## 5 Numa Observations by GPM
### GPM-CO Precipitation Product Analysis  
[PERSON] et al. [28] have carried out a comparison of the precipitation retrieved from the AMSR2 and GMI overpasses shown in the previous section. Here we focus on the precipitation products available from the GPM-CO overpasses. For the GPM overpass over Numa on 16 November at 13:49 UTC, both GMI and DPR observations are available. The availability of the radar observation allows for a 3D insight of the storm. The reflectivity factor measured by the DPR is a proxy of the storm top height (Figure 9a). It is worth noting that the storm top height could be underestimated, because of the low sensitivity of the DPR (both Ku and Ka band) unable to detect the small ice particles in the upper cloud layers. At this stage of the storm development, the 3D structure provided by the DPR shows the presence of a quasi-cloud free region around the storm center (as identified by the mslp minimum at the time of the overpass) surrounded by clouds (precipitation) reaching a maximum height of about 6 km. Along the northwest to southeast direction, on the eastern side of the storm center, there is a rainband as high as \(\sim\)10 km. The limited Ku-band swath width does not allow analysis of the system on the western edge of the storm, but the GMI measurements (Figures 7 and 8) evidence that there are no rainbands developing in that region. Thanks to the availability of co-located radar and radiometer observations, the DPR Ku measurements can be related to the GMI TB behavior and to the 3D structure of the storm. To this end, we consider the vertical cross-section of the Ku-band reflectivity, corrected from attenuation effects (Z\({}_{\rm c}\)), along the across-track DPR Ku/Ka scan 5047 (indicated by the black dashed line in Figure 9a), and shown in Figure 9b. It is evident the coexistence of convective cores (e.g., 37.1\({}^{\circ}\)N, 18.8\({}^{\circ}\)E) embedded in stratiform regions (e.g., 36.7\({}^{\circ}\)N, 18.0\({}^{\circ}\)E) in the rainband. The shallow convection activity can be easily inferred from the high value of Z\({}_{\rm c}\), that is about 50 dBZ up to 4 km. These convective cores seem coincident with the areas of lower TBs at 89 GHz and intense lightning activity, shown in Figure 8a. On the other hand, the presence of stratiform clouds is evidenced by a signature of bright-band (BB) in some portions of the rainbands, i.e., a peak of Ku-band reflectivity factor in the vertical profile due to melting ice particles, more evident in other along-track cross-sections (as shown in [PERSON] et al. (2018)). The height of the BB signal is coherent with the freezing level height (\(\sim\)2400 m) inferred from the corresponding ECMWF reanalysis temperature profile. The precipitation rate estimated by GMI, obtained from the combination of the information provided by all the channels available, is shown in Figure 10a. It can be compared with the precipitation rate estimated from the Ku-band DPR measurements, shown in Figure 10b (the precipitation rate estimate from Ka-band is not shown because of its narrower swath, compared to DPR Ku-band). In the region of the storm seen by both instruments, there is a relatively good agreement between the patterns of precipitation, especially considering the nonuniform beam-filling effect related to the lower spatial resolution of the radiometer (in particular for the low frequency channels \(<\) 37 GHz) compared to the DPR, the different viewing angle, and the different approaches used for DPR and GMI to retrieve the surface precipitation. DPR shows very small areas of high rainfall rate which appear smoothed out in the GMI retrieval. As a matter of fact, the highest precipitation rate estimated from GMI is found in the southern portion of the main rainband around 35\({}^{\circ}\)N, where TBs at 89 GHz show an extended area of minimum values in Figure 8, and it is 19 mm/h, while the maximum DPR estimate is \(\sim\)80 mm/h in that region. Figure 9: **(a)** Storm top height (km) as reconstructed from the reflectivity factor measured by DPR at Ku-band.