Where we're at, where we're going

[Kevin Druff]

Looks like the -NAO goes bye bye in early Jan. Anyone have any ENSO/GWO/MJO ideas that blowtorch us for January?

From where do you get this idea? What brings you to that conclusions? In short, why should i buy what you're selling?

[Snow Wizard]

Looks like the -NAO goes bye bye in early Jan. Anyone have any ENSO/GWO/MJO ideas that blowtorch us for January?

I doubt it. It will stay negative and totally ruin the winter for the NW.

[HM]

Ok...but your post made it seem like the PNW has been waiting up until now for something good to happen. Spokane saw their snowiest November ever, and Seattle/Portland saw their third greatest Nov Arctic outbreak on record.

I think January is your time to really shine again.

I agree taco.

This -NAO block retrograding is beautiful and classic. Also, the rule of "double -NAO" blocking episodes still stands with this month. How awesome is this rule? Well...the MJO/Pacific cannot seem to trump it. We have a solid phase 5 MJO signal which should have destroyed this cold pattern by now and cannot.

I'll put this one in the back of my head for next time.

[Snow Wizard]

I agree taco.

This -NAO block retrograding is beautiful and classic. Also, the rule of "double -NAO" blocking episodes still stands with this month. How awesome is this rule? Well...the MJO/Pacific cannot seem to trump it. We have a solid phase 5 MJO signal which should have destroyed this cold pattern by now and cannot.

I'll put this one in the back of my head for next time.

What do you mean by a double -NAO?

[A-L-E-X]

I doubt it.  It will stay negative and totally ruin the winter for the NW.

I wasnt aware that the nao had any effect on your weather in the PNW.... does it?

[Snow Wizard]

I wasnt aware that the nao had any effect on your weather in the PNW.... does it?

In that it often forces a trough in the East. Of course that means a ridge is more likely in the West. That having been said this region has gotten hammered with a -NAO in place. It's just a but harder to pull off.

[HM]

What do you mean by a double -NAO?

The Don S. rule about the NAO always tanks twice when it's a legit block.

[A-L-E-X]

In that it often forces a trough in the East.  Of course that means a ridge is more likely in the West.  That having been said this region has gotten hammered with a -NAO in place.  It's just a but harder to pull off.

Ok, I was just wondering if it was a cause and effect deal-- I mean, a trough in the west usually does mean a ridge in the east and a ridge in the west usually does mean a trough in the east, but that has to do with what's going on in the Pacific (that is the pattern in the west causes the pattern in the east, not the reverse.)    I think when the trough in the east is Atlantic driven, you can still have a trough in the west, with a ridge in between (northern plains upper midwest).... think omega block 

[Snow Wizard]

Ok, I was just wondering if it was a cause and effect deal-- I mean, a trough in the west usually does mean a ridge in the east and a ridge in the west usually does mean a trough in the east, but that has to do with what's going on in the Pacific (that is the pattern in the west causes the pattern in the east, not the reverse.) I think when the trough in the east is Atlantic driven, you can still have a trough in the west, with a ridge in between (northern plains upper midwest).... think omega block

The trough on the western side of an Omega really can't do much for getting Arctic air in here. We need the -NAO to be west based so the cold air can be driven in from the NE.

Here is a prime example of why being the west side of an Omega sucks for the NW. Nothing but mild ocean air is forced in here.

[A-L-E-X]

Yeah, we want a west based neg nao too lol.  If the ridge in that omega is like 10 degrees deviated from the position on that map-- we're both golden.

[Isotherm]

Looks like the -NAO goes bye bye in early Jan. Anyone have any ENSO/GWO/MJO ideas that blowtorch us for January?

Disagree. This -NAO/AO episode should last through at least the first 10 days of January IMO, if past blocking events serve as a good guide to right now (they tend to last about 30-35 days, which would put us at about Jan 10th-15th for a complete pattern breakdown in the Arctic). So we may indeed see a period where the whole CONUS torches in the classic Jan thaw time frame of Jan 10-20, but I highly doubt the entire month is a blowtorch, and still expect the MW and NE US to finish slightly below avg temp wise. Don't think the Nina forcing really dominates in a major way until February, at least for the East. The -NAO has been a persistent signal thus far, and some people keep trying to get rid of it, but based on the backdrop of the current global regime (solar environment, decadal factors wrt AMO, NAO, recent trends, etc) I'd be very hesitant to forecast anything more than a near neutral NAO over the next 6-8 weeks.

