DISCUSSION: With the 2016 Summer Olympics right around the corner, here is what we can expect for the month of August in Rio de Janeiro, Brazil. Based off of Rio’s climatological past, August is often the coolest and driest month of the year for the city with an average temperature of 72°F and average precipitation of about 2 inches of rainfall. The capital of Brazil is classified as having a tropical savanna climate that closely borders a tropical monsoon climate according to the Köppen climate classification. Rio receives the majority of its rainfall during the summer months, which in the Southern hemisphere runs from December to March. August, therefore is winter in Brazil, but winters in Brazil are not cold by any means and no snow has ever been recorded in the capital since modern records have begun. Powerful cold fronts from Antarctica can often make their way through the city, but they moderate very quickly as the city is located right off of the Atlantic Ocean with water temperatures that sit at an average of 72°F as well. Air temperatures can vary wildly throughout the entire year in Rio, approaching 100°F several times a year, this combined with awfully high humidity levels can lead to heat index values approaching dangerous levels over 110°F. Other times of the year temperatures can dip down into the upper 30’s, this mainly occurs during the winter when the aforementioned polar fronts make their way through the region. The city receives over 42 inches of rainfall a year, with the bulk of that occurring during the summer months, when nearly half of the total rainfall falls between December and March alone. During this time period rainfall occurs quite often from extra-tropical cyclones off the adjacent Atlantic.
For the month of August the average high temperature in Rio reaches 79°F, meanwhile the average low temperature is right around 66°F. The city usually sees around 7 days of rainfall for the month of August, which means with the 2016 Summer Olympics lasting from August 5 to August 21 we can generally expect about 2 days of rainfall during this time period, in a typical year. Looking at the latest weather models, forecasters are predicting a terrific start to the 2016 Summer Olympics with temperatures right around average for this time of year with an abundance of sunshine! To learn more about other high-impact weather events from across Central and South America, be sure to click here!
DISCUSSION: Over 50,000 alpacas died during a recent cold snap in the Peruvian Andes. Clear skies over southern Peru caused by a persistent high pressure system have allowed temperatures to plummet in the nighttime hours. July is typically the coldest month of the year in Peru with an average temperature of only 20°F. However, temperatures this week have dropped as low as -5 °F. The dangerous cold has been devastating for poor, indigenous populations that rely on alpaca wool to make a living. The government of Peru has declared a state of emergency as the National Meteorological and Hydrological Service expects the cold temperatures to continue throughout the rest of the week. To learn more about other high-impact weather events from across South America, click here!
DISCUSSION: Though this particular event is not directly associated with the atmosphere, as of earlier yesterday afternoon a violent volcanic eruption took place in Eastern Guatamela. More specifically, this volcanic eruption was associated with the Santa Maria Santaguito volcano yesterday afternoon (which is located in far Eastern Guatemala). Despite the fact that this is a geologically-based phenomena, this volcanic eruption will undoubtedly have tremendous consequences on global atmospheric flow patterns. This is due in part to the fact that in the wake of a volcanic eruption there is often are tremendous quantities of volcanic ash ejected into the middle and upper portions of the atmosphere. As this dense volcanic ash becomes suspended in the middle-to-upper atmosphere, this can affect the amount of incoming solar radiation as well as the operations of globally-operating commercial aircraft. This danger to commercial aircraft is directly due to the volcanic ash compromising or sometimes even destroying the functional ability of aircraft engines; endangering passengers and crew around the world. Moreover, locally across Eastern Guetamala where there were clearly much higher concentrations of volcanic ash even within the lower portions of the atmosphere, the combination of locally-suspended volcanic ash coupled with nearby convection can act to "rain-out" (i.e., bring the toxic volcanic ash down to the surface by means of being enveloped by falling precipitation). Thereafter, volcanic ash particles can often get caught in rainfall runoff and seep into the ground which can compromise water resources utilized for things such as hygiene, cooking, drinking, and/or agricultural production. Hence, volcanic ash can have far-reaching impacts beyond the initial eruption period itself as a consequence of natural atmospheric processes which are often found to exacerbate the problem. To learn more about other high-impact weather from across Central and South America, be sure to click here!