The Kinematic Structure of a Wasatch Mountain Winter Storm during IPEX IOP3

Justin A. W. Cox NOAA/Cooperative Institute for Regional Prediction, and Department of Meteorology, University of Utah, Salt Lake City, Utah

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W. James Steenburgh NOAA/Cooperative Institute for Regional Prediction, and Department of Meteorology, University of Utah, Salt Lake City, Utah

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David E. Kingsmill Desert Research Institute, Reno, Nevada

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Jason C. Shafer NOAA/Cooperative Institute for Regional Prediction, and Department of Meteorology, University of Utah, Salt Lake City, Utah

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Brian A. Colle Institute for Terrestrial and Planetary Atmospheres, State University of New York at Stony Brook, Stony Brook, New York

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Olivier Bousquet Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada

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Bradley F. Smull Department of Atmospheric Sciences, University of Washington, Seattle, Washington

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Huaqing Cai Desert Research Institute, Reno, Nevada

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Abstract

The influence of orographic circulations on the precipitation structure of a Wasatch Mountain winter storm is examined using observations collected during the third intensive observing period (IOP3) of the Intermountain Precipitation Experiment (IPEX). The event featured the passage of a midlevel (700–550 hPa) trough followed 3 h later by a surface trough. Prior to and during the midlevel trough passage, large-scale southwesterly flow impinged on the Wasatch Mountains. Low-level confluence was observed between this southwesterly flow and along-barrier southerly flow within 20–40 km of the Wasatch Mountains. This confluence zone, which moved toward the Wasatch Mountains during and following the passage of the midlevel trough, was accompanied by low-level convergence and precipitation enhancement over the upstream lowlands. Dual-Doppler analysis revealed the presence of a shallow along-barrier jet near the base of the Wasatch Mountains that was surmounted by southwesterly cross-barrier flow at mid- and upper-mountain levels. This cross-barrier flow produced strong (1–2 m s−1) ascent as it interacted with the steep windward slopes of the Wasatch Mountains, where precipitation was roughly double that observed in the lowlands upstream. Flow deflection and splitting were also observed near the highest terrain features. A narrow region of strong subsidence, which at times exceeded 2 m s−1, was found to the lee of the Wasatch and, based on radar imagery, appeared to modulate hydrometeor spillover aloft. Processes contributing to the evolution of the near-barrier flow field, including topographic blocking, diabatic effects, and surface friction contrasts, are discussed.

Corresponding author address: Justin A. W. Cox, Dept. of Meteorology, University of Utah, 135 South 1460 East, Room 819, Salt Lake City, UT 84112. Email: jacox@met.utah.edu

Abstract

The influence of orographic circulations on the precipitation structure of a Wasatch Mountain winter storm is examined using observations collected during the third intensive observing period (IOP3) of the Intermountain Precipitation Experiment (IPEX). The event featured the passage of a midlevel (700–550 hPa) trough followed 3 h later by a surface trough. Prior to and during the midlevel trough passage, large-scale southwesterly flow impinged on the Wasatch Mountains. Low-level confluence was observed between this southwesterly flow and along-barrier southerly flow within 20–40 km of the Wasatch Mountains. This confluence zone, which moved toward the Wasatch Mountains during and following the passage of the midlevel trough, was accompanied by low-level convergence and precipitation enhancement over the upstream lowlands. Dual-Doppler analysis revealed the presence of a shallow along-barrier jet near the base of the Wasatch Mountains that was surmounted by southwesterly cross-barrier flow at mid- and upper-mountain levels. This cross-barrier flow produced strong (1–2 m s−1) ascent as it interacted with the steep windward slopes of the Wasatch Mountains, where precipitation was roughly double that observed in the lowlands upstream. Flow deflection and splitting were also observed near the highest terrain features. A narrow region of strong subsidence, which at times exceeded 2 m s−1, was found to the lee of the Wasatch and, based on radar imagery, appeared to modulate hydrometeor spillover aloft. Processes contributing to the evolution of the near-barrier flow field, including topographic blocking, diabatic effects, and surface friction contrasts, are discussed.

Corresponding author address: Justin A. W. Cox, Dept. of Meteorology, University of Utah, 135 South 1460 East, Room 819, Salt Lake City, UT 84112. Email: jacox@met.utah.edu

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  • Atlas, D., R. C. Srivastava, and R. S. Sekhon, 1973: Doppler radar characteristics of precipitation at vertical incidence. Rev. Geophys. Space Phys., 11 , 135.

    • Search Google Scholar
    • Export Citation
  • Bell, G. D., and L. F. Bosart, 1988: Appalachian cold-air damming. Mon. Wea. Rev., 116 , 137161.

