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Category: Severe convection

Mesoscale Convective Vortex helps to force the development of a Mesoscale Convective System over northwest South Dakota

5-minute CONUS Sector GOES-19 (GOES-East) Nighttime Microphysics RGB + daytime True Color images from the CSPP GeoSphere site (above) showed a remnant Mesoscale Convective Vortex (MCV) that migrated eastward from southeastern Montana to northwestern South Dakota — where it helped to force the rapid development of a slow-moving Mesoscale Convective System (MCS) during the afternoon... Read More

Hail in the Samoan Archipelago

In the evening of 28 July 2025, residents of the Samoan island of Upolu experienced an intense thunderstorm which produced hail, a very rare event for maritime tropical Pacific environments. Social media videos show 1 – 2 cm hailstones falling around residents excited to see such novel conditions. The forecasters... Read More

Decaying Mesoscale Convective System’s outflow boundary produces a low-level undular bore, along with a vertically-propagating gravity wave

5-minute CONUS Sector GOES-19 (GOES-East) Nighttime Microphysics RGB images from the CSPP GeoSphere site (above) depicted a nocturnal arc of low-level cloud bands (pale shades of white) associated with an undular bore produced by the outflow boundary from a decaying Mesoscale Convective System (MCS) over northern Iowa on 28 July 2025 — however, the boundary... Read More