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2012 ENSO Thread


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Looks like the prospects of a well established Niño are diminishing, and I suspect that Neutral or a very weak warm episode is looking more likely. 90/30/1 day SOI are now all positive, with trade winds still blowing anomalously strong near the dateline. Looks like some dampening of the winds is occurring soon, but anomalies still more on the easterly side of things...with no signs of a well established WWB going thru. Models are now playing catch up, with the latest CFS v2 now below mod Niño strength in it's latest iteration.

Earlier period

post-29-0-15140600-1337040279_thumb.gif

Latest period

post-29-0-43861300-1337040278_thumb.gif

A good 0.5 trimming in SSTs

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The CFS2 still too warm IMO. My winter forecast is based on an ONI peak of 0.4 ONI (in OND), and a monthly peak of 0.6 give or take 0.1 in November. As much as I want to go ahead and post the analogs and all the other teleconnecting goodies for the Mid-Atlantic and Southeast snowcast for winter 2012-13, someone reminded me it's May. Which means MCS season, which will serve as a test for my analogs. :-)

Maps on the MCS tracks later.

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For the first time in a while, I'm seeing a suggestion based on the Euro model that there will probably be a couple of days of strong negative SOI's..say late this week. However, I still don't see a strong suggestion of a very sustained strongly negative string of SOI's just yet. That would be an indicator of an emerging El Nino.

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Does anybody else think that the models are being too aggressive with the El Niño? Euro and Eurosip are high end weak El Niño (plausible), to solid moderate El Niño (questionable). Eurosip average looks like is over the weak El Niño treshold a month from now... not gonna happen.

post-29-0-97937100-1337695889_thumb.gif

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Does anybody else think that the models are being too aggressive with the El Niño? Euro and Eurosip are high end weak El Niño (plausible), to solid moderate El Niño (questionable). Eurosip average looks like is over the weak El Niño treshold a month from now... not gonna happen.

Energy mets are saying to wait until the fall for the Nino to show up (if at all). Kinda makes sense given the AAM and SOI over the last month. Doesn't look like we'll have any MJO help for a while, either.

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Energy mets are saying to wait until the fall for the Nino to show up (if at all). Kinda makes sense given the AAM and SOI over the last month. Doesn't look like we'll have any MJO help for a while, either.

I'm in the same bandwagon...but that would almost discard a moderate or strong El Niño, IMO.

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For the first time in a while, I'm seeing a suggestion based on the Euro model that there will probably be a couple of days of strong negative SOI's..say late this week. However, I still don't see a strong suggestion of a very sustained strongly negative string of SOI's just yet. That would be an indicator of an emerging El Nino.

Looking at the latest Euro runs, the strong negatives for late this week still look on schedule. Also, we may be about to go into a fairly long string of negatives. If so, perhaps this could help get the warming to resume in June.

The decent chances for a weak El Nino this fall/winter appear to be intact. From my perspective, this would offer the best shot at a very cold 2012-3 winter in the E US. If along with the weak Nino there were to be a DJF +PDO as well as DJF -NAO, those prospects would be very good.

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Looking at the latest Euro runs, the strong negatives for late this week still look on schedule. Also, we may be about to go into a fairly long string of negatives. If so, perhaps this could help get the warming to resume in June.

The decent chances for a weak El Nino this fall/winter appear to be intact. From my perspective, this would offer the best shot at a very cold 2012-3 winter in the E US. If along with the weak Nino there were to be a DJF +PDO as well as DJF -NAO, those prospects would be very good.

Larry, the new Euro seasonal forecast off the free site (May's forecast released on the 22nd of the month on the fee site) says mod to weak is a good bet....fwiw since it is an ENSO forecast after all

http://www.ecmwf.int...ensemble mean!/

http://www.ecmwf.int...plumes!201205!/

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Larry, the new Euro seasonal forecast off the free site (May's forecast released on the 22nd of the month on the fee site) says mod to weak is a good bet....fwiw since it is an ENSO forecast after all

http://www.ecmwf.int...ensemble mean!/

http://www.ecmwf.int...plumes!201205!/

Thanks, Mitch. Yes, those Euro maps do suggest a west-based moderate. Based on how the SOI is behaving (still no long, strong string of SOI's), there's plenty of reason to hope for a weak (quite possibly west based, too). The one thing I don't prefer seeing is the -PDO that it still suggests. Despite it still being way too early to predict the next fall/winter ENSO, I'm already starting to get excited about the next winter's potential. The prospects would be helped immensely if we could attain a +PDO and -NAO for DJF. One thing about the PDO is that there may very well be somewhat of a chicken-egg thing going on with it. For shoots and giggles, here is the CFS link for the upcoming DJF (it is cold for the U.S. and the polar opposite of last winter):

http://twitter.com/B...0/photo/1/large

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Thanks, Mitch. Yes, those Euro maps do suggest a west-based moderate. Based on how the SOI is behaving, there's plenty of reason to hope for a weak (quite possibly west based, too). The one thing I don't prefer seeing is the -PDO that it still suggests. Despite it still being way too early to predict the next fall/winter ENSO, I'm already starting to get excited about the next winter's potential. The prospects would be helped immensely if we could attain a +PDO and -NAO for DJF. One thing about the PDO is that there may very well be somewhat of a chicken-egg thing going on with it. For shoots and giggles, here is the CFS link for the upcoming DJF (it is cold for the U.S. and the polar opposite of last winter):

http://twitter.com/B...0/photo/1/large

well, SSTA in the Gulf of Alaska in early 1/10 wasn't so hot, so maybe there's still some hope

http://weather.unisy...anom-100103.gif

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Looking at the latest Euro runs, the strong negatives for late this week still look on schedule. Also, we may be about to go into a fairly long string of negatives. If so, perhaps this could help get the warming to resume in June.

