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Winter 2016/2017 because its never too early


Ginx snewx

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On September 29, 2016 at 6:31 PM, USCAPEWEATHERAF said:

I don't know Powderfreak, one area that is very fickle for New England winters is Cape Cod especially Harwich, Chatham, Brewster, Orleans, Eastham, Wellfleet, Truro and Provincetown

Fickle pickles in Ptown....scooter has a great getaway there.

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9 hours ago, uncle W said:

the AO is tanking now and forecast to be near -4 soon...the nao is also forecast to go negative but with lesser agreement...could be the beginning of a -ao/nao season...

 

Well...I'm not sure about the AO but a -NAO during OCT does not usually bode well for NAO in winter.  I remember Anthony discussing this last year & showing data.  Doesn't mean it's gospel...but historically a -NAO OCT is not good for winter.

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1 hour ago, stadiumwave said:

 

Well...I'm not sure about the AO but a -NAO during OCT does not usually bode well for NAO in winter.  I remember Anthony discussing this last year & showing data.  Doesn't mean it's gospel...but historically a -NAO OCT is not good for winter.

some good winters followed a -nao October...some were -nao winters also...2010 was negative all year until February 2011...

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

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51 minutes ago, uncle W said:

some good winters followed a -nao October...some were -nao winters also...2010 was negative all year until February 2011...

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

 

True....but plenty of others where -NAO didn't pan out for winter including the recent years of 2012,2013,2014.  PAC bailed us out 2013 & 2014. I think -EPO shots will be on the table again but OCT will make us nervous with the PAC as the warm blob will probably disappear due to a pattern of persistent troughing in the GOA coming up.  But don't panic, the same occurred in mid SEPT-midOCT in 2013:

http://www.ospo.noaa.gov/data/sst/anomaly/2013/anomnight.10.14.2013.gif

 

Here was the 500mb pattern for that year mid-SEPT through mid-OCT:

wNGhwdF.gif

A similar pattern of GOA troughing is getting ready to emerge.

BTW the warm blob returned late NOV into DEC that year.  But we know that story :)

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24 minutes ago, stadiumwave said:

 

True....but plenty of others where -NAO didn't pan out for winter including the recent years of 2012,2013,2014.  PAC bailed us out 2013 & 2014. I think -EPO shots will be on the table again but OCT will make us nervous with the PAC as the warm blob will probably disappear due to a pattern of persistent troughing in the GOA coming up.  But don't panic, the same occurred in mid SEPT-midOCT in 2013:

http://www.ospo.noaa.gov/data/sst/anomaly/2013/anomnight.10.14.2013.gif

 

Here was the 500mb pattern for that year mid-SEPT through mid-OCT:

wNGhwdF.gif

A similar pattern of GOA troughing is getting ready to emerge.

BTW the warm blob returned late NOV into DEC that year.  But we know that story :)

what ever it takes for one good storm is all I'm looking for...Last year the AO/NAO were very negative just before the January Blizzard...the rest of the year was mostly positive...

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22 minutes ago, CoastalWx said:

The PAC SSTs are a function of the H5 pattern...not the other way around. The reason why the warm blob came back was due to ridging in that area, forced by tropical forcing. 

We need a custom WPAC SST index . Most recent studies on the blob hone in on the Tropical WPAC as the main culprit . That region has

seen record SST's for an extended period of time.

Screen shot 2016-10-04 at 8.01.10 AM.png

 

 

 

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11 minutes ago, bluewave said:

We need a custom WPAC SST index . Most recent studies on the blob hone in on the Tropical WPAC as the main culprit . That region has

seen record SST's for an extended period of time.

Screen shot 2016-10-04 at 8.01.10 AM.png

 

 

 

It makes sense from a physical standpoint. All that latent heat released will excite the jet and force a downstream ridge response in that region.  Sure maybe the normally cold waters being 2C warmer may have some feedback, but it's substantially less when compared to the west pac tropical forcing. I think people find the NE PAC SSTs as an easy answer to explaining the persistent ridging there, but I find those SSTs to be highly overrated. 

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59 minutes ago, CoastalWx said:

The PAC SSTs are a function of the H5 pattern...not the other way around. The reason why the warm blob came back was due to ridging in that area, forced by tropical forcing. 

 

While I generally agree with you or it least it makes better sense to me currently; however, there are others in the field who would disagree.  There's a peer reviewed study about the causes of the severe winter of 2013-14 that flat out says the cause of persistent high pressure over the N. PAC that year was due to SST's way above normal.  Not saying I agree...but I'm not saying they're conclusion is wrong:

 

