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Old 06-04-2016, 05:34 AM
 
Location: Near the Coast SWCT
64,980 posts, read 47,284,481 times
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Latest PDO. May 2016 1.46. Down from 1.60 previous month.


May 2015 had a more neutral PDO than this year.. A more positive PDO meant more Jet stream dips in the Eastern U.S.


May 2016 on paper wont show it because last 7 days we got torched. But May 2015 was warm overall and more consistently. A lower PDO means less troughs digging into the East.


Pacific Decadal Oscillation (PDO) | Teleconnections


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Old 06-04-2016, 06:04 AM
 
21,894 posts, read 11,560,257 times
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Quote:
Originally Posted by Cambium View Post
Latest PDO. May 2016 1.46. Down from 1.60 previous month.


May 2015 had a more neutral PDO than this year.. A more positive PDO meant more Jet stream dips in the Eastern U.S.


May 2016 on paper wont show it because last 7 days we got torched. But May 2015 was warm overall and more consistently. A lower PDO means less troughs digging into the East.


Pacific Decadal Oscillation (PDO) | Teleconnections



Would still make it top 10 strongest +PDO signals for the month of May since 1900. We had more above average days than below here for May. So if in fact +PDO means more frequent dips in the jet for the eastern US, it wasn't the case for the Midwest this May.


Also, May of 1995 had a +PDO index of 1.46 and we know how that summer turned out (also La Nina transition year). The PDO was at +1.80 in May of 83'. Summer also scorcher.
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Old 06-04-2016, 07:09 AM
 
Location: Near the Coast SWCT
64,980 posts, read 47,284,481 times
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Quote:
Originally Posted by chicagogeorge View Post
Would still make it top 10 strongest +PDO signals for the month of May since 1900. We had more above average days than below here for May.

May 2016 At MDW ..


11 Days above normal
2 normal
18 days below normal


How will you squeeze through that one? More days below normal.


And how about overall... Check out the departures each week. Looks like Chicago was below normal 3 of the 4 weeks.


Don't fight it George.





Quote:
Originally Posted by chicagogeorge View Post
So if in fact +PDO means more frequent dips in the jet for the eastern US, it wasn't the case for the Midwest this May.
.

Wrong... See above. There were more dips than ridges East of the Rockies.


Let me guess, you're going to find 1 month, 1 yr that goes against the average. lol
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Old 06-04-2016, 07:19 AM
 
21,894 posts, read 11,560,257 times
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Quote:
Originally Posted by Cambium View Post
May 2016 At MDW ..


11 Days above normal
2 normal
18 days below normal


How will you squeeze through that one? More days below normal.


And how about overall... Check out the departures each week. Looks like Chicago was below normal 3 of the 4 weeks.


Don't fight it George.
Count them again. More than half the days saw above normal temps.



1981-2010 Normals | Data Tools | Climate Data Online (CDO) | National Climatic Data Center (NCDC)






Quote:


Wrong... See above. There were more dips than ridges East of the Rockies.


Let me guess, you're going to find 1 month, 1 yr that goes against the average. lol

NAO was negative for a good chunk of May as was the AO index which is why a good chunk of May was below normal for the east. Can't blame everything on the +PDO. If that was the case then why were we torched for 10 of the last 11 months (all of which had a super +PDO). Oh that's right, El Nino. PDO wasn't a factor.

Last edited by chicagogeorge; 06-04-2016 at 07:28 AM..
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Old 06-04-2016, 07:25 AM
 
Location: Mid Atlantic USA
12,087 posts, read 9,599,089 times
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Quote:
Originally Posted by Cambium View Post
Latest PDO. May 2016 1.46. Down from 1.60 previous month.


May 2015 had a more neutral PDO than this year.. A more positive PDO meant more Jet stream dips in the Eastern U.S.


May 2016 on paper wont show it because last 7 days we got torched. But May 2015 was warm overall and more consistently. A lower PDO means less troughs digging into the East.


Pacific Decadal Oscillation (PDO) | Teleconnections

I've said this to George over and over and he simply doesn't believe it. Thanks.
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Old 06-04-2016, 07:32 AM
 
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See my post above. Tell me, did Chicago have more above normal days or below in May?


Tom, which was a more significant factor during the May cold spell. The +PDO or the -AO/-NAO that dominated the first half of the month?

