Heat wave: how it is measured and how far in advance it can be forecast
In the middle of the heat wave that affects a large part of the country and after the red, orange and yellow level alerts deployed throughout the Argentine map, specialists from the National Meteorological Service (SMN) analyzed this extreme phenomenon. From the institution revealed how is the temperature measurement process, his variation through the years and spread a series of points to take into account in these cases.
When asked by THE NATION, Cindy Fernandez, SMN meteorologist, pointed out that extreme heat situations can be anticipated well in advance. “We began to talk about this particular wave between seven and 10 days before it was possible to reach 40 degrees in much of the country,” he said.
“It was already clear that temperatures were going to be very high, with values well above normal. Heat is a variable that has been confidently forecast for quite some time in advance. Later, as it develops, it is adjusted how many degrees can be reached, “added the meteorologist.
The specialist indicated that very extreme temperatures, high or low, can be forecast even 10 days in advance, while other variables such as rainfall is not as predictable. “To say if it is going to rain in a city, you cannot go beyond 5 or 6 days. The shorter the term, the more reliable the forecast will be, in that case. highlighted the meteorologist.
After temperatures above 40 degrees were recorded today in more than forty locations, Fernández remarked that the Heat waves are common in Argentina and there are usually several episodes throughout the summer. “We must bear in mind that we are just reaching the middle of the season, that is, there are still at least two more months of heat left, with which is possible that we will have a heat wave again, “he warned.
However, the meteorologist considered that “It is unlikely” that a heat wave of this type will be repeated since it is “extraordinary”, by presenting certain characteristics that differentiate it from others.
In the first place, the meteorologist remarked that this type of phenomenon occurs once every 20 or 30 years. Also, unlike other heat waves, this one affected much of the country, from Patagonia to the north.
“In this case, historical maximums and minimums are recorded. They are breaking a lot of records, which are temperatures never seen since there is a record. In addition, the phenomenon is remarkable for its persistence. All this makes this wave extraordinary.” Fernandez remarked.
The meteorologist warned that although these types of phenomena will continue to be sporadic, they are expected to occur much more frequently in the future. “Extraordinary heat waves always happened, in the past they have also been recorded in the year ’57 or in the ’70s, but what is observed is that there is a tendency in recent years for these extreme phenomena to become frequent due to climate change”, Fernandez concluded.
Meanwhile, another of the particularities that characterize this heat wave is the lack of thermal sensation, since this is directly associated with humidity levels.
“In this particular heat wave, an air mass is registered that is completely dry, so there is no thermal sensation or we can say that it is equal to the temperature,” the meteorologist highlighted.
For his part, the SMN meteorologist Lucas Berengua explained to THE NATION that the temperature measurement is carried out in weather stations, certain places that comply with international regulations of exhibition and certain design and, in turn, must be supervised by the National Meteorological Service.
“The regulations, in short, determine a place with the necessary air circulation and require very specific requirements for each of the measuring instruments. For example, temperature is measured within “weather coats” which are wooden boxes, properly oriented, treated with white paint and at a certain height of 1.50 meters”, explained Berengua.
Within the “meteorological coats” are mercury thermometers with which a meteorological observer performs the readings and the corresponding analysis.
On the other hand, the meteorologist stressed that this observation method has been used since the beginning of meteorology, although with the technological update new measurement procedures have been appearing, such as digital thermometers waves automatic stations.
“The methods coexist and both serve to determine the temperature with the globally regulated requirements”, added Berengua.