287
Precipitation Estimate Using NEXRAD Ground-Based Radar Images
hydrologic and ecological modeling and analysis. In southern plains, NEXRAD is
more effective for precipitation estimation.
12.4.2  PeRfoRMance of nexRad in waRM SeaSon veRSuS cold SeaSon
Accumulated precipitation depth in cold (October–March) and warm (April–
September) seasons in 2003 and 2004 (Figure 12.3) shows that, in the I grid, accumulated precipitation depth was much larger in the cold season than that, in the warm
season. However, NEXRAD estimated that precipitation depth in the cold season is
lower than or similar to that in the warm season. In the cold season, the NEXRAD
estimated precipitation is only 9.4%–21.3% (2003) and 10.6%–21.1% (2004) of the
precipitation depth observed at rain gauges. In contrast, the NEXRAD estimated
preciptation in the warm season accounts for 33.6%–54.4% (2003) and 32.2%–59.3%
(2004) of the observed accumulated precipitation. In the G grid, NEXRAD performed much better for estimating accumulated precipitation in both the warm and
cold seasons. The substantial difference between NEXRAD performance in the cold
(a)
(b)
700
600
500
400
Accumulated rainfall (mm)
Accumulated rainfall (mm)
300
200
100
0
700
800
900
1000
600
500
400
300
200
100
0
2003 cool
season
2004 cool
season
2003 warm
season
2004 warm
season
2003 cold
season
2004 cold
season
2003 warm
season
2004 warm
season
147_PCP
167_PCP
155_PCP
rmsp_PCP
Gauge mean
NEXRAD
Gauge mean
P49
P48
P46
P44
NEXRAD
FIGURE 12.3  Accumulated precipitation depth in cold and warm seasons. (a) I grid. (b) G
grid.