January 2013 Pattern Discussion

[earthlight]

After a bit of a "cold" shot (which admittedly is becoming somewhat tempered as it approaches) in the first several days of January, signals are strong for a moderation in temperatures and a generally unfavorable pattern for snow and cold by the 2nd and 3rd weeks of the month. The MJO won't be much of a help with forecast models indicative of a transition to phases 4 and 5 during this period. Although things are may seem bleak for a while if and when this does come to fruition, it definitely isn't the end of the story. By Late January and early February, stratospheric pattern change signals a reshuffling of the polar vortex and the *potential* for a significant intrusion of cold air. This warming is already underway, but we have to continue to monitor the exact developments in the stratosphere as we move forward.

We can see the bad pattern with the Pacific Jet dominating the pattern here at 144 hours on the GFS...and the warming already underway at 10mb below that. We can continue to build on this discussion as we move through the month.

[IntenseBlizzard2014]

Let's hope the Stratosphere will work in our favor.

[PB GFI]

The STRAT warming has so many problems 1. Its a 10 to 20 day lag for the cold to even show up in Canada That gets you to  week 3- 4   2.Theres no guarentee that the cold ends up on our side of the pole ( ALA , last year ) 3 . " if  " the 2 above happen TO come to pass , theres nothing holding it  from  pouring into the west coast with a neg EPO  , then modify as it comes east , because in 3 weeks the snow cover through the mid section is goin to be erased .

The way i hear the Euro weeklies being spoke about , its 2 weeks of a trof in the west and then a pacific zonal flow for the entire 48.

( the Euro doesnt see the trought back in the east week 4 ) from what i am reading .

I know the CFS  sees a  coldJAN ( READ  bluewaves piece ) . I read Don Sutherlands piece this morning on the Philly  thread where he think this is just a 2 week warmup .

So there are still  conflicting outcomes thats hav yet o be set in stone . A . i dont like POS  EPO I dont like trofs in Alaska  - I am a big PAC guy and think everything revloves around it . That has always been my go to . the 240 hr Euro really shows the PV retrograding back towards N alaska and thats not good . I hav always believed that all pattern changes are 3 week mins .

They dont change week to week . We had 3 weeks warm Then we will wind up with 3 weeks " cold " prob Normal ... and now we are goin back into the warmth after this weekend  again , Thats Feb 1 in my book . Not closing the door on the winter , but i think I am for JAN .

 

 

[nzucker]

I think the warmth is going to be much more extreme to our southwest than here. For NYC, it looks like an up and down pattern that averages near normal through the middle of the month. 

[H2Otown_WX]

The STRAT warming has so many problems 1. Its a 10 to 20 day lag for the cold to even show up in Canada That gets you to  week 3- 4   2.Theres no guarentee that the cold ends up on our side of the pole ( ALA , last year ) 3 . " if  " the 2 above happen TO come to pass , theres nothing holding it  from  pouring into the west coast with a neg EPO  , then modify as it comes east , because in 3 weeks the snow cover through the mid section is goin to be erased .

The way i hear the Euro weeklies being spoke about , its 2 weeks of a trof in the west and then a pacific zonal flow for the entire 48.

( the Euro doesnt see the trought back in the east week 4 ) from what i am reading .

I know the CFS  sees a  coldJAN ( READ  bluewaves piece ) . I read Don Sutherlands piece this morning on the Philly  thread where he think this is just a 2 week warmup .

So there are still  conflicting outcomes thats hav yet o be set in stone . A . i dont like neg EPO I dont like trofs in Alaska  - I am a big PAC guy and think everything revloves around it . That has always been my go to . the 240 hr Euro really shows the PV retrograding back towards N alaska and thats not good . I hav always believed that all pattern changes are 3 week mins .

They dont change week to week . We had 3 weeks warm Then we will wind up with 3 weeks " cold " prob Normal ... and now we are goin back into the warmth after this weekend  again , Thats Feb 1 in my book . Not closing the door on the winter , but i think I am for JAN .

