LA NINA!!

[rainstorm]

https://www.fnmoc.navy.mil/products/OTI ... nomaly.gif

[Wnghs2007]

YAY!!!!!!!!!!!!!!!!!!


Yes it does look like a week LA NINA has developed I hope that it last.

[Typhoon_Willie]

Interesting stuff indeed!

[weatherluvr]

We'll see if it lasts.

Another interesting feature is that the cold anomoly off the Northeast US is fading, and a warmer than average area is developing a little further offshore, in the Gulf Stream. Still cold temps off the Southeast coast, though.

[Matthew5]

Yes it doe's look like La nina is developing

[Derek Ortt]

Still a bit above normal in the 3.4 and 4 regions. However, this does look like the weak nina that formed in 2001 and we all know how devestating that season was for the NW Carib

[cycloneye]

As Derek said el nino area 3 is not cooled down to the point that may get to a full la nina creteria and that is the most important sector of the equatorial pacific to look at when ENSO forecasts are concerned and that area is from 120w to 160w.But being el nino 1-2 region west of South America very cool (Temps of -4C)that cancels what el nino 3 can do so I can say a weak la nina is there now although NOAA still is MUM about it but let's see in the next update later this month if they officlally declare la nina.

[wxman57]

I've been watching that cool area expand for months off the coast of S. America. Surely doesn't look even remotely like any El Nino this season.

[rainstorm]

if it persists, the season should be quite active

[Stormsfury]

if it persists, the season should be quite active

Actually, if it continues this trend and expands, the potential exists for more hurricanes to storms ratio ... and more majors ...

SF

[rainstorm]

very true

[Wnghs2007]

well it is very true that that will happen...I will be so excited...hehe

[USAwx1]

if it persists, the season should be quite active

Actually, if it continues this trend and expands, the potential exists for more hurricanes to storms ratio ... and more majors ...

SF

Lets also not forget a more active CV season. But for La Nina conditions to be acheived, anomalously cold SSTA must hold for at least 3 months over the Equatorial Pacific.

[Anonymous]

The difference between sea surface and subsurface temps from this time last year are not that significant. The western regions are slightly warmer and the east is slightly cooler this year.

[Windtalker]

Since I'm new, I have some questions....The last STRONG La Nina was in 1988 and we only had 10 named storms that year...one being "Gilbert" a monster...how can everyone say that in a La Nina year to expect more storms..I'm alittle confused but what else is new...Thanks http://www.erh.noaa.gov/bgm/lanina.html ftp://ftp.nhc.noaa.gov/pub/storm_archiv ... at/atl1988

[Guest]

Is it possible we're seeing a shift in the QBO? From easterly to Westerly??? Just wanted to ask to see what everyone had to say before I post the answer.

[Stormsfury]

Is it possible we're seeing a shift in the QBO? From easterly to Westerly??? Just wanted to ask to see what everyone had to say before I post the answer.

Actually, the QBO went WESTERLY in February of this year ... CDC hasn't updated the April numbers yet, but January 2004 was -4.61, followed by 2.61 monthly average in February ...

http://www.cdc.noaa.gov/Correlation/qbo.data

[rainstorm]

yikes. more majors

[MWatkins]

I have just a couple of additions to many of the points covered throught this thread...hard to refer to any one post with what I'm going to cover...so here goes:

We didn't have a cool ENSO event last year. If anything it was slightly warm during the key months, but nothing significant in terms of interference with the Atlantic season. The last significant Nina was 1999/2000 if I remember correctly.

I have not read any research to suggest that QBO and ENSO events are dependant on each other. Granted a warm ENSO creates increased vertical shear, it does so further down in the troposphere than the winds measured way up where the QBO index is determined.

In fact, in the last several years there are some good examples of a westerly (anomalous) QBO during the key months of the Atlantic season, and clunker Atlantic years (this is from the set of data Stormsfury posted yesterday):

http://www.cdc.noaa.gov/Correlation/qbo.data

2002: Nino Year, westerly QBO
1999: Nina Year, westerly QBO
1997: Biggest Nino ever observed, westerly QBO

In fact, if I remember correctly (and I have to, as the 1997 seasonal forecast from CSU is a dead-link right now) one of the reasons Gray had a big initial number for 1997 was a westerly QBO. This big deal is when these two (along with other factors) are in phase.

As far as I know, the theory is that westerly QBO is related to Atlantic hurricane intensity, but has nothing to do with the Nina/Nino circulation. (If anyone has any research contrary to this anywhere please post it here...I'd love to see it). In fact I don't recall Gray making such a big deal out of the QBO in the last few years...although it may still be a part of his predictor set.

The Atlantic basin is probably the most complex and least straight-forward basin for seasonal prediction. Atlantic dry air intrusion, susceptibility to SST fluctuations, Nina/Nino, and many other factors coming together at any one time make for lots of variance.

Also, and another critical note that I repeat all the time...April and May are by far the most difficult months to predict which way ENSO is going to go. By next month we should have a good idea. For example, although a nino was well on the way in 1997, the 1982 nino started out with a small but pronounced cold tongue in April/May before all heck broke loose.

MW

[Rainband]

Thanks everyone for your input on this situation