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Global Indices/map questions thread


weatherwiz

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I thought a thread on this would be a terrific idea.  If anyone has questions about intepretations or anything related to global indices, all that information can be posted here in one thread.  I think this could be a thread with incredible value, input, and discussion.  Being someone who is trying to understand the charts and maps more instead of using just numerical values, this could be a great thread for just that.   

 

I'll get the ball rolling with an interprertation of the 500mb pattern for December of 1957.  The surface temperatrure anomalies are pretty much a toaster bath for the continental United States, outside of FL where below-average anomalies occurred. 

 

Looking towards the NAO region, we see below-average height anomalies located over Greenland (indicative of a +NAO), however, just south of Greenland we see an area of above-average anomalies which does seem to intrude into the NAO region (indicate of slight -NAO).  However, given those above-average anomalies are displaced further south, they dip into the northeastern US, helping to lead to the above-average warmth. 

 

What would be the best way to classify this NAO state?  If I had to guess I would say slightly positive b/c the majoirty of the height anomalies in the NAO region correlate to +NAO

 

BubJ7uc9hM.png

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I've been using this link for SSTA reanalysis...only issue is there are like 6 different methods so I have no clue which one to use or whatever...so I just flip through them all

 

http://www.esrl.noaa.gov/psd/cgi-bin/gcos_wgsp/printpage.pl

 

 

When I looked at the Top 10 Positive NAO Dec's (Hurrel's version)

 

it was a 50/50 split between warm/cold SSTA's just south of Greenland

 

I just did the top 10 -NAO Dec and 8 of the 10 all had warm SSTA's just south of Greenland...1 of the years had neutral anomalies and only Dec of '95 had cold SSTA's around Greenland.  

 

 

Not that this all really means much I guess b/c it is the top 10 strongest of each

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I've been using this link for SSTA reanalysis...only issue is there are like 6 different methods so I have no clue which one to use or whatever...so I just flip through them all

 

http://www.esrl.noaa.gov/psd/cgi-bin/gcos_wgsp/printpage.pl

 

 

When I looked at the Top 10 Positive NAO Dec's (Hurrel's version)

 

it was a 50/50 split between warm/cold SSTA's just south of Greenland

 

I just did the top 10 -NAO Dec and 8 of the 10 all had warm SSTA's just south of Greenland...1 of the years had neutral anomalies and only Dec of '95 had cold SSTA's around Greenland.  

 

 

Not that this all really means much I guess b/c it is the top 10 strongest of each

this goes back to 84

http://www.ospo.noaa.gov/Products/ocean/sst/anomaly/

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  • 1 month later...

How do you distinguish between the EPO region and the PNA region and where does the overlap occur?  

 

If it fair to say that during extreme phases of say the EPO you should also expect the same sign from the PNA...or vice versa?  

 

Below is the 500mb map for top 5 positive/negative EPO Decembers and it looks like there is a big overlap between the two regions?

 

RtDYcnVGvG.png

_Rer0KhvGW.png

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When is your outlook due, Paul?

I was so hoping to have it out but I just have like no time. I'm swamped during the week at school and then work all weekend.

I have a crap load typed up but I'm not terribly happy with it. I like an educational-type approach in which I try to go into vast detail about everything in hopes to educate the reader a bit...but doing that makes things into a war and piece type deal.

My thoughts though are this...

When it comes to snowfall I really don't know what to side with. I think this will be an extremely active winter with numerous storms around but not sure if we will see a pattern predominately favorable for snow or not.

I am worried about temps...big time which could in fact influence how we do in terms of snow...I understand that our snowfall is closely related to precip than temps but my fear is we really roast into Canada and we don't really have a source for colder air.

My big interest is within the Stratosohere and how the vortex in the lower Stratosohere evolves. I've actually developed a major interest in the influences of the Stratosohere. We want to continue to see the vortex take major hits and weaken...this would work to reduce the zonal ends and could enhance the possibility for SSW's to occur. However, given the QBO strength it may be very hard to reduce the zonal winds so I think the NAO and AO may be more positive.

