Summer 2023 [JJA] – Objective LWT

Summer started in a very anticyclonic mood with negative zonality (E’lies). The rot soon set in, and by the 19th of June the summer had turned when positive zonality (W’lies) was restored, and that’s basically where we’ve been since then. The meridional index has switched between spells of negative and positive, as it tends to do across our part of the world, and generally cyclonic. There were a couple of days with a gale index above the threshold of 30, but neither tie in with the named storms of Antoni (5 Aug) or Betty (18-19 Aug). 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, in their wisdom, decided not to name the deep low on the 15th of July that produced a GIGI Gale Index of 40.5, but I reckon it was the equal of either of the two that were named.

You may have noticed that I’ve put some work into smartening up the front end of my application that visualises objective LWTLWT Lamb Weather Types are often used in UK-based analyses, with individual weather patterns based on the eight primary cardinal directions (N, NE, E, SE, S, SW, W, NW) plus cyclonic (C), anticyclonic (A) and unclassified (U) types., the data for which I download from the CRU at the UEA. I’m quite proud of the app, and it works very well. I am so glad that the CRU have kept the objective series going after H.H.Lamb’s death in 1997. I do have the objective LWT algorithm, which I run on six hourly gridded reanalysis data in a seperate application as well , which gives a more detailed view of how weather types unfold.

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