Editorial Type:
Article
Article Type:
Research Article

Terrain Influences on Synoptic Storm Structure and Mesoscale Precipitation Distribution during IPEX IOP3

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

Search for other papers by Jason C. Shafer in
Current site
Google Scholar
PubMed Close
,
W. James Steenburgh NOAA Cooperative Institute for Regional Prediction, and Department of Meteorology, University of Utah, Salt Lake City, Utah

Search for other papers by W. James Steenburgh in
Current site
Google Scholar
PubMed Close
,
Justin A. W. Cox NOAA Cooperative Institute for Regional Prediction, and Department of Meteorology, University of Utah, Salt Lake City, Utah

Search for other papers by Justin A. W. Cox in
Current site
Google Scholar
PubMed Close
, and
John P. Monteverdi San Francisco State University, San Francisco, California

Search for other papers by John P. Monteverdi in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Feb 2006
DOI:
https://doi.org/10.1175/MWR3051.1
Page(s):
478–497
Restricted access

Abstract

The influence of topography on the evolution of a winter storm over the western United States and distribution of precipitation over northern Utah are examined using data collected during the third intensive observing period (IOP3) of the Intermountain Precipitation Experiment (IPEX). The analysis is based on high-density surface observations collected by the MesoWest cooperative networks, special radiosonde observations, wind profiler observations, Next-Generation Weather Radar (NEXRAD) data, and conventional data. A complex storm evolution was observed, beginning with frontal distortion and low-level frontolysis as a surface occluded front approached the Sierra Nevada. As the low-level occluded front weakened, the associated upper-level trough moved over the Sierra Nevada and overtook a lee trough. The upper-level trough, which was forward sloping and featured more dramatic moisture than temperature gradients, then moved across Nevada with a weak surface reflection as a pressure trough.

Over northern Utah, detailed observations revealed the existence of a midlevel trough beneath the forward-sloping upper-level trough. This midlevel trough appeared to form along a high-potential-vorticity banner that developed over the southern Sierra Nevada and moved downstream over northern Utah. A surface trough moved over northern Utah 3 h after the midlevel trough and delineated two storm periods. Ahead of the surface trough, orographic precipitation processes dominated and produced enhanced mountain precipitation. This period also featured lowland precipitation enhancement upstream of the northern Wasatch Mountains where a windward convergence zone was present. Precipitation behind the surface trough was initially dominated by orographic processes, but soon thereafter featured convective precipitation that was not fixed to the terrain. Processes responsible for the complex vertical trough structure and precipitation distribution over northern Utah are discussed.

Corresponding author address: Jason C. Shafer, Dept. of Meteorology, Lyndon State College, 1001 College Rd., Lyndonville, VT 05851. Email: jason.shafer@lyndonstate.edu

Abstract

The influence of topography on the evolution of a winter storm over the western United States and distribution of precipitation over northern Utah are examined using data collected during the third intensive observing period (IOP3) of the Intermountain Precipitation Experiment (IPEX). The analysis is based on high-density surface observations collected by the MesoWest cooperative networks, special radiosonde observations, wind profiler observations, Next-Generation Weather Radar (NEXRAD) data, and conventional data. A complex storm evolution was observed, beginning with frontal distortion and low-level frontolysis as a surface occluded front approached the Sierra Nevada. As the low-level occluded front weakened, the associated upper-level trough moved over the Sierra Nevada and overtook a lee trough. The upper-level trough, which was forward sloping and featured more dramatic moisture than temperature gradients, then moved across Nevada with a weak surface reflection as a pressure trough.

Over northern Utah, detailed observations revealed the existence of a midlevel trough beneath the forward-sloping upper-level trough. This midlevel trough appeared to form along a high-potential-vorticity banner that developed over the southern Sierra Nevada and moved downstream over northern Utah. A surface trough moved over northern Utah 3 h after the midlevel trough and delineated two storm periods. Ahead of the surface trough, orographic precipitation processes dominated and produced enhanced mountain precipitation. This period also featured lowland precipitation enhancement upstream of the northern Wasatch Mountains where a windward convergence zone was present. Precipitation behind the surface trough was initially dominated by orographic processes, but soon thereafter featured convective precipitation that was not fixed to the terrain. Processes responsible for the complex vertical trough structure and precipitation distribution over northern Utah are discussed.

