A very anomalous weather pattern will be developing over southern South America. An unseasonably strong and deep trough will dominate the region until at least next wekend, according to the latest forecast model outputs. This system will interact with a tropical, very humid and unstable air mass already in place over Córdoba, Santa Fe, Entre Ríos and central and northern Buenos Aires and La Pampa, in central Argentina, as well as over much of Uruguay.

During the day Wednesday 3 a very strong low level jet will develop, reaching velocities of about 60 knots (see figure), interacting with a short wave related to the trough and leading to the potential for formation of severe weather conditions, with the chance for tornadic supercells over Entre Ríos, Santa Fe, northern Buenos Aires and over Uruguay. We'll see if we can chase those cells!

After that, unstable conditions will remain until the weekend, with a potentially very active Friday as well. There is also the chance for very heavy rains, which could lead to dangerous floodings with total amounts of about 600 mm (24 inches) from today and until the end of this week (only a 7-day period!) as some rivers in the region are already near their flooding stages.