 

So what you're saying is you don't like negative or positive EPO's?

[PB GFI]

So what you're saying is you don't like negative or positive EPO's?

 

Pos mate , sorry - Gona flood lower 48 with PAC air .

[H2Otown_WX]

Pos mate , sorry - Gona flood lower 48 with PAC air .

 

Haha, figured it was a typo just wanted to make sure. 12z ECM doesn't looks all that bad at least for the next 9 or 10 days but I guess we'll just have to wait and see.

[PB GFI]

I think the warmth is going to be much more extreme to our southwest than here. For NYC, it looks like an up and down pattern that averages near normal through the middle of the month. 

 

Dont think the Northeast escapes a strong progged  SE ridge .Is ur argument DC is warmer ? sure, but are likely  still above and  thats not going to yield the results we want .

[PB GFI]

Haha, figured it was a typo just wanted to make sure. 12z ECM doesn't looks all that bad at least for the next 9 or 10 days but I guess we'll just have to wait and see.

 

Thanks for the correction ,

Widen out the Operational over 240 - and i just see the canadian  PV take a road trip back towards Alaska , I think once its back there it could be there for 2 weeks .......

 

You  CT  guys did well in - pna - noa pattern , killed us here on the coast .

[H2Otown_WX]

Thanks for the correction ,

Widen out the Operational over 240 - and i just see the canadian  PV take a road trip back towards Alaska , I think once its back there it could be there for 2 weeks .......

 

You  CT  guys did well in - pna - noa pattern , killed us here on the coast .

Eh, I don't know about that. The snow I've had so far came with PNA spikes in early November and then our most recent one in late December. The -PNA/-NAO pattern is one that has produced occasionally but it didn't work out very well in the first 3 weeks of December.

[RUNNAWAYICEBERG]

what im concerned about is if the bad pattern takes too long to get good again. guidance usually tries to portray a cold/snowy pattern too soon so if in fact we relax for two weeks after this "cold" snap, we are almost into Feb. Considering how awful Mar has become for cold and snow the past half decade or so, we have 4 weeks to get something going again.

 

weenie alert: Im moving to Charlotte by the end of this month so Jan is my last chance at big snows for the REST OF MY LIFE!

[Brian5671]

what im concerned about is if the bad pattern takes too long to get good again. guidance usually tries to portray a cold/snowy pattern too soon so if in fact we relax for two weeks after this "cold" snap, we are almost into Feb. Considering how awful Mar has become for cold and snow the past half decade or so, we have 4 weeks to get something going again.

 

weenie alert: Im moving to Charlotte by the end of this month so Jan is my last chance at big snows for the REST OF MY LIFE!

 

It's warm down there-summer goes from mid May to late september...90 degrees will feel normal  you by mid June...LOL--it's a great place though. 

[CooL]

New Euro weeklies out - JAN CXL . " blood red from the Miss east , No NEG NAO - most important POS EPO ......

sorry guys , wish I had better news

Think most of us know the first 3 weeks of January are on life support

[Isotherm]

The EPO is ultimately the key to getting severe and widespread cold into the US. We saw a -EPO burst in late December and we're seeing the effects right now, with arctic chill across New England and the Mid-west. However, heights are lowering rapidly in AK and thus the arctic air isn't pressing very far southward (will be confined to the nern tier as well).

 

Looks to me like this upcoming -EPO pulse will be more stable in that the mid level doesn't simply pinch off, but maintains in a meridional N-S fashion up to the pole. I think we'll see the AO begin to trend back negative as well, in tandem with the EPO decline.

 

The EPO should be trending negative as the Eastern warm period is occurring next week. Consequently, the warm surge shouldn't be a long duration event as the north pacific is quickly reshuffling and will lower heights in the US thereafter. Probably an East Coast ridge hanging on a bit longer, but I don't think we're looking a prolonged major positive departures.

 

 

 

Then by the 12th the EPO ridging has extended to the pole and the AO is clearly negative.

