Track Deflection of Typhoon Nesat (2017) as Realized by Multiresolution Simulations of a Global Model

Huang, Ching Yuang; Huang, Chien Chung; Skamarock, William C.

doi:10.1175/mwr-d-18-0275.1

Cited by 13 publications

(13 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both settings also give reasonable results in capturing TC characteristics such as track and intensity (e.g. Huang et al 2017Huang et al , 2019 and for "climatological" studies (e.g. Davis et al 2016;Michaelis et al 2019).…”

Section: Introductionmentioning

confidence: 90%

Performance of MPAS-A and WRF in predicting and simulating western North Pacific tropical cyclone tracks and intensities

Lui¹,

Tse²,

Tam

et al. 2020

Theor Appl Climatol

View full text Add to dashboard Cite

Performances of the Model for Prediction Across Scales-Atmosphere (MPAS-A) in predicting and the Weather Research and Forecasting (WRF) model in simulating western North Pacific (WNP) tropical cyclone (TC) tracks and intensities have been compared. Parallel simulations of the same historical storms that made landfall over southern China, namely, TCs Hope (1979), Gordon (1989), Koryn (1993), Imbudo (2003), Dujuan (2003), Molave (2009), Hato (2017) and Mangkhut (2018), were carried out using WRF and MPAS-A, with initial conditions (and, for WRF, lateral boundary conditions as well) taken from ERA-interim. For MPAS-A, the model was integrated using a standard 60-to-3-km variable-resolution global grid mesh and also on 160-to-2-km grids customized to cover the TC tracks with the highest resolution mesh. The WRF model was integrated using a 15-km/3-km nested domain. No TC bogus scheme was applied when initializing the MPAS-A and WRF simulations. It was found that while TC tracks were reasonably captured by the two models configured variously, the storm intensities were underestimated in general. Given MPAS-A runs were initial value predictions whereas WRF runs were dynamically downscaled from ERA-interim, the finding that MPAS-A has comparable (or slightly better) performance as (than) WRF is noteworthy. To further examine the sensitivity of the MPAS-A TC forecasts to the initial data, additional experiments were carried out for TCs Molave and Hope using ERA5 reanalysis as initial conditions. The ERA5 initialized runs showed significant (slight) improvement in intensity (track) evolution, suggesting that the underestimated TC intensity is likely related to inferior representation of storms in the ERA-interim initial fields. Furthermore, additional runs using another customized 60-to-2-km mesh showed a reasonable improvement in capturing the TC tracks, suggesting that the track forecast accuracy of MPAS-A in TC can be sensitive to the grid resolution in the coarsest part of the variable-resolution mesh used.

show abstract

Section: Introductionmentioning

confidence: 90%

Performance of MPAS-A and WRF in predicting and simulating western North Pacific tropical cyclone tracks and intensities

Lui¹,

Tse²,

Tam

et al. 2020

Theor Appl Climatol

View full text Add to dashboard Cite

show abstract

“…To further investigate the different motions of the typhoon centre at low and upper levels using model results, the PV tendency diagnostic approach following Wu and Wang (2000) is employed. This method has been used in related studies (Wu and Wang, 2001; Chan et al ., 2002; Hsu et al ., 2013; Wang et al ., 2013; Chen et al ., 2017; Huang et al ., 2019). In a quasi‐Lagrangian frame that moves with the TC, the WN‐1 component of inviscid PV tendency equation is

{((), \frac{\partial P}{\partial t})}_{1} = {normalΛ}_{1} [- V \cdot \nabla_{normalh} P - w \frac{\partial P}{\partial z} + \frac{1}{ρ} \nabla_{3} \cdot (Q q) + R],

where P is PV; V and w are (storm‐relative) horizontal wind vector and vertical velocity, respectively; ∇ h and ∇ 3 are horizontal and three‐dimensional gradient operator, respectively; Q is diabatic heating rate; q is three‐dimensional absolute vorticity vector; ρ is air density; R represents the residual term; and Λ 1 denotes the operator to obtain the (azimuthal) WN‐1 component.…”

Section: Pv Tendency Diagnostic Analysesmentioning

confidence: 99%

“…To further investigate the different motions of the typhoon centre at low and upper levels using model results, the PV tendency diagnostic approach following Wu and Wang (2000) is employed. This method has been used in related studies (Wu and Wang, 2001;Chan et al, 2002;Hsu et al, 2013;Wang et al, 2013;Chen et al, 2017;Huang et al, 2019). In a quasi-Lagrangian frame that moves with the TC, the WN-1 component of inviscid PV tendency equation is…”

Section: Pv Tendency Diagnostic Analysesmentioning

confidence: 99%

On the separation of upper and low‐level centres of tropical storm Kong‐Rey (2013) near Taiwan in association with asymmetric latent heating

