Has the NINA Peaked?

[mitchnick]

If it hasn't, it certainly has taken a well needed break. Weekly Sea Surface Temps have been rising in all areas since mid-October except 1+2 which fell and then have risen. Its the most unstable of ENSO regions so this does not bother me with my thought. Here are the weekly Sea Surface Temp Anomalies since early October:

ENSO 1+2 3 3.4 4

06OCT2010 18.7-2.1 23.2-1.7 24.8-1.8 27.1-1.4

13OCT2010 18.9-2.0 23.0-1.9 25.1-1.5 27.1-1.3

20OCT2010 19.1-1.9 23.2-1.7 25.1-1.5 27.0-1.4

27OCT2010 19.8-1.4 23.6-1.4 25.2-1.4 27.0-1.4

03NOV2010 19.7-1.7 23.4-1.6 25.2-1.3 27.0-1.4

10NOV2010 19.5-2.0 23.5-1.5 25.2-1.3 27.2-1.2

While at the same time, these have been the anomalous 850 winds

Considering how much temp anomalies have been drifting back toward 0 since October 17 as depicted on the above map and also considering the 850 temp anomalies that occurred that still resulted in the warming, it seems reasonable to believe ENSO regions 3, 3.4 and 4 will continue to warm in the coming week(s) with the forecast also shown on that map.

Also, the TAO map depiction has warmed considerably. Anomalies have been moving toward 0 in areas between ENSO 3 and 4 that were near or greater than -2C. Here's the map:

And finally, below is a link to the TAO site map of sub-surface temps 11/1 through 11/14. Note on the top map (actual water temps) how the warmer waters on the far left side of the screen are moving to the right (eastward toward the dateline) and how the Anomaly map (on thebottom) is showing the greater than -1C waters dissipating all around and west of the dateline (180 degrees).

http://www.ncdc.noaa...14&endyear=2010

Will it continue? I don't know, but it certainly suggests that the mega NINA feared 6-8 weeks ago is out of the picture and maybe, just maybe, we can get this NINA down below -1C in ENSO 3.4.

OK mets, your thoughts?

[Ender]

There's also been considerably warming, though still not into anomalously warm readings, off the WA/OR/NCAL coasts and back towards the Aleutians. Interesting if nothing else.

[usedtobe]

If it hasn't, it certainly has taken a well needed break. Weekly Sea Surface Temps have been rising in all areas since mid-October except 1+2 which fell and then have risen. Its the most unstable of ENSO regions so this does not bother me with my thought. Here are the weekly Sea Surface Temp Anomalies since early October:

ENSO 1+2 3 3.4 4

06OCT2010 18.7-2.1 23.2-1.7 24.8-1.8 27.1-1.4

13OCT2010 18.9-2.0 23.0-1.9 25.1-1.5 27.1-1.3

20OCT2010 19.1-1.9 23.2-1.7 25.1-1.5 27.0-1.4

27OCT2010 19.8-1.4 23.6-1.4 25.2-1.4 27.0-1.4

03NOV2010 19.7-1.7 23.4-1.6 25.2-1.3 27.0-1.4

10NOV2010 19.5-2.0 23.5-1.5 25.2-1.3 27.2-1.2

While at the same time, these have been the anomalous 850 winds

Considering how much temp anomalies have been drifting back toward 0 since October 17 as depicted on the above map and also considering the 850 temp anomalies that occurred that still resulted in the warming, it seems reasonable to believe ENSO regions 3, 3.4 and 4 will continue to warm in the coming week(s) with the forecast also shown on that map.

Also, the TAO map depiction has warmed considerably. Anomalies have been moving toward 0 in areas between ENSO 3 and 4 that were near or greater than -2C. Here's the map:

And finally, below is a link to the TAO site map of sub-surface temps 11/1 through 11/14. Note on the top map (actual water temps) how the warmer waters on the far left side of the screen are moving to the right (eastward toward the dateline) and how the Anomaly map (on thebottom) is showing the greater than -1C waters dissipating all around and west of the dateline (180 degrees).

http://www.ncdc.noaa...14&endyear=2010

Will it continue? I don't know, but it certainly suggests that the mega NINA feared 6-8 weeks ago is out of the picture and maybe, just maybe, we can get this NINA down below -1C in ENSO 3.4.

OK mets, your thoughts?

The 850 winds have been light recently so there hasn't been much upwelling. Look at the forecast easterly winds that are forecast. Looks to me like we'll have another period of cooling later this month especially after the 20th.