"The severe 2013/14 winter (December–March) in the Midwest was dominated by a persistent atmospheric circulation pattern anchored to a North Pacific Ocean that was much warmer than average. Strong teleconnection magnitudes of the eastern Pacific oscillation (−EPO), tropical Northern Hemisphere pattern (+TNH), and second-lowest Hudson Bay 500-hPa geopotential height field are indicators that led to severe winter weather across the eastern United States. Unlike in previous cold and snowy midwestern winters, Atlantic Ocean blocking played little to no role in the winter of 2013/14. The primary atmospheric feature of the 2013/14 winter was the 500-hPa high pressure anchored over the North Pacific in response to the extremely warm sea surface temperature anomalies observed of +3.7 standard deviations. Only one other severe midwestern winter (1983/84) since 1950 featured a similar Pacific blocking. The accumulated winter season severity index, which is a metric that combines daily snowfall, snow depth, and temperature data for the winter season, was used to compare the 2013/14 winter with past winters since 1950. Detroit, Michigan, and Duluth, Minnesota, experienced their worst winter of the 55-yr period. Seven climate divisions in northern Illinois, eastern Iowa, and parts of Wisconsin experienced record-cold mean temperatures. These climate conditions were associated with a number of impacts, including a disruption to the U.S. economy, the second-highest ice coverage of the Great Lakes since 1973, and a flight-cancellation rate that had not been seen in 25 years."

 

http://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-15-0084.1?journalCode=apme

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3 minutes ago, stadiumwave said:

 

While I generally agree with you or it least it makes better sense to me currently; however, there are others in the field who would disagree.  There's a peer reviewed study about the causes of the severe winter of 2013-14 that flat out says the cause of persistent high pressure over the N. PAC that year was due to SST's way above normal.  Not saying I agree...but I'm not saying they're conclusion is wrong:

 

"The severe 2013/14 winter (December–March) in the Midwest was dominated by a persistent atmospheric circulation pattern anchored to a North Pacific Ocean that was much warmer than average. Strong teleconnection magnitudes of the eastern Pacific oscillation (−EPO), tropical Northern Hemisphere pattern (+TNH), and second-lowest Hudson Bay 500-hPa geopotential height field are indicators that led to severe winter weather across the eastern United States. Unlike in previous cold and snowy midwestern winters, Atlantic Ocean blocking played little to no role in the winter of 2013/14. The primary atmospheric feature of the 2013/14 winter was the 500-hPa high pressure anchored over the North Pacific in response to the extremely warm sea surface temperature anomalies observed of +3.7 standard deviations. Only one other severe midwestern winter (1983/84) since 1950 featured a similar Pacific blocking. The accumulated winter season severity index, which is a metric that combines daily snowfall, snow depth, and temperature data for the winter season, was used to compare the 2013/14 winter with past winters since 1950. Detroit, Michigan, and Duluth, Minnesota, experienced their worst winter of the 55-yr period. Seven climate divisions in northern Illinois, eastern Iowa, and parts of Wisconsin experienced record-cold mean temperatures. These climate conditions were associated with a number of impacts, including a disruption to the U.S. economy, the second-highest ice coverage of the Great Lakes since 1973, and a flight-cancellation rate that had not been seen in 25 years."

 

http://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-15-0084.1?journalCode=apme

Are they talking about the very far NPAC or NPAC in general? The whole basin was pretty warm.  I've seen work from Paul Roundy, Ventrice etc showing the Tropical forcing anomalies and then resulting H5 pattern. It made sense to me. I don't see how cold ocean waters that are above normal have the energy to completely overwhelm a hemispheric pattern. It would have to be done by conduction since convection and latent heat don't exist like it does further south. We see GOAK troughs over the warmer NE PAC all the time and bring it back to normal or below. I think it helps feedback, but I don't agree that the warmer NE PAC waters are the main reason for the ridging there. 

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I've learned that attribution studies can sometimes come to hasty conclusions immediately following an anomalous event. But often, we should wait for more papers to come out before taking them at face value. 

 

One example was the extreme -NAO blocks we saw frequently from 2009-2013. There was a lot of people rushing attribution to low sea ice. Then we basically have gone 3-4 years straight without the huge NAO blocking. 

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8 minutes ago, ORH_wxman said:

I've learned that attribution studies can sometimes come to hasty conclusions immediately following an anomalous event. But often, we should wait for more papers to come out before taking them at face value. 

 

One example was the extreme -NAO blocks we saw frequently from 2009-2013. There was a lot of people rushing attribution to low sea ice. Then we basically have gone 3-4 years straight without the huge NAO blocking. 

Right. You tend to get people who come to conclusions rather quickly from anomalous events. I can't blame them...people and we as a community want to know. It's natural. Like the so called NOAA group who decided that the heavy rain event back in LA was 40% attrubited to AGW. How do you come to that conclusion? It was basically a stalled TD. Unless you can say that TD was a result of AGW....maybe instead of 26" of rain, the max would have been 24.45"  We have had many 20"+ events traced back to stalled tropical systems. 

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55 minutes ago, CoastalWx said:

Right. You tend to get people who come to conclusions rather quickly from anomalous events. I can't blame them...people and we as a community want to know. It's natural. Like the so called NOAA group who decided that the heavy rain event back in LA was 40% attrubited to AGW. How do you come to that conclusion? It was basically a stalled TD. Unless you can say that TD was a result of AGW....maybe instead of 26" of rain, the max would have been 24.45"  We have had many 20"+ events traced back to stalled tropical systems. 

When do your "must read" discussions of the Euro monthlies begin? :)

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