  • Blazek, T. R., 2000: Analysis of a Great Basin cyclone and attendant mesoscale features. M.S. thesis, Dept. of Meteorology, University of Utah, 122 pp. [Available from Department of Meteorology, University of Utah, 135 South 1460 East, Salt Lake City, UT 84112.].

  • Bougeault, P., and Coauthors, 2001: The MAP special observing period. Bull. Amer. Meteor. Soc., 82 , 433462.

  • Bousquet, O., and B. F. Smull, 2003a: Observations and impacts of upstream blocking during a widespread orographic precipitation event. Quart. J. Roy. Meteor. Soc., 129 , 391409.

    • Search Google Scholar
    • Export Citation
  • Bousquet, O., and B. F. Smull, 2003b: Airflow and precipitation fields within deep Alpine valleys observed by airborne Doppler radar. J. Appl. Meteor., 42 , 14971513.

    • Search Google Scholar
    • Export Citation
  • Braun, S. A., R. Rotunno, and J. B. Klemp, 1999: Effects of coastal orography on landfalling cold fronts. Part I: Dry, inviscid dynamics. J. Atmos. Sci., 56 , 517533.

    • Search Google Scholar
    • Export Citation
  • Bruintjes, R., T. Clark, and W. Hall, 1994: Interaction between topographic airflow and cloud and precipitation development during the passage of a winter storm in Arizona. J. Atmos. Sci., 51 , 4867.

    • Search Google Scholar
    • Export Citation
  • Bryan, G. H., and M. J. Fritsch, 2000: Moist absolute instability: The sixth static stability state. Bull. Amer. Meteor. Soc., 81 , 12071230.

    • Search Google Scholar
    • Export Citation
  • Colle, B. A., and C. F. Mass, 1995: The structure and evolution of cold surges east of the Rocky Mountains. Mon. Wea. Rev., 123 , 25772610.

    • Search Google Scholar
    • Export Citation
  • Colle, B. A., and C. F. Mass, 1996: An observational and modeling study of the interaction of low-level southwesterly flow with the Olympic Mountains during COAST IOP4. Mon. Wea. Rev., 124 , 21522175.

    • Search Google Scholar
    • Export Citation
  • Cooper, W. A., and C. P. R. Saunders, 1980: Winter storms over the San Juan Mountains. Part II: Microphysical processes. J. Appl. Meteor., 19 , 927941.

    • Search Google Scholar
    • Export Citation
  • Cox, J. A. W., 2002: Kinematic structure of a Wasatch Mountain snowstorm. M.S. thesis, Dept. of Meteorology, University of Utah, 60 pp. [Available from Department of Meteorology, University of Utah, 135 South 1460 East, Room 819, Salt Lake City, UT 84112-0110.].

  • Cressman, G. P., 1959: An operational objective analysis system. Mon. Wea. Rev., 87 , 367374.

  • Crum, T. D., R. L. Alberty, and D. W. Burgess, 1993: Recording, archiving, and using WSR-88D data. Bull. Amer. Meteor. Soc., 74 , 645653.

    • Search Google Scholar
    • Export Citation
  • Dunn, L. B., 1987: Cold air damming by the Front Range of the Colorado Rockies and its relationship to locally heavy snows. Wea. Forecasting, 2 , 177189.

    • Search Google Scholar
    • Export Citation
  • Dunn, L. B., 1992: Evidence of ascent in a sloped barrier jet and associated heavy-snow band. Mon. Wea. Rev., 120 , 914924.

  • Durran, D. R., 1986: Mountain waves. Mesoscale Meteorology and Forecasting, P. S. Ray, Ed., Amer. Meteor. Soc., 472–492.

  • Durran, D. R., and J. B. Klemp, 1982: On the effects of moisture on the Brunt–Väisälä frequency. J. Atmos. Sci., 39 , 21522158.

  • Foote, G. B., and P. S. du Toit, 1969: Terminal velocity of raindrops aloft. J. Appl. Meteor., 8 , 249253.

  • Fritsch, J. M., J. Kapolka, and P. A. Hirschberg, 1992: The effects of subcloud-layer diabatic processes on cold air damming. J. Atmos. Sci., 49 , 4970.

    • Search Google Scholar
    • Export Citation
  • Fritsch, J. M., and Coauthors, 1998: Quantitative precipitation forecasting: Report of the Eighth Prospectus Development Team, U. S. Weather Research Program. Bull. Amer. Meteor. Soc., 79 , 285299.

    • Search Google Scholar
    • Export Citation
  • Fujita, T., 1963: Analytical mesometeorology: A review. Severe Local Storms, Meteor. Monogr., No. 27, Amer. Meteor. Soc., 77–125.

  • Heggli, M. F., and R. M. Rauber, 1988: The characteristics and evolution of supercooled water in wintertime storms over the Sierra Nevada: A summary of microwave radiometric measurements taken during the Sierra Cooperative Pilot Project. J. Appl. Meteor., 27 , 9891015.

