Stationary or retrograde

 If yesterday was a day of sparse in reviews it was, in fact, a day of bounty compared to today.  I was tempted to leave nothing but this line and let you look at the scenery but, you know, I do realise we have sponsors to keep happy so time for some content.

Weatherwise we are in January and January tends to be the coldest and generally driest months round here.  Arnedo’s average maximum  is 9.5oC. This compares to 11.5 in December and 12 in February.  February just gets the average minimum at 1.8oC, compared to January’s 1.9 - but I think we can over look that.  April and May are the wettest, with about 6cm of rain across 14 days.  January has fewest days rain - about 4, and at 3cm is marginally less than July and August but more than September [2.1] and October [2.7cm].  Use this knowledge wisely.

I thought I’d look up weather events - snowy days etc but am having trouble finding the exact site I am looking for.  Obviously the 2024 floods are on people's minds at the present.  I did consider volcanoes - but the Canaries are not a place we have been yet.  Let's do earthquakes.

The 1816 North Atlantic earthquake occurred on 2nd February somewhere between the Azores Islands and Lisbon.  The estimated magnitude 8.3–8.9 earthquake had an epicenter offshore in the Atlantic Ocean, and was felt in Lisbon at 00:40 local time. Little is known about the quake, but it is believed to be one of the largest to have struck the Atlantic.  The quake was felt in Seville  but no damage was reported. That is a bit of a disappointment really.

The 1884 Andalusian earthquake (Spanish: Terremoto de Andalucía de 1884) occurred on 25th December 1884 at 9:08 p.m in the south of Spain, and had an estimated magnitude of 6.7m . It shook a poor region where many of the houses were built without foundations, with lime or mud mortar, and with weak joints. More than 10,000 buildings were badly damaged, of which 4,399 were completely destroyed. There were over 1,200 deaths and 1,500 serious injuries, however, many people were in the streets celebrating Christmas hence casualties were not higher. The heavy snow that followed the earthquake caused further suffering and deaths. Help was slow to arrive at first, but as the news spread food and blankets arrived, then tents, and then donations from around the world helped with reconstruction.

Diverted back to the path of righteousness I have now read up about Cold Drops.  A cold drop is a term used in Spain and France that has commonly come to refer to any high impact rainfall event occurring in the autumn along the Spanish Mediterranean coast or across France. The Spanish-language name of gota fría was directly adapted from the term Kaltlufttropfen introduced by German meteorologists, and became very popular in 1980s Spain as a blanket term to refer to any high-impact rainfall event.

What Wiki says is “In the Spanish Levante, these events are typically caused by the interaction of upper-level low pressure systems strangled and ultimately detached from the zonal (eastward) circulation displaying stationary or retrograde (westward) circulation with humid warmer air masses that form over an overheated Mediterranean Sea in the Autumn. The Spanish equivalent of cut-off low is DANA (Depresión Aislada en Niveles Altos). Such recurring synoptic configurations are not necessarily associated to cold drop events.” This is one of those ones where I understand individual words but not the whole thing.

The events this cause can have great impact. The great Valencia flood on 14th October 1957 was the result of a three-day-long cold drop and caused the deaths of at least 81 people.  The Vallès floods on 25th September 1962 in the wider Barcelona area were caused by a cold drop,  producing heavy rain, overflowing the Llobregat and Besòs rivers. The official death toll was 617.  On the night of 29th-30th October 2024, a DANA event caused considerable loss of life and extensive damage, especially in the Valencian Community and the provinces of Albacete, Almería, and Málaga.

With this sobering knowledge we will push on.