lighter on their precipitation amounts for tonight. Looks to me to be more along the lines of “Snow Advisory” amounts (1-3″) than it does anything more serious to support the current Winter Storm Warning. Most data this morning suggests .10-.20″ across the metro area. Under normal circumstances that is good for perhaps 1-2″ of snow. But if we see more cold air advection than presently forecast, the precipitation could be a bit more. But as usually is the case, we just wont know for sure until it gets going later today. We all know it wont take much to pile up a few inches if you get caught under a heavier shower. Colder modified arctic air is still on tap after the storm passes. As mentioned below we are going to be very close to setting several new temperature records (both low and high) over the next few days. Then it looks like another system arrives on Saturday. That one could start out as snow before changing over to rain. More on that later.
So, the bottom line is — 1-3″ across the metro area is likely this evening and overnight before clearing out by Thursday afternoon. Thursday night and Friday will be near record cold with highs in the 30’s and lows well below freezing. If we get any snow cover on the ground followed by clearning, Friday and Saturday’s morning low temperatures could challenge the current daily records.
Bring On The Snow!
Good afternoon! Well, it looks like our wait for snow may finally be over. For those of you who don’t like late season snows in the valley, you better jump in the car and head south and do it soon. The threat of a significant area wide valley snowfall event is increasing this afternoon. Snow has already been reported falling at several valley locations this morning across western Oregon and Washington. In advance of this rare late season storm, Winter Storm Watches and Warnings have been issued by the National Weather Service from the Cascade Mountains to the Pacific Ocean and from the Canadian boarder to Northern California. This also includes coastal communities.
A very cold trough of low pressure will slide down the coastline of Washington this evening, bringing with it colder air and the threat for snow to the valley floor tonight and Wednesday morning. Later Wednesday, a stronger system will take a similar path along the coastline. If the the track of the second system progresses as currently forecasted, snow will fall and likely accumulate down to the valley floor Wednesday through Thursday. Even the beaches of Oregon and Washington are likely to see some accumulating snow. This is the best chance for an area wide valley snow event since the white Christmas of 2008. Snow will likely become even more concentrated overnight Wednesday night. The most significant snowfall will occur Wednesday night and Thursday morning. Although predicting snowfall totals is arduous at valley locations, it now appears likely that enough snow will fall to cause commuting issues anytime between Wednesday morning and Friday morning. This week’s weather pattern has some similarities to the February 12th 1995 storm that brought 3-5″ of snow to most valley locations in and around Portland and as much as 6-10″ in the hills above the metro area. As the system slides south on Thursday, it will be replaced by modified arctic air that will persist into the weekend. If western Oregon and Washington valley locations receive enough snow cover, temperature records from Thursday through Saturday morning could be in jeopardy at several locations. Some of these temperature records have stood for as long as 60 years in Portland, for example.
Here is a quick look at late season snowfall records for the months of February and March, followed by daily temperature records at the Portland International Airport for the next few days. The period of record for this review is 1940-2011 —
7.6″ – 3/8/1951 * Daily record for month of March
6.1″ – 2/19/1993 * Daily record for month of February
5.2″ – 2/12/1990
5″ – 2/2/1949
4.1″ – 2/18/1949
4″ – 2/9/1939
3.6″ – 2/12/1995
3.2″ – 2/28/1962
2.8″ – 2/17/1986
2.3″ – 2/15/1990
Record coldest daytime highs and overnight lows —
Wednesday 2/23 – High 41 degrees in 1942, Low 25 degrees in 1993
Thursday 2/24 – High 38 degrees in 1994, Low 25 degrees in 1969
Friday 2/25 – High 40 degrees in 1994, Low 23 degrees in 1969
Saturday 2/26 – High 38 degrees in 1971, Low 20 degrees in 1962
Sunday 2/27 – High 40 degrees in 1971, Low 19 degrees in 1960