Re: Long Range Thread 15.0

[algae888]

Get ready for some winter weather in about a week to ten days. All major models mighty cold. Could see some white too!!

[frank 638]

bring it on its almost nov and it still warm out some trees has color on them i am tired of this spring weather we should have this in april and may not now .bring on the cold frost cooler conditions i can not wait

[docstox12]

Get ready for some winter weather in about a week to ten days. All major models mighty cold. Could see some white too!!

AL, that fits in nicely with the first flurries time around these parts from Oct 15 on.It's going to be a real shock to get that kind of cold after the summer in October we are having.What a shame for this years Fall colors!

[sroc4]

I have to be honest here, and I'm hoping I'm wrong, it just does not look all that cold on a sustainable level; but rather, more on a transient level.  At first glance it may look cold, but I worry that the center of the mean trough actually ends up too far west allowing the SE ridge to rebound enough such that our neck of the woods ends up warm overall due to the SW flow aloft as we end Oct. as well as the first 1-2 weeks of Nov.  This is supported by the MJO forecasts that both Euro and GFS agree on propagating through phase 6 into 7 then possibly 8.   The modeling is starting to support this too.  The EPS is starting to show it more clearly that the GEFS.  Take a look.

First the MJO:  Here is the latest forecast from GFS and Euro: (NOTE: the corrected GFS and Euro MJO has the MJO coming  back into the COD)






Now lets look at the modeling.  Again we have a recurving typhoon and an MJO wave amplification through phases 5-6(which favor cold in the east this time of year) that will amplify the pattern such that by next week we get a nice cold shot.  This is agreed upon in both the EPS and GEFS camps.  





But unfortunately that seems to only lasts a few days before we rebound into the warm sector.




Then the question is to we go back to the cold pattern?  Again I would argue that as we get closer in time we cont to see a trend away from below normal anomalies and move more towards the normal to above normal anomalies in the modeling.  That trend already has begun esp in the Euro ens.  There is a negative anomaly that is consistently showing up off the SW coast.  By day ten on the EPS you can see it aids in the enhancement of the STJ and leads to the Mean trough to be further west over the CONUS in a progressive orientation.  This in turn enhances the SE ridge such that it puts us into the SW flow aloft.  Day 13 and day 15 hint at a similar orientation.  






Does this make sense though?  Again I argue yes.  First off we have the underlying base state that is La Nina like which tends to favor a western trough S Eastern ridge configuration.  Look back at the MJO forecasts above.  Now see below the MJO temp composites.  Below are the differences between the composites for the Sept/Oct/Nov vs the Oct/Nov/Dec period.  Both on avg favor the SE ridge over our area in phase 7, but the SON composite also indicates a warm pattern in the east in phase 8 as well.  This actually matches up nicely with the look on the Euro ensembles day 10-15 as we end Oct and head into the first week of Nov.   The O/N/D composite does seem to favor cooler temp anomalies in the east however in phase 8 suppressing the SE ridge.  


 
As you can see below the GEFS are a little different in the same time frame regarding the configurations of the Mean trough and ridge.  You can see day 10 (hr 240) the SE ridge is centered off the EC in the Atlantic and the mean trough is further east.  However reading between the lines I do believe the euro camp may be more correct with its trough ridge orientation in this time frame.  I still think given the base state of the atmosphere and the current MJO forecasts sustained cold in the east is not in the cards just yet through the first 1-2 weeks of Nov.  Again I REALLY hope I'm wrong but I just don't see it yet.  On the bright side as we head deeper into the season the transient cold shots we do get may be complimented by the first flakes to some of our N&W friends.  

[algae888]

Scott only one other thing that you haven't looked at and that is the EPO forecast which is supposed to be very negative late month into November. I also thinks as the wavelengths start lengthening as we head into November the models are having a tough time picking up how far east the cold will come. With the ridging over Alaska and the EPO region and also in the Nao domain I can't help but think that we will be cold here.

[sroc4]

Scott only one other thing that you haven't looked at and that is the EPO forecast which is supposed to be very negative late month into November. I also thinks as the wavelengths start lengthening as we head into November the models are having a tough time picking up how far east the cold will come. With the ridging over Alaska and the EPO region and also in the Nao domain I can't help but think that we will be cold here.

