Meteorological Characteristics and Overland Precipitation Impacts of Atmospheric Rivers Affecting the West Coast of North America Based on Eight Years of SSM/I Satellite Observations

Abstract The pre-cold-frontal low-level jet within oceanic extratropical cyclones represents the lower-tropospheric component of a deeper corridor of concentrated water vapor transport in the cyclone warm sector. These corridors are referred to as atmospheric rivers (ARs) because they are narrow relative to their length scale and are responsible for most of the poleward water vapor transport at midlatitudes. This paper investigates landfalling ARs along adjacent north- and south-coast regions of western North America. Special Sensor Microwave Imager (SSM/I) satellite observations of long, narrow plumes of enhanced integrated water vapor (IWV) were used to detect ARs just offshore over the eastern Pacific from 1997 to 2005. The north coast experienced 301 AR days, while the south coast had only 115. Most ARs occurred during the warm season in the north and cool season in the south, despite the fact that the cool season is climatologically wettest for both regions. Composite SSM/I IWV analyses showed landfa...

[1]  Duane E. Waliser,et al.  Preferred Latitudes of the Intertropical Convergence Zone , 1994 .

[2]  C. Schär,et al.  Idealised Numerical Experiments of Alpine Flow Regimes and Southside Precipitation Events , 2000 .

[3]  R. E. Hart,et al.  Use of Normalized Anomaly Fields to Anticipate Extreme Rainfall in the Mountains of Northern California , 2008 .

[4]  James P. Hollinger,et al.  SSM/I instrument evaluation , 1990 .

[5]  R. Rotunno,et al.  Mechanisms of Intense Alpine Rainfall , 2001 .

[6]  C. W. Newton,et al.  Atmospheric circulation systems: their structure and physical interpretation , 1969 .

[7]  R. T. Beaumont.  Mt. Hood Pressure Pillow Snow Gage , 1965 .

[8]  S. Avery,et al.  Passive microwave remote sensing of rainfall with SSM/I: Algorithm development and implementation , 1994 .

[9]  J. O. Rhea.  Orographic Precipitation Model for Hydrometeorological Use. , 1977 .

[10]  K. Cehak.  ReviewAtmospheric circulation systems: PALMÉN, E. and C.W. NEWTON (1969): Their Structure and Physical Interpretation 603 pp., 250 figs., 23 tables. International Geophysics Series, vol. 13. New York/ London: Academic Press. $ 26.00 , 1971 .

[11]  M. Dettinger,et al.  Flooding on California's Russian River: Role of atmospheric rivers , 2006 .

[12]  W. Emery,et al.  Atmospheric water vapour over oceans from SSM/I measurements , 1990 .

[13]  F. Martin Ralph,et al.  Use of Information by National Weather Service Forecasters and Emergency Managers during CALJET and PACJET-2001 , 2007 .

[14]  D. Trabant.  Measurement and Evaluation of Snowpacks , 1990 .

[15]  T. Bergeron.  On the Physics of Fronts , 1937 .

[16]  D. Cayan,et al.  Precipitation structure in the Sierra Nevada of California during winter , 1999 .

[17]  F. Wentz.  A well‐calibrated ocean algorithm for special sensor microwave / imager , 1997 .

[18]  F. Weng,et al.  Retrieval of cloud liquid water using the special sensor microwave imager (SSM/I) , 1994 .

[19]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[20]  K. Browning,et al.  Structure of low‐level jet streams ahead of mid‐latitude cold fronts , 1973 .

[21]  P. Neiman,et al.  The statistical relationship between upslope flow and rainfall in California's coastal mountains: Observations during CALJET , 2002 .

[22]  M. A. Goodberlet,et al.  Ocean surface wind speed measurements of the Special Sensor Microwave/Imager (SSM/I) , 1990 .

[23]  F. Martin Ralph,et al.  Dropsonde Observations in Low-Level Jets over the Northeastern Pacific Ocean from CALJET-1998 and PACJET-2001: Mean Vertical-Profile and Atmospheric-River Characteristics , 2005 .

[24]  J. Gyakum,et al.  Heavy Cold-Season Precipitation in the Northwestern United States: Synoptic Climatology and an Analysis of the Flood of 17-18 January 1986 , 1999 .

[25]  Thomas J. Jackson,et al.  THE NAME 2004 FIELD CAMPAIGN AND MODELING STRATEGY , 2006 .

[26]  Yong Zhu,et al.  A Proposed Algorithm for Moisture Fluxes from Atmospheric Rivers , 1998 .

[27]  Toby N. Carlson,et al.  Mid-Latitude Weather Systems , 1991 .

[28]  Ronald B. Smith.  The Influence of Mountains on the Atmosphere , 1979 .

[29]  K. Katsaros,et al.  Mesoscale and synoptic scale features of North Pacific weather systems observed with the scanning multichannel microwave radiometer on Nimbus 7 , 1986 .

[30]  Keith A. Browning,et al.  Organization of Clouds and Precipitation in Extratropical Cyclones , 1990 .

[31]  K. Katsaros,et al.  Satellite-Derived Integrated Water-Vapor Distribution in Oceanic Midlatitude Storms: Variation with Region and Season , 1991 .

[32]  G. Wick,et al.  Satellite and CALJET Aircraft Observations of Atmospheric Rivers over the Eastern North Pacific Ocean during the Winter of 1997/98 , 2004 .