January Pattern and Storm Discussion

[ncwinterwxman]

True...but 9 times out of 10, you really need a favorable MJO to see any SUSTAINED period of major cold...all else being equal

 Even if the MJO weren't to progress into 7 and 8, I don't think that means we can't get cold. I think of it as more of a guide than anything. I'm sure there have been numerous exceptions where it got cold without the MJO in 7/8/1 incuding being within the circle. Of course, being in 7/8/1 would up the odds of cold over being in other stages.

 

 

[GaWx]

True...but 9 times out of 10, you really need a favorable MJO to see any SUSTAINED period of major cold...all else being equal

 

The idea of a partial correlation is well accepted and is what I assume. It definitely helps the chance for sustained cold if the MJO is in certain stages. However, I think that 9 times out of 10 (90% correlation) may be pushing it a good bit. This is based on my looking back at actual cold periods and checking the respective MJO stages. The correlation isn't nearly that strong.

 

 Also, one of the coldest months on record, Jan. 1977, was mainly within the circle throughout the month.

[BrierCreekWx]

The idea of a partial correlation is well accepted and is what I assume. It definitely helps the chance for sustained cold if the MJO is in certain stages. However, I think that 9 times out of 10 (90% correlation) may be pushing it a good bit. This is based on my looking back at actual cold periods and checking the respective MJO stages. The correlation isn't nearly that strong.

 

 Also, one of the coldest months son record, Jan. 1977, was mainly within the circle throughout the month.

In that case, the MJO was having no impact either favorably or unfavorably.

[wxbrad]

The one thing that has me a bit concerned is the tendency for the guidance to keep the cold air in the Northeast. Which could lead to the surface arctic ridging in the northeast and thus a major CAD set-up in the southeast. We are way over due for a major ice storm in the Carolinas and this could be an ideal pattern for one. 

 

[ncwinterwxman]

The idea of a partial correlation is well accepted and is what I assume. It definitely helps the chance for sustained cold if the MJO is in certain stages. However, I think that 9 times out of 10 (90% correlation) may be pushing it a good bit. This is based on my looking back at actual cold periods and checking the respective MJO stages. The correlation isn't nearly that strong.

 

 Also, one of the coldest months son record, Jan. 1977, was mainly within the circle throughout the month.

 

Partial correlation sounds better...I tend to exaggerate sometimes   I wasn't trying to say that you HAD to have a favorable MJO to have sustained cold by any means...however, for these winters where you don't have a firm ENSO signal, a change in MJO phase can be the boost you need to get a REAL pattern change.  Remember the pattern change that the CFS was showing back in mid December that had EVERYONE (even DT) saying that January was going to be extremely cold (several degrees below normal) from coast to coast?  Well, those same forecasters failed to check the MJO forecasts and as a result, that call busted.  In fact, DT came back a few days ago and admitted it.  The CFS had missed the roaring Pacific jet that was being forecasted by many of the major global models. 

[ncwinterwxman]

Strongly agree...today's EURO certainly had that look for sure

The one thing that has me a bit concerned is the tendency for the guidance to keep the cold air in the Northeast. Which could lead to the surface arctic ridging in the northeast and thus a major CAD set-up in the southeast. We are way over due for a major ice storm in the Carolinas and this could be an ideal pattern for one. 

 

 

[nchighcountrywx]

If the MJO plays out the way shown here on the 15 day forecast, we'll get left out.

 

Hope that will not be the case.

My bad, I was looking at the 00z run by mistake. This only goes to show what a difference a 12 hour forecast can make at 240 hours out, and how silly it is to even look at model runs this far out. The 00z Euro had a monster southeast ridge and the PV way too far west, while the 12z Euro still did not depict anything more than marginal cold for the southeast with the PV shifted several hundred miles east and much less ridging.

 

I still see no definitive reason to be getting excited at this point. 

 

 

 

[packbacker]

Partial correlation sounds better...I tend to exaggerate sometimes   I wasn't trying to say that you HAD to have a favorable MJO to have sustained cold by any means...however, for these winters where you don't have a firm ENSO signal, a change in MJO phase can be the boost you need to get a REAL pattern change.  Remember the pattern change that the CFS was showing back in mid December that had EVERYONE (even DT) saying that January was going to be extremely cold (several degrees below normal) from coast to coast?  Well, those same forecasters failed to check the MJO forecasts and as a result, that call busted.  In fact, DT came back a few days ago and admitted it.  The CFS had missed the roaring Pacific jet that was being forecasted by many of the major global models. 

 

Well the CFS hasn't busted yet, but I do agree it will probably bust for the SE, but for the other 45 or so states it will probably verify, we will have to wait an see just how cold it gets the last 10 days of the year.  It's going to take a lot to overcome as we (SE) will have a few +20F days.

 

[BrierCreekWx]

If the MJO plays out the way shown her on the 15 day forecast, we'll get left out.

 

Hope that will not be the case.