Corresponding author address: Jason C. Shafer, Dept. of Meteorology, Lyndon State College, 1001 College Rd., Lyndonville, VT 05851. Email: jason.shafer@lyndonstate.edu

Save
Cover Monthly Weather Review
Monthly Weather Review

  • Alter, J. C., 1919: Normal precipitation in Utah. Mon. Wea. Rev, 47 , 633–636.

  • Baer, V. E., 1991: The transition from the present radar dissemination system to the NEXRAD Information Dissemination Service (NIDS). Bull. Amer. Meteor. Soc, 72 , 29–33.

    • Search Google Scholar
    • Export Citation

  • Benjamin, S. G., and Coauthors, 2004: An hourly assimilation-forecast cycle: The RUC. Mon. Wea. Rev, 132 , 495–518.

  • 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 Dept. of Meteorology, University of Utah, 145 South 1460 East, Room 819, Salt Lake City, UT 84112-0110.].

  • Bluestein, H. B., 1986: Fronts and jet streaks: A theoretical perspective. Mesoscale Meteorology and Forecasting, P. S. Ray, Ed., Amer. Meteor. Soc., 173–215.

    • Search Google Scholar
    • Export Citation

  • Blumen, W., 1992: Propagation of fronts and frontogenesis versus frontolysis over orography. Meteor. Atmos. Phys, 48 , 37–50.

  • Cheng, L., 2001: Validation of quantitative precipitation forecasts during the Intermountain Precipitation Experiment. M.S. thesis, Dept. of Meteorology, University of Utah, 137 pp. [Available from Dept. of Meteorology, University of Utah, 145 South 1460 East, Rm. 819, Salt Lake City, UT 84112-0110.].

  • Colle, B. A., J. B. Wolfe, W. J. Steenburgh, D. E. Kingsmill, J. A. W. Cox, and J. C. Shafer, 2005: High-resolution simulations and microphysical validation of an orographic precipitation event over the Wasatch Mountains during IPEX IOP3. Mon. Wea. Rev, 133 , 2947–2971.

    • Search Google Scholar
    • Export Citation

  • Cox, J. A. W., W. J. Steenburgh, D. E. Kingsmill, J. C. Shafer, B. A. Colle, O. Bousquet, B. F. Smull, and H. Cai, 2005: The kinematic structure of a Wasatch Mountain winter storm during IPEX IOP3. Mon. Wea. Rev, 133 , 521–542.

    • Search Google Scholar
    • Export Citation

  • Daly, C., R. P. Neilson, and D. L. Phillips, 1994: A statistical-to-topographic mode for mapping climatological precipitation over mountainous terrain. J. Appl. Meteor, 33 , 140–158.

    • Search Google Scholar
    • Export Citation

  • Dickinson, M. J., and D. Knight, 1999: Frontal interaction with mesoscale topography. J. Atmos. Sci, 56 , 3544–3559.

  • Egger, J., and K. P. Hoinka, 1992: Fronts and orography. Meteor. Atmos. Phys, 48 , 3–36.

  • Elliott, R. D., 1958: California storm characteristics and weather modification. J. Meteor, 15 , 486–493.

  • Grubisić, V., 2004: Bora-driven potential vorticity banners over the Adriatic. Quart. J. Roy. Meteor. Soc, 130 , 2571–2603.

  • Hess, S. L., and H. Wagner, 1948: Atmospheric waves in the northwestern United States. J. Meteor, 5 , 1–19.

  • Hevesi, J. A., A. L. Flint, and J. D. Istok, 1992: Precipitation estimation in mountainous terrain using multivariate geostatistics. Part II: Isohyetal maps. J. Appl. Meteor, 31 , 677–688.

    • Search Google Scholar
    • Export Citation

  • Hobbs, P. V., J. D. Locatelli, and J. E. Martin, 1996: A new conceptual model for cyclones generated in the lee of the Rocky Mountains. Bull. Amer. Meteor. Soc, 77 , 1169–1178.

    • Search Google Scholar
    • Export Citation

  • Hoffman, E. G., 1995: Evolution and mesoscale structure of fronts in the western United States: A case study. M.S. thesis, Dept. of Earth and Atmospheric Sciences, State University of New York at Albany, 287 pp.

  • Horel, J. D., and C. V. Gibson, 1994: Analysis and simulation of a winter storm over Utah. Wea. Forecasting, 9 , 479–494.

  • Horel, J. D., and Coauthors, 2002: Mesowest: Cooperative mesonets in the western United States. Bull. Amer. Meteor. Soc, 83 , 211–225.

