![]() ![]() 1) results in many regions where the lowest beams of the operational NEXRAD radars are blocked or overshoot shallow precipitation. The complex terrain of both the Coastal Ranges and the Sierra Nevada ( Fig. The Bay Area of California and surrounding areas are uniquely challenging for quantitative precipitation estimates (QPE). Additional surface measurements of precipitation, streamflow, and soil moisture are also included, and will be used to initialize and validate forecasts produced for the region ( ). The project includes the installation of a number of gap-filling X-band dual-polarization radars that can observe precipitation in areas that are a significant distance from the nearest National Weather Service (NWS) operational radar (WSR-88D), or where the operational radar beam is blocked by the complex terrain in the area. 1) at high spatial and temporal resolution. ![]() ![]() The AQPI project seeks to provide improved monitoring and forecasting of precipitation processes, streamflow, and coastal flooding for the Bay Area and surrounding region ( Fig. Additionally, it is important to accurately measure and predict the precipitation that occurs with these storms in order to enact flood control procedures and prevent storm sewer system backups.īecause of the need for accurate forecasts of precipitation to force hydrologic models and for storm-water utilities to prepare for the possibility of heavy precipitation, a partnership between San Francisco Bay Area water entities and the National Oceanic and Atmospheric Administration (NOAA) called the Bay Area Advanced Quantitative Precipitation Information (AQPI) project was developed. This precipitation must be managed in such a way that it can be stored and released for use throughout the year for irrigation, recreation, residential needs, and ecological conservation ( Dettinger et al. The results highlight both the need for additional observations and the need to account for uncertainty in the reference dataset when validating forecasts in this area.Īccurate estimates of precipitation in California are necessary because the state generally receives most of its annual precipitation during a few significant storms that occur during the cool season, often associated with atmospheric rivers (ARs) ( Dettinger et al. While the products seem to agree fairly well on the timing of precipitation, intensity estimates differ, sometimes by an order of magnitude. Substantial differences exist between the various products at accumulation periods ranging from hourly to annual, with standard deviations among the products exceeding 100% of the mean. The products were linearly interpolated to 3-km grid spacing, which is the resolution of the operational forecast model to be validated. In this paper we examine 10 gridded, high-resolution (≤10 km, hourly) precipitation estimates to assess the uncertainty of high-resolution quantitative precipitation estimates (QPE) in areas of complex terrain. To quantify improvements in forecast precipitation, model validation studies require a reference dataset to compare against. To improve monitoring and prediction of these events at spatial and temporal resolutions of interest to area water managers, the Bay Area Advanced Quantitative Precipitation Information project was developed. The complex terrain of this region further complicates the situation, with terrain interactions that are not currently captured in most operational forecast models and inadequate precipitation measurements to capture the large variability throughout the area. The Bay Area of California and surrounding region receives much of its annual precipitation during the October–March wet season, when atmospheric river events bring periods of heavy rain that challenge water managers and may exceed the capacity of storm sewer systems. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |