## 2 Observational Dataset Description  
The observational analysis of Numa has been carried out by using both spaceborne and ground-based data.  
Two overpasses by the GPM-CO available for Numa are analyzed in this study. The GPM-CO carries the most advanced spaceborne precipitation MW radiometer (GMI) and the first spaceborne dual-frequency precipitation radar (DPR). The GMI is equipped with 13 different channels: 10 GHz, 19 GHz, 37 GHz, 89 GHz, and 166 GHz (in dual polarization V and H), and 23 GHz, 183.31 \(\pm\) 3 GHz, and 183.31 \(\pm\) 7 GHz (V polarization only). The DPR allows for a 3D insight of precipitation structure. Simultaneous observations by the DPR and GMI are only available for the overpass during Numa development phase, because of the narrower radar swath size (245 km for Ku-band, and 125 km for Ka-band) compared to GMI (885 km). Measurements by the other GPM constellation radiometers are also considered. At the time of NUMA, ten satellites, equipped with five different radiometers, were available, providing overpasses at 1-h temporal resolution over the Mediterranean area (on average). In the present paper, besides the GMI, the two other conically scanning radiometers in the constellation are considered: the Advanced Microwave Scanning Radiometer 2 (AMSR2) on board JAXA's GCM W1 satellite, providing measurements at spatial resolution comparable to GMI (roughly three times higher than the other radiometers) and the Special Sensor Microwave Imager and Sounder (SSMIS) on board the U.S. DMSP satellites F16, F17, F18. The official NASA/JAXA GPM products [31] are used in the study, specifically 1C-R and 1C intercalibrated brightness temperatures (TBs), for GMI and the other radiometers respectively, the 2A-CLIM GPRF product for GMI, AMSR2, and SSMIS [32], and the 2A-DPR product for DPR [33]. Moreover MODIS Corrected Reflectance (true color) images [34] are used to describe the upper-level cloud structure during Numa TLC phase. Optimized Coastal Ocean wind product [35], retrieved from ASCAT scatterometer measurements, is used to analyze the RAMS-ISAC surface wind forecast.  
Besides space-based observations, ground-based data are also used in the analysis. In particular, the operational dual-polarization weather radar (hereinafter GR) located in Pettinascura (39.37\({}^{\circ}\)N, 16.62\({}^{\circ}\)E, \(\sim\)1700 m asl), Calabria region, Italy, and managed by the Civil Protection Department of Italy, provided measurements during Numa's mature phase, when it was approaching land. In addition, lightning data from the ground-based low-frequency (VLF/LF, between 1 and 200 KHz) LIghtning NETwork (LINET) are used in this study. The LINET network counts over 550 sensors in several countries around the world, with very good coverage over a wide area in central Europe and central and western Mediterranean (from 10\({}^{\circ}\) W to 35\({}^{\circ}\) E in longitude and from 30\({}^{\circ}\) N to 65\({}^{\circ}\) N in latitude). The system measures the time (temporal resolution is about 512 ms), the horizontal and vertical location of VLF sources, their amplitude, and it is also able to discriminate between cloud-to-ground (CG) and intracloud (IC) strokes, and their polarity [29; 36]. The 3D discrimination method, based on time of arrival (TOA) difference triangulation technique, is reliable (with a position accuracy of 125 m) when the sensor baseline does not exceed \(\sim\) 200 km. Moreover LINET allows for estimation of IC emission height, although at least four sensors are needed for a reliable determination of the IC stroke height [36; 37].