The Formation and Structure of Tropical Cyclones in the Indian Sea Areas

Koteswaram, P.; GEORGE, C. A.

doi:10.2151/jmsj1923.35a.0_309

Cited by 6 publications

(5 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many efforts have been devoted to investigate the asymmetric rainfall distribution in landfalling TCs and the associated physical mechanisms responsible for the rainfall asymmetries. Some earlier studies based on land‐based rain gauge data showed that rainfall near the coast in a landfalling TC was often concentrated to the right of the storm track in the Northern Hemisphere [ Koteswaram and Gaspar , ; Miller , ]. This right‐favored feature of rainfall in landfalling TCs was also reported later in other observational studies using data including aircraft, ship, buoy and land‐based rain gauge data [ Powell , , ], and numerical modeling studies [ Tuleya and Kurihara , ; Jones , ].…”

Section: Introductionsupporting

confidence: 54%

A diagnostic study on heavy rainfall induced by Typhoon Utor (2013) in South China: 1. Rainfall asymmetry at landfall

Meng

Wang

2016

JGR Atmospheres

View full text Add to dashboard Cite

After striking the Philippines on 11 August 2013, Typhoon Utor made its second landfall over southern South China on 14 August and brought heavy rainfall, causing widespread damages after its landfall. The heavy rainfall associated with Utor includes three main episodes: rainfall at landfall, postlandfall rainfall in the inner core region, and postlandfall rainfall induced by the intensification of southwesterly monsoon flow. In part 1 the rainfall at landfall is analyzed and diagnosed using the surface mesonet observations and the high-resolution European Centre for Medium-Range Weather Forecasting Interim reanalysis (ERA-Interim) data. Results show that when Utor approached and made landfall over the southern coast of South China, it was embedded in a deep-layer (200-850 hPa) easterly northeasterly vertical wind shear (VWS) environment with heavy rainfall mostly occurring downshear left in its southwestern quadrant. Under a favorable environment with moderate convective available potential energy and moderate low-level VWS, a surface cold pool was found in the west-southwestern quadrants of Utor triggered by the middle-lower tropospheric dry air intrusion from inland to the north. Both frontogenesis and quasi-balanced, ageostrophic Q-vector diagnostics demonstrate that the quasi-balanced forcing near the surface cold cool contributed to the enhancement of convection in the west-southwestern quadrants of Utor. It is concluded that the environmental VWS and the consequent surface cold pool dynamics play an important role in rainfall asymmetry in Utor when it made landfall over the southern coast of South China.

show abstract

Section: Introductionsupporting

confidence: 54%

A diagnostic study on heavy rainfall induced by Typhoon Utor (2013) in South China: 1. Rainfall asymmetry at landfall

Meng

Wang

2016

JGR Atmospheres

View full text Add to dashboard Cite

show abstract

“…According to previous studies (Koteswaram andGaspar 1956, Miller 1958), the rainfall maximum of landfalling tropical cyclones is often located in their front quadrants with a preference for the onshore side due to the effect from increased surface friction. However, at landfall the four southern hemisphere tropical cyclones analysed in this study all had their rainfall maximum located in their frontright quadrant where the cyclonic winds went offshore.…”

Section: General Considerationmentioning

confidence: 93%

“…Early studies based on rain gauge data found that coastal rainfall associated with tropical cyclones is generally more intense to the right side of the tracks of northern hemisphere tropical cyclones (Koteswaram andGaspar 1956, Miller 1958). Recent numerical studies (e.g.…”

Section: Introductionmentioning

confidence: 99%

Rainfall distribution of five landfalling tropical cyclones in the northwestern Australian region

Li¹,

Cheung²,

Chan³

et al. 2013

AMOJ

View full text Add to dashboard Cite

Rain gauge data, satellite IR brightness temperature and radar-estimated rain rate for five tropical cyclones from the 2005-06 to 2009-10 seasons that made landfall along the northwestern coast of Australia are analysed. It is the first time that the spatial rainfall distribution of landfalling tropical cyclones in the southern hemisphere has been systematically investigated. It is found that the distributions of rainfall are more concentrated in the right side of the track of the landfall tropical cyclones, which is the offshore flow position. Potential mechanisms responsible for this observed asymmetry in rainfall distribution are discussed. These include the tropical cyclone motion direction, deep-tropospheric vertical wind shear and land-sea contrast in surface properties. Topography is considered to have less effect since Western Australia is relatively flat. The rainfall maxima are found in the front and downshear quadrants for these tropical cyclones, which is consistent with previous studies. The changes in vertical wind shear when these tropical cyclones moved to the south are largely attributed to the prevailing environmental flow. Three numerical simulations are performed; one with a realistic land surface, one with all topography removed and one with all land removed. These simulations show that the land surface effects play an important role in determining the asymmetry in rainfall distribution, which explains why in some cases the observed maximum rainfall does not follow closely the vertical wind shear direction when making landfall.