 

 

[JBG]

Feels like 2011-2.

[PB GFI]

The EPO is ultimately the key to getting severe and widespread cold into the US. We saw a -EPO burst in late December and we're seeing the effects right now, with arctic chill across New England and the Mid-west. However, heights are lowering rapidly in AK and thus the arctic air isn't pressing very far southward (will be confined to the nern tier as well).

 

Looks to me like this upcoming -EPO pulse will be more stable in that the mid level doesn't simply pinch off, but maintains in a meridional N-S fashion up to the pole. I think we'll see the AO begin to trend back negative as well, in tandem with the EPO decline.

 

The EPO should be trending negative as the Eastern warm period is occurring next week. Consequently, the warm surge shouldn't be a long duration event as the north pacific is quickly reshuffling and will lower heights in the US thereafter. Probably an East Coast ridge hanging on a bit longer, but I don't think we're looking a prolonged major positive departures.

 

 

 

Then by the 12th the EPO ridging has extended to the pole and the AO is clearly negative.

 

 

YEH  , I wrote yesterday the winner of the EPO battle is the winner of the month

The GFS is much more progressive with the ridge into alaska  week 2 , where as European has the western trough pulled really far back , has the ridge west of Hawaii , showing a pos EPO  and shows nothing but ridging in the east thru week 4 .

The issue I have believing the CFS or GFS s colder look after day 10 is that the Euro weeklies and its ensembles match up from week 1 in the US , EUROPE and ASIA , so they are pretty locked on after next week .Hoping the GFS is scoring a coupe is like believing AROD gona come through in a big spot .  How often did u ever see that ?

I for one am rooting against the Euro , maybe it blows up this time . nothing is 100 percent , so its the weather and we always have a shot , unless AROD is up , then turn away from your televisons if you have a weak stomach .

[bluewave]

The way the pattern is aligned, we would need the PNA to stay positive while the EPO

is negative to get it cold here. You can see how the PNA only stayed positive

for a brief amount of time before dropping again. This pattern allows the trough

axis to remain over the West while a series of cutters run up into the Lakes

to our west.

 

 

 

The Euro and its ensembles will do much better in a pattern like this since the OP GFS will

tend to break the SE Ridge down too quickly. The GFS ensembles do better than the OP

GFS. This is where the famous GFS pushing the cold further out in time comes into play.

 

 

The problem is that this type of a pattern can lock in for a while since we

saw the tendency for the SE Ridge to persist through much of December.

 

 

 

 

 

 

 

 

 

 

 

[easternsnowman]

YEH  , I wrote yesterday the winner of the EPO battle is the winner of the month

The GFS is much more progressive with the ridge into alaska  week 2 , where as European has the western trough pulled really far back , has the ridge west of Hawaii , showing a pos EPO  and shows nothing but ridging in the east thru week 4 .

The issue I have believing the CFS or GFS s colder look after day 10 is that the Euro weeklies and its ensembles match up from week 1 in the US , EUROPE and ASIA , so they are pretty locked on after next week .Hoping the GFS is scoring a coupe is like believing AROD gona come through in a big spot .  How often did u ever see that ?

I for one am rooting against the Euro , maybe it blows up this time . nothing is 100 percent , so its the weather and we always have a shot , unless AROD is up , then turn away from your televisons if you have a weak stomach .

        The euro has not been that good this winter especially in the long range.

[bluewave]

        The euro has not been that good this winter especially in the long range.

 

The Euro ensemble means have been beating the GFS and its ensembles day1-10. But the Euro

was too cold for this first week of January just like the GFS. So if that trend holds, we could be looking

at some real January warmth the next few weeks. It even underestimated the SE Ridge which isn't a good

sign.

 

240 for now

 

 

now

 

 

 

[IntenseBlizzard2014]

It feel down to 19F here last night. That happened a couple of weeks later last year.

[PB GFI]

        The euro has not been that good this winter especially in the long range.

