1 / 19

David Wang, Michael Smith, D.J. Seo Hydrology Laboratory Office of Hydrological Development

COMPARISON OF MEAN AREAL PRECIPITATION ESTIMATES FROM WSR-88D AND HISTORICAL GAGE NETWORKS OVER CHEAT RIVER BASIN, WV. David Wang, Michael Smith, D.J. Seo Hydrology Laboratory Office of Hydrological Development National Weather Service/NOAA. Objectives.

lexine
Download Presentation

David Wang, Michael Smith, D.J. Seo Hydrology Laboratory Office of Hydrological Development

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. COMPARISON OF MEAN AREAL PRECIPITATION ESTIMATES FROM WSR-88D AND HISTORICAL GAGE NETWORKS OVER CHEAT RIVER BASIN, WV David Wang, Michael Smith, D.J. Seo Hydrology Laboratory Office of Hydrological Development National Weather Service/NOAA

  2. Objectives • Long term goal is to effectively use NEXGEN data for hydrological forecasting; • Evaluating radar-based MAPX quality over the Cheat River Basin, WV, which is selected as a study basin for Distributed Model Inter-comparison Project (DMIP);

  3. MAPX Calculation • Period: Mar. 1, 1996 - Dec. 31, 1999 • MAPX are calculated using NEXRAD Stage III data, which are archived at Hydrology Laboratory, NWS; • Stage III HRAP grid are in resolution of 4 X 4 km;

  4. MAP Calculation • Period: Oct. 1, 1952 - Dec. 31, 1999 • Calculated from the National Climatic Data Center (NCDC) archives; • The domain covered Cheat River Basin has 16 valid hourly gages and 45 daily gages; • Quality control procedures are applied to various stages of calculation by using Interactive Double Mass Analysis (IDMA);

  5. MAP Calculation (cont.) • Daily value for a station is distributed • into hourly values based on the nearby • hourly observations; • Missing values are estimated by 1/d^2; • MAP are calculated by multiplying pre- • determined weighting factors station observed • precipitation; d

  6. Radar Coverage over Cheat River Basin

  7. Monthly and annual averaged hourly MAP & MAPX (mm) on different conditions over Cheat River Basin Note: 1). Ratio is MAPX/MAP; 2). Missing values are removed from the calculations; 3). Term “unconditional” means MAP>=0 and MAP>=0.

  8. Caption: Red -- Station WV8986 hourly precipitation; Pink -- MAPX time series; Yellow -- Corrected MAPX time series; White -- MAP time series.

  9. Caption: Red -- Station WV8986 hourly precipitation; Pink -- MAPX time series; Yellow -- Corrected MAPX time series; White -- MAP time series.

  10. Caption: Pink -- MAPX time series; Yellow -- Corrected MAPX time series; White -- MAP time series.

  11. Caption: Pink -- MAPX time series; Yellow -- Corrected MAPX time series; White -- MAP time series.

  12. Caption: Pink -- MAPX time series; Yellow -- Corrected MAPX time series; White -- MAP time series.

  13. Caption: Red -- Station WV8986 hourly precipitation; Pink -- MAPX time series; Yellow -- Corrected MAPX time series; White -- MAP time series.

  14. Correction of MAPX time series • Divide MAPX range into 10 section based on the occurrence probability; • Calculate the correction factor for each section (MAP/MAPX) in cold and warm seaon; • Apply correction factors to MAPX time series;

  15. Summary of Results • Long-term annual MAP is 52.87 in, PRISM annual MAP is 54.15 in, 4-year averaged MAPX is 30.87 in; • Radar-based MAPX is under-estimated by about 41% with comparison to MAP; • MAPX time series over Cheat River Basin is usable after correction by multiplying correction factors;

More Related