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The Mystical Month of February--Long Range Discussion


Ji

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40 minutes ago, psuhoffman said:

@C.A.P.E. something else is causing the SE ridge. 

Look at this...

39A82BFE-5024-482D-9698-C8DC4B7892A2.thumb.png.6e09fc8495edbe4ed4c7870510f9f734.png

the pacific is right. That ridge isn’t being pumped by the pac if anything the pac is trying to fight it. Trough east of Hawaii. The north pac ridge has pushed east into a true poleward -epo ridge.  Pna is neutral but ridging is trying to press into the west. -NAO. -AO. Ridge bridge 

And the se ridge remains!!!!  And it’s not just a temporary thing. It’s only somewhat muted by all that then bounces right back!

8BB6903C-77B5-4C2D-93B5-A1A080814254.thumb.png.97ce121989e9e93ac92514c55f963a99.png

there is another problem somewhere causing that ridge. I have no idea what it is. But the issue is if there is another cause and it’s a dominant influence expecting the mjo to help might not work. Looks like even on runs where the pattern gets right in EVERY other way that ridge fights and wins. 

TNH? Maybe it is related...

https://www.cpc.ncep.noaa.gov/data/teledoc/tnh.shtml

https://www.cpc.ncep.noaa.gov/data/teledoc/tnh_map.shtml

That map of the positive phase looks mighty familiar lol.

eta- another image I found:

regrz500_tnh.png.94d4c474954d5c76d97bbefff290e9ca.png

 

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57 minutes ago, psuhoffman said:

@C.A.P.E. something else is causing the SE ridge. 

Look at this...

39A82BFE-5024-482D-9698-C8DC4B7892A2.thumb.png.6e09fc8495edbe4ed4c7870510f9f734.png

the pacific is right. That ridge isn’t being pumped by the pac if anything the pac is trying to fight it. Trough east of Hawaii. The north pac ridge has pushed east into a true poleward -epo ridge.  Pna is neutral but ridging is trying to press into the west. -NAO. -AO. Ridge bridge 

And the se ridge remains!!!!  And it’s not just a temporary thing. It’s only somewhat muted by all that then bounces right back!

8BB6903C-77B5-4C2D-93B5-A1A080814254.thumb.png.97ce121989e9e93ac92514c55f963a99.png

there is another problem somewhere causing that ridge. I have no idea what it is. But the issue is if there is another cause and it’s a dominant influence expecting the mjo to help might not work. Looks like even on runs where the pattern gets right in EVERY other way that ridge fights and wins. 

My goodness...and people wonder why we're losing our minds in here, lol A mystery se ridge that won't budge even when all else wants to play nice...mercy! When ya figure out the mystery, let me know...lol Can you recall any other winters where we saw this?

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5 minutes ago, Maestrobjwa said:

My goodness...and people wonder why we're losing our minds in here, lol A mystery se ridge that won't budge even when all else wants to play nice...mercy! When ya figure out the mystery, let me know...lol Can you recall any other winters where we saw this?

We may have "solved" the mystery. Read instead of just looking at the pictures lol.

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7 minutes ago, C.A.P.E. said:

We may have "solved" the mystery. Read instead of just looking at the pictures lol.

From doing the reading at the CPC site, it doesn't seem that the + phase of the TNH is strongly correlated with warm temperatures in the east.  Which is surprising given that it seems to pump the SER.

Correlated with cold temperature over much of the rest of the CONUS though.

image.png.ca0ae6a77ade2a314845e22ac87dfaa0.png

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11 minutes ago, cbmclean said:

From doing the reading at the CPC site, it doesn't seem that the + phase of the TNH is strongly correlated with warm temperatures in the east.  Which is surprising given that it seems to pump the SER.

Correlated with cold temperature over much of the rest of the CONUS though.

image.png.ca0ae6a77ade2a314845e22ac87dfaa0.png

Its clearly a combination of things. I think this almost has to be part of why the pattern seems to never progress as expected, despite the other indices supporting it.

eta- the east has not been that warm overall, but a persistent SE ridge is problematic when it comes to storm tracks, as we know.