 

The Euro  weeklies  are  a little weaker in its week 3 and week 4 range .  However the problem has been its biased  colder in its  week 3- 4 only to turn warmer once  2 weeks out .

So lets  hope thats not the case because its already warm week 3- week 4 . I am rooting for the GFS , but the Euro has my attention .

[ag3]

The Euro ensemble means have been beating the GFS and its ensembles day1-10. But the Euro

was too cold for this first week of January just like the GFS. So if that trend holds, we could be looking

at some real January warmth the next few weeks. It even underestimated the SE Ridge which isn't a good

sign.

 

240 for now

 

Geopotential32at32500hPa_North32America_240.gif

 

now

 

Geopotential32at32500hPa_North32America_0.gif

 

The main reason it and other models are so warm is the monster H5 low that cuts off near the Mexico/CA border. Allowing the Pac flood gate to enter the whole country. If that system doesn't occur or doesn't close off, the warmth will be muted. If it's stronger then progged, the warmth will be much greater then shown.

[SnoSki14]

I guess this is payback for all those KU's we had. The trough sets up too far west for us even though there's a lot of cold air in the long range, so this is great for places like the plains/midwest. If we're going to go extreme, then might as well set some record highs. 

[Jefflaw77]

I guess this is payback for all those KU's we had. The trough sets up too far west for us even though there's a lot of cold air in the long range, so this is great for places like the plains/midwest. If we're going to go extreme, then might as well set some record highs. 

 

Sounds like mid/late december 2012... Midwest/plains gets into the action while the NE is high and dry.. oh well...

[CooL]

I like the look of the GEFS post day 10 for a big pattern change after a few cutters

[bluewave]

We are going to be very mild here over the next ten days or so. But what looks like the coldest

temperatures in about 2 years are poised to enter the Rockies and Plains States in the day

10-15 time frame. 

 

 

 

 

 

The Euro ensemble mean is forecasting the strongest Northern Hemisphere polar vortex

to finally enter North America. The last time we saw this was later January into

early February 2011. If we get a rising PNA around this period, the PV would be

able to slide SE to down around James Bay and eventually push an Arctic front

through our area.

 

 

 

 

[NEG NAO]

The Euro ensemble mean is forecasting the strongest Northern Hemisphere polar vortex

to finally enter North America. The last time we saw this was later January into

early February 2011. If we get a rising PNA around this period, the PV would be

able to slide SE to down around James Bay and eventually push an Arctic front

through our area.

 

 

The Key words here is if we get a rising PNA otherwise the pacific jet is going to continue to overwhelm the pattern even if a  neg nao develops - the AO going negative should help also - and the MJO going into phase 7/8 after mid month is a positive ...............

[bluewave]

The Key words here is if we get a rising PNA otherwise the pacific jet is going to continue to overwhelm the pattern even if a  neg nao develops - the AO going negative should help also - and the MJO going into phase 7/8 after mid month is a positive ...............

 

That's right. Once the El Nino faded early, it left a -PDO pattern to dominate the Pacific side giving

the Pacific Jet free reign here. The ridging  south of Alaska is going to have to progress far enough

to the east over Western NOAM to get it cold here after the mid month warm up. It will need to

progress one more step east than December and mid-January to get us on the path to double

digit down temperature departure days.

 

step....1

 

 

step....2

 

 

step...3????

 

[IntenseBlizzard2014]

That's right. Once the El Nino faded early, it left a -PDO pattern to dominate the Pacific side giving

the Pacific Jet free reign here. The ridging south of Alaska is going to have to progress far enough

to the east over Western NOAM to get it cold here after the mid month warm up. It will need to

progress one more step east than December and mid-January to get us on the path to double

digit down temperature departure days.

step....1

12.png

step....2

00zECMWFENS500mbHeightAnomalyNA240.gif

step...3????

wk3.wk4_20130104.z500.gif

This is exactly how I envisioned it.

[Weathergun]

Most amplified MJO pulse, so far this season, might be getting into phases 7/8 later this month. Which would support the 500mb pattern shown below: