Long Range Outlook: First Wet & Cold Pattern In 2 Months?

We are now in our 7th week of upper-level ridging and/or split flow giving us warmer than normal weather.  In fact most of the past three months we’ve seen ridging over the West Coast or just a little bit to the east or west of us.  The only significant breakdown of the ridge was around Christmas when several cold and wet storms moved through the region.

It appears that this pattern will persist another 8-10 days, but all long-range models show a change in the last few days of February.  Models have been showing this for the past 4-5 days too.  To highlight:

  • Mild and dry weather continues for about one more week across the Pacific Northwest
  • Wetter and cooler weather arrives the last couple of days of February…plan to finish dry weather projects by that time.
  • Ski areas may see their best snow conditions since Christmas NEXT weekend (Feb 28/Mar 1).  But nothing will change for this coming weekend; lots of thin spots down low still.
  • It’s possible some closed ski areas could open up again by the first full weekend of March

Today was great, tomorrow looks the same, and then a mix of clouds and sun coming up the last few days of this week as the ridge breaks down a little.  Then the ridge pops back up quite strong to our west over the weekend.  Look at Sunday:

gfs_sunday

With the ridge slightly to our west, we get a cooler push of air out of southwest Canada Sunday and Monday.  Not an arctic blast by any means, but we likely won’t see 60 degree days.  More typical low-mid 50s instead with the gusty east wind.  I noticed both the GEM and ECMWF (12z runs) had a very strong pressure gradient on Sunday, but the 00z GFS does not.  The 00z GEM on the other hand has a significantly colder push of air, one that would give us high temps in the 40s with more of a winter feel Sunday/Monday.

Beyond that, the upper-level ridge then takes a few days to flatten, then redevelop much farther west.  Here’s the 00z GFS for Saturday the 28th, and the following Wednesday the 4th of March.  gfs_sat28

gfs_wed_4 Wow…quite a change from what we’ve seen in January and February!  This can be a great pattern for mountain snow, the GFS would give us snow levels 2,000-4,000′ through period.

Is there much confidence in this pattern change?  I think so…take a look at the 00z GFS, 00z GEM, and 12z ECMWF ensembles.  It’s 500mb height and anomaly:  gfs_mar3 gem_mar3 ecm_mar3

They are all in almost perfect agreement by Tuesday, March 3rd…two weeks from now.  At least the ensemble averages are…this leads to high confidence of a pattern change towards colder and somewhat wetter as we head into March.  The first significant rain and mountain snow arrives a week from Thursday, the 26th.

A huge question is whether it’s a temporary change…like back at Christmas.  Or is it the classic switch to wet/cool as meteorological spring arrives?  Good question.  The monthly run of the ECMWF from last night implies it’s going to last longer than a week.  Here is the map for week 3, March 1st-8th…pattern is the same.

500za_week3_bg_NA

Then week 4 which takes us into mid-March:

500za_week4_bg_NA

Still the same pattern with the upper level high out over the Aleutian islands.

Chief Meteorologist Mark Nelsen

35 Responses to Long Range Outlook: First Wet & Cold Pattern In 2 Months?

  1. Mowa says:

    U. Wa atmos shows first weather hitting 2/26. We’ll hope.

  2. It is going to be a day late but will it fall a dollar short?

  3. February flowers bring March showers. Wait, is that how it goes?

  4. Sapo says:

    Sweet! The mountains need it. I was driving through Government Camp yesterday, and there is NO SNOW. There is nothing, anywhere, and the snow on the mountain is extremely minimal. The mountains need this cold/wet period!

  5. W7ENK says:

    Well, this is definitely good news for the mountains! My only concern is, how long can we sustain it. Hopefully, for the sake of a decent snowpack, it sticks around for a while. For the sake of our sanity in the lowlands however, I’m not so sure… I don’t think I can handle yet another cool and crappy lead-in to summer in such short order.

    So conflicted right now!! :-/

    • JJ78259 says:

      Well Eric I can still remember a few years ago it was dry till half way through March and the week of Spring Break was a total wash out. Come think about it, has Portland ever had a dry Spring Break Weather Dan must Know. Going to Florida this year for the break.

    • W7ENK says:

      1993.

      Unfortunately when I go to look it up, this angry dude named Brutus gets in the way and says he can’t find the data I’m looking for… 😦

    • David B. says:

      Was 93 the epically cold and rainy summer we had one year in the 1990s? I remember that year. Made use of my fireplace multiple times in July and August. A real bummer summer.

