About this site

I started this website just for fun, because I made a few plots I wanted to share with the world in a better way than me just irregularly tweeting them. Because I didn’t set up the site with a specific plan in mind, it’s a mix between a front-end WordPress site and a back-end University of Reading site where the files and image loops are stored. Maybe one day I’ll find the time to turn it into something more coherent.

Please feel free to use and share any images from this site on social media or elsewhere, with credit where appropriate. If you experience any issues with the site, or have any suggestions, please contact me (the easiest way is to tweet me). Thanks for visiting!

About the data processing

The data are retrieved from the NCEP NOMADS server. Issues with NOMADS may cause problems with data updates; unfortunately these are more frequent than they should be. The data analysis is performed on the Reading Academic Computing Cluster (RACC) at the University of Reading, primarily using Python. Issues with the RACC or other university IT services may interfere with what is shown on this website. Check the status of the website below for known issues.

About the forecast models

This site uses the 00Z runs of the NCEP Global Forecast System (GFS) and Global Ensemble Forecast System (GEFS) retrieved on a 0.5° grid. The former is a deterministic model run out to 16 days, while the latter is a 31-member ensemble run out to 35 days (as of the implementation of GEFSv12 on 23 September 2020).

The NCEP Climate Forecast System version 2 (CFSv2) became operational in March 2011. In raw form, it is run as a 4-member ensemble 4 times per day. Typically, this is turned into a time-lagged 16-member ensemble, i.e. today’s 00Z initialisations are combined with the 06, 12, and 18Z initialisations from yesterday. Following the style used in the S2S database, the subseasonal stratosphere forecasts shown here run out to 44 days using a time-lagged 16-member ensemble. Bias correction is applied for forecasts initialised during November-March inclusive, whereby the difference between the 1999-2010 model hindcast climate and ERA5 reanalysis is subtracted. The 4-weekly 500 hPa anomalies use a 16-member ensemble (1 day, 4 runs of 4 members), while the 6-monthly 700 hPa anomalies use a 40-member ensemble (10 days of 4 members).

Site status

This page will be updated manually when I am aware of problems with the site.

2022-01-17 1006 EST: Site updated and functioning normally following server issues. Thanks for your patience.

2021-11-29: I now work at Columbia University, whilst the processing and plotting underpinning this site is still taking place at the University of Reading. As a result, it is not guaranteed in the long-term. I will work on a solution soon.

Change log

2021-12-29: Reorganised menus and tidied up the site. Eddy heights & waves plot now shows eddy heights, 60N zonal wind as a function of pressure, and wavenumber amplitudes in a simple 3-panel figure.