The Portuguese Institute of the Sea and Atmosphere (IPMA) have confirmed that in addition to the tornadoes seen on Thursday 28th March, over the Tagus River in Lisbon, the southern edge of Storm Nelson also caused a tornado in the Silves area.
The tornado in the Algarve were reported in the late afternoon of March 28th in Benaciate, S. Bartolomeu de Messines, Silves after analyzing “radar observations, documentation and reports”.
“This tornado, in Silves, destroyed two prefabricated houses, damaged other homes and caused telecommunications and power poles to fall, plus some large trees, damaging vehicles. The extent and width of the path of destruction of this tornado is unknown”, says the statement.
IPMA stated that the “preliminary analysis of the effects of the destruction reported at the site indicates that the tornado reached an intensity of at least F1/T2 (classic Fujita scale/Torro scale)”, but that these values are still provisional.
“Based on the analysis of the elements available so far, the tornado started in the early afternoon of March 28th over the water of the Tagus river, probably east of the Vasco da Gama Bridge, between 2:21 pm and 2:24 pm."
“In the central and southern regions, when a frontal swell passed from northwest to southeast, the necessary ingredients were gathered for the formation of clouds with vertical development, sometimes with a supercell (SC) nature. These disturbances are characterized by the presence of a mesocyclone (MC), which corresponds to an organized rotational movement in the cloud, but which only establishes itself at altitude”, said the IPMA.
“Only under very specific conditions is it possible for a tornado to form from the aforementioned mesocyclone. Tornado implies, by definition, the presence of a vortex in contact with the surface”.
Source IPMA
