Influence of Environmental Vertical Wind Shear on the Intensity of Hurricane-Strength Tropical Cyclones in the Australian Region

Paterson, Linda A.; Hanstrum, Barry N.; Davidson, Noel E.; Weber, Harry C.
December 2005
Monthly Weather Review;Dec2005, Vol. 133 Issue 12, p3644
Academic Journal
NCEP–NCAR reanalyses have been used to investigate the impact of environmental wind shear on the intensity change of hurricane-strength tropical cyclones in the Australian region. A method of removing a symmetric vortex from objective analyses is used to isolate the environmental flow. A relationship between wind shear and intensity change is documented. Correlations between wind shear and intensity change to 36 h are of the order of 0.4. Typically a critical wind shear value of ∼10 m s-1 represents a change from intensification to dissipation. Wind shear values of less than ∼10 m s-1 favor intensification, with values between ∼2 and 4 m s-1 favoring rapid intensification. Shear values greater than ∼10 m s-1 are associated with weakening, with values greater than 12 m s-1 favoring rapid weakening. There appears to be a time lag between the onset of increased vertical wind shear and the onset of weakening, typically between 12 and 36 h. A review of synoptic patterns during intensification-weakening cycles revealed the juxtaposition of a low-level anticyclone on the poleward side of the storm and an approaching 200-hPa trough to the west. In most cases, intensification commences under weak shear with the approach of the trough, but just prior to the onset of high shear. Further, based on described cases when wind shear was weak but no intensification occurred, it is suggested that weak shear is a necessary but not a sufficient condition for intensification. It is illustrated here that the remote dynamical influence of upper-level potential vorticity anomalies may offset the negative effects of environmental shear.


Related Articles

  • A Climatology of Hurricane Eye Formation*. Vigh, Jonathan L.; Knaff, John A.; Schubert, Wayne H. // Monthly Weather Review;May2012, Vol. 140 Issue 5, p1405 

    This paper presents a climatology of the initial eye formations of a broad set of Atlantic tropical cyclones (TCs) during 1989-2008. A new dataset of structure and intensity parameters is synthesized from the vortex data messages transmitted by routine aircraft reconnaissance. Using these data...

  • Environmental Vertical Wind Shear with Hurricane Bertha (1996). Zehr, Raymond M. // Weather & Forecasting;Apr2003, Vol. 18 Issue 2, p345 

    Hurricane Bertha (1996) was influenced by vertical wind shear with highly variable direction and magnitude. The paper describes a unique method for determining the vertical tilt of a tropical cyclone vortex using satellite and aircraft data. Hurricane Bertha's vortex tracks at three levels are...

  • Barrier Jets during TAMEX. Li, Jun; Chen, Yi-Leng // Monthly Weather Review;Apr98, Vol. 126 Issue 4, p959 

    A barrier jet is frequently found along the northwestern coast of Taiwan in the prefrontal southwesterly flow regime during the Taiwan Area Mesoscale Experiment (TAMEX). It has a maximum wind speed of 14 m s 21 at approximately 1 km above the surface with a vertical wind shear approximately 10...

  • Effects of Vertical Wind Shear on the Intensity and Structure of Numerically Simulated Hurricanes. Frank, William M.; Ritchie, Elizabeth A. // Monthly Weather Review;Sep2001, Vol. 129 Issue 9, p2249 

    Presents information on a study which examined the effects of vertical wind shear on the structure and intensity of hurricanes. Background on hurricanes; Methodology; Results of the study.

  • A Statistical Analysis of the Effects of Vertical Wind Shear on Tropical Cyclone Intensity Change over the Western North Pacific. Wang, Yuqing; Rao, Yunjie; Tan, Zhe-Min; Schönemann, Daria // Monthly Weather Review;Sep2015, Vol. 143 Issue 9, p3434 

    The effect of vertical wind shear (VWS) between different pressure levels on TC intensity change is statistically analyzed based on the best track data of tropical cyclones (TCs) in the western North Pacific (WNP) from the Joint Typhoon Warning Center (JTWC) and the ECMWF interim reanalysis...

  • Meridional oscillation in genesis location of tropical cyclones in the postmonsoon Bay of Bengal. Fan, Kaigui; Wang, Xidong; Foltz, Gregory R.; Balaguru, Karthik // Climate Dynamics;Aug2019, Vol. 53 Issue 3/4, p2103 

    It is found that the average genesis location of tropical cyclones (TCs) in the postmonsoon (October–December) Bay of Bengal (BoB) shows a notable meridional oscillation during 1980–2015. During years when the average genesis location shifts northward (north-years), the average...

  • Observed Inner-Core Structural Variability in Hurricane Dolly (2008)*. Hendricks, Eric A.; McNoldy, Brian D.; Schubert, Wayne H. // Monthly Weather Review;Dec2012, Vol. 140 Issue 12, p4066 

    Hurricane Dolly (2008) exhibited dramatic inner-core structural variability during a 6-h rapid intensification and deepening event just prior to making landfall in southern Texas at 1800 UTC 23 July. In particular, the eyewall was highly asymmetric from 0634-1243 UTC, with azimuthal wavenumber m...

  • Discrepancies in Different Precipitation Data Products in the Bay of Bengal during Summer Monsoon Season. Qi, Li; Wang, Yuqing // Advances in Meteorology;5/24/2015, Vol. 2015, p1 

    In the east Bay of Bengal (BoB), the precipitation maximum always lies near the eastern coast on the windward side of Mountain Araka Yoma in the summer monsoon season. In this study, different precipitation products are compared in terms of their representation of the offshore rainfall maximum...

  • Experts Predict Memorable 2010 Hurricane Season. Gilkey, Eric V. // Claims;Jul2010, Vol. 58 Issue 7, p9 

    The article reveals that the primary drivers for tropical activity have significantly reversed course in 2010, which sets the stage for an exceedingly active hurricane season. According to Dr. Todd Crawford, chief meteorologist of Weather Services International (WSI), the El Niño phenomenon...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics