## 3 Results
### Wind Analysis
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Difference**} & **Time Interval** & **MB mm** & **MB\%** & **MP mm** & **MP\%** & **PB mm** & **PB\%** \\ \hline SLWE-IMERG & 2010–2020 & 177.1 & 13.4 & 219.3 & 15.6 & 163.3 & 11.2 \\ SLWE-RG & 2010–2020 & 193.1 & 21.6 & 234.2 & 23.7 & 96.2 & 6.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Average annual difference (2010–2020) between snow level water equivalents (SLWE) and IMERG data and average annual difference (2010–2020) between SLWE and rain gauges data (RG); the values are given in mm (MB mm; MP mm; PB mm) and as a percentage of the annual average rainfall during the period 2010–2020 (MB%; MP%; PB%). but also to the geomorphology of the surrounding area. MB is somewhat shielded from the South and East by the northern part of the mountain itself, which reaches altitudes above 2000 m (Figure 4). In particular, much lower precipitation was observed at the MB rain gauge compared to the IMERG data, with daily mean wind speeds above 5 m/s for the E-SE (diff. of 2.5 mm per day) and SE-S (diff. of about 7 mm per day) directions. MP has a difference of 3.5 mm per day in the case of winds greater than 5 m/s blowing from the S-SE, while in the case of winds of the same magnitude, from the N-NE and W-SW, the rain gauge detects even more precipitation than the satellite, while for the other directions the observations are in agreement. PB has the same trend as MB, therefore with an underestimation of the rain gauge when the winds are stronger, especially for the N-NW direction (diff. of about 8 mm per day), but in general the precipitation measured by the rain gauge is higher than that measured by the satellite, compared to the other two weather stations investigated. The reason for these differences has been hypothesised to be the topography of the area, where both MB and PB are located on slopes, although with different percentages of prevailing winds, with very close and higher mountains on the north and east sides, which generates less precipitation, especially when there are strong winds. In the case of MP, it is located on a promontory within the Apennine chain, but the other mountains are at a sufficient distance not to cause significant shielding for the rain gauge (Figure 4). Figure 3: Average daily rainfall from 2010 to 2020 at different average wind speeds (0–2; 2–3; 3–4; 4–5; 5–7; 7–20) for MB (Monte Bove), MP (Monte Prata), PB (Pintura di Bolognola). Obviously, each case of each weather station has to be evaluated separately, but in the case of MB and PB, with the weather stations downwind for certain wind directions (Figure 5), it leads to an underestimation of the precipitation measured by the rain gauge compared to the IMERG data of about 30-50%. Obviously, although with the IMERG data there is less underestimation of the data from the high-altitude rain gauges, they cannot be considered completely reliable, as they probably also underestimate the real value of precipitation, as can be seen from the difference between the precipitation data of the PB rain gauge (at a lower altitude than the other two weather stations) and the satellite data. Figure 4: Annual percentage of prevailing wind direction from 2010 to 2020. Figure 5: Map of areas with higher altitude than the weather stations analysed.