A UK Gale Index

I’ve developed yet another Windows weather application, one that I have been meaning to write for several years now, it analyses reported hourly wind speed and gusts in SYNOPSYNOP SYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting weather observations made by manned and automated weather stations. SYNOP reports are typically mad hourly and consist of groups of numbers (and slashes where data is not available) describing general weather information, such as the temperature, barometric pressure and visibility at a weather station. observations from WMOWMO The World Meteorological Organisation is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics. block #03, and produces a simple daily and hourly gale index [GIGI Gale Index] for all available stations below 250M, which usually ends up being around 150 sites across the UKUK The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. and Ireland. I’ve done it to see how viable it would be for an organisation, such as the UKMOUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy, to come up with an objective, rather than a subjective way of naming storms. The screenshot above shows a data grid of hourly GI in the main form, with daily and hourly data from the 26th of September up to the 21st of December 2023. I have now analysed all hourly SYNOP data back to 2015, which is the year naming storms commenced in the UK.

The GI itself is very simple, and is just the sum of the mean Beaufort force for each station plus half the Beaufort force of it’s highest gust, from all stations for that hour. I’ve found that from looking at all previous named storms that an index of 100 equates to a gale and 200 to a named storm event. You can see the seven named storms we’ve seen since the start of the 2023/24 season. Using these values as a guide I can easily list all the named storms. Some of these were named other Met Services other than the UKMO, and a couple of the storms were named for their heavy rain rather that strong winds.

This is where the fun starts, because as you can see Pia, a storm named by the DMIDMI The Danish Meteorological Institute is the national meteorological service for Denmark and Greenland. on the 21st of December, had a maximum hourly GI of 709 which is at least twice as high as any of the previous named storm so far this season. It was eventually named, but surprisingly not by the UKMO. If you look down the table you’ll also notice storm Ciaran only had a GI of 169, and using the 200 threshold for storms as a guide it should not have been named. There are plenty more named storms like Ciaran that just didn’t make the grade. There are also other times when a GI exceeded 200 but that didn’t result in a storm being named. On looking back I’ve found that this often occurs when a low affects Scotland, and I beleive it’s because the UKMO link the naming of storms with their NSWWSNSWWS The National Severe Weather Warning Service is a service provided by the Met Office in the United Kingdom. The purpose of this service is to warn the public and emergency responders of severe or hazardous weather which has the potential to cause danger to life or widespread disruption. This allows emergency responders to put plans into place to help protect the public and also allowing the public to make necessary preparations.. Usually, but not always, if they issue an amber warning a storm automatically gets named, sometimes a yellow warning is all that’s required outside Scotland, but because the threshold for an amber strong wind warning is 80 mph (or higher) rather than 70 mph for elsewhere in the UK, amber warnings are rarer in Scotland. That’s the reason why I believe the UKMO didn’t choose to name Pia.
The next logical step is to break down the GI regionally because that’s it weakness.
Below is a ranked list of all the named storms since 2015 and all the missed events. As you can see I have also assigned each named storn a category from one to five. Ciara, a category five storm, had the highest maximum GI of any of them. In third place you’ll notice is the Ross-shire (or the unnamed) storm of January 2015 which I’ve included because it occurred just before the naming of storm commenced.

This application is still WIPWIP Work In Progress so ignore the mean column for now I will get round to fixing it.

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