Severe Weather Events Detected by Puerto Rico's TropiNet Dual-polarized Doppler X-band Radars Network

In order to improve nowcasting (warning) operations, new technologies that provide products to conduct research activities on precipitation and land surface processes of potentially hazardous weather are necessary. The need for improving weather radar coverage of the lower atmosphere is necessary to allow monitoring of precipitation and winds at low altitudes to positively impact forecast of flooding. This is especially true for regions with complex terrains, as well as urban and coastal areas. The Puerto Rico's west coast is a combination of all these conditions, where the coast and a range of mountains meet along with urban, making the warning for these areas very challenging and difficult. In addition, the TJUA NEXRAD located at Cayey is approximately 100 km from the west coast, has limitations observing the lower atmosphere in this area due to the complex topography and earth curvature. For this, University of Puerto Rico at Mayaguez sponsored by NSF-MRI developed network of X-band dual-polarized Doppler radars that focus in the observation of the lower atmosphere. The network consists of 3 radars that are strategically located along the west coast and can monitor the lower atmosphere of the west coast with high spatial (150m) and temporal resolution (1 minute), making the west region of Puerto Rico the most densely sampled lower atmosphere in the tropics. These radars have a 40 km maximum range, and their footprints overlap over urban, coastal and mountainous regions.

The UPRM radar infrastructure is already in place, and is currently run by faculty and graduate students. Recently several case studies where funnel clouds, waterspouts, and hail were reported in the west coast. The UPRM radars were able to observe these funnel clouds and waterspouts using it's Doppler capabilities. Moreover, hail detection was possible using polarimetric products (such as ZDR for HDR calculations) at low altitudes; very important for hail detection and algorithm development/improvements in the Tropics. These observations were invisible to the NEXRAD, as the comparison data depicted, and the higher resolution provided more detail in their structural development. These preliminary cases were a strong proof that improvement in Puerto Rico's West coast's nowcasting (warning) operation of NWS can be achieved using the short-range high-resolution radars from the UPRM.