## 3 Comparative Analyses Results
### Rain-Gauge vs. Satellite Precipitation Products
#### 3.2.2 MW Sensor-Based Product  
IMERG Products  
Figures 11a,b and 12a,b provide the rain accumulations estimated for our both case studies by EARLY and LATE products, respectively. The rain distribution over France was quite similar using either the EARLY or the LATE product for each of the case studies (Figures 11a and 12a for the April case, and Figures 11b and 12b for the June case). Locally, few differences appeared, such as precipitation fields that were more intense in EARLY than in LATE over the northern Alps and the Cevennes for the April case, and the precipitating band that seems more extended over the northeastern part of France in EARLY than in LATE for the June case. Figure 11: As in Figure 4, but for rain accumulations estimated by the IMERG-Early product. Figure 12: As in Figure 4, but for the IMERG-Late product. For the April case (Figures 11a,c and 12a,c), the most intense rainfall was localised over the same specific areas defined in Figure 2c. However, they seemed to be shifted compared to the rain-gauge observations (Figure 2a). For example, the most precipitating cells were located further south within the WMC area, whereas they were located further north within the DUR and SAL areas. Moreover, important rain amounts (higher than 50 mm) were also estimated over the northwestern part of France using both IMERG products, while the rain gauges did not measure such quantities over this region. Tables 2 and 3 show that the EARLY and LATE rain amounts were close to the RADOME observations for the WMC but that they were slightly shifted spatially, since the rain maximum estimated for EARLY and LATE was located at approx. 15 km to the observed one. Additionally, Figures 11c and 12c show that an underestimation by the IMERG products was present over the southern part of WMC, whereas an overestimation was present over the northern part (this spatial shift induces the quite low mean absolute biases obtained for this specific area; Table 3). Nonetheless, the IMERG products can highly overestimate the rain amounts as for the JUR area (where the mean absolute biases are +20.87 mm for EARLY and +24.69 mm for LATE; see Table 3). In the opposite, EARLY and LATE can also produce important underestimations, such as for the SAL area (where the mean absolute biases reach \(-15.51\) mm and \(-14.99\) mm, respectively). For this case, the IMERG products had difficulties in estimating the rain amounts over the reliefs of the south of France, especially over the Alps (DUR and SAL) and the Jura (JUR), but also along the Mediterranean coast. For the June case (Figures 11b,d and 12b,d), the more important rain amounts are mainly located over the NMC area as in RADOME observations but the maxima of rain obtained by either EARLY or LATE are approx. 2 times higher than measured by the rain gauges (the rain maximum was 136.7 mm in RADOME while it is equal to 223.86 mm and 211.99 mm for EARLY and LATE, respectively; see Table 2). These maxima are located at approx. 70 km further east than the Chastreix station (where the RADOME maximum is observed). Figures 11b and 12b also reveal moderate rain amounts over the northeastern part of France (in the vicinity of the Belgium and Luxembourg borders) in both IMERG products, which were not visible in the RADOME observations (Figure 2b), inducing positive biases over this region (Figures 11d and 12d). As the most intense precipitation amounts were estimated further east than observed, this entails an underestimation over the western part of the NMC in both IMERG products (negative biases), whereas this was the opposite in the eastern part (positive biases). Thus, the mean absolute biases (Table 3) obtained for EARLY and LATE products were quite small for this specific area: \(-4.55\) mm and \(-0.58\) mm, respectively. The two IMERG products provide similar precipitation estimations for both case studies. However, we can notice that LATE showed greater values of precipitation accumulations than EARLY for both cases (see Table 3). Initially, in the study of [PERSON] et al.