Dynamical and Precipitation Structures of Poleward-Moving Tropical Cyclones in Eastern Canada, 1979–2005

Shawn M. Milrad Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada

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Eyad H. Atallah Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada

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John R. Gyakum Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada

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Abstract

Tropical cyclones in the western North Atlantic basin are a persistent threat to human interests along the east coast of North America. Occurring mainly during the late summer and early autumn, these storms often cause strong winds and extreme rainfall and can have a large impact on the weather of eastern Canada. From 1979 to 2005, 40 named (by the National Hurricane Center) tropical cyclones tracked over eastern Canada. Based on the time tendency of the low-level (850–700 hPa) vorticity, the storms are partitioned into two groups: “intensifying” and “decaying.” The 16 intensifying and 12 decaying cases are then analyzed using data from both the National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR) and the NCEP global reanalysis. Composite dynamical structures are presented for both partitioned groups, utilizing both quasigeostrophic (QG) and potential vorticity (PV) perspectives. It is found that the proximity to the tropical cyclone and subsequent negative tilt (or lack thereof) of a precursor trough over the Great Lakes region is crucial to whether a storm “intensifies” or “decays.” Heavy precipitation is often the main concern when tropical cyclones move northward into the midlatitudes. Therefore, analyses of storm-relative precipitation distributions show that storms intensifying (decaying) as they move into the midlatitudes often exhibit a counterclockwise (clockwise) rotation of precipitation around the storm center.

Corresponding author address: Shawn M. Milrad, Dept. of Atmospheric and Oceanic Sciences, McGill University, 805 Sherbrooke St. West, Montreal QC H3A 2K6, Canada. Email: shawn.milrad@gmail.com

Abstract

Tropical cyclones in the western North Atlantic basin are a persistent threat to human interests along the east coast of North America. Occurring mainly during the late summer and early autumn, these storms often cause strong winds and extreme rainfall and can have a large impact on the weather of eastern Canada. From 1979 to 2005, 40 named (by the National Hurricane Center) tropical cyclones tracked over eastern Canada. Based on the time tendency of the low-level (850–700 hPa) vorticity, the storms are partitioned into two groups: “intensifying” and “decaying.” The 16 intensifying and 12 decaying cases are then analyzed using data from both the National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR) and the NCEP global reanalysis. Composite dynamical structures are presented for both partitioned groups, utilizing both quasigeostrophic (QG) and potential vorticity (PV) perspectives. It is found that the proximity to the tropical cyclone and subsequent negative tilt (or lack thereof) of a precursor trough over the Great Lakes region is crucial to whether a storm “intensifies” or “decays.” Heavy precipitation is often the main concern when tropical cyclones move northward into the midlatitudes. Therefore, analyses of storm-relative precipitation distributions show that storms intensifying (decaying) as they move into the midlatitudes often exhibit a counterclockwise (clockwise) rotation of precipitation around the storm center.

Corresponding author address: Shawn M. Milrad, Dept. of Atmospheric and Oceanic Sciences, McGill University, 805 Sherbrooke St. West, Montreal QC H3A 2K6, Canada. Email: shawn.milrad@gmail.com

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  • Abraham, J., C. Fogarty, and W. Strapp, 2002: Extratropical transitions of Hurricanes Michael and Karen: Storm reconnaissance with the Canadian Convair 580 aircraft. Preprints, 25th Conf. on Hurricanes and Tropical Meteorology, San Diego, CA, Amer. Meteor. Soc., 12D.4. [Available online at http://ams.confex.com/ams/pdfpapers/35168.pdf.].

    • Search Google Scholar
    • Export Citation
  • Agusti-Panareda, A., C. Thorncroft, G. Craig, and S. Gray, 2004: The extratropical transition of Hurricane Irene (1999): A potential-vorticity perspective. Quart. J. Roy. Meteor. Soc., 130 , 10471074.