Tell me, what is the forecast for the first two week of June for my region? Is the +PDO at work?

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Old 06-04-2016, 07:53 AM
 
Location: Mid Atlantic USA
12,087 posts, read 9,599,089 times
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Quote:
Originally Posted by chicagogeorge View Post
See my post above. Tell me, did Chicago have more above normal days or below in May?


Tom, which was a more significant factor during the May cold spell. The +PDO or the -AO/-NAO that dominated the first half of the month?

Tell me, what is the forecast for the first two week of June for my region? Is the +PDO at work?
Exactly as cambium stated. This time your spared and we are not, due to the orientation of the PDO. Next time could be different. A ridge will keep coming back to the west due to all that warmer than avg water against their coast.
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Old 06-04-2016, 08:13 AM
 
Location: Near the Coast SWCT
64,980 posts, read 47,284,481 times
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Quote:
Originally Posted by chicagogeorge View Post
Count them again. More than half the days saw above normal temps.
Quote:
Originally Posted by chicagogeorge View Post
See my post above. Tell me, did Chicago have more above normal days or below in May?


I apologize,, I was looking at April numbers. But 50% of the days isn't really saying much. Understand that clouds at night can prevent departures from being below normal so YOU CANT use simply how many days were above/below. We should be using the Jet stream itself.


And my comment still stands..


Excluding the last 7 days of May look at the mean positon of the jet.










And here is the departure. Clearly can see what a Positive PDO favors to produce


That below normal in SouthWest was a long duration Upper Low.


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Old 06-04-2016, 08:22 AM
 
21,894 posts, read 11,560,257 times
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Quote:
Originally Posted by tom77falcons View Post
Exactly as cambium stated.
So you deny that MDW had more above average days than below this May?

Do you deny that May was dominated by a negative NAO (-0.77) and negative AO (-0.036) which was the main reason why a good chunk of the month was below average from the east?

Btw, PNA was negative for May


Quote:
This time your spared and we are not, due to the orientation of the PDO. Next time could be different. A ridge will keep coming back to the west due to all that warmer than avg water against their coast.

Omg


Quote:
Originally Posted by Cambium View Post
I apologize,, I was looking at April numbers.

No problem

Quote:
But 50% of the days isn't really saying much. Understand that clouds at night can prevent departures from being below normal so YOU CANT use simply how many days were above/below.
50% is saying that the month was near normal, which it was, just slightly positive.


Quote:
We should be using the Jet stream itself.

Look at the NAO.


Quote:
And my comment still stands..


Excluding the last 7 days of May look at the mean positon of the jet.





And here is the departure. Clearly can see what a Positive PDO favors to produce


That below normal in SouthWest was a long duration Upper Low.



Again, look at the NAO. That was the reason why we had troughs in the East. Also, the PNA was negative at -0.85 for the month of May.



Cambium said this too:


Quote:
Originally Posted by Cambium View Post
Just having May and June in positive territory is not enough IMO and it's not even strong at that.

But again... why are you trying to make it seem like the PDO is the only thing to look at? Try filtering out the El Nino years, or adding a positive PNA to it. How about the AO with the +PDO? And how about winter instead of Summer. Like you said (& I agree) it affects the pattern much more in Spring, Fall and Winter.






http://research.jisao.washington.edu/pdo/PDO.latest


Because I showed this:




Quote:
July years with +PDO of 0.5 or greater
Quote:
I chose which had multiple months of +PDO prior and including that July.




Quote:
and more recent years (since 1980) using the 1981-2010 base period




But seriously, how can we ever sanitize teleconnections where just the PDO is looked at? Impossible. There will always be PNA/NAO/AO/EPO phases that interplay with the PDO/AMO.
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Old 06-04-2016, 10:49 AM
 
Location: Near the Coast SWCT
64,980 posts, read 47,284,481 times
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Check out the relationship between the PDO and the PNA.


ESRL : PSD : Climate Indices: Monthly Atmospheric and Ocean Time Series





Both are associated with the ridge west/trough pattern in the west and guess what that does down stream?


And take a look at why the PDO weakened in May.. the surface winds were coming from the Alaska-Pacific northwest coastal waters. Lets see if the PDO will drop more next month.


ESRL : PSD : Monthly/Seasonal Composites


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