The latest data sets from the international climate agencies and research agencies have come through and not much change in the data sets for the remainder of Spring and Summer 2021/22.
La Nina chances have not increased in probability for the season ahead, however the duration of La Nina thresholds has increased and now takes us through to February so that is interesting and has been noted, however that does not make an event make.
I will also point out the risk of an El Nino in the first half of next year is near zero, (never anything absolute in weather). Though the chances of an El NIno will increase in the back half of next week which is to be expected after 1 to 2 La Nina events, but again something to watch in the next few months and I will have a look at that as we track through November and December.
THE LATEST DATA
Rainfall Outlook - IRC - October through December 2021
Again the theme for the north, southeast and east, wetter as we go through the season into Summer. The wettest phase between November and January at this time.
Temperature Outlook - IRC - October through December 2021
Rainfall Outlook - IRC - November to January 2022
Temperature Outlook - IRC - November through January 2022
Rainfall Outlook - IRC - December through February 2022
Temperature Outlook - IRC - December through February 2022
Rainfall Outlook - IRC - January through March 2022
Temperature Outlook - IRC - January to March 2022
CPC Outlook - September Plume
The models have shifted further under the neutral values and indicate a La Nina event is underway through October onwards. The one outlier, NASA, does have a moderate reputation, and has held the line of a major La NIna event slowly resolving through next year and all other models continue to swing towards that outlier, so perhaps the truth lay somewhere in the middle is the takeaway.
ENSO - Dynamic Model Plume Forecast/Observation
Follow the blue line and marry that to the models on the side bar, to see which have a good accuracy and which have not got good accuracy.
ENSO Statistical Models Predictions/Observations.
Again follow the models against the blue line to find the data sets that are closest to the post. There are many good models FSU and UCLA that have got good research and forecast models and they forecast significant La Nina conditions, it is possible but not certain.
The % of models suggesting the ENSO phase.
La Nina is better than average chance of occurring during the coming 6 months and this data set reflects most climate agencies globally. The event likely to persist into the first half of the year before it backs off during late Summer and Autumn which is normal. Note the El Nino risk is coming up in the late Autumn and Winter and that is nothing to be too concerned about right now, as that reflects the seasonal shift. The risk of El NIno is elevated based off analogues of past La Nina and cooler phases, and it would no surprise me if we are dealing with an El NIno phase in 2022/23.
SUMMER OUTLOOK - TO BE UPDATED NEXT WEEK
%chance of exceeding median rainfall for Summer 2021/22
%chance of exceeding median temperatures for Summer 2021/22
More details coming up on the ENSO into October when the next full data set is available but the take away is, no change at the mid month update to the chances of a La Nina. I do think we will have to factor in an event for the summer but it will be a matter of how strong is the event expected to be? No one can answer that at all.