• Abraham, J., , K. Macdonald, , and P. Joe, 1991: The interaction of Hurricane Hugo with the mid-latitude westerlies. Preprints, 19th Conf. on Hurricanes and Tropical Meteorology, Miami, FL, Amer. Meteor. Soc., 124–129.

    • Search Google Scholar
    • Export Citation
  • Anthes, R. A., , Y-H. Kuo, , and J. R. Gyakum, 1983: Numerical simulations of a case of explosive marine cyclogenesis. Mon. Wea. Rev, 111 , 11741188.

    • Search Google Scholar
    • Export Citation
  • Bosart, L. F., , and D. B. Dean, 1991: The Agnes rainstorm of June 1972: Surface feature evolution culminating in inland storm redevelopment. Wea. Forecasting, 6 , 515537.

    • Search Google Scholar
    • Export Citation
  • Bristor, C. L., 1951: The great storm of November, 1950. Weatherwise, 4 , 1016.

  • Cardone, V. J., , R. E. Jensen, , D. T. Resio, , V. R. Swail, , and A. T. Cox, 1996: Evaluation of contemporary ocean wave models in rare extreme events: “Halloween storm” of October 1991 and the “storm of the century” of March 1993. J. Atmos. Oceanic Technol, 13 , 198230.

    • Search Google Scholar
    • Export Citation
  • DeGaetano, A. T., 2000: Climatic perspective and impacts of the 1998 northern New York and New England ice storm. Bull. Amer. Meteor. Soc, 81 , 237254.

    • Search Google Scholar
    • Export Citation
  • Dickinson, M. J., , L. F. Bosart, , W. E. Bracken, , G. J. Hakim, , D. M. Schultz, , M. A. Bedrick, , and K. R. Tyle, 1997: The March 1993 superstorm cyclogenesis: Incipient phase synoptic-and convective-scale flow interaction and model performance. Mon. Wea. Rev, 125 , 30413072.

    • Search Google Scholar
    • Export Citation
  • DiMego, G. J., , and L. F. 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. J., , and L. F. 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
  • Fujita, T. T., 1981: Tornadoes and downbursts in the context of generalized planetary scales. J. Atmos. Sci, 38 , 15111534.

  • Gaza, B., , and L. F. Bosart, 1990: Trough merger characteristics over North America. Wea. Forecasting, 5 , 314331.

  • Grumm, R. H., , and D. Nicosia, 1997: WSR-88D observations of mesoscale precipitation bands over Pennsylvania. Natl. Wea. Dig, 21 , 1023.

    • Search Google Scholar
    • Export Citation
  • Gyakum, J. R., 1983a: On the evolution of the QE II storm. Part I: Synoptic aspects. Mon. Wea. Rev, 111 , 11371155.

  • Gyakum, J. R., 1983b: On the evolution of the QEII storm. Part II: Dynamic and thermodynamic structure. Mon. Wea. Rev, 111 , 11561173.

    • Search Google Scholar
    • Export Citation
  • Gyakum, J. R., 1991: Meteorological precursors to the explosive intensification of the QEII Storm. Mon. Wea. Rev, 119 , 11051131.

  • Hakim, G. J., , L. F. Bosart, , and D. Keyser, 1995: The Ohio Valley wave-merger cyclogenesis event of 25–26 January 1978. Part I: Multiscale case study. Mon. Wea. Rev, 123 , 26632692.

    • Search Google Scholar
    • Export Citation
  • Hakim, G. J., , D. Keyser, , and L. F. Bosart, 1996: The Ohio Valley wave-merger cyclogenesis event of 25–26 January 1978. Part II: Diagnosis using quasigeostrophic potential vorticity inversion. Mon. Wea. Rev, 124 , 21762205.

    • Search Google Scholar
    • Export Citation
  • Hoskins, B., , and P. J. Valdes, 1990: On the existence of storm-tracks. J. Atmos. Sci, 47 , 18541864.

  • Jarvinen, B. R., , C. J. Neumann, , and M. A. S. Davis, 1984: A tropical cyclone data tape for the North Atlantic basin, 1886–1983: Contents, limitations, and uses. NOAA Tech. Memo. NWS NHC 22, 21 pp.

