AUTUMN UK MODEL OUTLOOK
So, I’m back with my long-range model discussions for the upcoming season: Autumn. We can say that summer has been a fairly good one this year, but will autumn disappoint? Let’s take a look at some of the models!
First thing is first; I am looking at the trends shown by the CFS V2 model monthly and weekly. As you probably remember, this is the American Model that gives long-range outputs. On the monthly outlook, I want you to notice that there is a ridge of above normal heights/pressure (yellow/orange) to the east or northeast. This has been a continuous trend through the members for a while now! A higher pressure in this area would suggest that the east would be drier and warmer, while the west of the UK would be more susceptible to an unsettled Atlantic attack!
It is also the same with the CFS V2 weekly forecasts, as we approach September, things seem to build to the east, further backing up this evidence! Much of these signals are what I expect to happen as I have seen these signals unfold.
Another model I look at is the JMA Monthly Seasonal model. This is the Japanese model and it certainly seems as if it is reading from the same book as the CFS V2.
Yet again, high pressure building to the east and northeast leaving warmer and drier conditions to the east!
As we look into the CFS V2 for October, we see that there is a trend through all members of some lower heights/lower pressure building over Greenland and the NW, with occasional higher pressure runs from the south. To me, this suggests an unsettled forecast for October, with more rainfall.
The JMA Seasonal Model as a whole looks also to display this trend!
The CFS V2 Model shows us a very interesting scenario in the latter members. It shows a possibility of a colder wind (maybe the continent). As you see, there is lower heights over western Europe that could indicate a colder wind from the East. However, in the previous runs it looks pretty unsettled from the west! This one is anyone’s game!
JMA Model presents higher pressure to the north and south but leaves a clear gateway for the Atlantic. Very uncertain trends, as per usual with LR Models.
Autumn as a whole (All Evidence Below)
- The JMA Model shows us an average of quite an unsettled 3 month mean.
- The Beijing Climate Model also shows an unsettled mean for 3 months.
- The Met Office Ensemble Mean shows a similar trend.
- A warm and significantly wetter JAMSTEC Model over 3 months would suggest an active Jetstream in the Autumn.
- The Russian model shows a warm and wet Autumn, along with the Brazilian Model
Summary from Model Suggestions
September: warmer and drier in the east of UK, higher pressure to the east.
October: Unsettled, lower pressure dominated. Take caution though.
November: Unsure, mixed signals.
3 Month Mean: Average of unsettled, warm and wet.
As I always sign off these discussions, this is not my forecast, it is a model discussion! Feel free to post your thoughts to me, I will soon be doing a September monthly forecast!
Cheers, take care!