As is often the case with August, it’s been the most changeable and most influenced month by the tropics. Again though, high pressure and warmth has been a mainstay for the most part despite cool, unsettled start and finish.
The presence of Ex-Tropical Storm Dexter, helped produce summer’s 4th heatwave with widespread record heat from Spain to Germany. Some stations with a long period of record witnessed their hottest day on record while the North of England and Scotland’s sweated their hottest August day in 22 years.
Upper heights from 1-20th Aug.
The month commenced the Storm Floris on the 4th and shall end at least unsettled, possibly stormy thanks to the remnants of Tropical Storm Fernand.
While confidence is relatively high for a trough dominated first 10 days of September with a series of lows developing within a deep upper trough and sweeping across UK/Ireland/France, there’s increasing model suggestion for high pressure making a comeback towards mid month and potentially holding beyond over or perhaps just west of UK/Ireland.
CFSv2 weeklies show this.
This suggests something warmer, drier and sunnier BUT the 30-day below shows a UK trough in the means through Sept 27th, albeit potential always for fluctuation in between. Will also depend on tropical activity and potential for recurves which can boost high and low pressure over WE.
Wet start, drier mid… but late month??
Cool to warm?
It will be interesting to see the month whether a cool first half beats a warmer 2nd or will it balance out?
Have we a 5th heatwave of 2025 or are we done with 30C+ in England, Wales and 26C+ Scot, NI, ROI? My hunch is we are done with any ‘significant’ heat…
It will be worth watching the combination of a low pressure dominated first half to Sept and unusually warm surrounding seas. … Sure, wetter than average but how wet would be the question and will the warmer than average waters fuel more rain?
Tropical activity and MJO go somewhat hand in hand but if we see a return to phases 1-2 which support a more favourable Atlantic, this could also support a -NAO.
A return to ridging sure but ‘where’. Over, east or west of UK will prove important to temperature.
I have always believed in La Nina driving an overall drier Europe while wetter with El Nino. Remember on the back end of the previous El Nino the very wet 10-12 month period while the most recent 10-12 months following La Nina has been opposite. Of course there is month-by-month variation but there’s certainly a trend when looking long term.
Interesting to see GFS Ens, ECM & CFSv2 all with a trough over UK & Ireland 27 Aug-27 Sept…
With a lean towards wetter. Keep in mind the warm surrounding waters…
While I can’t see any significant tropical activity within the next 2 weeks, one cannot rule out a ramp up in activity mid to late month. If we see further recurves then those WILL LIKELY INFLUENCE OUR WEATHER for better or worse. So, trough to start followed by ridge middle means a big ? beyond say the 18/20th.
The Verdict…
Cooler, wetter, more unsettled first half with drier, more settled second half for MUCH of UK & Ireland. Average to below average temperatures. Warmer, drier Iberia, France, Italy into E/SE Europe
Recent Comments