October 2017 PNW Discussion Thread

[VancouverIslandSouth]

Typical easterly flow at night and northerly flow by day with a ridge.    The moisture is shunted way far to the north and west.

 

Well at least we shouldn't need to worry about drought anymore after the upcoming week.

[Phil]

Euro looks insanely wet for southern BC next week. What’s it showing, 5-8”. 12”+ in the mountains?

Yeah, that's a legit firehose verbatim.

[TT-SEA]

Well at least we shouldn't need to worry about drought anymore after the upcoming week.

 

I assume you mean you and your neighbors.    The rest of us are marching along through one of the wettest years in recorded history. 

[TT-SEA]

Euro looks insanely wet for southern BC next week. What’s it showing, 5-8”. 12”+ in the mountains?

 

Total rain over the next 10 days per the ECMWF...

 

[Front Ranger]

I assume you mean you and your neighbors.    The rest of us are marching along through one of the wettest years in recorded history. 

 

SEA is just over 29" YTD. Yearly average is almost 39". So no...it could possibly end up that way, but you're doing some major extrapolating.

[TT-SEA]

SEA is just over 29" YTD. Yearly average is almost 39". So no...it could possibly end up that way, but you're doing some major extrapolating.

 

Well... it does apply to the water year that just ended.

[TT-SEA]

SEA is just over 29" YTD. Yearly average is almost 39". So no...it could possibly end up that way, but you're doing some major extrapolating.

 

And they will close the gap pretty good next week.    Then you have November and December which could easily bring 5 inches or more each.

[Front Ranger]

And they will close the gap pretty good next week.    Then you have November and December which could easily bring 5 inches or more each.

 

Even if SEA get's 15" more rain this year, it wouldn't be a top 10 wettest year.

[Front Ranger]

I'm guessing Jim will point this out at some point, but getting a serious AR event in the late October - mid November time frame has historically been an omen of good things. Quite a few examples of that.

[TT-SEA]

Even if SEA get's 15" more rain this year, it wouldn't be a top 10 wettest year.

See above... should have said just finished one of the wettest water years ever.

 

And still... SEA is currently running almost 6.5 inches above normal for the year and that will go up substantially over the next week.

[Phil]

This MJO wave is a monster. I'm going to have to look back at previous -ENSO years with late October MJO pulses to see how they played out, but this strikes me as unusually early for such a wave.

 

Taken verbatim, this could actually force a WWB sometime in early November.

 

GEFS:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCPE_BC_phase_21m_small.gif

 

EPS:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_MANOM_51m_small.gif

[TT-SEA]

This MJO wave is a monster. I'm going to have to look back at previous -ENSO years with late October MJO pulses to see how they played out, but this strikes me as unusually early for such a wave.

 

Taken verbatim, this could actually force a WWB sometime in early November.

 

 

 

What does that mean?

[Phil]

What does that mean?

Westerly wind burst...which could initiate a downwelling oceanic kelvin wave and modestly warm the ENSO SSTs on a low frequency basis, starting in the second half of November.

[Phil]

Hmmm...starting to look like we're preparing for a period of major amplification next month, maybe centered towards November 15-25 and lasting several weeks.

 

Worth noting that the ECMWF/CFS weeklies actually have a legitimate SSW event in mid/late November, which is quite early by climatological standards. This might be something to watch since it would be timed perfectly with the completion of the poleward propagating AAM-I cycle, with the major MJO wave moving into the WHEM at the time as well. Oooof.

[VancouverIslandSouth]

Westerly wind burst...which could initiate a downwelling oceanic kelvin wave and modestly warm the ENSO SSTs on a low frequency basis, starting in the second half of November.

 

What's up with the "tropics" this year? Ireland getting pummeled by a hurricane:

 

 

 

[Front Ranger]

See above... should have said just finished one of the wettest water years ever.

 

And still... SEA is currently running almost 6.5 inches above normal for the year and that will go up substantially over the next week.

 

Looks like western WA is running just a bit above normal YTD overall. Some areas above, some below. Considerably wetter for western OR.

 

[Front Ranger]

Hmmm...starting to look like we're preparing for a period of major amplification next month, maybe centered towards November 15-25 and lasting several weeks.

 

Worth noting that the ECMWF/CFS weeklies actually have a legitimate SSW event in mid/late November, which is quite early by climatological standards. This might be something to watch since it would be timed perfectly with the completion of the poleward propagating AAM-I cycle, with the major MJO wave moving into the WHEM at the time as well. Oooof.

 

Is getting a SSW event that early in the season usually a positive or negative for more high latitude blocking later on, in your opinion?

[Phil]

What's up with the "tropics" this year? Ireland getting pummeled by a hurricane:

 

 

 

In my opinion, the +SIOD/-QBO is likely the culprit for the shift in the tropics this summer. And yikes, that could be quite the sting jet. Should be extratropical by then, I would think?

[VancouverIslandSouth]

In my opinion, the +SIOD/-QBO is likely the culprit for the shift in the tropics this summer. And yikes, that could be quite the sting jet. Should be extratropical by then, I would think?

 

It should be a transitioning hurricane at that point. That's in under 2 days from now and it looks like a total beast at the moment. I've seen category 4 hurricanes that look less impressive than this; it's unprecedented for that region of ocean.

 

[Phil]

Is getting a SSW event that early in the season usually a positive or negative for more high latitude blocking later on, in your opinion?

I think (in this case) it's a good thing (for the PNW) as long as it's just a moderate event and the vortex isn't completely taken out, given where ENSO/QBO are stationed.

