The Climatological Impact of Recurving North Atlantic Tropical Cyclones on Downstream Extreme Precipitation Events

Pohorsky, Roman; Röthlisberger, Matthias; Grams, Christian M.; Riboldi, Jacopo; Martius, Olivia (2019). The Climatological Impact of Recurving North Atlantic Tropical Cyclones on Downstream Extreme Precipitation Events. Monthly Weather Review, 147(5), pp. 1513-1532. American Meteorological Society 10.1175/MWR-D-18-0195.1

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This study provides the first climatological assessment of the impact of recurving North Atlantic tropical cyclones (TCs) on downstream precipitation extremes. The response is evaluated based on time-lagged composites for 146 recurving TCs between 1979 and 2013 and quantified by the area affected by precipitation extremes (PEA) in a domain shifted relative to the TC–jet interaction location, which often encompasses major parts of Europe. The statistical significance of the PEA response to the TCs is determined using a novel bootstrapping technique based on flow analogs. A statistically significant increase in PEA is found between lags +42 and +90 h after the TC–jet interaction, with a doubling of the PEA compared to analog cases without recurving TCs. A K-means clustering applied to the natural logarithm of potential vorticity fields [ln(PV)] around the TC–jet interaction points reveals four main flow configurations of North Atlantic TC–jet interactions. Two main mechanisms by which recurving TCs can foster precipitation extremes farther downstream emerge: 1) an “atmospheric river–like” mechanism, with anomalously high integrated vapor transport (IVT) downstream of the recurving TCs and 2) a “downstream-development” mechanism, with anomalously high IVT ahead of a downstream trough. Hereby, the analog bootstrapping technique separates the impact of the TC from that of the midlatitude flow’s natural evolution on the PEA formation. This analysis reveals an unequivocal effect of the TCs for the atmospheric river–like cases, while for the downstream-development cases, a substantial increase in PEA is also found in the analogs without a TC.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geography
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geography > Physical Geography > Unit Impact
08 Faculty of Science > Institute of Geography > Physical Geography

UniBE Contributor:

Pohorsky, Roman; Röthlisberger, Matthias and Romppainen-Martius, Olivia

Subjects:

500 Science > 550 Earth sciences & geology
900 History > 910 Geography & travel

ISSN:

0027-0644

Publisher:

American Meteorological Society

Projects:

[245] Mobiliar Lab für Naturrisiken Official URL

Language:

English

Submitter:

Hélène Christine Louise Barras

Date Deposited:

22 May 2019 09:17

Last Modified:

22 May 2019 09:17

Publisher DOI:

10.1175/MWR-D-18-0195.1

Uncontrolled Keywords:

Extratropical cyclones; Large-scale motions; Rossby waves; Extreme events; Precipitation

BORIS DOI:

10.7892/boris.130379

URI:

https://boris.unibe.ch/id/eprint/130379

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