Perhaps Sunday/Monday I can comlete what I have written.

Northern NewEngland could see onehelluva winter

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I was so hoping to have it out but I just have like no time. I'm swamped during the week at school and then work all weekend.

I have a crap load typed up but I'm not terribly happy with it. I like an educational-type approach in which I try to go into vast detail about everything in hopes to educate the reader a bit...but doing that makes things into a war and piece type deal.

My thoughts though are this...

When it comes to snowfall I really don't know what to side with. I think this will be an extremely active winter with numerous storms around but not sure if we will see a pattern predominately favorable for snow or not.

I am worried about temps...big time which could in fact influence how we do in terms of snow...I understand that our snowfall is closely related to precip than temps but my fear is we really roast into Canada and we don't really have a source for colder air.

My big interest is within the Stratosohere and how the vortex in the lower Stratosohere evolves. I've actually developed a major interest in the influences of the Stratosohere. We want to continue to see the vortex take major hits and weaken...this would work to reduce the zonal ends and could enhance the possibility for SSW's to occur. However, given the QBO strength it may be very hard to reduce the zonal winds so I think the NAO and AO may be more positive.

Perhaps Sunday/Monday I can comlete what I have written.

Northern NewEngland could see onehelluva winter

Tell me about it.....I share your preference.

Write as though your audience knows zero.

 

The +QBO thing is overrated imho.....take a look at my last blog post.

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Tell me about it.....I share your preference.

Write as though your audience knows zero.

The +QBO thing is overrated imho.....take a look at my last blog post.

I hope one day I seriously get more time to do weather stuff again. It's really been forever since I've been able to spend a solid deal of time working on things.

My interest with the QBO is merely on its influence on the Polar vortex and even the Stratosohere and how it can correlate to episodes of SSW. I did come across some articles which talked about it and they were rather interesting.

One thing I guess is this winter the QBO is supposed to end up being very positive (so very strong westerlies) and I guess what this could do is work to go against upper tropospheric-lower stratospheric responses with the plat vortex and could make it very difficult to weaken. I guess SAI and tropospheric disturbances will help to eat away at it but with the QBO so westerly it may never weaken enough to allow for good blocking to become established.

I will take a look at your post tomorrow...I should be pretty free in the afternoon since I banged out a ton of school stuff this weekend.

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I hope one day I seriously get more time to do weather stuff again. It's really been forever since I've been able to spend a solid deal of time working on things.

My interest with the QBO is merely on its influence on the Polar vortex and even the Stratosohere and how it can correlate to episodes of SSW. I did come across some articles which talked about it and they were rather interesting.

One thing I guess is this winter the QBO is supposed to end up being very positive (so very strong westerlies) and I guess what this could do is work to go against upper tropospheric-lower stratospheric responses with the plat vortex and could make it very difficult to weaken. I guess SAI and tropospheric disturbances will help to eat away at it but with the QBO so westerly it may never weaken enough to allow for good blocking to become established.

I will take a look at your post tomorrow...I should be pretty free in the afternoon since I banged out a ton of school stuff this weekend.

I know what a +QBO entails, but it is only one factor.

 

You need to maintain a breadth of perspective, not be so obsessed with any one indicator.

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I know what a +QBO entails, but it is only one factor.

You need to maintain a breadth of perspective, not be so obsessed with any one indicator.

Believe me...my mind is very open. However, given the overall strength of the QBO I think it could be a bigger player...just like say if the NAO or AO were in an extreme state they would be the decisive factor more than likely.

I think the wild card this winter could perhaps be the EPO, however, it's certainly possible the EPO signal is not very strong enough to play a major role on the pattern.

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Believe me...my mind is very open. However, given the overall strength of the QBO I think it could be a bigger player...just like say if the NAO or AO were in an extreme state they would be the decisive factor more than likely.

