Groundhog Day!

Snapshot This will give you something to discuss this evening…A little hedgehog at the Oregon Zoo today saw his shadow around mid-morning.  Theoretically that means six more weeks of winter here in Portland.  I noticed that if we would have put that little lady rodent in a car and driven her around the Metro area she might have had a different forecast…so instead of doing that, I've come up with the forecast myself based on the sky conditions at 10am!

Later I'll post my thoughts on the extremely benign forecast weather pattern the next 7 days or so.  You won't want to miss it!

10:20pm:  Looks real quiet the next 3-5 days.  A ridge of high pressure in the upper atmosphere over us moves a bit off to the southeast the next few days.  That splits the offshore cold front, with some energy going into California and the rest into Northern British Columbia.  Drew and I were talking earlier about this…we never saw split flow last winter and none so far this winter.  It's like the good (bad) old days of the early 2000s isn't it?  The split sticks around through the weekend.  I do notice that a more organized trough passes through on Monday, which drops snow levels quite low again.  Then there is significant disagreement among models beyond that time.  We either go back to mild/ridgy, or more progressive flow with occasional weather systems moving into the Pacific Northwest.  Depends on which model and run you look at.  I sure don't see a significant cold/snowy pattern for now.  Keep in mind that we don't have major arctic outbreaks after the middle of February due to the increasing sun angle.  After last winter/spring, we should all be very clear on the fact that it CAN snow into March, or even April in the hills, even though it's unlikely after late February.  So I think it's now safe to say that the coldest/snowiest period of the winter was back in mid-late December.

In the short term, air quality is REALLY bad this evening…into the Unhealthy for Some category around town.  Increasing easterly flow (over 4 mb. PDX-DLS) this evening may help to clear us out a bit tomorrow.  We'll see…Mark Nelsen

100 Responses to Groundhog Day!

  1. TV Weather Producer says:

    He is 2.

  2. Tetraforce (The hidden fourth piece of The Triforce says:

    39F and mostly clear.

  3. Tetraforce (The hidden fourth piece of The Triforce says:

    Does anyone know London is buried under a foot of snow? http://www.csmonitor.com/2009/0204/p07s02-woeu.html And they are more mild then we usually are! 😛

  4. Tetraforce (The hidden fourth piece of The Triforce says:

    Nah only the people who are jerks will be punished by God.
    I certinalty hope you don’t bicker and fight with them but that’s YOUR problem cause I cannot control what you say/do.
    The good news is I don’t have to read the bickering.
    Until I see actual proof I am going to pull out the BS card on the LRC theroy. t-h-e-o-r-y.
    The PNA, EPO.etc have a better chance for good forecasting as far as I am conerned.

  5. yevgeniy.beaverton says:

    Is pierce younger then 18 years old?

  6. Rob "Wrath" - Elevation 300' -Far S.E. Portland- says:

    [Surface gradients]
    As of 10 PM——-| +/- Hourly Change
    PDX-DLS: -6.0 mb | 0.1mb Increase
    TTD-DLS: -6.5 mb | No Change

  7. TV Weather Producer says:

    young hunter pierce holds the claim of youngest AMS meeting attendee.