[CT Rain]

The 850 winds have been light recently so there hasn't been much upwelling. Look at the forecast easterly winds that are forecast. Looks to me like we'll have another period of cooling later this month especially after the 20th.

Yeah, if that forecast is right we're back to the upwelling and more cooling. We'll see if the models keep delaying the onset of the stronger trades.

[nzucker]

The 850 winds have been light recently so there hasn't been much upwelling. Look at the forecast easterly winds that are forecast. Looks to me like we'll have another period of cooling later this month especially after the 20th.

Also, most of the warming came during the MJO/+AAM bursts, not from the periods when the trade winds were occurring as the OP claims. The ENSO regions appear warmer currently because we just had a strong MJO wave that set off westerly wind bursts across most of the area, which you can see from the Albany u-wind forecast chart. The period of low AAM activity this summer created intense ENSO cooling; now that we're headed back to that regime with an incoherent signal from the MJO, I would imagine cooling will begin again. The subsurface is about as cold as it has ever been, and AAM has totally tanked in the last few weeks, which should serve to strengthen the La Niña.

[VAwxman]

The subsurface is about as cold as it has ever been,

I don't know about that part. Per TAO site there is a very small -4C bubble now. There was a huge -4C area and even some -6C bubbles at times 2-3 months ago. But I agree the upcoming pattern should lead to some cooling.

[nzucker]

There's also been considerably warming, though still not into anomalously warm readings, off the WA/OR/NCAL coasts and back towards the Aleutians. Interesting if nothing else.

Hmm?

11/11 SSTs:

11/14 SSTs:

It looks to me as if the main warm pool, the one around 130W and 35N, actually dissipated during this time period. There were some warm waters that surfaced right along the immediate coast, but that's literally a tiny area when compared to the overall trend. Given the forecasted Aleutian ridge and Pac NW trough, expect a more -PDO configuration to become apparent in the next week. The waters near the Aleutians should warm as the warm pool in the West Pacific expands northeast, and the waters near the immediate coastline should cool significantly.

[nzucker]

I don't know about that part. Per TAO site there is a very small -4C bubble now. There was a huge -4C area and even some -6C bubbles at times 2-3 months ago. But I agree the upcoming pattern should lead to some cooling.

The NOAA map at 55m still shows a large pool of -5C anomalies, and it looks to be about as cold as it was this summer:

[mitchnick]

The 850 winds have been light recently so there hasn't been much upwelling. Look at the forecast easterly winds that are forecast. Looks to me like we'll have another period of cooling later this month especially after the 20th.

Wes, like I said in my original post, there have been a decent amount of Trade winds since October 17, but the SSTA have risen during the period in ENSO 3-4. Actually, when I saw the 850 anomaly map this morning, I figured if it could warm .2C since 10/13 with those anomalies there should be at least continued warming with the forecast period anomalies. But, maybe my bias is getting the better of me.

[nzucker]

Wes, like I said in my original post, there have been a decent amount of Trade winds since October 17, but the SSTA have risen during the period in ENSO 3-4. Actually, when I saw the 850 anomaly map this morning, I figured if it could warm .2C since 10/13 with those anomalies there should be at least continued warming with the forecast period anomalies. But, maybe my bias is getting the better of me.

Yes this is a very good point, Mitch. We've seen some impressive trade bursts, but the ENSO state hasn't really changed much. I think the missing variable, however, is the MJO. We had two significant MJO waves in late October and November which reversed the effect of the dominant easterly winds, allowing warmer surface waters from Indonesia to cover up the cold anomalies in the ENSO areas. You can see that the AAM this fall was highly unusual for a strong La Niña, and now it's reverting back to the expected state. I think the combination of -AAM/-PDO means that we'll see both stronger upwelling and more enhancement of the California current which might help the Niña as well. Interesting times ahead.

Regardless of the ENSO strength, the SE ridge is already making itself patently apparent.

[mitchnick]

Yes this is a very good point, Mitch. We've seen some impressive trade bursts, but the ENSO state hasn't really changed much. I think the missing variable, however, is the MJO. We had two significant MJO waves in late October and November which reversed the effect of the dominant easterly winds, allowing warmer surface waters from Indonesia to cover up the cold anomalies in the ENSO areas. You can see that the AAM this fall was highly unusual for a strong La Niña, and now it's reverting back to the expected state. I think the combination of -AAM/-PDO means that we'll see both stronger upwelling and more enhancement of the California current which might help the Niña as well. Interesting times ahead.