The decent chances for a weak El Nino this fall/winter appear to be intact. From my perspective, this would offer the best shot at a very cold 2012-3 winter in the E US. If along with the weak Nino there were to be a DJF +PDO as well as DJF -NAO, those prospects would be very good.

Not sure about warming resuming in June...looks like the -SOI isn't doing much wrt trade winds where it matters

u.anom.30.5S-5N.png

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Not sure about warming resuming in June...looks like the -SOI isn't doing much wrt trade winds where it matters

Based on today's model guidance for the next 10-14 days, I largely concur. The solid negative SOI's into the weekend are intact. I project the following:

5/24: -8

5/25: -16

5/26: -24

5/27: -23

However, after this period, the trend is in the positive direction with no solid negatives suggested to return into at least early June. So, if there is going to be an El Nino, this would tend to favor weak over moderate to strong. As of right now, it looks to me like the best chances for the fall/winter peak are either weak El Nino or neutral positive with lesser chances for a moderate Nino and neutral negative. It is going to be fun to follow.

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Based on today's model guidance for the next 10-14 days, I largely concur. The solid negative SOI's into the weekend are intact. I project the following:

5/24: -8

5/25: -16

5/26: -24

5/27: -23

However, after this period, the trend is in the positive direction with no solid negatives suggested to return into at least early June. So, if there is going to be an El Nino, this would tend to favor weak over moderate to strong. As of right now, it looks to me like the best chances for the fall/winter peak are either weak El Nino or neutral positive with lesser chances for a moderate Nino and neutral negative. It is going to be fun to follow.

I think we are on the same page, since I favor those same ranges that you do. My previous guess was a peak between +0.7-+0.9, now I think it will be around +0.4-+0.7...with ASO trimonthly around 0-+0.3 (this for the heart of hurricane season)

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I think we are on the same page, since I favor those same ranges that you do. My previous guess was a peak between +0.7-+0.9, now I think it will be around +0.4-+0.7...with ASO trimonthly around 0-+0.3 (this for the heart of hurricane season)

I also think that what is occurring now bodes at least a little better for those who don't want a weak hurricane season as far as the MDR is concerned. I've found that there does seem to be a decent + and perhaps somewhat leading (say perhaps by a few weeks) correlation between the SOI and MDR activity. Although there are other factors to consider, the July and August SOI's will be important for the heart of the season MDRwise in my opinion based on history. However, if the current SOI trend is any indication, the chances are increasing that the July and August SOI's won't be solidly negative. We'll see.

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It appears that the 5/2012 SOI will be ~-1 to 0. Keeping that in mind, here are the May SOI's for previous first year El Nino's back to 1950 along with the respective Nino strengths using the 1971-2000 climo. for ONI based Nino classification that I've used for a number of years (W = weak; M = moderate; S = strong):

1951: -11.5 W

1957: -11.5 S

1963: +2.5 W

1965: -0.4 S

1968: +14.3 W

1972: -24.0 S

1976: +2.5 W

1982: -7.1 S

1986: -5.6 M

1991: -17.9 S

1994: -11.6 M

1997: -19.0 S

2002: -13.8 M

2004: +13.0 W

2006: -7.7 M

2009: -5.0 S

Going from most +SOI to most -SOI for May, here were the following Nino peaks: W, W, W, W, S, S, M, S, M, W, S, M, M, S, S, S

Note that the three most -SOI May's, -24.0, -19.0, and -17.9, all preceded a strong Nino. Also, note that the four +SOI May's all preceded a weak Nino.

5 W avg. preceding May SOI +4.2 (range: +14.3 to -11.5)

4 M avg. preceding May SOI -9.7 (range: -5.6 to -13.8)

7 S avg. preceding May SOI -12.1 (range: -0.4 to -24.0)

So, only one of the 11 moderate to strong Nino's, 1965-6, had a preceding May SOI near the 5/12 SOI.

My point is that there is some predictive power from the May SOI, which is favoring a weak Nino peak over moderate or strong if there will be a Nino.

------------------------------------------------------------------------------------

I used the following link's table for ONI based Nino classification:

http://www.cpc.ncep....000_climo.shtml

I used the following link's table for monthly SOI's:

http://www.longpaddock.qld.gov.au/seasonalclimateoutlook/southernoscillationindex/soidatafiles/MonthlySOIPhase1887-1989Base.txt

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Why do you figure te SOI will go positive again?