 

A major early-season SSW occurred in Nov/Dec 1996, which amplified the pattern but it was a too much - too soon type deal and proved costly for he second half of that winter.

[ShawniganLake]

This MJO wave is a monster. I'm going to have to look back at previous -ENSO years with late October MJO pulses to see how they played out, but this strikes me as unusually early for such a wave.

 

Taken verbatim, this could actually force a WWB sometime in early November.

 

GEFS:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCPE_BC_phase_21m_small.gif

 

EPS:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_MANOM_51m_small.gif

I saw ‘81 referenced in this regard, I think.

[Phil]

For reference, here's that record-breaking early winter SSW event in 1996/97 as expressed through the 30mb U-Wind. The vortex recovery was insane, with a midwinter-strength vortex lasting into April of 1997.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/81DEFCB3-A4CB-4E16-BA5A-178798EA85EE_zpspz3cartt.jpg

 

While the -QBO had already reached peak maturation at that point, it was a low solar/-QBO50/-ENSO winter. That event sparked a significant MJO wave, which produced the downwelling oceanic kelvin wave that initiated the 1997/98 super niño, under the aid of the very strong late-winter PV and the subsequently powerful FW, under the developing +QBO at that time.

 

The philosophical question is, did a fluky SSW/MJO actually initiate the super-niño and subsequent climate shift, or are these SSW/MJOs somehow a conduit through which the climate system re-equilibrates? Because something very similar happened in January of 2013, with that SSW/MJO event preceding the transition into the +PDO/+NAO regime that's dominated since.

 

Maybe this time around, we'll transition into a more desirable subdecadal regime.

[Phil]

Notable AAM loss since June. Some of this likely related to the developing -QBO.

 

http://climate.cod.edu/gensini/GWO/web/MR-latest-365days.png

[Phil]

I saw ‘81 referenced in this regard, I think.

Hmm..interesting. There was definitely an MJO in 1981, but genesis was 7 weeks later vs this year. The event in August/September that year was a behemoth however it was more IO-centric, and given the time of year, it produced that big western heatwave.

 

http://www.atmos.albany.edu/facstaff/roundy/waves/hovsdet/7.5S_7.5N/1981.png

[wx_statman]

For comparison's sake, today's 36 at PDX came more than 6 weeks earlier than last year. In 2016 we didn't see a 36 degree low until Dec. 4th! In fact, we didn't see a reading below 39 until that date. Previously the latest we had gone was Nov. 16, 1941. Interesting that both January's of 1942 and 2017 ended up cold. 

[Phil]

I think a case could be made for 1984.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/7AE9A2E6-3603-4E13-9527-0D022DA930F0_zpshot9mego.jpg

[SilverFallsAndrew]

Most of NW Oregon may not see rain until Thursday. 

[DareDuck]

Timmy did you head up to the snow today? I hiked up to the top of red chair at Bachelor. Can't believe I was able to ski 2' of fresh powder on October 14th.

[Kayla]

I've been monitoring your data on Wunderground, and it looks like you're dropping into the 20s on a consistent basis already. Is that typical for your area?

 

It's below average but not by a whole lot at this point in the year. The average low in Bozeman on this date is 32F so 20's are becoming pretty common at this point.

 

This latest trough has actually been less impressive than the early October trough when I dropped down to 18F. It's definitely been a lot more impressive for areas further to the west (Eastern OR/WA and ID).

[ShawniganLake]

Hmmm...starting to look like we're preparing for a period of major amplification next month, maybe centered towards November 15-25 and lasting several weeks.

Worth noting that the ECMWF/CFS weeklies actually have a legitimate SSW event in mid/late November, which is quite early by climatological standards. This might be something to watch since it would be timed perfectly with the completion of the poleward propagating AAM-I cycle, with the major MJO wave moving into the WHEM at the time as well. Oooof.

Uh oh. I thought we want a warm November

 

[Timmy]

Timmy did you head up to the snow today? I hiked up to the top of red chair at Bachelor. Can't believe I was able to ski 2' of fresh powder on October 14th.

I don’t get there until tomorrow. I’ll have to head up Monday if there is still some left

[Jesse]

Most of NW Oregon may not see rain until Thursday.

Disappointing model trends in the mid range. Today may have been our last below average day for a little while.

[Timmy]

Disappointing model trends in the mid range. Today may have been our last below average day for a little while.

Hopefully it will keep my mushrooms warm! It’s been a terrible season so far.

[Phil]

Uh oh. I thought we want a warm November

 

3AAA5BBF-9BB3-4B00-A379-7C5DC146EBA7.png

Well, I'd guess I'd rephrase it. You want an Aleutian/NPAC Low in November, which is usually a warm pattern but not necessarily all the time. There are other patterns that can sustain the Siberian High other than just Aleutian Low, but it's the easiest way to do it IMO.

[Jesse]

Hopefully it will keep my mushrooms warm! It’s been a terrible season so far.

TMI.

[Timmy]

TMI.

You jel?

[TT-SEA]

SEA holding at 55 for the last 3 hours... frost seems unlikely tonight.    Skies have totally cleared out now... not sure why they are reporting mostly cloudy.   

[Jesse]

Today was the fifth consecutive sub-60 high at PDX.

[Timmy]

Today was the fifth consecutive sub-60 high at PDX.

Incredible!

 

Had frost this morning here

[wx_statman]

Disappointing model trends in the mid range. Today may have been our last below average day for a little while.

 

Feels a bit like 2005. Cool Sep 15-Oct 15 period transitioned to a mild soup right around this time. Lasted a couple weeks.