Regardless of the ENSO strength, the SE ridge is already making itself patently apparent.

being in the MA, if there was no SE Ridge, what would I biatch about then?

[atownwxwatcher]

SE Ridge does not seem to apparent thru the first 15 days of November...

October however was a different story...

[usedtobe]

Yes this is a very good point, Mitch. We've seen some impressive trade bursts, but the ENSO state hasn't really changed much. I think the missing variable, however, is the MJO. We had two significant MJO waves in late October and November which reversed the effect of the dominant easterly winds, allowing warmer surface waters from Indonesia to cover up the cold anomalies in the ENSO areas. You can see that the AAM this fall was highly unusual for a strong La Niña, and now it's reverting back to the expected state. I think the combination of -AAM/-PDO means that we'll see both stronger upwelling and more enhancement of the California current which might help the Niña as well. Interesting times ahead.

Regardless of the ENSO strength, the SE ridge is already making itself patently apparent.

Good post, With the GLAAM back in negative territory and another fairly strong burst of trade winds expected, it sure seems like the temps will cool again. As for the southeast ridge not being apparent the 1st half of November, it's not supposed to be. That's pretty typical of a nina.

[tacoman25]

SE Ridge does not seem to apparent thru the first 15 days of November...

October however was a different story...

Pretty typical. SE ridge doesn't usually start to assert itself prominently until sometime in late Dec/early Jan during Ninas.

EDIT: I see Usedtobe just said basically the same thing.

[VAwxman]

SE Ridge does not seem to apparent thru the first 15 days of November...

October however was a different story...

It wasn't that stout in Oct either really, but that happens sometimes in fall and early winter in ninas. It is interesting how mild Oct turned out in the east though despite these upper air anomalies.

[HKY_WX]

I think we've peaked overall. That doesn't mean there will not be more cooling episodes, as ENSO wax's and wane's. But IMO the peak has been reached on the MEI and this goes pretty well with the ENSO dynamical/statistical models.I think what will be interesting for winter is just how fast it breaks down.

[tacoman25]

I think we've peaked overall. That doesn't mean there will not be more cooling episodes, as ENSO wax's and wane's. But IMO the peak has been reached on the MEI and this goes pretty well with the ENSO dynamical/statistical models.I think what will be interesting for winter is just how fast it breaks down.

Doesn't MEI usually peak before ONI anyway?

[skierinvermont]

The 850 winds have been light recently so there hasn't been much upwelling. Look at the forecast easterly winds that are forecast. Looks to me like we'll have another period of cooling later this month especially after the 20th.

But look at the chart he posted... we've had 3 such bursts which look even stronger than the upcoming one and we warmed during that period.

[usedtobe]

But look at the chart he posted... we've had 3 such bursts which look even stronger than the upcoming one and we warmed during that period.

That's a good point, We'll see.

[skierinvermont]

Yes this is a very good point, Mitch. We've seen some impressive trade bursts, but the ENSO state hasn't really changed much. I think the missing variable, however, is the MJO. We had two significant MJO waves in late October and November which reversed the effect of the dominant easterly winds, allowing warmer surface waters from Indonesia to cover up the cold anomalies in the ENSO areas. You can see that the AAM this fall was highly unusual for a strong La Niña, and now it's reverting back to the expected state. I think the combination of -AAM/-PDO means that we'll see both stronger upwelling and more enhancement of the California current which might help the Niña as well. Interesting times ahead.

Regardless of the ENSO strength, the SE ridge is already making itself patently apparent.

Isn't the whole point of the MJO waves that they decrease the wind anomalies? And yet we had large wind anomalies in October and the upcoming trade burst if anything looks weaker than the last 3.

Btw the wind anomalies in October were just as large as in September when the Nina was strengthening.

Personally I am beginning to think that either there is some variable we are missing besides the winds (because the winds seem to have been favorable for strengthening), or that we would just need some massive winds to get this to strengthen more. Maybe because of (A)GW -1.6 is the new -1.9.

[nzucker]

It wasn't that stout in Oct either really, but that happens sometimes in fall and early winter in ninas. It is interesting how mild Oct turned out in the east though despite these upper air anomalies.

I think the GoA low prevented any arctic air from making the trip to the East Coast despite the lower than normal 500mb heights. We also have to take into account that global temperatures are very high following the strong El Niño, with heat migrating from the tropics to the mid-latitudes, so that mutes any colder signal from the jet stream.

