The critical period for many has begun, many in SA are crying out for 1 decent drop of rainfall to take their crops along the line before harvest begins. Some are not wanting rainfall after being deluged in recent months. Some want the warmer weather to get the growth going, and these same people do not want to see a frost risk on the forecast.
All these elements are on the table, Spring is a notoriously tough time to forecast but there are drivers underpinning the forecasts that can give you some insights into what is heading our way.
Before I go on with my forecasts - the rule of thumb with weather, the further you go out in the distance, the less accurate the forecast. That rule applies at any weather agency. The models are limited by the one issue it cannot override, we are dealing with a natural science that sometimes changes from hour to hour!
CLIMATE OUTLOOK VIDEO
Rainfall Outlook for the next 6 weeks - MODERATE CONFIDENCE
% chance of exceeding rainfall for the next 6 weeks - September 15th to October 29th 2021.
Temperature Outlook for the next 6 weeks - MODERATE CONFIDENCE
%chance of exceeding rainfall for the next 6 weeks - September 15th to October 29th 2021
CLIMATE DRIVERS - More details can be found in the video blog.
Southern Annular Mode - Next 2 weeks - NEUTRAL
Indian Ocean - NEGATIVE - WET PHASE.
Some warming is ongoing over the basin northwest of WA which is expected to increase over the coming 4-6 weeks.
IOD - Modelling October
IOD - Modelling November
ENSO - NEUTRAL - HIINTS OF POSSIBLE LA NINA IN SUMMER.
3 out of the 7 global model agencies (1 of high reputation) suggesting a La Nina is developing this spring and summer, but more likely to remain neutral based off this data.
DATA - Refer to the video for notes on the below data sets.
Euro Rainfall Next 6 weeks - September 15th-October 29th 2021 - MODERATE CHANCE
Euro Rainfall Anomalies Next 6 weeks - September 15-October 29th 2021 - MODERATE CHANCE
GFS Rainfall Next 5 weeks - September 15th-October 22nd 2021 - LOW CHANCE
GFS Rainfall Anomalies Next 5 weeks - September 15th-October 22nd 2021 - LOW CHANCE
CMC Rainfall Next 4 weeks - September 15th-October 11th 2021 - MODERATE CHANCE
CMC Rainfall Anomalies Next 4 weeks - September 15th-October 11th 2021 - MODERATE CHANCE
CFS Rainfall Next 6 weeks - September 15th-October 29th 2021 - LOW CHANCE
CFS Rainfall Anomalies - OCTOBER - LOW CHANCE
CANSIPS Rainfall Anomalies - OCTOBER - MODERATE CHANCE
Euro Rainfall Anomalies - OCTOBER - HIGH CHANCE
Euro Temperature Anomalies - OCTOBER - MODERATE CHANCE
CFS Temperature Anomalies - OCTOBER - LOW CHANCE
CANSIPS Temperature Anomalies - OCTOBER - MODERATE CHANCE
Make sure you check back tomorrow with a look at the ENSO OUTLOOK AND DRIVERS UPDATE with fresh data looking into Spring and Summer - I will have another write up on that.