    • Search Google Scholar
    • Export Citation
  • Anthes, R., 1990: Advances in the understanding and prediction of cyclone development with limited-area fine-mesh models. Extratropical Cyclones: The Erik Palmén Memorial Volume, C.W. Newton and E.O. Halopainen, Eds., Amer. Meteor. Soc., 221–253.

    • Search Google Scholar
    • Export Citation
  • Atallah, E. H., and L. Bosart, 2003: The extratropical transition and precipitation distribution of Hurricane Floyd (1999). Mon. Wea. Rev., 131 , 10631081.

    • Search Google Scholar
    • Export Citation
  • Atallah, E. H., L. F. Bosart, and A. Aiyyer, 2007: Precipitation distribution associated with landfalling tropical cyclones over the eastern United States. Mon. Wea. Rev., 135 , 21852206.

    • Search Google Scholar
    • Export Citation
  • Bluestein, H., 1992: Synoptic-Dynamic Meteorology in Midlatitudes. Vol. I. Oxford University Press, 431 pp.

  • Bosart, L. F., and D. Dean, 1991: The Agnes rainstorm of June 1972: Surface feature evolution culminating in inland storm redevelopment. Wea. Forecasting, 6 , 515536.

    • Search Google Scholar
    • Export Citation
  • Bosart, L. F., and G. M. Lackmann, 1995: Postlandfall tropical cyclone reintensification in a weakly baroclinic environment: A case study of Hurricane David (September 1979). Mon. Wea. Rev., 123 , 32683291.

    • Search Google Scholar
    • Export Citation
  • Browning, K., G. Vaughan, and P. Panagi, 1998: Analysis of an ex-tropical cyclone after its reintensification as a warm-core extratropical cyclone. Quart. J. Roy. Meteor. Soc., 124 , 23292356.

    • Search Google Scholar
    • Export Citation
  • Browning, K., A. Thorpe, A. Montani, D. Parsons, M. Griffiths, P. Panagi, and E. Dicks, 2000: Interactions of tropopause depressions with an ex-tropical cyclone and sensitivity of forecasts to analysis errors. Mon. Wea. Rev., 128 , 27342755.

    • Search Google Scholar
    • Export Citation
  • Carr, F. H., and L. Bosart, 1978: A diagnostic evaluation of rainfall predicitability for Tropical Storm Agnes, June 1972. Mon. Wea. Rev., 106 , 363374.

    • Search Google Scholar
    • Export Citation
  • Colle, B., 2003: Numerical simulations of the extratropical transition of Floyd (1999): Structural evolution and responsible mechanisms for the heavy rainfall over the northeast United States. Mon. Wea. Rev., 131 , 29052926.

    • Search Google Scholar
    • Export Citation
  • Darr, J., 2002: Quantitative measurements of extratropical transition in the Atlantic basin. Preprints, 25th Conf. on Hurricanes and Tropical Meteorology, San Diego, CA, Amer. Meteor. Soc., 13D.2. [Available online at http://ams.confex.com/ams/pdfpapers/36228.pdf.].

    • Search Google Scholar
    • Export Citation
  • Dickinson, M., L. Bosart, K. Corbosiero, S. Hopsch, K. Lombardo, M. Novak, B. Smith, and A. Wasula, 2004: The extratropical transitions of eastern Pacific Hurricane Lester (1992) and Atlantic Hurricane Andrew (1992): A comparison. Preprints, 26th Conf. on Hurricanes and Tropical Meteorology, Miami, FL, Amer. Meteor. Soc., 17D.2. [Available online at http://ams.confex.com/ams/pdfpapers/75685.pdf.].

    • Search Google Scholar
    • Export Citation
  • DiMego, G., and L. Bosart, 1982a: The transformation of Tropical Storm Agnes into an extratropical cyclone. Part I: The observed fields and vertical motion computations. Mon. Wea. Rev., 110 , 385411.