[A-L-E-X]

Disagree. This -NAO/AO episode should last through at least the first 10 days of January IMO, if past blocking events serve as a good guide to right now (they tend to last about 30-35 days, which would put us at about Jan 10th-15th for a complete pattern breakdown in the Arctic). So we may indeed see a period where the whole CONUS torches in the classic Jan thaw time frame of Jan 10-20, but I highly doubt the entire month is a blowtorch, and still expect the MW and NE US to finish slightly below avg temp wise. Don't think the Nina forcing really dominates in a major way until February, at least for the East. The -NAO has been a persistent signal thus far, and some people keep trying to get rid of it, but based on the backdrop of the current global regime (solar environment, decadal factors wrt AMO, NAO, recent trends, etc) I'd be very hesistant to forecast anything more than a near neutral NAO over the next 6-8 weeks.

I also think after it "goes away" sometime in January with a classic January thaw-- it will return again later in February.  The history of severe blocks like this is that they tend to repeat several times throughout the winter.  Whatever is causing them doesnt just go away-- its too stable a pattern once it sets in.  Besides, isnt the la nina starting to weaken?

[Isotherm]

I also think after it "goes away" sometime in January with a classic January thaw-- it will return again later in February. The history of severe blocks like this is that they tend to repeat several times throughout the winter. Whatever is causing them doesnt just go away-- its too stable a pattern once it sets in. Besides, isnt the la nina starting to weaken?

Alex, agree. The Nina will begin to weaken by Jan and Feb, and I think we'll have another period of good blocking probably around the time frame you noted into the first part of March. Usually signalling like this in the front part of the winter sends up a warning flag -- the Nina we're dealing w/ here is unlike the ninas of the 80s, 90s, or 00s Arctic/Atlantic wise, and I'd say the pattern evolution thus far has proven to most that we're more analogous to the 50s ninas (especially in the respect of NAO/AO regime). I'm glad this AO/NAO episode is coming to fruition as it lends good support to the solar ideas I noted in my outlook, but I didn't anticipate a block of the magnitude we're seeing either.

[okie333]

Alex, agree. The Nina will begin to weaken by Jan and Feb, and I think we'll have another period of good blocking probably around the time frame you noted into the first part of March. Usually signalling like this in the front part of the winter sends up a warning flag -- the Nina we're dealing w/ here is unlike the ninas of the 80s, 90s, or 00s Arctic/Atlantic wise, and I'd say the pattern evolution thus far has proven to most that we're more analogous to the 50s ninas (especially in the respect of NAO/AO regime). I'm glad this AO/NAO episode is coming to fruition as it lends good support to the solar ideas I noted in my outlook, but I didn't anticipate a block of the magnitude we're seeing either.

I anticipated it fully, or at least mentioned it as a distinct possibility. It's the one you haven't seen yet that I didn't anticipate the strength of.

[Isotherm]

I anticipated it fully. It's the one you haven't seen yet that I didn't anticipate the strength of.

Ya, of course you did.

[okie333]

Ya, of course you did.

[Isotherm]

http://www.americanw...3746#entry73746

I see that you forecasted a -NAO/-AO for this winter, which I did as well (and strongly agree with you regarding the solar induced -NAO period of the last 2 years), but you can't say that you expected the historic bocking we're about to see with near off the chart AO values and a retrograding -NAO into northern Canada.

[okie333]

I see that you forecasted a -NAO/-AO for this winter, which I did as well (and strongly agree with you regarding the solar induced -NAO period of the last 2 years), but you can't say that you expected the historic bocking we're about to see with near off the chart AO values and a retrograding -NAO into northern Canada.

Call me crazy, but I think there is a chance that this winter may end up with more of a negative AO/NAO than last winter.

Source

[Yes_Probably_Maybe_No]

From where do you get this idea? What brings you to that conclusions? In short, why should i buy what you're selling?

Sorry, perhaps I misread some of the posts that stated early-mid January time frame for the -NAO signal to collapse.

Second part of those statements still stand, but some have answered it by saying around average temps. I have this idea in the back of my head that's telling me that once the -NAO disappears the ENSO forcing/MJO or perhaps reformed GWO signal will attempt to really flex their muscles, but apparently I'm alone with that.