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2 hours ago, C.A.P.E. said:

TNH? Maybe it is related...

https://www.cpc.ncep.noaa.gov/data/teledoc/tnh.shtml

https://www.cpc.ncep.noaa.gov/data/teledoc/tnh_map.shtml

That map of the positive phase looks mighty familiar lol.

eta- another image I found:

regrz500_tnh.png.94d4c474954d5c76d97bbefff290e9ca.png

 

We are obviously in a +TNH pattern BUT I never understood it to be a pattern causation. I thought it was just like the pna, epo, wpo, NAO.... a measure of the pattern. Not something that caused the pattern like the mjo, enso, soi, solar, qbo, amp, pdo. Some of those matter more than others but those are all key things that CAUSE patterns like the epo, pna, and NAO.  Yea a favorable epo or pna gives us a snow chance but to predict that you need to understand what causes a favorable epo or pna ridge. I always thought of the TNH as an effect not a cause. I’m looking for the cause behind the +TNH because a -soi and mjo phases 8-2 usually correlate with a -TNH pattern.   Hope I’m making sense. 

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Just now, psuhoffman said:

We are obviously in a +TNH pattern BUT I never understood it to be a pattern causation. I thought it was just like the pna, epo, wpo, NAO.... a measure of the pattern. Not something that caused the pattern like the mjo, enso, soi, solar, qbo, amp, pdo. Some of those matter more than others but those are all key things that CAUSE patterns like the epo, pna, and NAO.  Yea a favorable epo or pna gives us a snow chance but to predict that you need to understand what causes a favorable epo or pna ridge. I always thought of the TNH as an effect not a cause. I’m looking for the cause behind the +TNH because a -soi and mjo phases 8-2 usually correlate with a -TNH pattern.   Hope I’m making sense. 

I dunno. Not all that familiar with the TNH and whether it is considered a forcing element or not. DT has mentioned it in recent winters as playing a big role- esp 13-14 I believe when the "blob" made headlines. 

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28 minutes ago, psuhoffman said:

We are obviously in a +TNH pattern BUT I never understood it to be a pattern causation. I thought it was just like the pna, epo, wpo, NAO.... a measure of the pattern. Not something that caused the pattern like the mjo, enso, soi, solar, qbo, amp, pdo. Some of those matter more than others but those are all key things that CAUSE patterns like the epo, pna, and NAO.  Yea a favorable epo or pna gives us a snow chance but to predict that you need to understand what causes a favorable epo or pna ridge. I always thought of the TNH as an effect not a cause. I’m looking for the cause behind the +TNH because a -soi and mjo phases 8-2 usually correlate with a -TNH pattern.   Hope I’m making sense. 

It seems to be a "land-sea interaction index vs the PNA". The Earth's rotation speeds up 0.00001ms and slows down etc. that is my theory. I call it the AAM as a better measurement, they are similar but different. We are in a long term +TNH since 2013. Maybe it's subsurface currents. 

y-Cvw-Xobg-Jc.png

yy.png

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39 minutes ago, psuhoffman said:

We are obviously in a +TNH pattern BUT I never understood it to be a pattern causation. I thought it was just like the pna, epo, wpo, NAO.... a measure of the pattern. Not something that caused the pattern like the mjo, enso, soi, solar, qbo, amp, pdo. Some of those matter more than others but those are all key things that CAUSE patterns like the epo, pna, and NAO.  Yea a favorable epo or pna gives us a snow chance but to predict that you need to understand what causes a favorable epo or pna ridge. I always thought of the TNH as an effect not a cause. I’m looking for the cause behind the +TNH because a -soi and mjo phases 8-2 usually correlate with a -TNH pattern.   Hope I’m making sense. 

Does it have to have a cause?  Many natural process are stochastic in nature.  Or put less pretentiously, maybe its just bad luck?

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48 minutes ago, C.A.P.E. said:

I dunno. Not all that familiar with the TNH and whether it is considered a forcing element or not. DT has mentioned it in recent winters as playing a big role- esp 13-14 I believe when the "blob" made headlines. 

I’m in the prelim stages of reading up but so far it seems the TNH causes the pacific warm blob. Reading a study about that. It also correlated to an Atlantic cold pool.  But what I’m not seeing so far is the causation of the TNH and it’s relationship to other pattern drivers like the mjo and soi. 