show abstract

“…These processes may act individually or collectively, and all three may be important at different times in a storm's life cycle. Interactions between hurricanes and external larger-scale circulations have been shown to be important to hurricane intensity changes in many papers over the last 50 yr (e.g., Riehl 1948Riehl , 1950Palmer 1951;Simpson 1952; Koteswaram and George 1957;Ramage 1959;Yanai 1961;Colón and Nightingale 1963;Erickson 1967;Sadler 1976;Frank 1977;Pfeffer and Challa 1981;Velden 1987;Merrill 1988a,b;Lee et al 1989;Molinari andVollaro 1989, 1990; Challa and Pfeffer 1990;Bosart and Bartlo 1991;Montgomery and Farrell 1993;Wu and Emanuel 1993;Molinari et al 1995;Bosart and Lackmann 1995;Elsberry and Jeffries 1996;Merrill and Velden 1996;Briegel and Frank 1997;Shi et al 1997;Challa et al 1998;DeMaria and Huber 1998;Krishnamurti et al 1998;Molinari 1998;Molinari et al 1998;Zehr 1998). As noted by Molinari (1998), important unresolved issues regarding hurricane-trough interactions include 1) what is meant by a trough interaction, 2) how does a synoptic-scale trough interact with a mesoscale hurricane, 3) what is the role of vertical shear, 4) how do the core dynamics respond to the interaction, 5) how does the nature of the interaction vary as a function of the storm maximum potential intensity, and 6) how do identifiable parameters exist to predict whether the interaction will lead to storm strengthening or weakening?…”

Section: Introductionmentioning

confidence: 99%

Environmental Influences on the Rapid Intensification of Hurricane Opal (1995) over the Gulf of Mexico

Bosart¹,

Bracken²,

Molinari³

et al. 2000

Monthly Weather Rev

187

119

View full text Add to dashboard Cite

Hurricane Opal intensified rapidly and unexpectedly over the Gulf of Mexico between 1800 UTC 3 October and 1000 UTC 4 October 1995. During this period the storm central pressure decreased from 963 to 916 hPa and sustained winds reached 68 m s Ϫ1. Analyses that include high-resolution GOES-8 water vapor winds and European Centre for Medium-Range Weather Forecasts (ECMWF) and National Centers for Environmental Prediction (NCEP) gridded datasets are employed to examine the rapid intensification phase of Opal. Opal first reached tropical storm strength on 29-30 September 1995 as it interacted with a trough while situated over the Yucatan Peninsula. Opal deepened moderately (ϳ20 hPa) in the 24 h ending 1200 UTC 2 October as it achieved minimal hurricane strength and as it turned northeastward. The deepening occurred in conjunction with an environmental flow interaction as determined by an Eliassen balanced vortex outflow calculation. As Opal accelerated toward the Gulf coast by 1200 UTC 3 October, it approached the equatorward jet-entrance region of a progressive synoptic-scale trough. The trough tail extended southwestward toward the lower Texas coast. As the poleward portion of the trough moved eastward, the equatorward end of the trough lagged behind, stretched meridionally, and partially fractured as it encountered a deformation region over the northwest Gulf. Enhanced outflow and increased divergence in the upper troposphere poleward of Opal was associated with the deformation zone and the partially fractured trough tail. An analysis of the 300-200-hPa layer-averaged divergence and 6-h divergence change based on an analysis of the water vapor winds shows a significant increase in the magnitude and equatorward extension of the divergence core toward Opal that begins at 1200 UTC 3 October and is most apparent by 1800 UTC 3 October and 0000 UTC 4 October. This divergence increase is shown to precede convective growth in the eyewall and the onset of rapid intensification and is attributed to a jet-trough-hurricane interaction in a low-shear environment. Calculations of balanced vortex outflow based on the ECMWF and NCEP gridded datasets confirms this interpretation. A crucial finding of this work is that the jet-trough-hurricane interaction and explosive intensification of Opal begins near 0000 UTC 4 October when the storm is far from its maximum potential intensity (MPI), and the 850-200-hPa shear within 500 km of the center is weak (2-3 m s Ϫ1). In this first stage of rapid intensification the winds increase by almost 15 m s Ϫ1 to 52 m s Ϫ1 prior to the storm reaching an oceanic warm-core eddy. The second stage of rapid intensification occurs between 0600 and 1000 UTC 4 October when Opal is over the warm-core eddy and sustained winds increase to 68 m s Ϫ1. During this second stage conditions are still favorable for a jet-trough-hurricane interaction as demonstrated by the balanced vortex outflow calculation. Opal weakens rapidly after 1200 UTC 4 October when the storm is near its MPI, the shear is increasing, and t...

show abstract

The Formation and Structure of Tropical Cyclones in the Indian Sea Areas

Cited by 6 publications

References 11 publications

A diagnostic study on heavy rainfall induced by Typhoon Utor (2013) in South China: 1. Rainfall asymmetry at landfall

A diagnostic study on heavy rainfall induced by Typhoon Utor (2013) in South China: 1. Rainfall asymmetry at landfall

Rainfall distribution of five landfalling tropical cyclones in the northwestern Australian region

Environmental Influences on the Rapid Intensification of Hurricane Opal (1995) over the Gulf of Mexico

Contact Info

Product

Resources

About