[HM]

Disagree. This -NAO/AO episode should last through at least the first 10 days of January IMO, if past blocking events serve as a good guide to right now (they tend to last about 30-35 days, which would put us at about Jan 10th-15th for a complete pattern breakdown in the Arctic). So we may indeed see a period where the whole CONUS torches in the classic Jan thaw time frame of Jan 10-20, but I highly doubt the entire month is a blowtorch, and still expect the MW and NE US to finish slightly below avg temp wise. Don't think the Nina forcing really dominates in a major way until February, at least for the East. The -NAO has been a persistent signal thus far, and some people keep trying to get rid of it, but based on the backdrop of the current global regime (solar environment, decadal factors wrt AMO, NAO, recent trends, etc) I'd be very hesitant to forecast anything more than a near neutral NAO over the next 6-8 weeks.

Isotherm, hasn't the NAO been negative for 25 days already?

http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/nao.png

[Isotherm]

Isotherm, hasn't the NAO been negative for 25 days already?

http://www.esrl.noaa.../images/nao.png

HM, I should have clarified. I was mainly referring to the AO which is just beginning to tank now. If this episode of -AO blocking persists 25-35 days, that should put us around January 10th for a pattern break down.

[tacoman25]

HM, I should have clarified. I was mainly referring to the AO which is just beginning to tank now. If this episode of -AO blocking persists 25-35 days, that should put us around January 10th for a pattern break down.

1917, 1942, 1950, and 1955 are probably the best overall guides to how the pattern evolves from here. Except possibly more of a robust -AO/-NAO signal than most of those years, based on what we have seen so far.

[HM]

HM, I should have clarified. I was mainly referring to the AO which is just beginning to tank now. If this episode of -AO blocking persists 25-35 days, that should put us around January 10th for a pattern break down.

Sounds good, thanks. The sun has been absolutely dead after the uptick in October. The MJO is screaming in phase 5 and soon negative tendency will begin. Nothing seems to be able to trump the NAO/AO state at this point. This is why the pattern is so interesting through the rest of the month; however, it may lead to more disappointments than one might expect with such a -NAO anomaly. The wavelengths being more east than a typical coastal storm track has me worried. Whatever comes next week, has to go negatively tilted big time.

[HM]

HM, I should have clarified. I was mainly referring to the AO which is just beginning to tank now. If this episode of -AO blocking persists 25-35 days, that should put us around January 10th for a pattern break down.

This is somewhat akin to 1995. You know, for fun...if you plot analogs for similar tropical tracks....and even take away 1995....you get a very cold December look.

[mitchnick]

Sounds good, thanks. The sun has been absolutely dead after the uptick in October. The MJO is screaming in phase 5 and soon negative tendency will begin. Nothing seems to be able to trump the NAO/AO state at this point. This is why the pattern is so interesting through the rest of the month; however, it may lead to more disappointments than one might expect with such a -NAO anomaly. The wavelengths being more east than a typical coastal storm track has me worried. Whatever comes next week, has to go negatively tilted big time.

on a positive note, that has been happening a lot this fall and early winter, would you agree?

[HM]

on a positive note, that has been happening a lot this fall and early winter, would you agree?

It definitely has and that's why this one's legit. And let's not forget the Thursday event either, especially for you folks in the Mid Atlantic. Just the fact that the s/w in the STJ can trend stronger, when sampled, can lead to a more phased solution when we get closer to the event.

[varicweather]

It definitely has and that's why this one's legit. And let's not forget the Thursday event either, especially for you folks in the Mid Atlantic. Just the fact that the s/w in the STJ can trend stronger, when sampled, can lead to a more phased solution when we get closer to the event.

Definitely a sreaming pac jet in the next two weeks set up by the upper level trough in the NW Pacific. Note the 130+ knot winds on 200mb map on 18z GFS coming ashore behind the incubating gulf low:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/fp0_120.shtml

Note also the long fetch formed by two churning upper level lows in this satellite imagery:

http://www.ssec.wisc.edu/data/geo/index.php?satellite=west&channel=ir4&coverage=fd&file=jpg&imgoranim=8&anim_method=flash

The Pacific will supply ample moisture and plenty of upper level dynamics combined with the -nao to provide plenty of storminess in

the East

[okie333]

http://www.accuweather.com/blogs/anderson/...nto-january.asp

Beyond the obvious mega west-based -NAO, can anyone (preferably someone with access to the raw output) interpret this for the USA?