I guess what I mean by causation...is the TNH seems to be measured of the jet pattern.  But what I’m looking for are things that cause the longwave patterns. 

Enso and other sst anomalies, for example, aren’t patterns. They are things that cause patterns. The mjo is related to a pattern but it’s just a measure of convection that is known to affect the longwave patterns.  Solar is another example although our ability to understand and use that one is more limited. 

Another issue is simply saying that is our snow problem would be a leap since some of our snowiest months have been a +TNH  and some were analogs.  February 2015 and 2003 were +TNH.  All 3 winter months of 2013/14.  February 2007.  February 2006.  January 1996.  All +TNH.  

Also since 2006 we have had 26 + months and only 12 - ones. It’s only calculated Dec to February.  So it’s predominantly positive. Also in that time by my estimate we have had 10 legit snowy months in the region.  7 were during a +TNH and 3 a -TNH. 

Im obviously not an expert on this. I’ve never used it much but that’s because when I did look into it once I found it of little “predictive” value and a weak correlation to snow here. The quick look at the data seems to still suggest that  

But there is no denying we are in a +TNH pattern and at this time it’s a bad one.  But I don’t understand the correlation to causation well enough to make that useful and I see no pattern in the data to suggest a + vs - TNH favors snow here.  

 

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8 minutes ago, cbmclean said:

Does it have to have a cause?  Many natural process are stochastic in nature.  Or put less pretentiously, maybe its just bad luck?

Physics dictates it has a cause. Just because we don’t understand the cause doesn’t make it random.  The cause might be something we lack the ability to measure or even comprehend but it has a cause. 

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2 minutes ago, psuhoffman said:

Physics dictates it has a cause.

While this statement seems intuitive, it is by no means universally agreed upon by scientists and philosophers.  Some physical processes may not be causal in the way that we understand.  Take radioactive beta decay for an example.  We can define with great precision the probability that any given atom will spontaneously decay, but explaining why this atom decays as opposed to the one next to it is a different matter.

I'm not just rolling or being silly.  I actually think it is a great philosophical point to ponder. 

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1 hour ago, Fozz said:

I can't recall any other non-Nina winter with as stubborn of a SE ridge as this one. If only it was around on Dec 9.

Good insights, Fozz.  I recommend that we all appeal to Mappie to do the yearly totals. 

I recommend that Mapgirl, without violating privacy concerns, share with the group her cartology creds.

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13 minutes ago, psuhoffman said:

I’m in the prelim stages of reading up but so far it seems the TNH causes the pacific warm blob. Reading a study about that. It also correlated to an Atlantic cold pool.  But what I’m not seeing so far is the causation of the TNH and it’s relationship to other pattern drivers like the mjo and soi. 

I guess what I mean by causation...is the TNH seems to be measured of the jet pattern.  But what I’m looking for are things that cause the longwave patterns. 

Enso and other sst anomalies, for example, aren’t patterns. They are things that cause patterns. The mjo is related to a pattern but it’s just a measure of convection that is known to affect the longwave patterns.  Solar is another example although our ability to understand and use that one is more limited. 

Another issue is simply saying that is our snow problem would be a leap since some of our snowiest months have been a +TNH  and some were analogs.  February 2015 and 2003 were +TNH.  All 3 winter months of 2013/14.  February 2007.  February 2006.  January 1996.  All +TNH.  

Also since 2006 we have had 26 + months and only 12 - ones. It’s only calculated Dec to February.  So it’s predominantly positive. Also in that time by my estimate we have had 10 legit snowy months in the region.  7 were during a +TNH and 3 a -TNH. 

Im obviously not an expert on this. I’ve never used it much but that’s because when I did look into it once I found it of little “predictive” value and a weak correlation to snow here. The quick look at the data seems to still suggest that  

But there is no denying we are in a +TNH pattern and at this time it’s a bad one.  But I don’t understand the correlation to causation well enough to make that useful and I see no pattern in the data to suggest a + vs - TNH favors snow here.  

 

It's a good point. Maybe it has to do with global potential energy from ice melt with non-cyclonic-bombing lows evening out? (It seems to have a Space connection.)

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15 minutes ago, psuhoffman said:

Physics dictates it has a cause. Just because we don’t understand the cause doesn’t make it random.  The cause might be something we lack the ability to measure or even comprehend but it has a cause. 

