Level 2

A downburst is a powerful, localized downdraft that rapidly descends from a convective storm and spreads outward upon reaching the ground, producing intense, often damaging straight-line winds.

One of the strongest downbursts we recorded in Porto Alegre exhibited Doppler radial velocities approaching 160 km/​h. Radar data further revealed strong horizontal vorticity near the outflow boundary, which was tilted into a vertical orientation, ultimately leading to the brief formation of a weak tornado.

Supercells are highly organized thunderstorms with deep, rotating updrafts (mesocyclones) capable of producing severe weather like large hail, damaging winds, and tornadoes.

On May 19, 2025, our radar detected a supercell near Toulouse with a strong hailcore, showing hail up to 5 cm, a pronounced Three-Body Scatter Spike, low RhoHV at 6 km, and ZDR around 0 dB, indicating large, dry hail within the intense updraft.

Another intense supercell occurred also in Toulouse, France, on May 19, 2025, showing a 45 m/​s Doppler velocity difference within its mesocyclone at 2.5 km altitude. The supercell then continued moving northeast and, between 13:00 and 14:30 UTC, affected the southern suburbs of Toulouse and neighboring towns, where intense downbursts accompanied by large hail were reported. In some locations, hailstones exceeded 5 cm in diameter. The supercell dissipated after 14:30 UTC, northeast of Toulouse.

This case featured a waterspout from a mini-supercell east of Tongatapu, with radar showing a hook echo and strong rotation from sea level up to 500 meters.

A gust front is a boundary between cool outflow air and the surrounding warm air, capable of initiating new convection. One example is visible in the detailed in the PPI scan

On June 4, 2025, our radar in Austria detected several supercells producing strong winds, downbursts, and large hail up to 5 cm in diameter. The image shows one such supercell with a clear structure, including a Weak Echo Region (WER) and a hook echo.

The dendritic growth layer is a region within the troposphere where water vapor deposits directly onto ice crystals in a supersaturated environment, leading to the
formation of intricate, branched snowflakes. This process occurs under specific thermodynamic conditions, typically between about –12 °C and –18 °C, where the combination of temperature and humidity favors rapid crystal growth.

In September 2025, our newly installed radar in Senegal began observing convective activity, capturing several squall lines and downbursts. A notable event on September 12 showed a strong downburst with clear signs of intense outflow.

In May 2025, after upgrading a radar in Nyamata, Rwanda, we captured a strong downburst, showing a low-level divergence.

On 16 August 2025, the Tonga weather radar observed a low-level convergence line advancing from the southwest. Ahead of this feature, several discrete mini-supercells developed, showing stronger reflectivity cores and rotation signatures.

On 1 December 2024, severe supercells south of Porto Alegre produced large hail, damaging winds, and intense lightning, followed by a fast-moving squall line hitting the capital with gusts over 80 km/​h and heavy rain.

Gravity waves, also known as buoyancy waves, can sometimes be detected in weather radar data as alternating bands of enhanced and reduced reflectivity. Example shows such gravity waves over Porto Alegre, Brazil.

In January 2025, we installed an X‑band weather radar in Guba, located in the northeastern region of Azerbaijan. The radar became operational during what was, overall, a relatively calm meteorological year, with limited severe weather activity. Nevertheless, several interesting convective events were observed. Among them was a squall line that formed as a result of low-level flow convergence.