Agreed. To be honest, I don't see anything to drive this ballyhooed pattern change other than the MJO, and if it peters out in phase 7, I see no reason to believe a pattern change to something better than we've already had is coming at all. The AO going negative alone isn't going to do it - we've already seen that this winter. Just because a 240 hour forecast looks decent doesn't mean a pattern change is coming, and even if it is a "pattern change", it's quite possible it's going to change back to something very similar to the pattern we were in before, which is what happened just last winter after a "January thaw".

[Bevo]

The one thing that has me a bit concerned is the tendency for the guidance to keep the cold air in the Northeast. Which could lead to the surface arctic ridging in the northeast and thus a major CAD set-up in the southeast. We are way over due for a major ice storm in the Carolinas and this could be an ideal pattern for one. 

 

A couple of friends and myself were discussing this very thing on Saturday.  In my opinion, the latest guidance points to an ice issue if anything, which I personally have no love for. 

 

I believe delta mentioned this earlier as well.  At this point, I don't really see anything proving to me that the PAC isn't still pulling a wrench job on modeling - particularly beyond 5 days.  But if what is being shown comes to pass, I'm inclined to "guess" an ice scenario. As Mr. Garrison would say:

 

[burgertime]

Agreed. To be honest, I don't see anything to drive this ballyhooed pattern change other than the MJO, and if it peters out in phase 7, I see no reason to believe a pattern change to something better than we've already had is coming at all. The AO going negative alone isn't going to do it - we've already seen that this winter. Just because a 240 hour forecast looks decent doesn't mean a pattern change is coming, and even if it is a "pattern change", it's quite possible it's going to change back to something very similar to the pattern we were in before, which is what happened just last winter after a "January thaw".

 

Look no further than the 18z GFS in the LR. Quick cool down then back to square 1. 

[BullCityWx]

Look no further than the 18z GFS in the LR. Quick cool down then back to square 1.

I was going to say the same thing. The last 3 or 4 runs of the GFS say its going to be a short lived pattern change.

[BullCityWx]

I also want to note that only this winter could see the polar vortex drop into basically New England and we stay just a tiny bit below normal. Frustrating.

[jburns]

I was going to say the same thing. The last 3 or 4 runs of the GFS say its going to be a short lived pattern change.

 

It might be a good idea to know if it will happen before we worry about how long it will last and we are still a long way from knowing.

[FallsLake]

It might be a good idea to know if it will happen before we worry about how long it will last and we are still a long way from knowing.

 

But by day 16 it looks like the cold air is coming....... just kidding; well not really the GFS does show the cold coming again.

 

I think the real problem with the 18z GFS it that it has a storm system pushing north through the central US (day 14-15). This turns us warm again and makes us wait for the cold behind it. We have no idea if this is even close to right; but there will be cold air around, that is important.

[Mr Bob]

I was going to say the same thing. The last 3 or 4 runs of the GFS say its going to be a short lived pattern change.

 

The pattern is okay in the Euro ens means, weeklies and monthly going into Feb....what is this GFS thing you are talking about?

[Mr Bob]

^^^If that big 1040 HP sitting over the Lakes is real, then you'll get all the winter weather you can handle in the SE...of course, that's predicated on it being real and having a storm system in the area.

 

Exactly...it is Day 10...so we are just at conjecture stage....You have a pure Arctic high sliding eastward through the Lakes and single digits from St Louis to Columbus to NYC, you are going to have one hell of a CAD setting up....You have to account for undercutting of the Arctic air so I 40 corridor is in the mix too....Unfortunately, ice is going to be the main threat...If it were not to all vanish on the 00Z run of course...

[packbacker]

I was going to say the same thing. The last 3 or 4 runs of the GFS say its going to be a short lived pattern change.

 

Well this winter we are going to have to have some west coast ridging to beat down the SE ridge, maybe every winter we need that, if we don't get that we get the 18z GFS.  Hopefully the 11-15 day Euro ENS mean keeps some ridging out in the west.  Only thing I have access to is the control run of the Euro ENS and it keeps the ridge on the west coast through day 15 and thus more favorable pattern.

[BristowWx]

Look no further than the 18z GFS in the LR. Quick cool down then back to square 1.

Was reading in another forum the PAC ridge starts to break down on 1/20...if true there is a 3 day window before it starts to get ugly again

[BrierCreekWx]

The biggest wildcard going into the extended period is the MJO...if we can get at least a slowly decaying low amplitude phase 7, that would likely be enough to get the job done for a couple of weeks (hopefully)...

I strongly disagree with the bolded. There is often a lag time between reaching a favorable MJO phase and seeing the pattern change, and if the impulse is dying just after making it into phase 7 (which every single model and ensemble is showing) then I don't think it will have much of an impact.

[valkhorn]

I'm surprised there isn't a whole lot of discussion about the potential for flooding rains across much of the Southeast over the next 10 days:

 

[pcbjr]

The biggest wildcard going into the extended period is the MJO...if we can get at least a slowly decaying low amplitude phase 7, that would likely be enough to get the job done for a couple of weeks (hopefully)...

I strongly disagree with the bolded. There is often a lag time between reaching a favorable MJO phase and seeing the pattern change, and if the impulse is dying just after making it into phase 7 (which every single model and ensemble is showing) then I don't think it will have much of an impact.