    • Search Google Scholar
    • Export Citation
  • Junger, S., 1997: The Perfect Storm. Harper, 302 pp.

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

  • Knox, J. L., 1955: The storm “Hazel,” synoptic resume of its development as it approached southern Ontario. Bull. Amer. Meteor. Soc, 36 , 239246.

    • Search Google Scholar
    • Export Citation
  • Kocin, P. J., , and L. W. Uccellini, 1990: Snowstorms along the Northeastern Coast of the United States: 1955 to 1985. Meteor. Monogr., No. 44, Amer. Meteor. Soc., 280 pp.

    • Search Google Scholar
    • Export Citation
  • Kocin, P. J., , P. N. Schumacher, , R. F. Morales Jr., , and L. W. Uccellini, 1995: Overview of the 12–14 March 1993 superstorm. Bull. Amer. Meteor. Soc, 76 , 165182.

    • Search Google Scholar
    • Export Citation
  • Leathers, D. J., , D. R. Kluck, , and S. Kroczynski, 1998: The severe flooding event of January 1996 across north-central Pennsylvania. Bull. Amer. Meteor. Soc, 79 , 785797.

    • Search Google Scholar
    • Export Citation
  • Ludlum, D. M., 1951: Winter strikes early in 1951. Weatherwise, 4 , 131141.

  • Ludlum, D. M., 1952: An intense November storm. Weatherwise, 6 , 1819.

  • Ludlum, D. M., 1956: The Great Atlantic Low. Weatherwise, 9 , 6465.

  • Ludlum, D. M., 1958a: Winter 1957–1958: A divided nation. Weatherwise, 11 , 6773.

  • Ludlum, D. M., 1958b: Eve of spring snowstorm. Weatherwise, 11 , 109.

  • NOAA, 1959–2000: Storm Data. Vols. 1–42. [Available from NCDC, 151 Patton Ave., Asheville, NC 28801-S001.].

  • 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
  • Palmer, W. C., 1965: Meteorological drought. Research Paper 45, U.S. Department of Commerce Weather Bureau, Washington, DC, 58 pp.

  • Pearce, M. L., 1997: Non-classic and weakly forced convective events: A forecasting challenge for the dominant form of severe weather in the Mid Atlantic region of the United States. M.S. thesis, Dept. of Meteorology, The Pennsylvania State University, 106 pp. [Available from Dept. of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802.].

    • Search Google Scholar
    • Export Citation
  • Ruscher, P. H., , and T. P. Condo, 1996a: Development of a rapidly deepening extratropical cyclone over land. Part I: Kinematic aspects. Mon. Wea. Rev, 124 , 16091632.

    • Search Google Scholar
    • Export Citation
  • Ruscher, P. H., , and T. P. Condo, 1996b: Development of a rapidly deepening extratropical cyclone over land. Part II: Thermodynamic aspects and the role of frontogenesis. Mon. Wea. Rev, 124 , 16331647.

    • Search Google Scholar
    • Export Citation
  • Sanders, F., , and J. R. Gyakum, 1980: Synoptic-dynamic climatology of the “bomb.”. Mon. Wea. Rev, 108 , 15891606.

  • Schwartz, G., 1977: The day it snowed in Miami. Weatherwise, 30 , 50.

  • Simpson, R. H., 1974: The hurricane disaster-potential scale. Weatherwise, 27 , 169.

  • Treidl, R. A., 1959: The great Midwinter storm of 20–22 January 1959. Weatherwise, 12 , 4547.

  • Uccellini, L. W., 1986: The possible influence of upstream upper-level baroclinic processes on the development of the QEII storm. Mon. Wea. Rev, 114 , 10191027.

    • Search Google Scholar
    • Export Citation
  • van Loon, H., , and J. C. Rogers, 1978: The seesaw in winter temperatures between Greenland and northern Europe. Part I: General description. Mon. Wea. Rev, 106 , 296310.

