A Pattern Change?

I found this on the HPC website today, it’s the extended forecast discussion (Thursday through next Monday).

“THE SPLIT-FLOW REGIME SEEN SINCE AT LEAST NOVEMBER WILL CONTINUE…THOUGH WITH AN INCREASINGLY ZONAL PACIFIC JET CUTTING THROUGH THE EASTERN PACIFIC AND AIMING TOWARDS CALIFORNIA…SYSTEMS MOVING THROUGH THE SOUTHERN STREAM SHOULD BE MORE POTENT. IN KEEPING WITH THE SPIRIT OF WHAT IS EVOLVING INTO A MORE TYPICAL FLOW PATTERN DURING EL NINO CLIMATE REGIMES…”

I was about to post about what I see on the maps for the next 7-10 days, but that sums it up well.  I would mildly disagree with the statement  that we’ve been in a split-flow regime since at least November.  It has come and gone, and really didn’t appear until after Thanksgiving anyway.  BUT, it has been a persistent feature of the maps for the last 5-6 weeks.  As for the big change next week, it seems to occur right after the weekend. 

Several thoughts on the long range maps.   1.  California is going to turn very stormy next week!  Lots of deep lows approach the northern California coast and tons of rain, mountain snow.

2.  A very strong Pacific jet will be aimed well south of us.  Check out the upper-level height anomaly for the 6-10 day period.  That’s unusually far south.  Once again…California is going to get nailed.  But this is not a great pattern for good Cascade snowfall here in Northern Oregon, or heavy rain here for that matter.  We get the leftovers and lows don’t move far enough north to give us decent south wind.

3.  Any shift farther north than what we see in the maps could put us in great windstorm territory, but I don’t see it for now.

4.  Cooler, but only up above…we’ve been in constant inversions here in the Portland Metro area, so daytime highs may not show it, but in general it looks like a cooler regime begins early next week.  Much better for the mountains regardless how much snowfall they actually get.

5.  I like it!   Other than the east wind excitement at Crown Point, we’ve gone two weeks without anything very fun weatherwise.  I could go for a change.

Today’s Crown Point Report:  Day #6 of the weather geeks enjoying the wind out there.  The Friday night freezing rain/shortwave dropped the PDX-DLS gradient down to around 7 mb Saturday morning, but then it ramped up again, reaching another peak last night around midnight, with Corbett reporting it’s second highest gust of the event, 61 mph, and an average wind speed above 40 mph for several reports…that’s rare.  Then the gradient backed off again this morning, dropping the wind way down.  I don’t think Tyler Mode recorded gusts above 80 mph today.  He’s recorded 90-100 mph gusts in previous years out there.  I stopped by around 1pm.  Saw Tyler, Runrain, Antipex, Kyle (from Clackamas), Yevgeniy and his friend.  The highlight was a couple that pulled up with a Christmas Tree.  She took a video of him screaming into the wind while he held onto the tree (pretty funny), then they tossed it over the edge as it flew towards Troutdale.  Some sort of ancient Druid custom apparently resurrected in east Multnomah County?  Not sure.  Of course I don’t approve of littering, but it’s a bare tree being thrown back into the government-owned woods.  Lots of trees fall in that area every year, so it’s a form of recycling I suppose.

Chief Meteorologist Mark Nelsen

145 Responses to A Pattern Change?

  1. geo says:

    how strong would the winds be in the pdx area? gresham area?

    • Rob "Wrath" S.E. Portland says:

      Really hard to speculate. I mean you’d need the gradient to move right up over the Willamette Valley. I suppose if it did so G 70mph or so. Usually with a double barrel low you end up with low pressure kind of spread out all over from the north to south which in turn doesn’t allow for a steep pressure gradient to develop, but it appears the northern lobe is far enough away that the pressure gradient develops. If we see similar to this on the models over the coming days we can be concerned somewhat.

  2. Rob "Wrath" S.E. Portland says:

    Wind Storm ALERT!!!!

    I like this…. Yes there is a double barrel structure, but it appears the southern lobe/low will swing NE then NE right along the Coast in optimal track which could also allow for the tight gradient packing to the immediate south of its circulation to line up right over the Willamette Valley. In fact I count would could be a 12-14mb PDX-EUG gradient should that occur. Um I don’t need to tell anyone how potentially destructive this would be. That would be the all-time record max PDX-EUG gradient! It looks to be a quick mover which is helpful. We need to keep a close eye on this.

    The entire run is chunk full of possibilities with quick moving lows darting towards us from the southwest.
    http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?mm5d2_x_slp+///3

  3. 46.9F….0.48″ rain…Light ESE wind

  4. It’s still a chilly 49 out here in east county… I don’t think it’s been above 50 for quite some time!

  5. W7ENK says:

    Apparently, there’s lightning moving onshore South of the OR/CA border right now. Looks like it might be sweeping up this way over the next few hours? I didn’t really expect anything, but I thought it felt a little ‘muggy’ this afternoon. I hope we get some action overnight, that would be exciting! I still think it’s highly unlikely.

