Brief Rain This Week, Then Back to Dry

A weak cold front is sitting offshore this evening; that plus a second wetter and stronger front give us rain off/on through Thursday.  This appears to be another short & wet break in our prolonged drier and calmer than normal pattern that has persisted since Christmas.  The 00z GFS only has about 1/2″ rainfall the next 3 days, our RPM


has closer to 1″.  Either way, not a hugely wet set of days ahead, just, you know…the usual.

Beyond Thursday…BORING!  This has been a very slow winter with just a few interesting weather events here and there, mainly before Christmas.  I don’t see anything exciting for the next 10 days either.  That will take us to Valentine’s Day (a week from Thursday). 

Why so dead?  We keep seeing a similar pattern of upper-level ridging developing near or just off the West Coast.  When it was right over us in mid January we saw a strong inversion with cold air in the valleys and warm air in the mountains.  Well now we are heading towards the 2nd week of February.  Inversions can definitely still set up this time of year, but the increasing sun angle means more energy reaching the earth’s surface compared to a month ago.  The result is that the same freezing level (for example 8,000′) in February will produce warmer temps down here at sea level compared to last month.  It’s easier to get into the 50s as we head into mid-February.   Often in mid-late February we get some sort of “false spring” weather with high temps up around 60 or even above.  Right now I don’t see that between now and Valentine’s Day.  But we probably have more weather like Saturday’s on the way for this weekend and early next week.

Looking farther ahead…

Interesting maps at times the last 2 days with some models and some runs of those models indicating that somewhere beyond Valentine’s Day we’ll see the upper ridge back farther offshore and let colder air come down from the north.  The 12z ECMWF, GEM, and GFS all showed this on their ensembles around Day 12-16 (beyond today).  Now the GFS has backed off, in fact the 00z GFS keeps ridging over us throughout the entire 16 day period after Thursday!  It’s a bit of an outlier showing no rainfall for the following two weeks.  The GEM this evening has flatter ridging, but still no cold air nearby around the 14th (the farthest I get maps out so far).  Here is the 00z GFS ensemble chart, still showing some pretty decent spread in solutions, but generally signficantly warmer than the 12z run:


The 12z ECMWF ensemble is here, notice quite a few very cold members beyond the 14th:

So as of now, we can rule out any big cold spell, low elevation snow, or stormy weather before Valentine’s Day.  Beyond that is still very much up in the air.  We may be finished with any big snow/cold chances, or we may have the best of winter still awaiting us in the last two weeks of the month; it’s just too early to know.

Chief Meteorologist Mark Nelsen

45 Responses to Brief Rain This Week, Then Back to Dry

    IT IS 40.7F SW 13 G 20 ON MY HOME STATION.


  2. vernonia1 says:

    Glad that 8.0 earthquake was not near us! Hoping all will be well concerning tsunami for folks nearby.

  3. pappoose in scappoose says:

    522 PM PST TUE FEB 5 2013


  4. chiefWright (Marquam) says:

    Wicked, Wicked shower coming down S. of Canby. Hydroplaning on my way home, but it’s just little spits in Marquam. Just saw/heard flash/boom!

  5. runrain says:

    Excitement! Heavy shower here in West Linn with pea sized hail!

  6. Tyler Mode in Battle Ground says:

    January 2013 in Battle Ground and (Minnehaha)
    Highest High: 53.2, 8th (52.9, 8th)
    Lowest Low: 18.4, 21st (20.2, 21st)
    Highest Wind: SE 22, 9th (SE 23, 9th)
    Most Precip: 1.17″, 28th (0.84″, 28th)

    Total Precip: 5.52″ (3.61″)

    Avg High: 41.2 (41.8)
    Avg Low: 31.1 (31.5)
    Mean: 36.2 (36.7, tied with coldest January mean since 1996. This occurred in 2007).

    Also, at my Minnehaha station, the high of 31 on the 13th was my first subfreezing January high since 2007. Pretty sad.

  7. *BoringOregon* says:

    Well I guess if u want snow Boston is going to get hit hard they are saying over 18” of snow in Boston. But there not sure yet because it’s so far along that they don’t know. Wish I still lived out there !!

