For analogue #12 of Autumn 2018, we're going to be looking at El Niño Autumns that were preceded by La Niña Winters as 2017-18 was a weak La Niña season. When the NOAA 20th century reanalysis v2c generator begins to work again, we'll be looking at weak El Niño and moderate El Niño Autumns. We need to cover all possibilities as much as humanly possible!
The 500mb height anomaly reanalysis for Autumn overall looks very cold with northeasterlies being the dominant wind direction but also largely unsettled with a lot of above average heights over Greenland and Iceland.
The Septembers look identical to the reanalysis overall for Autumn with unsettled conditions and maybe fairly chilly. I say maybe because the alignment of the above average heights is a bit strange on this chart for September.
The Octobers look very anticyclonic with the above average heights from Greenland and Iceland ridging down to the UK and Ireland. Temperatures look fairly chilly as the wind would be from a northeasterly direction primarily. Reminds me of October 1993 in some ways which was a wet month over England & Wales along with eastern regions of Ireland from some heavy rain early in the month but it became anticyclonic for much of the period after the second week with.... *get this*... severe frosts developing. That sounds unusual to say about October I know but October 1993 really was cold thanks to the frosts and the alignment of the anticyclone in a similar position to how the below reanalysis shows.
In contrast to October, November signals an exceptionally wet and stormy pattern below. 2009 is in the analogue and the reanalysis gives striking comparisons to November 2009 which if you did not know was the wettest November on record for many places and featured record breaking floods to parts of Ireland and Cumbria.
Comments