The Balearic 112 emergency service will activate a yellow alert in the Balearics and an orange alert in the Serra de Tramuntana and northern Mallorca for rain and storms this Saturday. The head of the Emergencies Department, Aurelio Soto, issued the warning after the meeting of the Technical Advisory Committee of the Meteobal Plan this morning due to the activation of alerts for adverse weather conditions.
The State Meteorological Agency (Aemet) has activated yellow and orange warnings for rain and storms from midnight on Saturday until 11:59 p.m. on the same day. Soto explained that a cold front is expected to arrive, bringing rainfall, with particular intensity in the middle of the day and in the areas of the Serra de Tramuntana and the north of Mallorca, where up to 150 litres per square metre could accumulate in 12 hours.
In view of this forecast, the Directorate-General for Emergencies and the Interior will declare a yellow alert level on all the islands, except in the Serra and the north of Mallorca, where an orange alert level will be declared. The head of the department has therefore asked the general public to take extreme precautions and to limit their movements and activities outdoors, especially in the orange alert areas. ‘Saturday is a good day to stay at home,’ he said, arguing that the rains are expected to be intense in the Serra but could move to other areas.
The Emergency Services have recommended that local councils activate their municipal plans and, with regard to planned outdoor activities, they have advised restricting them, especially in areas with an orange alert. The cold front is expected to have passed by Sunday and the weather is expected to return to normal.
According to weather experts, the front will feature a Cyclogenesis - the development or strengthening of cyclonic circulation in the atmosphere (a low-pressure area). Cyclogenesis is an umbrella term for at least three different processes, all of which result in the development of some sort of cyclone, and at any size from the microscale to the synoptic scale. Tropical cyclones form due to latent heat driven by significant thunderstorm activity, developing a warm core. Extratropical cyclones form as waves along weather fronts before occluding later in their life cycle as cold core cyclones. Mesocyclones form as warm core cyclones over land, and can lead to tornado formation. Waterspouts can also form from mesocyclones, but more often develop from environments of high instability and low vertical wind shear.
The process in which an extratropical cyclone undergoes a rapid drop in atmospheric pressure (24 millibars or more) in a 24-hour period is referred to as explosive cyclogenesis, and is usually present during the formation of a nor’easter. Similarly, a tropical cyclone can undergo rapid intensification.
The anticyclonic equivalent, the process of formation of high-pressure areas, is anticyclogenesis. The opposite of cyclogenesis is cyclolysis.