    • Search Google Scholar
    • Export Citation
  • DiMego, G., and L. Bosart, 1982b: The transformation of Tropical Storm Agnes into an extratropical cyclone. Part II: Moisture, vorticity, and kinetic energy budgets. Mon. Wea. Rev., 110 , 412433.

    • Search Google Scholar
    • Export Citation
  • Elsberry, R., 2002: Predicting hurricane landfall precipitation: Optimistic and pessimistic views from the symposium on precipitation extremes. Bull. Amer. Meteor. Soc., 83 , 13331339.

    • Search Google Scholar
    • Export Citation
  • Elsberry, R., 2004: Comments on “The influence of the downstream state on extratropical transition: Hurricane Earl (1998) case study” and “A study of the extratropical reintensification of former Hurricane Earl using Canadian Meteorological Centre regional analyses and ensemble forecasts.”. Mon. Wea. Rev., 132 , 25112513.

    • Search Google Scholar
    • Export Citation
  • Fogarty, C., 2002a: Hurricane Michael, 17–20 October 2000. Part I: Summary report and storm impact on Canada. Meteorological Service of Canada, 39 pp.

    • Search Google Scholar
    • Export Citation
  • Fogarty, C., 2002b: Operational forecasting of extratropical transition. Preprints, 25th Conf. on Hurricanes and Tropical Meteorology, San Diego, CA, Amer. Meteor. Soc., 12D.1. [Available online at http://ams.confex.com/ams/pdfpapers/33172.pdf.].

    • Search Google Scholar
    • Export Citation
  • Fogarty, C., and J. Gyakum, 2005: A study of extratropical transition in the western North Atlantic Ocean, 1963–1996. Atmos.–Ocean, 43 , 173191.

    • Search Google Scholar
    • Export Citation
  • Foley, G., and B. Hanstrum, 1994: The capture of tropical cyclones by cold fronts off the west coast of Australia. Wea. Forecasting, 9 , 577590.

    • Search Google Scholar
    • Export Citation
  • Gyakum, J., 2003: The extratropical transformation: A scientific challenge. Atmosphere–Ocean Interactions, W. Perrie, Ed., Vol. 1, WIT Press, 47–81.

    • Search Google Scholar
    • Export Citation
  • Harr, P., and R. Elsberry, 2000: Extratropical transition of tropical cyclones over the western North Pacific. Part I: Evolution of structural characteristics during the transition process. Mon. Wea. Rev., 128 , 26132633.

    • Search Google Scholar
    • Export Citation
  • Harr, P., R. Elsberry, and T. Hogan, 2000: Extratropical transition of tropical cyclones over the western North Pacific. Part II: The impact of midlatitude circulation characteristics. Mon. Wea. Rev., 128 , 26342653.

    • Search Google Scholar
    • Export Citation
  • Hart, R. E., and J. Evans, 2001: A climatology of the extratropical transition of Atlantic tropical cyclones. J. Climate, 14 , 547564.

    • Search Google Scholar
    • Export Citation
  • Hart, R. E., J. L. Evans, and C. Evans, 2006: Synoptic composites of the extratropical transition life cycle of North Atlantic tropical cyclones: Factors determining posttransition evolution. Mon. Wea. Rev., 134 , 553578.

    • Search Google Scholar
    • Export Citation
  • Hoskins, B., M. McIntyre, and A. Robertson, 1985: On the use and significance of isentropic potential vorticity maps. Quart. J. Roy. Meteor. Soc., 111 , 877946.

    • Search Google Scholar
    • Export Citation
  • Jones, S., and Coauthors, 2003: The extratropical transition of tropical cyclones: Forecast challenges, current understanding and future directions. Wea. Forecasting, 18 , 10521092.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437471.

  • Klein, P., P. Harr, and R. Elsberry, 2000: Extratropical transition of western North Pacific tropical cyclones: An overview and conceptual model of the transformation stage. Wea. Forecasting, 15 , 373395.

