South America Forecast Discussion

First autum storm "Mate Amargo" in Argentina

By: sasastorm, 8:18 PM GMT on April 23, 2013

After the storm famous "Monte Hermoso" and catastrophic storms that hit the city of La Plata and Buenos Aires seems that this forming a new weather situation very similar to that of La Plata. In this case again low pressure system approaching from the Pacific Ocean is generating a lot of air entering middle level along the ridge. The low pressure system began surface far south to the latitude of the province of Tierra del Fuego. The same to meet a widespread anticyclone to the south, but off the coast of Argentina ended up losing the train of waves or wave pattern (this means that the atmosphere can be represented by waves and somehow be able to use of mathematics associated) ... This wave pattern is very limited south to the latitude of the Drake Passage, which implies that very classic westerly winds in Patagonia winds gave way to the northern sector and this is what drove air ingress warm as south (relatively warmer air). This ended up generating an anomalous situation for the time of year, as these winds are responsible for the penetration of colder air from the south on the continent and could not restore the cooler air that is characteristic of the time of year.
This low pressure system unable to advance west begins a new path to the north but it does so very slowly. This low pressure system is another low pressure system crosses lower latitudes, so that by the morning of Wednesday, uniting and deepening were completed. The dynamics of the same drive air from the Pacific Ocean along the Patagonian cordillera and will continue along its entire path ending at latitudes of the provinces of Catamarca. This deadlock eventually disrupt the atmosphere at levels very similar situation means than last event in the city of La Plata. This dynamic implies that bring a lot of moist air from the Pacific Ocean region on which to the day Wednesday, Thursday and Friday. On Friday, after noon, the winds intensified reaching important values ​​hovering around 80 km / hr mainly affecting the provinces of Catamarca, La Rioja and San Juan not ruling but somewhat lower values ​​of the same importance to the provinces Salta and Mendoza.
Well
now will occur on Friday, two very important things that will eventually intensify to severe events especially on the side of the Andean provinces of Mendoza and Neuquen. The first is the position of the low thermal-orographic's very important NW to end up position when more severe storms that develop in the aforementioned This low thermal region is responsible for entering the warm unstable air over the central region to meet the entry of moist air from the Pacific begin to take shape the primeas convection. The obvious direction of northern warm mass is juxtaposed with the westbound air mass average shear generating a very important area responsible for severe storms increase alertness and with water on the slopes of Argentina ... If the predicted values ​​are what really precipitated teminaràn by then we have a very complex situation that can result in landslides on the  warning area and affecting a very direct way cecanas populations.
Towards the saturday morning ends with engaging the lower layer jet just below the jet height will be positioned from Catamarca to Bs As creating a
major shear region on the provinces of San Luis and west of Cordoba. With the entry of the night of Saturday the low thermal will fade but will
give way to the formation of a low just above the central region
(cyclogenesis) will drive stronger storms over the provinces of San
Luis, Cordoba and Santa Fe main difference with the previous situation of severe storms is that mid-level disturbance will move fast on country causing severe storms  but not as abundant as occurred in the city of La Plata ... As you go through the day Saturday storms will move from west to east  ending up affecting the province of Buenos Aires to the afternoon of
that day. During the night of Saturday and Sunday morning storms move over the coast but with a somewhat lower intensity on the contrary of what happens on the mouth of the Rio de la Plata and deepen the system by making energy of the warm current of Brazil. It is possible that during this movement ends up affecting so moderate to southern Uruguay cities.
One of the most important issues of this situation is the intensity of the
wind blowing steadily and strong on Friday the direction preferably NW
...


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Very Tragic flooding in La Plata, Argentina

By: sasastorm, 8:32 PM GMT on April 05, 2013

During these days we witnessed the flood that hit the province of Buenos Aires, little we can add to the magnitude of what happened in the city of La Plata. The storm that hit Buenos Aires was heading towards La Plata, there was little time to take risks and rainy weather event occurred on the city recorded 311 millimeters of rain in some areas up to 400 mm!.
Starting at 5 pm La Plata began to be under water, in two hours the city was almost completely flooded. At 7 in the morning when I put in a situation of this tragedy, the official number of fatalities was 51.
A low pressure system located at middle levels of the atmosphere drove much humid air from the Atlantic Ocean as it moved around the storm system was retrofitted from warm surface air but especially with a high water content.
This mid-level disturbance remained in the province of Buenos Aires for almost 24 hours straight aggravating the situation further.
the problem is that the flood was already saturating the stream "El Gato" which is about 35 miles long and crosses the Partido de La Plata and Ensenada, keep in mind that in this basin is home to about 400,000 people.



This stream was being subject of lengthy discussions since its deplorable state had to assume the worst. The cat is receiving sewage, industrial waste and container obviously stormwater discharges, by collapsing emptied its waters in the city of La Plata and its surroundings, making the city into a veritable disaster area.
water came almost to the roofs of the houses, 1.70 meters high, and when the water began to drain household furniture and wax were impregnated with oily substances, hydrocarbons and presumably all the filth that pours into the creek.