    • Search Google Scholar
    • Export Citation
  • Watson, B., 1993: New respect for nor'easters. Weatherwise, 46 , 1823.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 117 117 18
PDF Downloads 105 105 18

Using Normalized Climatological Anomalies to Rank Synoptic-Scale Events Objectively

View More View Less
  • 1 Department of Meteorology, The Pennsylvania State University, University Park, Pennsylvania
  • | 2 National Weather Service, State College, Pennsylvania
© Get Permissions
Restricted access

Abstract

A method for ranking synoptic-scale events objectively is presented. NCEP 12-h reanalysis fields from 1948 to 2000 are compared to a 30-yr (1961–90) reanalysis climatology. The rarity of an event is the number of standard deviations 1000–200-hPa height, temperature, wind, and moisture fields depart from this climatology. The top 20 synoptic-scale events from 1948 to 2000 for the eastern United States, southeast Canada, and adjacent coastal waters are presented. These events include the “The Great Atlantic Low” of 1956 (ranked 1st), the “superstorm” of 1993 (ranked 3d), the historic New England/Quebec ice storm of 1998 (ranked 5th), extratropical storm Hazel of 1954 (ranked 9th), a catastrophic Florida freeze and snow in 1977 (ranked 11th), and the great Northeast snowmelt and flood of 1996 (ranked 12th).

During the 53-yr analysis period, only 33 events had a total normalized anomaly (MTOTAL) of 4 standard deviations or more. An MTOTAL of 5 or more standard deviations has not been observed during the 53-yr period. An MTOTAL of 3 or more was observed, on average, once or twice a month. October through January are the months when a rare anomaly (MTOTAL ≥ 4 standard deviations) is most likely, with April through September the least likely period. The 1960s and 1970s observed the fewest number of monthly top 10 events, with the 1950s, 1980s, and 1990s having the greatest number. A comparison of the evolution of MTOTAL to various climate indices reveals that only 5% of the observed variance of MTOTAL can be explained by ENSO, North Atlantic oscillations, or Pacific–North American indices. Therefore, extreme synoptic-scale departures from climatology occur regardless of the magnitude of conventional climate indices, a consequence of a necessary mismatch of temporal and spatial scale representation between the MTOTAL and climate index measurements.

Corresponding author address: Dr. Robert E. Hart, Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802. Email: hart@ems.psu.edu

Abstract

A method for ranking synoptic-scale events objectively is presented. NCEP 12-h reanalysis fields from 1948 to 2000 are compared to a 30-yr (1961–90) reanalysis climatology. The rarity of an event is the number of standard deviations 1000–200-hPa height, temperature, wind, and moisture fields depart from this climatology. The top 20 synoptic-scale events from 1948 to 2000 for the eastern United States, southeast Canada, and adjacent coastal waters are presented. These events include the “The Great Atlantic Low” of 1956 (ranked 1st), the “superstorm” of 1993 (ranked 3d), the historic New England/Quebec ice storm of 1998 (ranked 5th), extratropical storm Hazel of 1954 (ranked 9th), a catastrophic Florida freeze and snow in 1977 (ranked 11th), and the great Northeast snowmelt and flood of 1996 (ranked 12th).

During the 53-yr analysis period, only 33 events had a total normalized anomaly (MTOTAL) of 4 standard deviations or more. An MTOTAL of 5 or more standard deviations has not been observed during the 53-yr period. An MTOTAL of 3 or more was observed, on average, once or twice a month. October through January are the months when a rare anomaly (MTOTAL ≥ 4 standard deviations) is most likely, with April through September the least likely period. The 1960s and 1970s observed the fewest number of monthly top 10 events, with the 1950s, 1980s, and 1990s having the greatest number. A comparison of the evolution of MTOTAL to various climate indices reveals that only 5% of the observed variance of MTOTAL can be explained by ENSO, North Atlantic oscillations, or Pacific–North American indices. Therefore, extreme synoptic-scale departures from climatology occur regardless of the magnitude of conventional climate indices, a consequence of a necessary mismatch of temporal and spatial scale representation between the MTOTAL and climate index measurements.

Corresponding author address: Dr. Robert E. Hart, Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802. Email: hart@ems.psu.edu

Save