    • WEATHERDAN says:

      Salem has indeed had years with totally dry and warm spring breaks. 1965, 1969, and 1979 to name a few. But more typically we have at least a few crummy days mixed in with the nice ones. Even in a warm Spring I would expect at least a couple of wet and cool days during Spring break. And yes 1993 was an overall cooler and wetter than normal Summer. Especially June and July. August-October was quite a bit dries and warmer. 1992 and 1994 were very hot Summers but 1993 was shortly after Mount Pinatubo erupted and caused worldwide disruptions. During the Winter of 92-93 we had a very cold snowy winter with 35 inches of snow in Salem. 1993 was the great Mississippi river flood with a cool wet Spring over much of the country. As for this change to some wet and cooler weather it was bound to happen. We always have some of it every Spring. The question remains is the cold weather over in the East and we will get it here. I don’t think so. It does look like at least a week of more normal weather in early March. Maybe even more. But temps should drop to about normal as Mark said and not way below normal. The ski resorts may see more snow as well. But how long will it last? And how much snow will the ski areas get? For those who want a March miracle I think you will be disappointed. But for you who want some late season great skiing you may be in luck. Maybe 3 feet in a two week time span. Even ski bowl may be able to re open temporarily. It did around Christmas. But I expect ski bowl will be closed for the season by early April. Most of our really cool and wet Springs came after cool and wet Winters. So what it looks like will happen is a return for a while to a more normal weather pattern for us in the first half of March. But as Mark said this is no Arctic blast. So If you wanted a end of the season snow down low forget it. Spring training starts this weekend and DST is now 19 days away. Also March is typically our first month with a high of at least 70. Chances are Spring breakers will see at least 2 days with a high of 60 or more and about .75 of rain. Peace.

    • High Desert Mat says:

      You seem to know it all Dan. Do you by chance have the lottery numbers for this Wednesday please?

    • Tyler Mode in Battle Ground says:

      In all honesty, those days with the quick moving heavy showers with sun breaks in between are usually perfect snow pack building days!

      I just don’t want the all day rain and cold and gloom we had in 2011.

      That was the first spring at my new house. I remember planting my new trees in mid March with pouring rain and snow…that was just fantastic.

    • WEATHERDAN says:

      Oh Matt I wish I knew it all, alas I do not. And if I did have the winning numbers I would play them and then when I won I would go bwa ha ha on the blog. Actually I have lived in this area for all of my 61 years and have detailed weather records going all the way back to 1892. I started reading books on weather when I was about 4 years old.I also took 3 courses on meteorology in college. But my degree is in education not meteorology. I have over 80 weather web sites bookmarked and check them frequently. After so many years in an area you sort of get a feel for what the weather is up to. I don’t mean to sound like a know it all because I’m not. But I also am not afraid to voice my opinion if I have one. I try not be rude to anybody on the blog but have on rare occasions. Peace.

  6. David B. says:

    Maybe now W7 will stop posting pictures of burning palms.

  7. MasterNate says:

    Better late than never for the mountains. Most likely just cold rain for us lowlanders but looks good for building snowpack. Lets steal a couple of months of winter from the East Coast.

  8. Well, if it’s going to get cool and wet, let it be sometime in the weeks of early spring. I don’t want a “Junuary” (or wet July) though!

  9. Benjamin (West Salem) says:

    Believe it or not, the 00z op run of the GFS was slightly warmer than many of the members for the end of the month and the start of March. Check out this decent looking GFS ens chart.http://www.wetterzentrale.de/pics/MT8_Portland_Oregon_USA_ens.png

  10. Longview 400 ft says:

    I am still refusing to grab my fork from the kitchen because I am hoping to see a flake or two before March 15th. I am also imagning what we all would be like to have December 2008 for six straight weeks. I am not sure if I should be grateful or jealous of those in the Boston area of the weather they have had the last few weeks?

    Could Feb. 28 be the weekend we see some flakes here locally?

  11. March of 2005 was incredible, at least the first half of the month. I did so much fishing that month. Was even catching bass while trout fishing, which just does not happen in March around here. Then things changed and we had about six weeks of cool wet weather. Redeemed the mountains a little after a pathetic snow year. The following summer was pretty average if I remember correctly.

  12. March of 2005 was incredible, at least the first half of the month. I did so much fishing that month. Was even catching bass while trout fishing, which just does not happen in March around here. Then things changed and we had about six weeks of cool wet weather. Redeemed the mountains a little after a pathetic snow year. The following summer was pretty average if I remember correctly.

  13. Just you wait…in the 2nd half of March we’ll probably have 6 days above 70 and 2 days above 80. The ridge is going to come back at some point or another.

  14. Chris s says:

    This isn’t gonna make weatherdan happy!!! Just a few days ago the best we could do was maybe get snow down to timberline elevation……just messing with ya, no hard feelings😊

  15. mariners1 says:

    It was bound to happen. A cold wet spring, that is. Just build up th snow pack, please.

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