Tropical cyclone-induced extreme winds in climate datasets: East coast of Australia

Abstract. Tropical cyclones are one of the most intense weather hazards over east coast of India and create a lot of devastation through gale winds and torrential floods while they cross the coast. So an attempt is made in this study to simulate track and intensity of tropical cyclone "Fanoos", which is formed over the Bay of Bengal during 5–10 December 2005 by using mesoscale model MM5. The simulated results are compared with the observed results of India Meteorological Department (IMD); results show that the cumulus parameterization scheme, Kain-Fritsch (KF) is more accurately simulated both in track and intensity than the other Betts-Miller (BM) and Grell Schemes. The reason for better performance of KF-1 scheme may be due to inclusion of updrafts and downdrafts. The model could predict the minimum Central Sea Level Pressure (CSLP) as 983 hPa as compared to the IMD reports of 984 hPa and the wind speed is simulated at maximum 63 m/s compared to the IMD estimates of 65 m/s. Secondly "Fanoos" development from the lagrangian stand point in terms of vertical distribution of Potential Vorticity (PV) is also carried out around cyclone centre.

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Spatial variations of North Atlantic landfalling tropical cyclone wind speed decay over the continental United States

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-20-0199.1 ◽

2021 ◽

Author(s):

Yi-Jie Zhu ◽

Jennifer M. Collins ◽

Philip J. Klotzbach

Keyword(s):

United States ◽

Wind Speed ◽

Tropical Cyclone ◽

Tropical Cyclones ◽

East Coast ◽

Gulf Coast ◽

Spatial Variations ◽

Decay Model ◽

Weak Intensity ◽

Landfalling Tropical Cyclones

AbstractUnderstanding tropical cyclone wind speed decay during the post-landfall stage is critical for inland hazard preparation. This paper examines the spatial variation of wind speed decay of tropical cyclones over the continental United States. We find that tropical cyclones making landfall over the Gulf Coast decay faster within the first 24 hours after landfall than those making landfall over the Atlantic East Coast. The variation of the decay rate over the Gulf Coast remains larger than that over the Atlantic East Coast for tropical cyclones that had made landfall more than 24 hours prior. Besides an average weaker tropical cyclone landfall intensity, the near-parallel trajectory and the proximity of storms to the coastline also help to explain the slower post-landfall wind speed decay for Atlantic East Coast landfalling tropical cyclones. Tropical cyclones crossing the Florida peninsula only slowly weaken after landfall, with an average of less than 20% post-landfall wind speed drop while transiting the state. The existence of these spatial variations also brings into question the utility of a uniform wind decay model. While weak intensity decay over the Florida peninsula is well estimated by the uniform wind decay model, the error from the uniform wind decay model increases with tropical cyclones making direct landfall more parallel to the Atlantic East Coast. The underestimation of inland wind speed by the uniform wind decay model found over the western Gulf Coast brings attention to the role of land-air interactions in the decay of inland tropical cyclones.

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An early warning system for inundation forecast due to a tropical cyclone along the east coast of India

Natural Hazards ◽

10.1007/s11069-020-04082-w ◽

2020 ◽

Vol 103 (2) ◽

pp. 2277-2293

Author(s):

Anup Kumar Mandal ◽

Ratheesh Ramakrishnan ◽

Smita Pandey ◽

A. D. Rao ◽

Prashant Kumar

Keyword(s):

Tropical Cyclone ◽

Early Warning ◽

Early Warning System ◽

East Coast ◽

Warning System ◽

East Coast Of India

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Idealized Large-Eddy Simulations of a Tropical Cyclone–like Boundary Layer

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-14-0244.1 ◽

2015 ◽

Vol 72 (5) ◽

pp. 1743-1764 ◽

Cited By ~ 9

Author(s):

Benjamin W. Green ◽

Fuqing Zhang

Keyword(s):

Boundary Layer ◽

Tropical Cyclone ◽

Partial Slip ◽

Inertial Oscillation ◽

Surface Drag ◽

Coriolis Parameter ◽

Centripetal Acceleration ◽

Eddy Simulation ◽

Large Eddy ◽

Extreme Winds

Abstract The tropical cyclone (TC) boundary layer (TCBL)—featuring extreme winds over a rough ocean—is difficult to study observationally. With increasing computational power, high-resolution large-eddy simulation (LES) has become an attractive tool to advance understanding of the TCBL. Here, an idealized Cartesian-based LES is employed to investigate boundary layers driven by extreme TC-like winds. The LES includes the effects of centripetal acceleration through an “effective” Coriolis parameter f* = f + 2Vg/R, with the Earth Coriolis parameter f, gradient wind Vg, and (fixed) radius R. Multiple LES experiments are conducted to elucidate how the boundary layer develops and persists in the strongly rotating TC environment. In all simulations, an overshooting jet develops, the height of which increases with Vg, R, and surface drag. Normalized jet strength also increases with R and drag but decreases with Vg. Turbulent diffusivity Km—which must be parameterized in mesoscale and global models but can be diagnosed by LES—varies considerably both within and among simulations. Also evident is a pseudo-inertial oscillation with a period close to the theoretical 2π/f* and an amplitude that decreases exponentially with time. The LES simulations agree with the linear theory for partial-slip Ekman spirals, except when the effects of Km overwhelmingly counter the effects of Vg.