Also, whenever we start talking about cause an effect, we always run into the causation chain problem: what causes the cause?  For example, above you mentioned the MJO and ENSO as drivers.  But something has to drive them right?  I know that a lot of research ink has been spent looking into the hows and whys of ENSO.  I for one am being driven crazy by the ineffability of the MJO.  Why is it strong some times and weak others?  Why does it move fast or slow?  Why does it sometime do loop-de-loops.

I'm not trying to be pointlessly argumentative.  I just have so much desire to understand, and so little knowledge.

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3 minutes ago, cbmclean said:

Also, whenever we start talking about cause an effect, we always run into the causation chain problem: what causes the cause?  For example, above you mentioned the MJO and ENSO as drivers.  But something has to drive them right?  I know that a lot of research ink has been spent looking into the hows and whys of ENSO.  I for one am being driven crazy by the ineffability of the MJO.  Why is it strong some times and weak others?  Why does it move fast or slow?  Why does it sometime do loop-de-loops.

I'm not trying to be pointlessly argumentative.  I just have so much desire to understand, and so little knowledge.

I have found in ENSO there are gravity waves (Rossby, Kelvin) that dictate the cause. 

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20 minutes ago, cbmclean said:

While this statement seems intuitive, it is by no means universally agreed upon by scientists and philosophers.  Some physical processes may not be causal in the way that we understand.  Take radioactive beta decay for an example.  We can define with great precision the probability that any given atom will spontaneously decay, but explaining why this atom decays as opposed to the one next to it is a different matter.

I'm not just rolling or being silly.  I actually think it is a great philosophical point to ponder. 

I think we are too quick to label things we don’t understand stochastic.  

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42 minutes ago, psuhoffman said:

I’m in the prelim stages of reading up but so far it seems the TNH causes the pacific warm blob. Reading a study about that. It also correlated to an Atlantic cold pool.  But what I’m not seeing so far is the causation of the TNH and it’s relationship to other pattern drivers like the mjo and soi. 

I guess what I mean by causation...is the TNH seems to be measured of the jet pattern.  But what I’m looking for are things that cause the longwave patterns. 

Enso and other sst anomalies, for example, aren’t patterns. They are things that cause patterns. The mjo is related to a pattern but it’s just a measure of convection that is known to affect the longwave patterns.  Solar is another example although our ability to understand and use that one is more limited. 

Another issue is simply saying that is our snow problem would be a leap since some of our snowiest months have been a +TNH  and some were analogs.  February 2015 and 2003 were +TNH.  All 3 winter months of 2013/14.  February 2007.  February 2006.  January 1996.  All +TNH.  

Also since 2006 we have had 26 + months and only 12 - ones. It’s only calculated Dec to February.  So it’s predominantly positive. Also in that time by my estimate we have had 10 legit snowy months in the region.  7 were during a +TNH and 3 a -TNH. 

Im obviously not an expert on this. I’ve never used it much but that’s because when I did look into it once I found it of little “predictive” value and a weak correlation to snow here. The quick look at the data seems to still suggest that  

But there is no denying we are in a +TNH pattern and at this time it’s a bad one.  But I don’t understand the correlation to causation well enough to make that useful and I see no pattern in the data to suggest a + vs - TNH favors snow here.  

 

I didn't realize we were trying to make a direct correlation between the TNH and above/below normal snowfall, rather to find some rationale for the persistence of the SE ridge despite other factors that argue against it.

Everything I read suggests that the +phase favors a SE ridge, which naturally becomes an inhibiting factor for snowfall in this region.

Overview of the TNH from CPC-

Quote

The Tropical/ Northern Hemisphere (TNH) pattern was first classified by Mo and Livezey (1986), and appears as a prominent wintertime mode during December-February. The positive phase of the TNH pattern features above-average heights over the Gulf of Alaska and from the Gulf of Mexico northeastward across the western North Atlantic, and below-average heights throughout eastern Canada.

The TNH pattern reflects large-scale changes in both the location and eastward extent of the Pacific jet stream, and also in the strength and position of the climatological mean Hudson Bay Low. Thus, the pattern significantly modulates the flow of marine air into North America, as well as the southward transport of cold Canadian air into the north-central United States.

 

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