I think the wild card this winter could perhaps be the EPO, however, it's certainly possible the EPO signal is not very strong enough to play a major role on the pattern.

It doesn't work like that....its not so simplistically linear.

How did the AO/NAO proxy fare last season?

Pretty stoutly positive....

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Exactly my point.

There are no independent variables, nothing has absolute proxy, and anything can be "overpowered".

Don't go nuts with the QBO...you are going to burn.

 

oh I'm not going to go nuts with the QBO, however, I will uise it as a reference for my thinking of how the AO will evolve for the winter. 

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oh I'm not going to go nuts with the QBO, however, I will uise it as a reference for my thinking of how the AO will evolve for the winter. 

I would use it as part of an explanation as to why the arctic will be so hostile for the first half, but anything beyond that is ill advised.

Just my 2 cents.

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I would use it as part of an explanation as to why the arctic will be so hostile for the first half, but anything beyond that is ill advised.

Just my 2 cents.

 

Actually that's very sound and is something I do believe.  I'm actually not really sure how this winter evolves after early to mid January or so.  My guess is we would really want to start seeing some major changes occurring within the stratosphere and polar vortex is we want big time weakening to occur.  One thing I would like to at least see are the 500mb zonal winds start weakening.  

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Actually that's very sound and is something I do believe.  I'm actually not really sure how this winter evolves after early to mid January or so.  My guess is we would really want to start seeing some major changes occurring within the stratosphere and polar vortex is we want big time weakening to occur.  One thing I would like to at least see are the 500mb zonal winds start weakening.  

The seeds of change are already being planted.

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Yes they are. In fact actually, changes could be occurring much quicker than anticipated. The second half of this month may actually be interesting. However, I'm not very sure if the changes happen THAT quickly

Doubtful.

I am just as confident that the changes will take their time, as I am that they will occur.

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Doubtful.

I am just as confident that the changes will take their time, as I am that they will occur.

Yeah I agree. I wouldn't be totally surprised if we saw potential for something around mid-to-late month, however, even if that is another cold rain event, a strong system could continue to work the pattern and shape it for changes.

DT posted something on Twitter I think yesterday showing that the QBO could perhaps getting ready to weaken which is good and there are numerous other signals shaping up which would produce a more favorable Stratosohere for SSW and the beginning of blocking.

The latest CFS was showing some insane blocking developing down the road (actually perhaps too much for my liking) but the CFS is hot on substantial changes occurring moving towards the end of this month and moving forward.

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Yeah I agree. I wouldn't be totally surprised if we saw potential for something around mid-to-late month, however, even if that is another cold rain event, a strong system could continue to work the pattern and shape it for changes.

DT posted something on Twitter I think yesterday showing that the QBO could perhaps getting ready to weaken which is good and there are numerous other signals shaping up which would produce a more favorable Stratosohere for SSW and the beginning of blocking.

The latest CFS was showing some insane blocking developing down the road (actually perhaps too much for my liking) but the CFS is hot on substantial changes occurring moving towards the end of this month and moving forward.

I have seen some hints of a cold shot around mid month....alluded to it in my FB update last night.

We'll see....could fail, but I wouldn't expect significant snow out of it, anyway.

 

I just posted about what DT said in the December thread.

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I have seen some hints of a cold shot around mid month....alluded to it in my FB update last night.

We'll see....could fail, but I wouldn't expect significant snow out of it, anyway.

 

I just posted about what DT said in the December thread.

 

If we do get a cold shot around mid-month it would likely be extremely brief (couple days?), however, it would mark the beginning of major changes which will slowly be taking place.  Basically...it's a start in the right direction

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Dec 18-20 seems to be the timeframe for a potential cold shot.

 

yeah there is some possibility for that, however, exactly how strong of a cold shot would it be?  I mean there doesn't appear to be a tremendous amount of cold air available.  Regardless, any shot looks quite brief and the pattern just goes right back to what its been

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