-EPO yes, but -NAO. I don't think the look is a true negative NAO(blocking over Greenland vs just anomalous Ridging in the N Atlantic as an extention of the SE/Bermuda ridge. The difference is I'm not seeing the true ridge bridge over the Arctic that forces the cold air south and keeps it there. This time of year I do not believe the -EPO, albeit forecasted strongly neg, is enough. Initially yes because of the amplification of the recurving typhoon, but after that as we head into the 7-15 day time frame this does not look like a -NAO at all. Neutral at best. The ens mean agrees with me. Climatology does not favor a cold/dense enough air mass from the -EPO alone to hit AND hold given the trop Pac influence on the big picture. Without a -NAO the -EPO discharges a cold, but not frigid air mass yet but the underlying influences from the MJO and ENSO status leads to it digging into the central plains but then lifting out over the GL rather than reaching the EC with any staying power. Again transient shots maybe but its a long way off so we shall see. This is simply my interpretation of course and might def be incorrect.

[rb924119]

You know? I find myself almost, almost, getting tired of saying this, but great discussion guys!!! Scott, I strongly agree with your train of thought, and have for quite sometime, as I think Frank does/has as well (we both commented when this was first brought up a while back). As you correctly (imho) stated, until we lose the persistent +SOI for a stretch of consecutive days, even if the MJO cooperates, we are going to need pretty much all of the teleconnections to be favorable, especially early, to offset it given the addition of anomalously warm Atlantic. I've been steadily losing my faith in the potential of this Winter since the end of August, unfortunately, given the progression of things, but you never know. Here's to hoping!! Ahaha

[algae888]

well scott and rb I respectfully disagree on upcoming pattern change and winter (wow rb didn't know you were down on winter). here is today's ensembles from eps and gefs.


that's a cold look and gefs continue that throughout entire run.


the most encouraging sing to me is the higher heights across the pole. this doesn't look transient to me but locked.

that's a closed UL ridge near the pole. 5 day ave.  a true -AO. if we can get the AO to be neg in November I've been reading that there is a very strong likely hood of the AO being neg. DJF. also here is the latest soi which should go neg and start warming the enso up again. we shall see but am getting more encouraged each passing day.

[algae888]

we go from this the last 6 weeks

to this

there is no sign of the Alaskan closed ULL (which is the thing that will kill this winter) on any guidance for next 2 weeks. that's a pattern change a significant one at that. say good bye to the +7 departures that we have seen over the last 6 weeks. good riddance to that! at our latitude we can work with +1or 2 and still do well with snow totals.

[Snow88]

This might be an early start to winter for a lot of places if the upcoming pattern holds. GFS has several inches of snow for some areas near the lakes.

[amugs]

PV perturbation happening with s heat flux poleward from the recurving typhoon.
Snowpack builds over Canada these next two weeks which will help start the cold flow when winds go to N&NW directions.

GEFS are hinting the look of winter to roll in Nov

[algae888]

Yes mugs polar vortex is taking a hit good to see ridging near the pole. We are do for a cold December and as Scott has said we're in a la nina Base state second year at that and they are notorious for cold December's. Give me a cold wintry December and January and I'll take my chances with February and March. tired of waiting till mid-January for winter to show up

[Snow88]

Anyone notice the tropical system down south?

[Frank_Wx]

Looks like we're heading into a pattern change. The GEFS and EPS are in agreement that we're headed toward a temp regime of normal to below normal temps around Halloween through the first week of November. The MJO is very active as Scott alluded to in a post yesterday. This type of tropical forcing will promote troughing over the eastern U.S. The question will be how long does the cold last? I am thinking it's a transient 7-10 period at the moment of normal to below temps then temps will rebound. This time of years it's pretty typical to go into transient patterns as the overall winter weather pattern begins to form.

[Math23x7]

Looks like we're heading into a pattern change. The GEFS and EPS are in agreement that we're headed toward a temp regime of normal to below normal temps around Halloween through the first week of November. The MJO is very active as Scott alluded to in a post yesterday. This type of tropical forcing will promote troughing over the eastern U.S. The question will be how long does the cold last? I am thinking it's a transient 7-10 period at the moment of normal to below temps then temps will rebound. This time of years it's pretty typical to go into transient patterns as the overall winter weather pattern begins to form.

Keep in mind that just because we have an extended cold stretch late-October to early November, it does not mean necessarily that is sustained.

