HR: 1340h
AN: A53A-0853    [Abstracts]
TI: A Regional NWP System for Southern California: Applications of GPS-Derived PWV Retrievals
AU: * Marcus, S L
EM: steven.marcus@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Kim, J
EM: jkim@atmos.ucla.edu
AF: University of California at Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095
AU: Chin, T M
EM: mike.chin@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Dickey, J O
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Danielson, D
EM: David.Danielson@noaa.gov
AF: Los Angeles/Oxnard National Weather Service Forecast Office, 520 North Elevar Street, Oxnard, CA 93030
AU: Jacobson, C
EM: chris.jabobson@noaa.gov
AF: Los Angeles/Oxnard National Weather Service Forecast Office, 520 North Elevar Street, Oxnard, CA 93030
AU: Laber, J
EM: jayme.laber@noaa.gov
AF: Ventura County Watershed Protection District, 800 South Victoria Avenue, Ventura, CA 93009
AB: Complex local orographic and meteorological characteristics make natural hazards, such as flash-flooding and wildfires during the wet and dry seasons, respectively, an important concern in the Southern California region. Precipitation in Southern California is characterized by an extreme seasonal cycle with a high frequency of heavy downpours during the wet season. As many of the densely-populated areas are located in valleys and on surrounding hillsides, heavy precipitation events that last only a few hours can cause substantial amounts of damage. In addition, hot and dry conditions at the end of summer combined with high fuel loads due to dry vegetation, make wildfires another leading source of natural disasters in the region. Hence, improving quantitative precipitation and fire-weather forecasting is a crucial concern for reducing the damages from weather-related natural hazards. The dense Southern California Integrated GPS Network (SCIGN) provides precipitable water vapor (PWV) data at high temporal and spatial resolution from over 200 receivers located throughout the greater Los Angeles area. These constitute important local data for improving the accuracy of initial water vapor fields for quantitative forecasting and process modeling that are crucial for short-term NWP. Here, we review recent collaborative efforts towards application of SCIGN data to studies of water vapor variability in the Southern California region and applications of the GPS-derived water vapor data to fine-scale regional forecasting. The focus of this presentation includes retrieval of PWV from GPS receivers over complex terrain, the effects of the additional GPS-PWV data on regional simulations, and their implications for useful NWP lead times.
DE: 3329 Mesoscale meteorology
DE: 3337 Numerical modeling and data assimilation
DE: 3354 Precipitation (1854)
DE: 3360 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting