## 3 Comparative Analyses Results
### Rain-Gauge vs. Satellite Precipitation Products
#### 3.2.1 IR Sensor-Based Product  
Two IR sensor-based satellite precipitation products were used in this study: PDIR and GHE (see Section IR Sensor-Based Satellite Products). Figures 9 and 10 present the spatial distribution of the accumulated rain amounts for both cases, estimated using PDIR and GHE, respectively, as well as the results from the comparative analyses with the rain-gauge observations (using the point-pixel method described in Section 2.2). For the April case, Figure 9a shows that the PDIR product had difficulties locating the most intense rain amounts for the WMC area (i.e., more north than in the RADOME observations) and estimating the rain amounts over the south of France, especially for the CEV and SAL areas. For the June event (Figure 9b), the location of the watered area was better represented. However, the rain amounts retrieved by the PDIR product were seriously underestimated in that case. This was confirmed by the rain amounts given in Table 2: the maxima of the accumulated rain amounts were lower than observed by the rain gauges (by approx. 30% for the specific area defined over the south of France (Figure 2c) for the April case and by approx. 44% for the June case). Moreover, Table 2 reveals the important spatial error in the PDIR product because, for almost all the specific area, the rain maxima were located far from (up to 239.07 km for WMC) their RADOME counterparts. Figure 9c,d and Table 3 confirm the general underestimation of the rain amounts by the PDIR product, since the absolute biases for both cases were negative locally and on average. Figure 9: As in Figure 4, but for the PDIR product. Nevertheless, for the June event we can note that the PDIR rain amounts were slightly overestimated over the northeast part of France (Figure 9d), which could reveal a too-northerly trajectory of the precipitating system in PDIR. A strong underestimation was observed by comparing the PDIR estimations to RADOME observations (Table 3). Figure 10a shows the representation of the precipitation amounts estimated by GHE during the April case. GHE tends to over-represent moderate to strong precipitation patterns and these strong intensity watered areas were more extended to the north than what RADOME observed. The highest precipitation amounts were observed over the southeast of the country and especially over the southern parts of the Alps. Table 2 reveals that all the estimated GHE maximums were larger than their RADOME counterparts over the eastern parts of the country. For the south and southwest areas, the GHE maximums tended to slightly underestimate the RADOME maximums (70.45 mm and 72.12 mm for GHE vs. 75.9 mm and 85.1 mm for RADOME over the WMC and CEV areas, respectively). However, the distance between the observed and estimated maximums was close to 100 km for the SAL, DUR, CEV, and JU areas, revealing that the GHE maximums tended to be slightly shifted from the RADOME maximums. For every area of interest, the GHE median values were greater than the RADOME ones (Table 3). This indicates that the moderate-intensity precipitation patterns were more frequent with GHE than with RADOME. The spatial bias distribution (Figure 10c) shows that GHE tended to overestimate the precipitation amounts observed over the Mediterranean littoral and to the north of the southern areas of interest (DUR, CEV, and WMC). Small areas of underestimation were observed in the east and southern parts of the WMC area, where the RADOME maximum was observed, but the trend shows a clear overestimation over every area of interest as seen in Table 3.  
Figure 10: As in Figure 4, but for the GHE product. As for the June event (in Figure 10b), GHE estimated moderate-intensity precipitation amounts from the NMC area to the French-Belgium border. The GHE moderate-intensity estimations were more extended to the north than the RADOME observations, as seen with the April case.