Here is the 11 day stretch from October 27th to November 6th in 2011:

Date High Low Anomaly
10/27 61 38 -4
10/28 49 36 -10.5
10/29 45 33 -14 (day of snowstorm)
10/30 46 33 -13
10/31 53 37 -7.5
11/01 55 45 -2.5
11/02 57 42 -2
11/03 59 46 +1
11/04 53 41 -4.5
11/05 49 36 -8
11/06 54 38 -4.5

10 of those 11 days were below normal and it was 6.3 degrees below average during that stretch.  Then, as I mentioned a while back, in the 167-day stretch from November 7th, 2011 to April 21st, 2012, there were only 25 days with below normal temperatures.

Until a sustained super negative NAO/AO couplet shows up, I'm not gonna get too excited for the winter.

[amugs]

WOW look how deep that trough is - big time signal for a storm IMO

[amugs]

Cohen saying nue NOrth South elongation of Polar Vortex.
Cold air will dump into Canada and Central plains and bleed east for early November

[sroc4]

Cohen saying nue NOrth South elongation of Polar Vortex.
Cold air will dump into Canada and Central plains and bleed east for early November

Unfort Im not so sure that look really benefits us unless the center of the PV shifts further south from where it is.  Plus that is the 10mb map.  What does 30mb 50mb and 70mb look like.  That configuration does not translate 1:1 per se.  In addition that is a long way off and the LR Strat forecasts are just as subject to change as the 500mb heights are as well.  That said even if that where to come true the orientation is such that we still get a western and SW zonal flow over much of the CONUS.  The coldest air will be felt in the N Plains and central Canada like you mentioned but the SE ridge would likely flex with this look verbatim.  

Unfort the more I look at the LR ensemble forecasts the more confident I am becoming at the return to above normal after the start of the new month.  Write up to follow sometime in the next day or so.

[amugs]

Until a sustained super negative NAO/AO couplet shows up, I'm not gonna get too excited for the winter.

Mike that would not work - it would suppress everything on us to North Carolina. We need a moderate N NAO and AO to do the job IMO. A SN EPO would be tremendous as it was in 2014-15 for us. No red blob for sure there but if the warmer waters from the leftover Super Nino keep moving NE then the PDO maybe able to help in that dept.


From JD site with current SST's


QBO East vs West diagrams and resulting air masses

[amugs]

EPO
EPS


EURO goes insanely N - if this were J-F winter we'd be sneezing icicles!!

[algae888]

mugs that is great! temps over the next few weeks look to get back to normal which is a BIG PATTERN CHANGE! also very active. winter set-up starting to take shape. Canada will be flooded with cold air and snow pack. it is still very early and I really do not want snow in October or early November except for a few flurries to get us in the mood for winter season. mid fall snow doesn't end up well for us. let's get -epo, ao and nao now relax mid month and then come back for the start of December. remember la nina's usually produce cold and snowy Decembers. oh and sea surface temps are on the rise again. moderate nina looks very unlikely att.

[algae888]

also pattern that we are headed into would produce snow here in winter even with the s/e ridge. that ridge can help at times. just have to seen where the baroclinic zone sets up. in winter the cold would penetrate further south than early November.

[amugs]

AL cocnur. Recurving typhoon helpING us out.
Look at what the Ukie serve up for the anniversary of Indore say Sandra??

[jmanley32]

AL cocnur. Recurving typhoon helpING us out.
Look at what the Ukie serve up for the anniversary of Indore say Sandra??

Lets hope this does not start to look worse in a few days, we def do not need a destructive storm,  a good wind and rain (or snow but for god sakes its 70 not go count on that) weould be fine by me.

[amugs]

More recurving typhoons to kick start things as we enter Brovember!


This will bring heat flux up to the poleward region wakening the PV

[algae888]

no sign of the gulf of Alaska low which would flood Canada and the U. S. with warmth. clearly very different than the last two years.

[Frank_Wx]

Notice as westerlies formed over the Dateline we saw slight warming in Nino region 3.4. That is unlikely to last as we're still in a La Nina base state and easterlies are likely to regain power toward the 2nd week of NOV.





Also, I will not be issuing a Winter Outlook this year. Time does not allow it. Extensive research has to go into these outlooks to gather all the facts. I will leave it to the pro's to handle.

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