    • Search Google Scholar
    • Export Citation

  • Keyser, D., 1986: Atmospheric fronts: An observational perspectives. Mesoscale Meteorology and Forecasting, P. S. Ray, Ed., Amer. Meteor. Soc., 216–258.

    • 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 , 971–1000.

    • Search Google Scholar
    • Export Citation

  • NCDC, 2000: Storm Data. Vol. 42, No. 2, 127 pp.

  • Peck, E. L., and M. J. Brown, 1962: An approach to the development of isohyetal maps for mountainous areas. J. Geophys. Res, 67 , 681–694.

    • Search Google Scholar
    • Export Citation

  • Reynolds, D. W., and A. P. Kuciauskas, 1988: Remote and in situ observations of Sierra Nevada winter mountains clouds: Relationship between mesoscale structure, precipitation and liquid water. J. Appl. Meteor, 27 , 140–156.

    • Search Google Scholar
    • Export Citation

  • Sanders, F., 1999: A proposed method of surface map analysis. Mon. Wea. Rev, 127 , 945–955.

  • Schär, C., M. Sprenger, D. Lüthi, Q. Jiang, R. B. Smith, and R. Benoit, 2003: Structure and dynamics of an Alpine potential-vorticity banner. Quart. J. Roy. Meteor. Soc, 129 , 825–855.

    • Search Google Scholar
    • Export Citation

  • Schultz, D. M., and C. A. Doswell III, 2000: Analyzing and forecasting Rocky Mountain lee cyclogenesis often associated with strong winds. Wea. Forecasting, 15 , 152–173.

    • Search Google Scholar
    • Export Citation

  • Schultz, D. M., and R. J. Trapp, 2003: Nonclassical cold-frontal structure caused by dry subcloud air in northern Utah during the Intermountain Precipitation Experiment (IPEX). Mon. Wea. Rev, 131 , 2222–2246.

    • Search Google Scholar
    • Export Citation

  • Schultz, D. M., and Coauthors, 2002: Understanding Utah winter storms: The Intermountain Precipitation Experiment. Bull. Amer. Meteor. Soc, 83 , 190–210.

    • Search Google Scholar
    • Export Citation

  • Schumacher, P. N., D. J. Knight, and L. F. Bosart, 1996: Frontal interaction with the Appalachian Mountains. Part I: A climatology. Mon. Wea. Rev, 124 , 2453–2468.

    • 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, 65 pp. [Available from Dept. of Meteorology, University of Utah, 135 South 1460 East, Rm. 819, Salt Lake City, UT 84112-0110.].

  • Spencer, P. L., F. H. Carr, and C. A. Doswell, 1996: Diagnosis of an amplifying and decaying baroclinic wave using wind profiler data. Mon. Wea. Rev, 124 , 209–223.

    • Search Google Scholar
    • Export Citation

  • Splitt, M. E., and J. D. Horel, 1998: Use of multivariate linear regression for meteorological data analysis and quality assessment in complex terrain. Preprints, 10th Symp. on Meteorological Observations and Instrumentation, Phoenix, AZ, Amer. Meteor. Soc., 359–362.

  • Steenburgh, W. J., 2003: One hundred inches in one hundred hours: Evolution of a Wasatch Mountain winter storm cycle. Wea. Forecasting, 18 , 1018–1036.

    • Search Google Scholar
    • Export Citation

  • Steenburgh, W. J., and T. R. Blazek, 2001: Topographic distortion of a cold front over the Snake River Plain and central Idaho Mountains. Wea. Forecasting, 16 , 301–314.

    • Search Google Scholar
    • Export Citation

  • Stewart, J. Q., C. D. Whiteman, W. J. Steenburgh, and X. Bian, 2002: A climatological study of thermally driven wind systems of the U.S. Intermountain West. Bull. Amer. Meteor. Soc, 83 , 699–708.

    • Search Google Scholar
    • Export Citation

  • Westrick, K. J., C. F. Mass, and B. A. Colle, 1999: The limitations of the WSR-88D radar network for quantitative precipitation measurement over the coastal western United States. Bull. Amer. Meteor. Soc, 80 , 2289–2298.

    • Search Google Scholar
    • Export Citation

  • Wood, V. T., R. A. Brown, and S. V. Vasiloff, 2003: Improved detection using negative elevation angles for mountaintop WSR-88Ds. Part II: Simulations of the three radars covering Utah. Wea. Forecasting, 18 , 393–403.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 116 43 3
PDF Downloads 76 23 0