    • Search Google Scholar
    • Export Citation
  • Hill, G. E., 1978: Observations of precipitation-forced circulations in winter orographic storms. J. Atmos. Sci., 35 , 14631472.

  • Hobbs, P. V., 1975: The nature of winter clouds and precipitation in the Cascade Mountains and their modification by artificial seeding. Part I: Natural conditions. J. Appl. Meteor., 14 , 783804.

    • Search Google Scholar
    • Export Citation
  • Horel, J., and Coauthors, 2002: Mesowest: Cooperative mesonets in the western United States. Bull. Amer. Meteor. Soc., 83 , 211225.

  • Huggins, A. W., 1995: Mobile microwave radiometer observations: Spatial characteristics of supercooled cloud liquid water and cloud seeding implications. J. Appl. Meteor., 34 , 432446.

    • Search Google Scholar
    • Export Citation
  • Jorgensen, D. P., T. Matejka, and J. D. DuGranrut, 1996: Multibeam techniques for deriving wind fields from airborne Doppler radars. J. Meteor. Atmos. Phys., 59 , 83104.

    • Search Google Scholar
    • Export Citation
  • Kain, J. S., S. M. Goss, and M. E. Baldwin, 2000: The melting effect as a factor in precipitation-type forecasting. Wea. Forecasting, 15 , 700714.

    • Search Google Scholar
    • Export Citation
  • Klimowski, B. A., and Coauthors, 1998: The 1995 Arizona Program: Toward a better understanding of winter storm precipitation development in mountainous terrain. Bull. Amer. Meteor. Soc., 79 , 799813.

    • Search Google Scholar
    • Export Citation
  • Lazarus, S. M., C. M. Ciliberti, J. D. Horel, and K. A. Brewster, 2002: Near-real-time applications of a mesoscale analysis system to complex terrain. Wea. Forecasting, 17 , 9711000.

    • Search Google Scholar
    • Export Citation
  • Long, A. B., B. A. Campistron, and A. W. Huggins, 1990: Investigations of a winter mountain storm in Utah. Part I: Synoptic analyses, mesoscale kinematics, and water release rates. J. Atmos. Sci., 47 , 13021322.

    • Search Google Scholar
    • Export Citation
  • Marwitz, J. D., 1980: Winter storms over the San Juan Mountains. Part I: Dynamical processes. J. Appl. Meteor., 19 , 913926.

  • Marwitz, J. D., 1987a: Deep orographic storms over the Sierra Nevada. Part I: Thermodynamic and kinematic structure. J. Atmos. Sci., 44 , 159173.

    • Search Google Scholar
    • Export Citation
  • Marwitz, J. D., 1987b: Deep orographic storms over the Sierra Nevada. Part II: The precipitation process. J. Atmos. Sci., 44 , 174185.

    • Search Google Scholar
    • Export Citation
  • Marwitz, J. D., and J. Toth, 1993: The Front Range blizzard of 1990. Part I: Synoptic and mesoscale structure. Mon. Wea. Rev., 121 , 402415.

    • Search Google Scholar
    • Export Citation
  • Mass, C. F., and M. D. Albright, 1987: Coastal southerlies and alongshore surges of the west coast of North America: Evidence of mesoscale topographically trapped response to synoptic forcing. Mon. Wea. Rev., 115 , 17071738.

    • Search Google Scholar
    • Export Citation
  • Mass, C. F., and W. J. Steenburgh, 2000: An observational and numerical study of an orographically trapped wind reversal along the west coast of the United States. Mon. Wea. Rev., 128 , 23632397.

    • Search Google Scholar
    • Export Citation
  • Medina, S., and R. A. Houze Jr., 2003: Air motions and precipitation growth in Alpine storms. Quart. J. Roy. Meteor. Soc., 129 , 345371.

    • Search Google Scholar
    • Export Citation
  • Mohr, C. G., and L. J. Miller, 1983: CEDRIC—A software package for Cartesian space editing, synthesis, and display of radar fields under interactive control. Preprints. 21st Conf. on Radar Meteorology, Edmonton, AB, Canada, Amer. Meteor. Soc., 559–574.

    • Search Google Scholar
    • Export Citation
  • Neiman, P. J., and M. A. Shapiro, 1993: The life cycle of an extratropical marine cyclone. Part I: Frontal-cyclone evolution and thermodynamic air–sea interaction. Mon. Wea. Rev., 121 , 21532176.

    • Search Google Scholar
    • Export Citation
  • Neiman, P. J., F. M. Ralph, A. B. White, D. E. Kingsmill, and P. O. G. Persson, 2002: The statistical relationship between upslope flow and rainfall in California’s coastal mountains: Observations during CALJET. Mon. Wea. Rev., 130 , 14681492.

