User guide
Context
This tool was built to understand the return period of strong and extreme wind gusts
across the UK's current synoptic observation network (METAR-only airfield sites are
excluded). A gust of a given strength means very different things at different sites -
a 70kt gust is unremarkable at an exposed mountain summit or coastal site but exceptional
at a sheltered inland location. Expressing gusts in terms of their return period, rather
than their raw speed, gives a like-for-like way to compare how extreme a given gust really
was at the site where it occurred.
Data
Wind data is MIDAS Open QC'd observations from CEDA. Despite CEDA's own quality control,
some false readings remain in the archive - the page author has investigated and filtered
out several specific oddities found during development. The recent extreme gust tables
below are a good way to sanity-check any single site's most extreme recent readings for
yourself.
Method
A peaks-over-threshold / Generalized Pareto Distribution model is fitted per site, using
each site's own 95th percentile of daily maximum gust as its threshold. Return level curves
are shown with a 95% confidence interval, available for return periods of 1 year or more
only.
Maps
Two modes are available, toggled in the sidebar: "Return period for a gust speed" (pick a
gust threshold, colours show how often it's exceeded at each site) and "Gust speed for a
return period" (pick a return period, colours show the expected gust speed at each site).
Click any station to load its detail plot below.
Plots
Use the checkboxes to add or remove the Annual, Summer (April to September), and Winter
(October to March) curves. These periods are offset from standard seasons to better match
the period when deciduous trees are in leaf across England and Wales (with tree fall leading
to many impacts). Hover the plot for exact values; use the toolbar above the plot (or the
Save PNG button) to save an image.
Disclaimer
This is a non-operational site. Despite using the QC'd data available from the UK Met
Office, analysis suggests some erroneous values remain present in the dataset - the author
has manually found and filtered out numerous such values. Please treat all information shown
as for guidance only, and refer to the Met Office's official channels for definitive
information.
Feedback
Please feel free to pass on any feedback and suggestions to
nick.silkstone@gmail.com.