The model consensus shows pressures going back down quite a bit at Darwin and back up somewhat at Tahiti once past the weekend. That translates into a rising SOI per the formula. I don't yet have a projection on how high it will rise, but I can safely say it will rise a good bit from the -20's I'm projecting this weekend. The models suggest no return to solid negatives at least until after the first week in June.

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5 W avg. preceding May SOI +4.2 (range: +14.3 to -11.5)

4 M avg. preceding May SOI -9.7 (range: -5.6 to -13.8)

7 S avg. preceding May SOI -12.1 (range: -0.4 to -24.0)

So, only one of the 11 moderate to strong Nino's, 1965-6, had a preceding May SOI near the 5/12 SOI.

My point is that there is some predictive power from the May SOI, which is favoring a weak Nino peak over moderate or strong if there will be a Nino.

May ended up slightly lower than I projected (~-2 vs. ~-1 to 0)). Regardless, what I said above still stands. If there is going to be an El Nino this fall/winter, the ~-2 May 2012 SOI would favor weak Nino over moderate or strong.

Regardless, looking ahead there does appear to be a shot at several days of strong negatives (say sub -30) around 6/8-11 based on the 0Z Euro. Admittedly, the 0Z/6Z GFS runs didn't suggest that. However, the 12Z GFS is coming around toward the 0Z Euro's view. We'll see.

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The latest models have backed off and don't suggest any real strong negative SOI's in the near future. As long as this continues, the chances for a moderate or stronger El Nino this fall will continue to drop. Weak Nino is still very much on the table, however.

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1) As per previous posts, based on history, the May '12 SOI in combo with current SST's is favoring either a weak Nino or a neutral positive in my mind for the most likely fall/winter ENSO.

2) The May '12 OHC (180-100W) of +0.48 somewhat favors a non-strong El Nino over neutral with a Nina's chances being quite low. Here's why:

- The avg. OHC for May's preceding Nino's is +0.66

- The avg. OHC for May's preceding neutral is +0.16

- The avg. OHC for May's preceding Nina's is -0.77

- Of the 13 May's preceding neutrals, only two had a higher OHC than +0.48 (1980 and 1989)

- Of the 9 May's preceding Nina's, none had a higher OHC than +0.48 and 8 of the 9 were -.18 or more negative

- All 5 May's that preceded strong Nino's were +0.58+ (range +0.58 to +2.01). This is consistent with the idea based on the 5/12 SOI of -2.4 that a strong Nino is unlikely.

- The 4 May's that preceded moderate Nino's averaged +.24 (range +0.07 to +0.54). This, alone, tells me to consider moderate Nino as a possibility despite the 5/12 SOI suggesting only a small chance for moderate Nino.

- The only May that preceded a weak Nino was +0.30 fwiw (low stat. sig.).

3) Looking at the latest weekly 3.4 SST of 0.0 (as of May 16, 2012), it is cooler than all seven prior mid-May's preceding Nino's. Those seven: +0.6, +0.4, +0.7, +0.2, +0.4, +0.3, and +0.4. Average of +0.4. This, alone, tells me to favor neutral somewhat over Nino and not to eliminate even a Nina.

Conclusion: Based on a combo of the May SOI, the current weekly SST's, and the May OHC, I'd have to go with moderate Nino, weak nino, neutral positive, and neutral negative as the four most likely possibilities for this fall/winter with weak Nino and neutral positive continuing to have the highest chance as of now.

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  • 2 weeks later...

The eq. OLR near the dateline is pretty negative right now. Let's see if it remains that way. There is a correlation between -OLR and a developing El Nino.

This current MJO push means business...strong westerly burst around Nino 3, which would probably translate into significant warming of ENSO 3 and 3.4 regions

post-29-0-95632000-1339358354_thumb.png

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Folks,

Per the 0Z 6/19 GFS and Euro, the progged SOI is in the -50's for 6/25, which is a solid sign of an oncoming El Nino. This would be the most negative daily SOI since 2/6/2010. This very negative SOI prog is largely due to very high Darwin pressures. The progged Darwin SLP for 6/25 is for just over 1017 mb. IF it verifies at 1017 mb+, it would be the highest daily averaged Darwin SLP since all the way back on 6/23/2004! (That was during a developing weak El Nino.) By the way, the highest daily averaged Darwin SLP going back to 6/6/1991 was 1,018.35 mb, which was on 6/22/2004.

Edit: Based on progged SOI's, it appears that the June SOI will very likely verify more negative than -10. My guess is for -11 to -14, a pretty solid negative monthly SOI and a sign of a likely impending El Nino. We'll see.

As we get into July and August, the SOI will become more interesting as far as MDR tropical development potential is concerned. If it were to pull back into -5 to -10 range, the MDR would still have a decent shot at being fairly active tropically as we approach the peak of the Atlantic tropical season. However, if it were to remain sub -10, the prospects for an active MDR would diminish substantially.

Edit #2: The 12Z 6/19 Euro is even more negative with respect to next week's SOI's!

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