    • Search Google Scholar
    • Export Citation
  • Overland, J. E., and N. A. Bond, 1995: Observations and scale analysis of coastal wind jets. Mon. Wea. Rev., 123 , 29342941.

  • Parish, T. R., 1982: Barrier winds along the Sierra Nevada Mountains. J. Appl. Meteor., 21 , 925930.

  • Peterson, T. C., L. O. Grant, W. R. Cotton, and D. C. Rogers, 1991: The effect of decoupled low-level flow on winter orographic clouds and precipitation in the Yampa River Valley. J. Appl. Meteor., 30 , 368386.

    • Search Google Scholar
    • Export Citation
  • Pierrehumbert, R. T., and B. Wyman, 1985: Upstream effects of mesoscale mountains. J. Atmos. Sci., 42 , 9771003.

  • Rauber, R. M., 1992: Microphysical structure and evolution of a central Sierra Nevada orographic cloud system. J. Appl. Meteor., 31 , 325.

    • Search Google Scholar
    • Export Citation
  • Rauber, R. M., and L. O. Grant, 1986: The characteristics and distribution of cloud water over the mountains of northern Colorado during wintertime storms. Part II: Spatial distribution and microphysical characteristics. J. Climate Appl. Meteor., 25 , 489504.

    • Search Google Scholar
    • Export Citation
  • Rauber, R. M., L. O. Grant, D. Feng, and J. B. Snider, 1986: The characteristics and distribution of cloud water over the mountains of northern Colorado during wintertime storms. Part I: Temporal variations. J. Climate Appl. Meteor., 25 , 468488.

    • Search Google Scholar
    • Export Citation
  • Reinking, R. F., J. B. Snider, and J. L. Coen, 2000: Influences of storm-embedded orographic gravity waves on cloud liquid water and precipitation. J. Appl. Meteor., 39 , 733759.

    • Search Google Scholar
    • Export Citation
  • Roeloffzen, J. C., W. D. Van Den Berg, and J. Oerlemans, 1986: Frictional convergence at coastlines. Tellus, 38A , 397411.

  • Rotunno, R., and R. Ferretti, 2001: Mechanisms of intense Alpine rainfall. J. Atmos. Sci., 58 , 17321749.

  • Sassen, K., 1984: Deep orographic cloud structure and composition derived from comprehensive remote sensing measurements. J. Climate Appl. Meteor., 23 , 568583.

    • Search Google Scholar
    • Export Citation
  • Sassen, K., R. M. Rauber, and J. B. Snider, 1986: Multiple remote sensor observations of supercooled liquid water in a winter storm at Beaver, Utah. J. Climate Appl. Meteor., 25 , 825834.

    • Search Google Scholar
    • Export Citation
  • Sassen, K., A. W. Huggins, A. B. Long, J. B. Snider, and R. J. Meitín, 1990: Investigations of a winter mountain storm in Utah. Part II: Mesoscale structure, supercooled liquid water development, and precipitation processes. J. Atmos. Sci., 47 , 13231350.

    • Search Google Scholar
    • Export Citation
  • Schultz, D. M., and Coauthors, 2002: Understanding Utah winter storms: The Intermountain Precipitation Experiment. Bull. Amer. Meteor. Soc., 83 , 189210.

    • Search Google Scholar
    • Export Citation
  • Shafer, J. C., 2002: Synoptic and mesoscale structure of a Wasatch Mountain winter storm. M.S. thesis, Dept. of Meteorology, University of Utah, 70 pp. [Available from Department of Meteorology, University of Utah, 135 South 1460 East, Room 819, Salt Lake City, UT 84112-0110.].

  • Smith, R., and Coauthors, 1997: Local and remote effects of mountains on weather: Research needs and opportunities. Bull. Amer. Meteor. Soc., 78 , 877892.

    • Search Google Scholar
    • Export Citation
  • Steenburgh, W. J., 2004: One hundred inches in one hundred hours: Evolution of a Wasatch Mountain winter storm cycle. Wea. Forecasting, 19 , 10181036.

    • Search Google Scholar
    • Export Citation
  • Steiner, M., O. Bousquet, R. A. Houze Jr., B. F. Smull, and M. Mancini, 2003: Airflow within major Alpine river valleys under heavy rainfall. Quart. J. Roy. Meteor. Soc., 129 , 411432.

    • Search Google Scholar
    • Export Citation
  • Wexler, R., R. J. Reed, and J. Honig, 1954: Atmospheric cooling by melting snow. Bull. Amer. Meteor. Soc., 35 , 4851.

  • Wurman, J., J. Straka, E. Rasmussen, M. Randall, and A. Zahrai, 1997: Design and deployment of a portable, pencil-beam, pulsed, 3-cm Doppler radar. J. Atmos. Oceanic Technol., 14 , 15021512.

    • Search Google Scholar
    • Export Citation
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