  8. “So much for the LRC’s Feb 2nd to Feb 5th time frame, eh?”
    http://www.lrcweather.com/index.php?option=com_content&view=article&id=100:the-lrc-2008-2009-a-long-range-forecast&catid=18:forecast&Itemid=33
    Posted January 7th.
    “February 1st-15th: The active and stormy phase of the pattern will return with many opportunities for heavier precipitation. The two week stretch of December 11th to December 25th produced some rather exciting weather set-ups across the United States”
    What is the active and stormier phase?
    “There is also a phase that allows for a retrogression of the troughiness into the western United states, but even when these western storms did form they would still regenerate and intensify as they approach the more dominant trough”
    CPC – 6-10 prognostic discussion
    “THE MODEL SOLUTIONS CONTINUE TO BE IN VERY GOOD AGREEMENT ON THE EXPECTED
    500-HPA HEIGHT PATTERN FOR THE 6-10 PERIOD OVER NORTH AMERICA. UPPER LEVEL
    RIDGES ARE FORECAST TO BE OVER THE EASTERN NORTH PACIFIC AND OVER EASTERN NORTH
    AMERICA, WITH A PRONOUNCED TROUGH IN BETWEEN, CENTERED JUST WEST OF THE ROCKY
    MOUNTAINS. BOTH THE PHASE AND AMPLITUDE OF THE 500-HPA CIRCULATION PATTERN
    PREDICTED BY TODAYS RUNS ARE SIMILAR TO YESTERDAYS SOLUTIONS, SO THERE ARE FEW
    CHANGES TO THE PREDICTED TEMPERATURE AND PRECIPITATION PATTERNS ISSUED ON
    YESTERDAYS FORECAST. THE WESTERN HALF OF THE CONUS IS EXPECTED TO EXPERIENCE
    BELOW NORMAL TEMPERATURES WHILE ABOVE NORMAL TEMPERATURES SHOULD PREDOMINATE IN
    THE EAST. A SIGNIFICANT SOUTHERLY COMPONENT TO THE UPPER LEVEL FLOW IS
    EXPECTED TO ENHANCE CHANCES OF ABOVE MEDIAN PRECIPITATION OVER MUCH OF THE
    EASTERN HALF OF THE NATION, AND THE WESTERN TROUGH SHOULD ENHANCE PRECIPITATION
    FROM THE SOUTHWESTERN CONUS TO THE CENTRAL ROCKIES. ”
    From the HPC Extended Forecast Discussion:
    “TELECONNECTIONS WITH A POSITIVE ANOMALY MOVING PAST 43N 155W
    FAVORS RIDGING FROM THE ALEUTIANS SOUTHWARD…BROAD/PROGRESSIVE
    TROUGHING ACROSS THE ROCKIES…BROAD RIDGING BETWEEN THE SOUTHEAST
    AND WESTERN SUBTROPICAL NORTH ATLANTIC…AND TROUGHING EAST OF
    NEWFOUNDLAND. THE MODELS AGREE ON THESE IDEAS. THE 00Z ECMWF AND
    06Z GFS ARE REASONABLY CLOSE TOGETHER AND ARE CLUSTERED AROUND THE
    00Z GEFS MEAN ALOFT. INTERESTINGLY…THE 00Z/06Z/12Z GEFS MEANS
    ARE MORE AMPLIFIED WITH A COUPLE SYSTEMS THAN THE HIGHER
    RESOLUTION 00Z ECMWF ENSEMBLE MEAN…WHICH IS NOT NORMALLY SEEN.”
    The remaining question is the arctic air…it is lagging behind the initial troughing. In Dec, the 14th marked the beginning through the last week of December where the deep ridging closed up off the EPAC.
    Looking in the mid range, the colder air begins to build and start dropping. Should this be even close to accurate, I am sure Vegas is excited about another shot at possible snowflakes
    http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_ten_168l.gif
    Looking at F6 data in Portland during your cold crazy stretch in December, it looks like arctic air reads to be about 10-15 degrees below mean temps. As mean temps in that stretch in December was about 42 degrees, Arctic air would be a mean temp around 28-32? That would be tougher in Feb than Dec for sure.
    Looking at the 0z, looks like 138 hr through about 216 hr, you are very near or within the surface freezing line. Its got a shot. Looks like a possible nice storm for you all about 7 days out. Maybe a few chance to get wet or snow before that.
    Dunno. I have chewed up enough space and will give you all a break and check back in a few weeks to see how things went…

  9. Aloha Rainshadow (Formerly Luvry in Aloha) says:

    My thoughts on ensembles, etc…
    1. This is the first time the ensembles have shown this broad of a cold trough over the west coast in the last month at that time frame…also, at that time frame there is a lot of variance between members so it is hard for the mean map to show a very cold anomaly.
    2. I’m looking at the trends at 150W, the ensembles and operational have been showing a strengthening of heights out there at the 150 mark all the way up into SW Alaska as a trend for the last 3 days.
    3. Each 12 hour period there are about 33% of the members going for 528 heights at 500(or just a bit + or -) and this trend has been towards colder rather than warmer in the hour 240 to 384 range.
    4. I don’t necessarily think models have been “backing” up the cold, these are two or three separate “cold spells” or systems that the models are trying to iron out and if you notice, the trough for around hour 144 has actually gotten colder on the ensembles in the last few runs. There is actually a cool little NW system progged after that and then it looks like possibly a major pattern shift with the high building out in the Epac. The Euro seems like it wants to jump onto that idea as well as you can see the start of a building ridge out there at 150.
    Just thinking out loud 🙂

  10. TV Weather Producer says:

    New AMS Meetings were announced today. We will have a weather sampler on Feb. 18th at Stark Street Pizza. Our March meeting will be at KPTV (thanks Mark and Drew for hosting) and we will recap the wild winter. The date for that meeting is March 12th. The Oregon AMS Website has more information if you are wanting more.
    TWP

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