Identification of storm surge events over the German Bight from atmospheric reanalysis and climate model data

Atmospheric Science Letters

Wild

Kruschke

et al. 2016

NOAA 20th century and ERA-20C reanalysis datasets are evaluated regarding the representation of extra-tropical cyclones and windstorms over the Northern and Southern Hemisphere during the respective 6-month winter seasons. The results indicate substantial differences in low-frequency variability between the two datasets -especially in the first half of the 20th century -expressed in different signs and/or magnitudes of long-term trends. This is hampering a reliable analysis of real long-term trends of cyclone and windstorm activity. However, higher-frequency variability is in good agreement between both datasets especially for the Northern Hemisphere.

Section: Methodsmentioning

confidence: 82%

Different long‐term trends of extra‐tropical cyclones and windstorms in ERA‐20C and NOAA‐20CR reanalyses

Atmospheric Science Letters

Wild

Kruschke

et al. 2016

“…This algorithm has also been applied in previous studies (e.g. Renggli et al ., ; Nissen et al ., ; ; Befort et al ., ; Kruschke, ; Wild et al ., ; Befort et al ., ). Note that, due to using 12‐hourly 925 hPa wind speeds rather than 6‐hourly 10 m wind speeds, a reduction in the number of windstorm events is seen.…”

Section: Identification and Tracking Of Cyclones And Windstormsmentioning

confidence: 99%

Seasonal forecast skill for extratropical cyclones and windstorms

Quart J Royal Meteoro Soc

Wild

Knight

et al. 2018

Self Cite

Extratropical cyclones and their associated extreme wind speeds are a major cause of vast damage and large insured losses in several European countries. Reliable seasonal predictions of severe extratropical winter cyclones and associated windstorms would thus have great social and economic benefits, especially in the insurance sector. We analyse the climatological representation and assess the seasonal prediction skill of wintertime extratropical cyclones and windstorms in three multi-member seasonal prediction systems: ECMWF-System3, ECMWF-System4 and Met Office-GloSea5, based on hindcasts over a 20-year period (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011). Small to moderate positive skill in forecasting the winter frequency of extratropical cyclones and windstorms is found over most of the Northern Hemisphere. The skill is highest for extratropical cyclones at the downstream end of the Pacific storm track and for windstorms at the downstream end of the Atlantic storm track. We also assess the forecast skill of windstorm frequency by using the North Atlantic Oscillation (NAO) as the predictor. Prediction skill improves when using this technique over parts of the British Isles and North Sea in GloSea5 and ECMWF-System4, but reduces over central western Europe. This suggests that using the NAO is a simple and effective method for predicting windstorm frequency, but that increased forecast skill can be achieved in some regions by identifying windstorms directly using an objective tracking algorithm. Consequently, in addition to the large-scale influence of the NAO, other factors may contribute to the predictability of windstorm frequency seen in existing forecast suites, across impact-relevant regions of Europe.Overall, this study reveals for the first time significant skill in forecasting the winter frequency of high-impact windstorms ahead of the season in regions that are vulnerable to such events.

“…reanalyses or climate models (e.g. Befort et al 2015, Wild et al 2015, Befort et al 2016, Walz et al 2018, Befort et al 2019 given that it incorporates the model-specific wind speed climatology implicitly accounting for potential biases. This overcomes the need to use absolute thresholds for TC related windstorm detection and is one main difference to many TC detection algorithms (e.g.…”

Section: Introductionmentioning

confidence: 99%

Objective identification of potentially damaging tropical cyclones over the Western North Pacific

Kruschke

Leckebusch

2020

Environ. Res. Commun.

Self Cite

An impact-oriented objective windstorm identification algorithm (WiTRACK ), originally developed and well established for studies on extra-tropical storms, is further developed to identify damage and loss related Tropical Cyclones (TC) over the Western North Pacific. Results based on JRA-55 reanalysis data reveal that WiTRACK is able to detect the majority of strong events with hitrates of about 77%/90%/98% for TCs of the three most severe categories. Using economic loss data for China, it is found that especially events with large losses are associated with a windstorm event identified by WiTRACK. Past loss events successfully tracked by WiTRACK are associated with substantially higher losses than those events, not identified by WiTRACK. Thus, even though less skilful than traditional detection schemes if evaluated for the totality of TC events, WiTRACK is a powerful tool to identify severe, damage and loss-related TC events which additionally benefits from its simplicity and minimal input data demands. The latter may allow to apply WiTRACK to datasets not meeting the data requirements of more complex TC detection schemes.