Recent April circulation patterns

Figure 1

Another product that I can generate from my reanalysis application is a 4×3 grid of charts for monthly mean pressure and anomalies. Here are the circulation patterns for the last 12 years of April’s (2006-2017). If I ever do acquire a monitor that is larger than my Dell 24″, I may be able to pack more into a single screenshot! There is a broad similarity between 2015 and this April. April 2015 was the sunniest on record in many regions across the UK, and a comparison between it and the incomplete chart for this year show that although the mean pressure anomalies were not as large, the centre of the positive anomaly was further east at around 1° west (+7 hPa) rather than 10° west (+11 hPa) as it is this year (fig 1).

I’ve added extra functionality to the application to allow the selection of any area at any zoom level from around the world, as this example shows for Australia in 2016 (fig 2).

Figure 2

I’ve had a quick look at some of the results that I have generated and compared them with those from the IRICS, which is part of the Earth Institute, at the University of Columbia, and they seem to be in reasonable agreement, where they might not agree so well is when comparing monthly anomalies, because I use some extra long long-term averages when I calculate anomalies for my charts.

Figure 3 – Courtesy of the IRI

You may ask why I bother to write a bespoke application to do this when you can access anomaly charts from this great site, and my answer is, I have the time and resources, I love climate and weather maps, and because that’s what I do.

Author: xmetman

An ex-metman passionate about all things to do with weather, climate and clouds

One thought on “Recent April circulation patterns”

  1. Interesting that the most similar patterns produce very similar results. This year has been (so far) the driest since 2007.

    2007: 1.8mm
    2011: 3.3mm
    2017: 2.3mm (up to 0900 on 28th)