Wang

Chen

et al. 2021

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

Tropical Storm (TS) Kong‐Rey (2013) moved northward off the eastern coast of Taiwan in late August. Satellite and radar observations indicated an asymmetric convective structure to the south and southwest of the typhoon centre. The maximum rainfall produced was also far from its centre and unlike the usual pattern in climatology, causing flooding, inundation, and casualties in southwestern Taiwan. Moreover, as a detached centre in the middle and upper levels moved over land, a highly tilted vertical structure was revealed and its cause is the focus of the present study. Even though vertical wind shear was present and might cause asymmetry in convective pattern at an early stage, the detachment of the centre aloft during the period of interest (28–29 August) is found to link to Taiwan's steep topography through model experiments and potential vorticity tendency diagnosis. With the uplifting of strong low‐level westerly flow by the topography, the intense convection in the control experiment is concentrated at the windward slopes (in southwestern Taiwan) and the wave‐number‐1 motion vector from the diabatic heating produces southwestward movement of the centre aloft, and thus leads to the detachment. On the other hand, in the sensitivity test without Taiwan terrain, the rainfall region shifts eastward toward the low‐level TC centre, and the detachment does not occur. Overall, with a weak vertical coupling of TS Kong‐Rey (2013), the impacts of topography can explain both the observed separation of its centres and the unusual rainfall pattern in Taiwan.

show abstract

“…It has not been rare to observe large track variations of tropical cyclones translating past an isolated high mountain or a mountain range over 3000-m height, such as the Central Mountain Range (CMR) in Taiwan Island over the western North Pacific (WNP), Réunion Island over the Indian Ocean east of Madagascar, and Hawai'i's Big Island (e.g., Chambers and Li 2011;Hsu et al 2018;Barbary et al 2019). Tropical cyclones moving past an isolated mountain range like the CMR have been widely investigated using observations and numerical models, and more recently with great attention to the track deflection prior to and after landfall at the mountain (e.g., Jian and Wu 2008;Lin and Savage 2011;Huang et al 2011;Chien and Kuo 2011;Hsu et al 2013Hsu et al , 2018Wu et al 2015;Tang and Chan 2016a,b;Huang et al 2016Huang et al , 2019Huang et al , 2020Lin et al 2016;Huang and Wu 2018). Significant modifications of the track of an approaching tropical cyclone can be induced as topographical effects of a mesoscale mountain not only modulate the core structure of the cyclone but also the environmental steering flow in which the cyclone is embedded.…”

Section: Introductionmentioning

confidence: 99%

Track Deflection of Typhoon Maria (2018) during a Westbound Passage Offshore of Northern Taiwan: Topographic Influence

Huang

Juan

Kuo

et al. 2020

Monthly Weather Review

Self Cite

View full text Add to dashboard Cite

This study applies a global model (FV3GFS) with stretched resolution of approximately 7 km for simulating Typhoon Maria (2018), which exhibited a sudden northward track deflection when approaching about 150 km northeast of Taiwan. As Maria approached land, the outer cyclonic flow at the western flank of the typhoon is split around the northern part of the Central Mountain Range (CMR) in Taiwan to converge east of Taiwan with the recirculating southerly flow around the southern corner of the CMR. Such strong convergence leads to northward deflection of the west-northwestward moving typhoon with the stronger wind mainly east of the vortex center. The radial inflow at low levels is intensified south of the vortex center and transports larger angular momentum (AM) inward with the enhanced upward motions and vertical mean AM advection to increase the azimuthal mean tangential wind in the lower-tropospheric eyewall. A vorticity budget of wavenumber-one decomposition indicates that the track deflection is dominated by horizontal vorticity advection in response to the intensifying flow. Numerical experiments with idealized WRF also support such northward track deflection as westward tropical cyclones approach a mountain range within an offshore meridional distance of about 200 km. The northward track deflection is only slightly amplified as the terrain height is considerably increased, consistent with the real-case simulation. However, the northward track deflection is not increased as the approaching vortex is initialized closer to the northern end of the mountain range, due to the enhanced east-west symmetry of wind structure in the inner vortex.

show abstract

Track Deflection of Typhoon Nesat (2017) as Realized by Multiresolution Simulations of a Global Model

Cited by 13 publications

References 38 publications

Performance of MPAS-A and WRF in predicting and simulating western North Pacific tropical cyclone tracks and intensities

Performance of MPAS-A and WRF in predicting and simulating western North Pacific tropical cyclone tracks and intensities

On the separation of upper and low‐level centres of tropical storm Kong‐Rey (2013) near Taiwan in association with asymmetric latent heating

Track Deflection of Typhoon Maria (2018) during a Westbound Passage Offshore of Northern Taiwan: Topographic Influence

Contact Info

Product

Resources

About