Cold Pools in the Columbia Basin

C. D. Whiteman Pacific Northwest National Laboratory, Richland, Washington

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S. Zhong Pacific Northwest National Laboratory, Richland, Washington

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W. J. Shaw Pacific Northwest National Laboratory, Richland, Washington

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J. M. Hubbe Pacific Northwest National Laboratory, Richland, Washington

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X. Bian Pacific Northwest National Laboratory, Richland, Washington

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J. Mittelstadt NOAA/NWS Forecast Office, Pendleton, Oregon

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Abstract

Persistent midwinter cold air pools produce multiday periods of cold, dreary weather in basins and valleys. Persistent stable stratification leads to the buildup of pollutants and moisture in the pool. Because the pool sometimes has temperatures below freezing while the air above is warmer, freezing precipitation often occurs, with consequent effects on transportation and safety. Forecasting the buildup and breakdown of these cold pools is difficult because the interacting physical mechanisms leading to their formation, maintenance, and destruction have received little study.

In this paper, persistent wintertime cold pools in the Columbia River basin of eastern Washington are studied. First a succinct meteorological definition of a cold pool is provided and then a 10-yr database is used to develop a cold pool climatology. This is followed by a detailed examination of two cold pool episodes that were accompanied by fog and stratus using remote and in situ temperature and wind sounding data. The two episodes illustrate many of the physical mechanisms that affect cold pool evolution. In one case, the cold pool was formed by warm air advection above the basin and was destroyed by downslope winds that descended into the southern edge of the basin and progressively displaced the cold air in the basin. In the second case, the cold pool began with a basin temperature inversion on a clear night and strengthened when warm air was advected above the basin by a westerly flow that descended from the Cascade Mountains. The cold pool was nearly destroyed one afternoon by cold air advection aloft and by the growth of a convective boundary layer (CBL) following the partial breakup of the basin stratus. The cold pool restrengthened, however, with nighttime cooling and was destroyed the next afternoon by a growing CBL.

Corresponding author address: C. D. Whiteman, K9-30, Battelle Northwest Laboratories, P.O. Box 999, Richland, WA 99352. Email: Dave.Whiteman@pnl.gov

Abstract

Persistent midwinter cold air pools produce multiday periods of cold, dreary weather in basins and valleys. Persistent stable stratification leads to the buildup of pollutants and moisture in the pool. Because the pool sometimes has temperatures below freezing while the air above is warmer, freezing precipitation often occurs, with consequent effects on transportation and safety. Forecasting the buildup and breakdown of these cold pools is difficult because the interacting physical mechanisms leading to their formation, maintenance, and destruction have received little study.

In this paper, persistent wintertime cold pools in the Columbia River basin of eastern Washington are studied. First a succinct meteorological definition of a cold pool is provided and then a 10-yr database is used to develop a cold pool climatology. This is followed by a detailed examination of two cold pool episodes that were accompanied by fog and stratus using remote and in situ temperature and wind sounding data. The two episodes illustrate many of the physical mechanisms that affect cold pool evolution. In one case, the cold pool was formed by warm air advection above the basin and was destroyed by downslope winds that descended into the southern edge of the basin and progressively displaced the cold air in the basin. In the second case, the cold pool began with a basin temperature inversion on a clear night and strengthened when warm air was advected above the basin by a westerly flow that descended from the Cascade Mountains. The cold pool was nearly destroyed one afternoon by cold air advection aloft and by the growth of a convective boundary layer (CBL) following the partial breakup of the basin stratus. The cold pool restrengthened, however, with nighttime cooling and was destroyed the next afternoon by a growing CBL.

Corresponding author address: C. D. Whiteman, K9-30, Battelle Northwest Laboratories, P.O. Box 999, Richland, WA 99352. Email: Dave.Whiteman@pnl.gov

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  • Air Weather Service, 1979: The use of the skew T, log p diagram in analysis and forecasting. AWS/TR-79/006 Revised, 157 pp. [Available from U.S. Air Force Air Weather Service, Scott Air Force Base, IL, 62225-5008.].

    • Search Google Scholar
    • Export Citation
  • Ayer, H. S., 1961: On the dissipation of drainage wind systems in valleys in the morning hours. J. Meteor, 18 , 560563.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Davidson, B., and Rao P. K. , 1963: Experimental studies of the valley–plain wind. Int. J. Air Water Pollut, 7 , 907923.