    • Search Google Scholar
    • Export Citation
  • Klein, P., P. Harr, and R. Elsberry, 2002: Extratropical transition of western North Pacific tropical cyclones: An overview and conceptual model of the transformation stage. Mon. Wea. Rev., 130 , 22402259.

    • Search Google Scholar
    • Export Citation
  • Koch, S., M. DesJardins, and P. Kocin, 1983: An interactive Barnes objective map analysis scheme for use with satellite and conventional data. J. Appl. Meteor., 22 , 14871503.

    • Search Google Scholar
    • Export Citation
  • Ma, S., H. Ritchie, J. Gyakum, J. Abraham, C. Fogarty, and R. McTaggart-Cowan, 2003: A study of the extratropical reintensification of former Hurricane Earl using Canadian Meteorological Centre regional analyses and ensemble forecasts. Mon. Wea. Rev., 131 , 13421359.

    • Search Google Scholar
    • Export Citation
  • Matano, H., and M. Sekioka, 1971a: On the synoptic structure of Typhoon Cora, 1969, as the compound system of tropical and extratropical cyclones. J. Meteor. Soc. Japan, 49 , 282294.

    • Search Google Scholar
    • Export Citation
  • Matano, H., and M. Sekioka, 1971b: Some aspects of extratropical transformation of a tropical cyclone. J. Meteor. Soc. Japan, 49 , 736743.

    • Search Google Scholar
    • Export Citation
  • Matano, J., 1958: On the synoptic structure of Hurricane Hazel, 1954, over the eastern United States. J. Meteor. Soc. Japan, 36 , 2331.

    • Search Google Scholar
    • Export Citation
  • McTaggart-Cowan, R., J. Gyakum, and M. Yau, 2003: The influence of the downstream state on extratropical transition: Hurricane Earl (1998) case study. Mon. Wea. Rev., 131 , 19101929.

    • Search Google Scholar
    • Export Citation
  • McTaggart-Cowan, R., J. Gyakum, and M. Yau, 2004a: The impact of tropical remnants on extratropical cyclogenesis: Case study of Hurricanes Danielle and Earl (1998). Mon. Wea. Rev., 132 , 19331951.

    • Search Google Scholar
    • Export Citation
  • McTaggart-Cowan, R., J. Gyakum, and M. Yau, 2004b: Reply. Mon. Wea. Rev., 132 , 25142519.

  • Mesinger, F., and Coauthors, 2006: North American Regional Reanalysis. Bull. Amer. Meteor. Soc., 87 , 343360.

  • Morgan, M., and J. Nielsen-Gammon, 1998: Using tropopause maps to diagnose midlatitude weather systems. Mon. Wea. Rev., 126 , 25552579.

    • Search Google Scholar
    • Export Citation
  • Palmén, E., 1958: Vertical circulation and release of kinetic energy during the development of Hurricane Hazel into an extratropical storm. Tellus, 10 , 123.

    • Search Google Scholar
    • Export Citation
  • Ritchie, E. A., and R. L. Elsberry, 2003: Simulations of the extratropical transition of tropical cyclones: Contributions by the midlatitude upper-level trough to reintensification. Mon. Wea. Rev., 131 , 21122128.

    • Search Google Scholar
    • Export Citation
  • Ritchie, E. A., and R. L. Elsberry, 2007: Simulations of the extratropical transition of tropical cyclones: Phasing between the upper-level trough and tropical cyclones. Mon. Wea. Rev., 135 , 862876.

    • Search Google Scholar
    • Export Citation
  • Thorncroft, C., and S. Jones, 2000: The extratropical transition of Hurricanes Felix and Iris in 1995. Mon. Wea. Rev., 128 , 947972.

  • Trenberth, K. E., 1978: On the interpretation of the diagnostic quasi-geostrophic omega equation. Mon. Wea. Rev., 106 , 131137.

  • Weese, S., 2003: A reanalysis of Hurricane Hazel (1954). M.S. thesis, Dept. of Atmospheric and Oceanic Sciences, McGill University, 123 pp.

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