But look at the chart he posted... we've had 3 such bursts which look even stronger than the upcoming one and we warmed during that period.

Yes, but those all took place during a period of high GLAAM which allowed for MJO waves to cancel out any cooling effect. We were cooling during the last trade burst until the winds turned westerly and muted the effect of the trades. The trades were strongest between November 1st and November 6th, and look at the change in the ENSO as per NOAA, major cooling:

11/1 SSTs

11/4 SSTs

Trade burst at the same time:

[skierinvermont]

Yes, but those all took place during a period of high GLAAM which allowed for MJO waves to cancel out any cooling effect. We were cooling during the last trade burst until the winds turned westerly and muted the effect of the trades. The trades were strongest between November 1st and November 6th, and look at the change in the ENSO as per NOAA, major cooling:

You are contradicting yourself.. you are saying that the GLAAM and the MJO made the high trade winds not high trade winds (not possible - high trade winds are high by definition). Except we did have high trade winds in October.. as high as September and both months were as high as they have been for this whole event (higher than they were in the spring or summer).

And as I've pointed out before.. the largest and most decisive warming in ENSO occurred during a large trade wind burst.

[weatherweather]

What are the implications for NE/MA winter if it has peaked vs still cooling?

[nzucker]

You are contradicting yourself.. you are saying that the GLAAM and the MJO made the high trade winds not high trade winds (not possible - high trade winds are high by definition). Except we did have high trade winds in October.. as high as September and both months were as high as they have been for this whole event (higher than they were in the spring or summer).

Huh?

No, I'm saying that the GLAAM and MJO allowed for interruption of the trade winds with strong westerly wind bursts that disrupted the cooling.

Also, I'm not sure if the only effect of +AAM on the Niña is to weaken the trades/initiate westerly wind bursts.

Finally, having a weak PDO signal might have an effect by not allowing colder waters from the north to be fed into the Niña via the California current. It seems we're finally headed towards a true -PDO pattern and eliminating those pesky warm SSTs near Central America. Unisys shows that area is one of the fastest cooling.

[skierinvermont]

No, I'm saying that the GLAAM and MJO allowed for interruption of the trade winds with strong westerly wind bursts that disrupted the cooling.

Except the trade winds were relatively strong and persistent compared to any other month of the Nina thus far.

[nzucker]

Except the trade winds were relatively strong and persistent compared to any other month of the Nina thus far.

Yes, but what about the interruption with westerlies?

Was that happening equally during the summer when we had a much lower AAM?

I don't see any reason it wouldn't be cooling with strong trades and a cold subsurface other than the AAM/MJO and potentially the PDO.

[ORH_wxman]

What are the implications for NE/MA winter if it has peaked vs still cooling?

More likely to see a cold pattern in late February or March if the cooling is over. ENSO will have little affect on winter after the next few weeks as it will then be out of that time range and into the affecting the spring pattern....most of the damage has been done WRT the winter pattern from ENSO's influence.

[skierinvermont]

I don't see any reason it wouldn't be cooling with strong trades and a cold subsurface other than the AAM/MJO and potentially the PDO.

Again.. you are contradicting yourself I believe. The whole point of the MJO and AAM is their effect on the trade winds. If you have strong trade winds.. it doesn't matter what the MJO/AAM are doing (unless there is some other mechanism where they effect ENSO besides via trade winds).

[nzucker]

Again.. you are contradicting yourself I believe. The whole point of the MJO and AAM is their effect on the trade winds. If you have strong trade winds.. it doesn't matter what the MJO/AAM are doing (unless there is some other mechanism where they effect ENSO besides via trade winds).

No I am not...stop arguing with me just for the sake of it.

If the +AAM causes westerly wind bursts to interrupt the trades, that is a mechanism in and of itself. Even if the trades are strong, a few days of westerly winds bringing warm waters from the high SST pool near Indonesia can disrupt the event. We have had two periods of strong MJO bursts/+AAM since mid-October, and that's why it's not cooling more. Period.

[skierinvermont]

Was that happening equally during the summer when we had a much lower AAM?

There were more interruptions with weaker trade winds over ENSO regions during June and July than in September. From the chart I am looking at I would rate August and October as the two months with the strongest most persistent trade winds, followed by September, then June and July. Probably the biggest burst occurred in late August and carried over into the first couple days of September.