  • Fast, J. D., Zhong S. , and Whiteman C. D. , 1996: Boundary layer evolution within a canyonland basin. Part II: Numerical simulations of nocturnal flows and heat budgets. J. Appl. Meteor, 35 , 21622178.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Furger, M., Whiteman C. D. , and Wilczak J. M. , 1995: Uncertainty of boundary layer heat budgets computed from wind profiler/RASS networks. Mon. Wea. Rev, 123 , 790799.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gill, G. C., 1983: Comparison testing of selected naturally ventilated solar radiation shields. NOAA Data Buoy Office Rep. (partial fulfillment of Contract NA-82-OA-A-266), 38 pp. [Available from NOAA/National Data Buoy Center, Bay St. Louis, MS 39529.].

    • Search Google Scholar
    • Export Citation
  • Lenschow, D. H., Stankov B. B. , and Mahrt L. , 1979: The rapid morning boundary-layer transition. J. Atmos. Sci, 36 , 21082124.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mayr, G. J., and McKee T. B. , 1995: Observations of the evolution of orogenic blocking. Mon. Wea. Rev, 123 , 14471464.

  • Petkovs̆ek, Z., 1974: Dissipation of the upper layer of all-day radiation fog in basins. Zb. Meteor. Hidrol. Rad, 5 , 7174.

  • Petkovs̆ek, Z., 1978: Model for the evaluation of mean emission potential of the air pollution with SO2 in basins. Arch. Meteor. Geophys. Bioclimatol, 26B , 199206.

    • Search Google Scholar
    • Export Citation
  • Petkovs̆ek, Z., 1980: Dynamik der oberen Grenze der Kaltluftseen in Talbecken. Abhandlungen des Meteorologischen Dienstes der Deutschen Demokratischen Republick, Vol. 16, No. 124, 63–65.

    • Search Google Scholar
    • Export Citation
  • Petkovs̆ek, Z., 1992: Turbulent dissipation of cold air lake in a basin. Meteor. Atmos. Phys, 47 , 237245.

  • Sauberer, F., and Dirmhirn I. , 1954: Über die Entstehung der extremen Temperaturminima in der Doline Gstettner-Alm (On the occurrence of extreme temperature minimums in the Gstettner-Alm Doline). Arch. Meteor. Geophys. Bioclimatol, 5B , 307326.

    • Search Google Scholar
    • Export Citation
  • Savoie, M. H., and McKee T. B. , 1995: The role of wintertime radiation in maintaining and destroying stable layers. Theor. Appl. Climatol, 52 , 4354.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Smith, R. B., Paegle J. , Clark T. , Cotton W. , Forbes G. , McGinley J. , Pan H-L. , and Ralph M. , 1997: Local and remote effects of mountains on weather: Research needs and opportunities. Bull. Amer. Meteor. Soc, 78 , 877892.

    • Search Google Scholar
    • Export Citation
  • Vrhovec, T., 1991: A cold air lake formation in a basin—A simulation with a mesoscale numerical model. Meteor. Atmos. Phys, 46 , 9199.

  • Vrhovec, T., and Hrabar A. , 1996: Numerical simulations of dissipation of dry temperature inversions in basins. Geofizika, 13 , 8196.

  • Whiteman, C. D., 1990: Observations of thermally developed wind systems in mountainous terrain. Atmospheric Processes over Complex Terrain, Meteor. Monogr., Amer. Meteor. Soc., No. 45, 5–42.

    • Search Google Scholar
    • Export Citation
  • Whiteman, C. D., McKee T. B. , and Doran J. C. , 1996: Boundary layer evolution within a canyonland basin. Part I: Mass, heat, and moisture budgets from observations. J. Appl. Meteor, 35 , 21452161.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Whiteman, C. D., Bian X. , and Zhong S. , 1999a: Wintertime evolution of the temperature inversion in the Colorado Plateau basin. J. Appl. Meteor, 38 , 11031117.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Whiteman, C. D., Zhong S. , and Bian X. , 1999b: Wintertime boundary layer structure in the Grand Canyon. J. Appl. Meteor, 38 , 10841102.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Whiteman, C. D., Hubbe J. M. , and Shaw W. J. , 2000: Evaluation of an inexpensive temperature datalogger for meteorological applications. J. Atmos. Oceanic Technol, 17 , 7781.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wolyn, P. G., and McKee T. B. , 1989: Deep stable layers in the intermountain western United States. Mon. Wea. Rev, 117 , 461472.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhong, S., Whiteman C. D. , Bian X. , Shaw W. J. , and Hubbe J. M. , 2001: Meteorological processes affecting the evolution of a wintertime cold air pool in the Columbia basin. Mon. Wea. Rev, in press.

    • Search Google Scholar
    • Export Citation
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