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Synthesis of Tropical Cyclone Tracks in a Risk Evaluation Perspective for the East Coast of India

Aquatic Procedia ◽

10.1016/j.aqpro.2015.02.052 ◽

2015 ◽

Vol 4 ◽

pp. 389-396 ◽

Cited By ~ 7

Author(s):

Bishnupriya Sahoo ◽

Prasad K. Bhaskaran

Keyword(s):

Tropical Cyclone ◽

Risk Evaluation ◽

East Coast ◽

East Coast Of India ◽

Cyclone Tracks ◽

Tropical Cyclone Tracks

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East coast lows and extratropical transition of tropical cyclones, structures producing severe events and their comparison with mature tropical cyclones

Journal of Southern Hemisphere Earth System Science ◽

10.1071/es21003 ◽

2021 ◽

Vol 71 (3) ◽

pp. 229

Author(s):

Jeff Callaghan

Keyword(s):

Tropical Cyclone ◽

Tropical Cyclones ◽

East Coast ◽

General Rule ◽

Heavy Rain ◽

Hurricane Sandy ◽

Extratropical Cyclones ◽

Sea Levels ◽

The Us ◽

Warm Region

Examination of events occurring over the last 53 years in the Australian Region have revealed in the minds of forecasters a common pattern in the development of severe extratropical cyclones which have affected the sub-tropical and temperate East Coast. To evaluate this theory 20 years of data were systematically examined and showed that this was true. To represent these many cases nine such events which delivered the largest impacts over the 53 years were chosen for study. These extratropical cyclones formed downstream of a tropopause undulation which can be easily identified as a warm region at the 200 hPa-level and the formation zone was in a region of heavy rain embedded in a region of warm air advection at 700 hPa. There were hardly any exceptions to this general rule, and one that occurred is presented and was also one of the most rapidly developing systems. This pattern is then evaluated against tropical cyclone events which move in the Australasian sub tropics and three different scenarios are described and compared with a mature severe tropical cyclone which intensified as it moved into the Australia sub tropics. Hurricane Sandy due to its devastating effect on the US sub-tropics in 2012 is examined as a benchmark case whose impact could affect the Australasian sub tropics in the future as sea levels rise with higher density populations.

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The influence of the coastal front on heavy rainfall events along the east coast

10.32469/10355/79565 ◽

2019 ◽

Author(s):

◽

Chasity B. Henson

Keyword(s):

Tropical Cyclone ◽

Heat Release ◽

Latent Heat ◽

Heavy Rainfall ◽

East Coast ◽

Latent Heat Release ◽

Rainfall Events ◽

Upper Level ◽

Heavy Rainfall Events ◽

Frontal Boundary

Coastal fronts are commonly found along the East Coast of the United States and can often be associated with intense rainfall and flooding due to elevated convection on the cold side of the boundary. Five heavy rainfall events ([greater to or equal than] 250 mm 24 hr-1) during the fall months along the East Coast were investigated using numerical weather prediction (NWP) models to determine the influence of an upper-level trough/cut-off low, an offshore tropical cyclone, a frontal boundary, and a moisture plume on the intense precipitation. Using experimental NWP simulations, it was determined that the tropical cyclone had an impact on the moisture plume and subsequent location of precipitation due to an associated deformation zone. The tropical cyclone prolonged the events by 6 hours, but inhibited the amount of moisture and resulting precipitation by deterring southeasterly flow. Evaporation from precipitation (surface heat fluxes) contributed to less than 25% (33%) of the precipitation, while latent heat release had the largest impact on the rain totals due to positive feedback from convection and an influence on the frontal boundary. Terrain also impacted the frontal boundary in each event, altering precipitation totals. Parcel trajectories confirmed regions of frontogenesis to be the main source of lift for the release of gravitational instability and convective initiation in each event, while the extratropical cyclone provided upper-level support for ascent and organized the plume of deep tropospheric moisture perpendicular to the front. Three of the five events lasted multiple days due to negative PV advection by the irrotational wind, in response to latent heat release in the region of convection, acting to slow the propagation of the upper-level low.

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