WEATHER SAFETY:

DANA STRIKES IN THE MEDITERRANEAN LAST WEEK

The recent severe weather event in the Balearic Islands, known as a DANA (Depresiรณn Aislada en Niveles Altos), caused significant damage on the Mediterranean coast, particularly to yachts and other marine vessels, and further ashore causing flash floods in southern cities and towns.ย  DANA is a meteorological phenomenon where a pocket of cold air detaches from the main atmospheric flow at high altitudes and moves over a warmer air mass. This interaction leads to the formation of highly unstable weather conditions, resulting in intense storms, heavy rainfall, and sometimes hail, especially in Mediterranean regions like the Balearics.

DANA is an example of a severe storm erupting from extreme temperature differentials that weather forecasters are unable to predict and in this case absolutely did not predict.

As mariners living and traveling on this ocean, this type of weather event begs us to ask:

What would we do?

How would we ride out a sudden unpredicted storm?

Deep keeled boats knocked down, MV powering into storm surge.ย  Choas.

During this particular DANA, winds reached speeds of over 40 knots, and rainfall was exceptionally heavy, with some areas experiencing nearly 50 liters of precipitation in an hour. The rapid accumulation of rain and the strong winds generated significant wave energy and storm surges, leading to the sinking of several boats and extensive damage to moorings and coastal infrastructure.

The energy generated by a DANA is significant due to the extreme temperature contrasts between the cold upper-level air and the warm surface air. This contrast fuels the severe weather, making the storms more intense and potentially destructive. The unpredictable and cyclonic nature of a DANA makes it challenging to forecast precise locations of impact, which is why such events often lead to sudden and widespread damage across affected areas.

Gerrit Haaland, a creative director at NauticFilm was in Spain watching the weather last week:

“It is correct that everyone knew this was going to happen. However, that morning, ALL the six major weather models PWE, ECMWF, GFS, UKMO, SPIRE and AROME predicted the arrival of the front to be much later and the wind speeds much lower.

Until now, I used to believe that when all the models are aligned, the prediction will be at least reasonably accurate. Seems I have to unlearn that.

I guess that with the record-breaking water temperatures in the Med, the weather is changing and the the weather models havenโ€™t caught up yet.

My learnings:
โ€ข Stop relying on weather forecasts too much, look up more.
โ€ข Donโ€™t consider everyone a moron who was out there yesterday. Could have happened to me just as well.

The destruction in the Balearics underscores the importance of preparedness, especially in regions prone to such meteorological phenomena, where the effects of climate change may be intensifying these eventsโ€‹ (Nautic Magazine)โ€‹ (Marine Industry News)โ€‹ (Olive Press News Spain)โ€‹ (Barcelona Yellow).

Danas Storm Path northward in Spain Last week

DANA (Depresiรณn Aislada en Niveles Altos) can occur in various maritime and coastal regions, but it is particularly common in the Mediterranean basin, including the Iberian Peninsula, the Balearic Islands, and the broader western Mediterranean area. The phenomenon is driven by the interaction between cold air aloft and warmer surface air, conditions that are frequently met in these regions due to their unique geographic and climatic characteristics.

Susceptible Maritime Areas:

  1. Western Mediterranean:
    • This area, including the Balearic Islands, southern France, and the coasts of Spain and Italy, is highly susceptible to DANA events. The warm waters of the Mediterranean Sea provide the necessary conditions for the warm air masses that interact with the cold air at high altitudes.
  2. Eastern Mediterranean:
    • Although less frequent, the eastern Mediterranean, including Greece and Turkey, can also experience DANA events under the right conditions.
  3. Southern Spain and North Africa:
    • The coastal areas along southern Spain, particularly around the Gulf of Cรกdiz and the Strait of Gibraltar, and parts of North Africa, can be affected by DANA, especially during the transitional seasons when the temperature contrasts are more pronounced.
  4. Atlantic Influences:
    • While less common, DANA events can occasionally influence maritime areas of the eastern Atlantic, especially near the coastlines of Portugal and Morocco, where the cold air masses can descend from higher latitudes.

Why These Areas? The Mediterranean climate, characterized by warm, dry summers and mild, wet winters, provides a fertile ground for the development of DANA. The sharp contrasts in temperature between the cold upper-level air and the warm sea surface create the unstable atmospheric conditions necessary for DANA formation. Additionally, the complex topography and the enclosed nature of the Mediterranean Sea contribute to the intensity and unpredictability of these eventsโ€‹ (Barcelona Yellow)โ€‹ (Mallorca Global Mag).