Modes of hurricane activity variability in the eastern Pacific: Implications for the 2016 season

Abstract

A gridded product of accumulated cyclone energy (ACE) in the eastern Pacific is constructed to assess the dominant mode of tropical cyclone (TC) activity variability. Results of an empirical orthogonal function decomposition and regression analysis of environmental variables indicate that the two dominant modes of ACE variability (40% of the total variance) are related to different flavors of the El Niño–Southern Oscillation (ENSO). The first mode, more active during the later part of the hurricane season (September–November), is linked to the eastern Pacific El Niño through the delayed oceanic control associated with the recharge‐discharge mechanism. The second mode, dominant in the early months of the hurricane season, is related to the central Pacific El Niño mode and the associated changes in atmospheric variability. A multilinear regression forecast model of the dominant principal components of ACE variability is then constructed. The wintertime subsurface state of the eastern equatorial Pacific (characterizing ENSO heat discharge), the east‐west tilt of the thermocline (describing ENSO phase transition), the anomalous ocean surface conditions in the TC region in spring (portraying atmospheric changes induced by persistence of local surface anomalies), and the intraseasonal atmospheric variability in the western Pacific are found to be good predictors of TC activity. Results complement NOAA's official forecast by providing additional spatial and temporal information. They indicate a more active 2016 season (~2 times the ACE mean) with a spatial expansion into the central Pacific associated with the heat discharge from the 2015/2016 El Niño.

Air‐sea fluxes for Hurricane Patricia (2015): Comparison with supertyphoon Haiyan (2013) and under different ENSO conditions

“…This paper confirms and supplements recent studies on the dominant control of oceanic subsurface properties on the modulation of TC intensity in the Eastern Pacific [ Balaguru et al ., ; Vincent et al ., ], and in particular related to ENSO dynamics [ Jin et al ., ; Boucharel et al ., ]. These studies focused on the delayed ENSO effect associated with the meridional heat discharge into the TC region that follows the wintertime peak of El Niño, therefore available for TC intensification during the next boreal hurricane season.…”

Combined effects of ENSO and PDO on Activity of Major Hurricanes in Eastern North Pacific

“…The effect of PDO on TC activities was single or synergistic through oceanic and atmospheric variables (Lupo 2011), which was similar to ENSO to some extent. Boucharel et al (2016) analyzed 1980-2012 seasonal ACE by empirical orthogonal functions analysis (EOF), indicating that the first two EOF modes are related to not only eastern and central Pacific ENSO, but also PDO. Both PDO signal and PDO-ENSO superposed signal affect interannual variation of TC frequency in ENP (Lupo et al 2008).…”

Coastal Wave Extremes around the Pacific and Their Remote Seasonal Connection to Climate Modes

“…To quantify the tropical cyclone activity in the northwestern Pacific, we calculated the monthly interannual anomalies of the accumulated cyclone energy (ACE), which represents an integrated measure of tropical storms intensity [39], averaged over the entire cyclonic basin (the red box on Figure 6b) following the method described in [40]. This ACE index anomalies are strongly correlated with the anomalous occurrence of wave extreme in this region (cf.…”