Simulations of the Extratropical Transition of Tropical Cyclones: Phasing between the Upper-Level Trough and Tropical Cyclones

Abstract

Whether the tropical cyclone remnants will become a significant extratropical cyclone during the reintensification stage of extratropical transition is a complex problem because of the uncertainty in the tropical cyclone, the midlatitude circulation, the subtropical anticyclone, and the nonlinear interactions among these systems. In a previous study, the authors simulated the impact of the strength of the midlatitude circulation trough without changing its phasing with the tropical cyclone. In this study, the impact of phasing is simulated by fixing the initial position and amplitude of the midlatitude trough and varying the initial position of the tropical cyclone. The peak intensity of the extratropical cyclone following the extratropical transition is strongly dependent on the phasing, which leads to different degrees of interaction with the midlatitude baroclinic zone. Many aspects of the simulated circulation, temperature, and precipitation fields appear quite realistic for the reintensifying and dissipating cases. Threshold values of various parameters in quadrants near and far from the tropical cyclone are extracted that discriminate well between reintensifiers and dissipators. The selection and distribution of threshold parameters are consistent with the Petterssen type-B conceptual model for extratropical cyclone development. Thus, these simulations suggest that phasing between the tropical cyclone and the midlatitude trough is a critical factor in predicting the reintensification stage of extratropical transition.

Simulated Sensitivity of Tropical Cyclone Size and Structure to the Atmospheric Temperature Profile

“…There are also two two-way nested innersquare domains of spatial sizes 2052 km (D2) and 720 km (D3) with grid spacing of 9-and 3-km resolution, respectively. D3 is capable of resolving moist processes within the eye and eyewall region, while both inner and outer rainbands are well resolved by D2 (e.g., Frank and Ritchie 2001;Ritchie and Frank 2007;Ritchie and Elsberry 2007;XW10a). D2 is initialized in the center of D1, which is large enough to ensure that D2 can move freely through the simulation without experiencing any boundary interactions with D1.…”

A Composite Perspective of the Extratropical Flow Response to Recurving Western North Pacific Tropical Cyclones

“…Of interest is that strong interactions may be analogous to the extratropical reintensification scenario associated with recurving TCs encountering a ''northwest'' midlatitude circulation pattern documented by Harr et al (2000): in their compositing study, Harr et al (2000) find that TCs recurving ahead of an upstream midlatitude trough (a northwest pattern) are favored to reintensify as extratropical cyclones. In contrast, the position of the TC center near the base of a trough during weak interactions is reminiscent of scenarios in which a recurving TC dissipates before completing ET [e.g., the case of TC Jangmi (2008) described in Grams et al (2013b) and the idealized scenarios of Ritchie and Elsberry (2007)].…”

“…The primary factors influencing the downstream flow response to TC recurvature are (i) the large-scale flow pattern into which the TC is moving (e.g., Harr and Dea 2009;Riemer et al 2008;Jones 2010, 2014), and (ii) the interaction between the TC and an extratropical disturbance such as a trough or jet streak (e.g., Klein et al 2002;Ritchie and Elsberry 2007;Jones 2010, 2014;Grams et al 2013b;Keller et al 2014). Characteristics of the recurving TC, such as size and intensity, are thought to be secondary factors (e.g., Harr and Dea 2009;Archambault et al 2013).…”

Comparing the Spatial Patterns of Rainfall and Atmospheric Moisture among Tropical Cyclones Having a Track Similar to Hurricane Irene (2011)

“…For all TCs forming after 1948, the average daily anomalies of the geopotential height of 500 hPa pressure for each TC on the day of landfall were obtained from the NCEP/NCAR reanalysis project [46], and the values for all 11 TCs were averaged together. The distance between the TC and middle-latitude circulation features as well as the strength of the middle-latitude features influence TC structure and hence its rainfall production [47].…”