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Weather Nowcasting: What It Is

Weather Nowcasting: What It Is

Nowcasting, it has little to do with casting models, it has to do with weather forecasts, who makes them and who watches them. This doesn't mean it's a niche concept: forecasts nowcasting they can save the lives of all of us so, in that sense, they are a mass issue.

The term derives from English, from now, "now", and [fore] casting, "forecast", and indicates the meteorological forecasts made in the very short term, which therefore concern the hours immediately following their creation, and in a territory of decidedly limited interest. More briefly it is about forecasts with high spatial and temporal resolution that show the evolution of time in the following minutes and up to a maximum of six hours, in a small area.

Web weather nowcasting

As you can guess, this kind of forecasts are well conveyed via the web, medium in which they can be updated in real time or almost and consulted quickly, even with one smartphone or tablet. Obviously the nowcasting predictions published in a paper newspaper or announced on TV every two or three hours are rather useless if not boring.

Via the web, however, they can be useful to spread the word of the arrival of extreme weather events such as thunderstorms, floods, hurricanes, tornadoes. Not fake news but information that come from industry experts which can be useful for those involved in public safety monitoring the hydrogeological cycle.

If you think about it, there are many activities that are closely related to time and who benefit greatly from knowing how the state of the atmosphere evolves in the immediate future. Just think to the nautical sector, to hiking, to the many outdoor sports competitions, to major events and to air flight assistance.

Weather Nowcasting: What It Is

Forecasts nowcasting or with high temporal and spatial resolution, they are predictions therefore that must quickly cross a lot of data to better approximate what is about to happen, in the following 6 hours maximum. Sometimes it is enough to look out the window to understand, true, but this is not always the case and there are occasions when the sky has some nasty surprises for us. It is the moment in which it shows itself the difference between nowcasting and "take a look" at the sky.

It is always one often empirical technique but that provides good results, crossing the specific knowledge acquired by professional meteorologists and meteorologists on local microclimates, on the influence of orography and also uses theoretical and mathematical meteorological models.

A part of the data used to process the nowcasting predictions they come from immediate, real-time observation of atmospheric conditions, also obtained through instruments and meteorological information from weather stations scattered in the area that interests us and in its vicinity. They are therefore very useful for nowcasting, i vertical atmospheric soundings, meteorological radars, free observations, satellite images and information regarding local atmospheric circulation.

Weather nowcasting: Arpa

Arpa and its site is an important one source of information and real and reliable data, to realize the predictions so closely. These are predictions not for the curious or for those who have to decide what to do in the afternoon, but essential for all that it concerns civil protection and storm, hurricane and strong wind disasters.

Heavy rainfall, the fateful "water bombs" as they are called in the newspaper headlines, are exceptional events that nowcasting predictions they can intercept so that the population and local administrations know what is about to happen.

Weather nowcasting in Italy

We are in Italy very alarmist as far as the weather is concerned, and not only that, and every summer that arrives, we announce “never before seen” heat waves, in autumn and in the middle seasons, anomalous rains, thunderstorms and catastrophes. They are not always false alarms and it is important understand how to really inquire to find out if it is really necessary to run for cover, postpone an excursion or a big event, or not.

There are bodies, institutions, such as the many Arpa in the regions or the site of the air force, where you can view reliable information. Let's make much attention to the time frame of the nowcasting forecasts which cover a maximum of the six following their issue. In general, other types of weather forecasts are also not reliable if they go so far as to describe what the weather holds in the future more distant than 2/3 days.

World weather nowcasting

The nowcasting predictions they are used all over the world but always concern limited areas, from time to time different. In America, a country often targeted by cyclones and tornadoes, they are widely used and consulted by individual citizens. There is a real "weather mania" overseas, with dedicated channels and almost star meteorologists. Without getting so infected but it is important to know that the nowcasting forecasts are a useful tool in some emergency contexts that can also occur in our small peninsula.

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Video: Precipitation Nowcasting with Satellite Imagery (May 2021).