Abstract
ABSTRACTWeather‐pattern, or weather‐type, classifications are a valuable tool in many applications as they characterize the broad‐scale atmospheric circulation over a given region. This study analyses the aspects of regional UK precipitation and meteorological drought climatology with respect to a new set of objectively defined weather patterns. These new patterns are currently being used by the Met Office in several probabilistic forecasting applications driven by ensemble forecasting systems. Weather pattern definitions and daily occurrences are mapped to Lamb weather types (LWTs), and parallels between the two classifications are drawn. Daily precipitation distributions are associated with each weather pattern and LWT. Standardized precipitation index (SPI) and drought severity index (DSI) series are calculated for a range of aggregation periods and seasons. Monthly weather‐pattern frequency anomalies are calculated for SPI wet and dry periods and for the 5% most intense DSI‐based drought months. The new weather‐pattern definitions and daily occurrences largely agree with their respective LWTs, allowing comparison between the two classifications. There is also broad agreement between weather pattern and LWT changes in frequencies. The new data set is shown to be adequate for precipitation‐based analyses in the UK, although a smaller set of clustered weather patterns is not. Furthermore, intra‐pattern precipitation variability is lower in the new classification compared to the LWTs, which is an advantage in this context. Six of the new weather patterns are associated with drought over the entire UK, with several other patterns linked to regional drought. It is demonstrated that the new data set of weather patterns offers a new opportunity for classification‐based analyses in the UK.
Highlights
Weather pattern classifications are useful for characterizing the broad-scale atmospheric circulation over a given region and time-scale
WP9 is anticyclonic, it is hard to discern from Figure 1 why it is linked with more precipitation in western regions as there is no indication of flow direction
This study demonstrates the applicability of a new set of 30 weather patterns to UK precipitation and meteorological drought analyses, and its advantages compared to Lamb weather types (LWTs)
Summary
Weather pattern classifications ( called weather types, circulation types or circulation patterns) are useful for characterizing the broad-scale atmospheric circulation over a given region and time-scale (often daily; Huth et al, 2008). Two of the most well-known European examples are the Grosswetterlagen (GWL; Hess and Brezowsky, 1952) and the Lamb weather types (LWTs; Lamb, 1972; Jenkinson and Collison, 1977). These classifications are intended to be used for many different applications, whereas some studies develop their own problem-specific classification system (Bárdossy and Filiz, 2005; Philipp et al, 2007; Casado et al, 2009; Prein et al, 2016). A comprehensive review of weather pattern classifications and applications was provided by Huth et al (2008)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
