The gridded weather typing classification version 2: A global‐scale expansion

Abstract

AbstractSynoptic climatology uses classifications of atmospheric data to relate the larger‐scale atmosphere to surface‐based responses. One of the two primary modes of classification is the weather typing classification, whereby the multivariate surface‐based meteorological conditions at an individual location are categorized into a daily weather type (WT), and this methodology is then iterated at numerous locations within the domain in order to identify synoptic‐scale air masses. One such classification that was recently developed is the gridded weather typing classification (GWTC) for North America. The current research describes the extension of this GWTC methodology, and dataset, to the global scale, along with a number of other key updates. Using data from the Climate Forecast System, the global GWTC (GWTC‐2) classifies every day from 1979 to present into one of 11 intuitive weather types. With half‐degree spatial resolution, this results in over 259,000 global locations and more than 3.7 billion location/days currently classified, with another 7–8 million added each month. Updates to the GWTC methodology also allow for the identification and visualization of more extreme weather types compared to the previous version, and the extension of the classification over the global ocean will allow for new oceanographic applications.