For analogue #13 of Autumn 2018, we're going to be looking at the Autumns that followed on from the driest Summers on record back to 1910 in the UK and Ireland.
The 500mb height anomaly reanalysis for Autumn overall shows above average heights over Greenland and Iceland into Scandinavia whilst below average heights over much of the North Atlantic and to the Bay of Biscay. This looks like a very southeasterly to easterly Autumn which would be warm at first in September but get colder as the Autumn goes on because the source of air is from the continent which also cools its temperatures down through the Autumn season though varying year to year on how cool it would get due to how Northern Hemisphere atmospheric patterns work out.
The Septembers look strange as there is below average heights over top of us but above average heights are pretty much blocking any cold coming out of the pole just to the north. This leaves me to believe that the mean wind direction would be southeasterly which in September would be very warm but with the below average heights, also unsettled.
October looks anticyclonic with the centre of the above average heights just to the northwest of Ireland meaning it'd be a northeasterly sourced months. October looks chilly but dry.
November has above average heights over Greenland down into southeastern Europe. When you usually have above average heights over Greenland in November, it translates to cold conditions but the fact that these heights go all the way down to southeastern Europe causes the wind direction to come from a southerly to southeasterly direction which would be exceptionally mild. It also looks fairly unsettled with average heights over us and below average heights near the southwest of Ireland but not a washout by any means.