    Seems odd for January…

  6. pgiorgio says:

    Nice weather graphic on Monday in the seven day forecast. Very original

  7. Yevgeniy aka Yev says:

    oh my god, hours 150-175 so far are showing extreme activity by OR and Ca coast, one of them is a windstorm, and another is 988 low making landfall is south OR
    WOW

  8. boydo3 N Albany says:

    Well, you could be here……..

    AKZ203-131430-
    CENTRAL BEAUFORT SEA COAST-
    INCLUDING…NUIQSUT…PRUDHOE BAY…ALPINE…DEADHORSE…KUPARUK
    221 PM AKST TUE JAN 12 2010
    .TONIGHT…CLOUDY WITH FLURRIES AND PATCHY FOG. A CHANCE OF SNOW
    AFTER MIDNIGHT. LOWS 20 TO 30 BELOW. SOUTHWEST WINDS TO 10 MPH.
    .WEDNESDAY…MOSTLY CLOUDY WITH A CHANCE OF SNOW. HIGHS 15
    TO 20 BELOW. WEST WINDS 10 TO 15 MPH. WIND CHILL TO 45 BELOW.
    .WEDNESDAY NIGHT…MOSTLY CLOUDY WITH FLURRIES. LOWS AROUND
    30 BELOW. WEST WINDS 10 TO 20 MPH. WIND CHILL TO 45 BELOW.
    .THURSDAY…CLOUDY WITH FLURRIES. PATCHY FOG. HIGHS 25 TO 30
    BELOW. SOUTHWEST WINDS 15 TO 20 MPH. WIND CHILL TO 45 BELOW.
    .THURSDAY NIGHT…MOSTLY CLOUDY. LOWS AROUND 35 BELOW. SOUTHWEST
    WINDS AROUND 15 MPH. WIND CHILL TO 45 BELOW.
    .FRIDAY…CLOUDY. HIGHS NEAR 25 BELOW.
    .FRIDAY NIGHT…CLOUDY. LOWS NEAR 35 BELOW.
    .SATURDAY…CLOUDY. HIGHS NEAR 25 BELOW.
    .SATURDAY NIGHT…CLOUDY. LOWS NEAR 35 BELOW.
    .SUNDAY…MOSTLY CLOUDY. HIGHS NEAR 25 BELOW.
    .SUNDAY NIGHT…MOSTLY CLOUDY. LOWS NEAR 30 BELOW.
    .MARTIN LUTHER KING JR DAY…MOSTLY CLOUDY. HIGHS NEAR 20 BELOW.
    .MONDAY NIGHT…MOSTLY CLOUDY. LOWS NEAR 25 BELOW.
    .TUESDAY…MOSTLY CLOUDY. HIGHS NEAR 20 BELOW.

    &&
    TEMPERATURE / PRECIPITATION
    DEADHORSE -30 -14 -32 -26 / 30 30 0 0

  9. JohnD says:

    Wow! Talk about a dead blog. I thought that Mark Hill’s long range (with commentary) was pretty compelling on Channel 8 this evening. Perhaps similar to Mark’s rendition, starting early-mid-next week he pointed out the likelihood of descending snow levels and cooler temperatures. I couldn’t help but notice, however, his inferences, allusions and graphics pointing to the huge cold air mass entrenching to the north–implying it to be perhaps just a matter of time before some of that (more direct) influence comes into play here. Part of that is wishful thinking on my part to be sure, but the implications were clearly part of his “upstream” portrayal. I, personally, am pretty optimistic. We’ll see!

  10. PDX Weather Nut says:

    I’d love to see some fresh snow in the mountains. We could use a bigger snowpack for summer drinking water as well. Mt. Hood was bare after all the heat we had last summer.

  11. Gordon says:

    Does anyone know why the Oregon Dept of Agriculture forecast that Pete Parson’s puts out has not been updated since Christmas Eve? I like to read that one because its pretty detailed and in english as opposed to the weatherese used in the Area Forecast Discussions

  12. Mr Data The Crazy House says:

    Here at the crazy house in Salem it’s a wonderful 68F and towring CU over the Cascades and I just looked at the Metar report for Bend and they are having light thunderstorms but no SPC alerts……….yet

    God I wish this boring pattern would be destroyed.

  13. Mr Data says:

    53.6F and light winds steady from the south

    (edited a bit by Mark)

  14. Steve Pierce (Vancouver, WA.) says:

    HA HA HA!

    Now there parody “crown point” videos airing all over the country —

  15. O.C. Paul says:

    PDO

  16. O.C.Paul says:

    Been a reader and fan of this blog for quite awhile and am a self-proclaimed, “weather geek”.
    Have read a lot lately about how the POD turns El Nino/La Nina assumptions upside down, This Dailymail link even talks about a mini ice age. In my dreams.

    http://www.dailymail.co.uk/sciencetech/article-1242011/DAVID-ROSE-The-mini-ice-age-starts-here.html?ITO=1490

    • Gidrons says:

      Interesting story. I liked the satellite picture of the British Isles covered entirely in snow

  17. Yevgeniy aka Yev says:

    You guys know where you can get the surface water temps data over past few months or so?

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