  8. Ben T says:

    Any model updates?

  9. pappoose in scappoose says:

    I really like a front that “will pack some punch.”
    I’m rather fond of Stray Albino Donkeys, as well!

    National Weather Service Portland or
    307 am PST Tuesday Feb 5 2013

    Then a stronger front is modeled to begin pushing onshore sometime late Wednesday afternoon or Wednesday night. This front looks like it will pack some punch…with some gusty coastal winds and Cascade snow. This front looks to be pretty quick moving…which should limit mountain snowfall somewhat…but will need to monitor for advisory potential. Behind the front…widespread shower activity
    should continue for much of Thursday as the broad upper level low pushes over the Pacific northwest. Snow levels will be dropping significantly as this cold pool pushes in…with Post frontal snow showers possibly dropping into the foothills and Coast Range. Another issue that bears watching is the potential for thunderstorms on Thursday afternoon and evening…mainly over the coastal waters as the cold pool is directly
    overhead. Model lifted indices are near or just below zero during
    this period.

  10. Tyler Mode in Battle Ground says:

    Just started raining here about a half hour ago. 0.03″ so far. Mild though with a temp of 44.

  11. W7ENK says:

    Happy Weatherpersons’ Day, Mark! Now, are you going to do a little dance for us or something??

  12. bgb41 says:

    2/4/2013 Oregon (All) Temperature Summary

    High:57 at HORSE CREEK(3402 ft) & CW5302 Roseburg(410 ft) and 13 other stations.
    Low: 46 at NEWPRT Cape Foul(1024 ft)

    High:29 at MORGAN MOUNTAIN(4200 ft)
    Low: 15 at CW0732 Seneca (4665 ft )

    Largest Diurnal Change: 32 degrees
    ALLISON (51/19 ) (5320 ft )
    CRAZYMAN FLAT (49/17) (6100 ft)

  13. Knud says:

    Yeah!!! Snow and ice are major bummers.

  14. How many members does each Euro run have, BTW?

    I’ll happily take the operational for the 00z GFS. Perfect false-spring weather for Presidents’ Weekend, and there’s still time very late month or in March for a quick hit of 0.5-2″ of snow in the lowlands. The Euro very long range suggests a chilly start to March and the other outlooks suggest the month of March as a whole will be quite a bit colder than climo, so there’s still some hope folks! Not for serious arctic air, but in a mild climate we can’t be too choosy when it comes to wintry weather…

    • Dave in SW PDX (235') says:

      I think there are 50 ensemble members in each Euro run, Karl.

    • EY (Oak Grove) says:

      You realize that what you’re hoping for is exactly what made so many of us angry last year: Really cool, ultra late snap of cool weather that brought SOME snow down to the valleys. Had it occurred in January/February we would have seen heavy, heavy snow falls.

      So yeah… No offense, but when we hit March? I don’t want to see ANY chance of snow. If it can’t come when we’ll benefit even mildly from it, I don’t want it to come at all. That’s why I’ve had such negative feelings about the climate the last few years here. Cold springs.

    • Lurkyloo says:

      I’m with EY on that one. March is supposed to be budding plants and such. Snow is awesome when the twinkle-lights are up and it “should” be wintry. I’m ready for a warm spring. This muck and “10 days out” nonsense is played out. Just sayin’. 🙂

  15. I love the trend on the ECMWF ensembles. Down.

  16. Ben T says:

    So you’re saying there is still a chance?

    • Mark Nelsen says:

      Of course, yep. But if we get to February 20th and models show a big ridge, then we’re done. Even last March, with all those close calls with snow or snowy mornings? ONE day had a high of 39, all the rest were 40s, 50s, or 60s.

    • Benjamin (West Salem) says:

      Here in Salem we did have enough to sled in and build a 6′ snowman (snow day). We had 3.5″ of snow in the street (7″ at my Grandmas’ house in South Salem). However, as you have said before it didn’t last real long, and it stated melting the minute the sun came out the following day.

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