 

Concur 110%.

 

Going into Phase 8 is the ticket ....

 

 

 

http://raleighwx.americanwx.com/MJO.html

[ncwinterwxman]

oops...I mistyped that...that should have said a slowly decaying moderate or strong phase 7...sorry...I screwed that up...I would like to see it go strongly into phase 7, phase 8, and then back around to 1 but I am not sure that we will get that much out of it...maybe a moderate amplitude 7 into a weak amplitude phase 8...sorry for any confusion...

 

oh and btw...while not all major SSWEs are created equal, the fact that we have BOTH a MAJOR SSWE AND a POTENTIAL MJO change going into the middle of the winter IS SIGNIFICANT...and does cause reason for slightly more optimism than usual...especially considering that it will be occurring near the time that the SE climatologically sees its best chance at wintry weather...trust me when I say this but I am typically very rarely optimistic for wintry weather in the SE US but when you have both of these factors together plus some of the other signs that we have seen that have recurred this winter (-AO, -NAO, -EPO, etc.), it is hard to hit the IGNORE button

 

http://raleighwx.americanwx.com/MJO/JanuaryPhase7500mb.gif

The biggest wildcard going into the extended period is the MJO...if we can get at least a slowly decaying low amplitude phase 7, that would likely be enough to get the job done for a couple of weeks (hopefully)...

 

Concur 110%.

 

Going into Phase 8 is the ticket ....

 

 

 

http://raleighwx.americanwx.com/MJO.html

 

 

[Cold Rain]

I really don't see any reason to believe this, but I hope you're right. I mean, the ensembles are very consistent with each other, for once. Barely getting into phase 7 and then dying probably won't have much of an impact on the pattern either. Studies have shown there is at least a week or more of lag on average between reaching phase 7 and the NAO actually going negative.

Just from intermittent observation over the last couple of years, the MJO forecasts seem to lose skill in the LR. Of course, it's no surprise that a model forecast plot loses skill in the LR, but it seems like the MJO forecasts can be really bad. I've also observed the models killing waves too quickly, especially if it a stronger one. It's all anecdotal, so it's not going to carry any weight in sort of scientific discussion. But that's why I'm not too pessimistic about what the models are showing.

Also, the MJO is only one factor...granted, it's one you'd like to have on your side, but it's just one of many factors that can get us cold.

[packbacker]

The 45 day CFS run on weatherbell shows a good 7 day period of cold starting around the 18th and than relaxes, we warm up and the cold returns but that is way out there. Be nice if we can get the cold to lock in for a good week relax and than reload.

[ncwinterwxman]

Agreed. To be honest, I don't see anything to drive this ballyhooed pattern change other than the MJO, and if it peters out in phase 7, I see no reason to believe a pattern change to something better than we've already had is coming at all. The AO going negative alone isn't going to do it - we've already seen that this winter. Just because a 240 hour forecast looks decent doesn't mean a pattern change is coming, and even if it is a "pattern change", it's quite possible it's going to change back to something very similar to the pattern we were in before, which is what happened just last winter after a "January thaw".

 

Don't forget the fact that we have a major SSWE that is ALREADY underway...

 

Edit:  Is that something you or someone could check out for us using climate datasets (i.e. the % of winters where a major SSWE in the middle of winter led to significant pattern change across the eastern US)?  I think that would be very interesting to say the least.

[BullCityWx]

I'm going to throw this out there as a possible analog:

January 2005?

[packbacker]

I'm going to throw this out there as a possible analog:

January 2005?

Well from SV the top 3 analogs that showed up from the 11-15 GEFS were Jan 77/85/94. You have the mean heights for 05?

[GaWx]

I'm going to throw this out there as a possible analog:

January 2005?

 

 Why are you picking Jan. 2005? Due to the warmth?

 

  I don't think Jan. 2005 is a good analog for two reasons:

 

1) That was a Nino, which is usually more favorable for Feb. cold than the current situation even though Jan. 2005 was warm. Actually, Jan. 2013 has a decent shot at being even warmer, but we'll see.

2) Dec. 2004 was much colder than Dec. of 2012

 

 My top Jan. analogs as of now, all of which followed a warm Dec., averaged warm 1/1-20, and were not during an El Nino:

 

 1890, 1909, 1923, 1932, 1937, and 1993

[calculus1]

I'm surprised there isn't a whole lot of discussion about the potential for flooding rains across much of the Southeast over the next 10 days:

 

I'm not.  It is what it is, but we have a dearth of posters from TN, AL, and MS.  The map you posted does not demonstrate flooding rains for NC, SC, or GA (where ~85% of our active posters in this sub-forum reside).  Ergo, you don't see much activity regarding this particular flooding phenomenon.

 

I'm not discouraging talk of this subject.  I'm just offering an explanation which you seemed to desire.  In fact, to further the discussion, here's the 7-day precip forecast just released from HPC.  Their map seems to favor the heaviest rains (not quite as heavy as the 18Z GFS) staying to the western side of MS and centered in LA, but the eastern extent of the rainfall seems to mirror your 18Z GFS posting quite closely.