La Nina chances

[Ken]

Yep, that's pretty much in line with most of the other guidance i.e. cooler than normal across the northern half of Australia and average to warmer than average across most of the southern half.

[Karl Lijnders]

Looks like the people at NOAA are suggesting La Nina (albeit a moderate event) to develop over the northern hemisphere fall (our spring) which could dramatically increase rainfall for our summer months.

Could be another summer of flooding rains and storms across northern and eastern Australia inlcuding VIC.

[Anthony Violi]

And yet i see the forecast for the next 12 months and its enough to vomit out my small intestines.

Given the climate is contuing to call, troughs are only going to get stronger again, as we will find out when we do it all again this Spring and summer. Warm water still sitting just East of OZ, all set up for another monstering.

[johnno]

JAMSTEC JULY RUN/FORECAST UPDATED TODAY

Dear Sensei and colleagues, Please find the monthly mean maps as attached below. Your comments are very appreciated. Best regards,Jing-Jia > Dear Sensei and colleagues,> > Please find the attached PDF for RIGC/JAMSTEC seasonal forecasts> initiated from 1 July 2011. > > Temporary highlights (to be finalized later):> > >

ENSO forecast: The current La Nina condition has finished during the> last month. Consistent with previous forecasts, our model> again shows that the La Nina condition would return back in> fall (Austral Spring) and persist out to 2012.> >

IO forecast: A weak positive IOD would occur in August to November> 2011; this may be related to current subsurface cooling condition> in the eastern equatorial Indian Ocean. Warmer-than-normal> sea surface temperature would persist west of Australia in> following seasons.> >

Regional forecast: Cool-wet condition in southern Africa would> return back late austral spring. Many parts of Australia would> have wet-cool condition during late austral spring to> summer. Southeastern China-western Japan would have a dry> condition in August but with above-normal Akisame (autumn> rain) in September. Northeastern China would have flooding> condition in August 2011. Most of India would have good> rains/flooding during late summer to fall associated with> the influence of La Nina and positive IOD.> > > > If you have any comments/suggestions/requests, please kindly inform> us. Thank you very much.> > Best regards,> Jing-Jia

[Karl Lijnders]

Enjoy the lull in rainfall while it lasts and drier air too!

[johnno]

Jamstec been bang on target so far.. August update of ENSO/IOD updated Today from Jamstec

Dear Sensei and colleagues, Please find the attached PDF for RIGC/JAMSTEC seasonal forecasts initiated from 1 August 2011. Temporary highlights (to be finalized later):

ENSO forecast: A La Nina condition is currently returning back; this has been correctly forecast since many months ago. An intermediate La Nina condition would occur late this year and persist out to 2012.

Indian Ocean forecast: A weak positive IOD would occur in boreal fall of 2011. Warmer-than-normal sea surface temperature would persist west of Australia in following seasons.

Regional forecast: Associated with the returning La Nina condition, cool-wet condition would occur in the southern Africa, Australia, and Brazil in following Austral summer. The La Nina would also help to reduce the surface temperature over many parts of the globe except the northern Eurasia and southern USA in following seasons. Wet/flooding condition would occur in Indonesia, India, the eastern Africa, and eastern China-Korea-western Japan during this boreal fall. If you have any comments/suggestions/requests, please kindly in form us. Thank you very much. Best regards,Jing-Jia.

Early days but Jamstec are now suggesting this could be a triple La Nina with La Nina conditions to persist right through 2012 I know its early days but gees its been spot on so far so something to keep an eye on.

[Pete]

Could someone please give me the link to Jamstec's reports please?

What a bummer - another La Nina. More flooding rains for northern WA and QLD? Increased cyclone activity?

On a better note - more severe thunderstorms in WA due to the warmer sea surface temperatures?

[Ken]

Hi Pete, here's the JAMSTEC link: http://www.jamstec.go.jp/frcgc/research ... st.html.en

Still a bit too early to tell for sure. Current consensus from latest guidance basically ranges from neutral to a weak-moderate La Nina. Tropical cyclone probability forecasts for the upcoming season will become available in the next couple of months. Below is the rainfall probability forecast from EC for Nov-Dec-Jan showing slight to moderate probabilities of wetter than normal conditions for parts of eastern Australia. However uncertainty is still a bit high because it partly depends on whether or not ENSO will dip into La Nina territory and also because it's 4 months out. EC is going for the wetter side of things while some others are going for more neutral rainfall:

[johnno]

Ken I think theres a good chance of happening infact we are in the start of the process of La Nina rebounding.. I agree won't be strong like 2010 but to me looks to be in the weak to moderate event stage if I had to guess right now by end of Spring into Summer. Easterlies have generally remain slighty above average across the Western and Central Pacific since June, no WWB since mid May which is a big help, 3.4 Nino has cooled half degree along in the past week or so infact most of the Pacific Equatorial has cooled the past fornight, sub-surface has anomalies up to -5c below normal! 30 day SOI after falling back to Neutral levels (around 0) in June have pushed back up in July +10.7 and generally holding around that mark so far for August.. All the indicators are there mate that we are in the process of swinging back to La Nina.. Jamstec has hardly put a foot wrong with its predictions the past 18 months.. Some of the other models seem to be more reactive rather than proactive and are responding to whats happening in the Pacific rather than forecasting at the moment especially NASA which is suppose to be 1 of the best models.. Up until June it was forecasting an El Nino and has suddenly taken a downward turn/change over the past month or 2 from El Nino to Cool Neutral/weak La Nina in a space of 1 month after it was saying El Nino all Year until June.

[johnno]

UNISY Map..

http://weather.unisys.com/surface/sst_anom.gif" onclick="window.open(this.href);return false;

Alot of cooling between 160w & 100w the past 2 weeks with all this area returning to blue and some of this area the blue has intensifed

[Ken]

The recent trends in the SST anomalies in the NINO regions (page 5 of 31) and upper ocean heat content (page 10 of 31) are particularly interesting:

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf

[johnno]

Here you go Pete...

http://www.jamstec.go.jp/frcgc/research ... index.html" onclick="window.open(this.href);return false;

Hope that helps

[johnno]

I don't think its a question of IF I think its more of a question of WHEN..

http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDYOC007.gif" onclick="window.open(this.href);return false;

Looks to be redeveloping and imminent