Rainfall data based on Next Generation Radar (NEXRAD) data from the U.S. National Weather Service provides complete spatial coverage of rainfall amounts for the State of Florida. The accuracy of NEXRAD data is enhanced when adjusted using the local rain-gage data (Huebner et al., 2003 and Skinner, 2006, Skinner 2008).
The NEXRAD coverage for the South Florida Water Management District area includes rainfall amounts for 15-minute intervals for the period January 1, 2002 to present for 2 km by 2 km grid resolution. (Please note that EDEN data is on a 400 m by 400 m grid.) The SFWMD receives “near real-time” 15-minute data (NRD) continuously. These NRD are compiled, verified, and quality-assured at the end of each month in the end-of-month (EOM) sets of 15-minute files. The EOM files use 81 additional rain gage data that are not available real-time and a proprietary algorithm based on the Brandes method (Brandes, 1975) to adjust radar rainfall values.
The precision for the gage-adjusted radar is considered to be the same as standard rain-gage precision which is typically reported to the nearest 1/100th of an inch. Because the radar is adjusted to agree with the rain gage, the precision for the rain gage used is the governing precision at 1/100th inch (written communication, Baxter Vieux). Daily gage-adjusted rainfall values were computed for the South Florida Water Management District by OneRain, Inc (www.onerain.com) from January 2002 to October 2007. Starting November 1, 2007, these data are provided by Vieux. Inc (www.vieuxinc.com/rainviuex.html).
EDEN staff receives the EOM data monthly as daily rainfall totals for grid cells in the EDEN project domain approximately 25 days after the month ends. Daily rainfall data (in inches) for EDEN gage locations were compiled from the EOM data and assembled into Excel spreadsheets by area. On a monthly basis, this compilation of data will be updated with the additional data for the previous month.
For more information about the rainfall data from the SFWMD, go to Appendix 2-1 (page 57) of the 2008 South Florida Environmental Report Volume I (http://my.sfwmd.gov/SFER).
For more information about EDEN (Everglades Depth Estimation Network), visit the links to the right.
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