Exceptional rainfall, Valencia area, Spain

[jack.h...@gmail.com]

Typical media reporting: concentrating on the floods and misery (including deaths) but nothing about the reasons for the intense rain.

Obviously severe thunderstorms but any links with explanations such as synoptic situation; convergence?

Jack

[Nick Gardner]

The very heavy rainfall was caused from what the Spanish call a gota fria or what we would call a cut off low with cold air aloft. I gather that if they occur in the autumn then they bring about huge amounts of rain with Valenica particularly badly affected (as it has been in the past). I'm no meteorologist but I think the warmth of the Med Sea plays an important role in the rainfall.

Nick

Otter Valley, Devon.

[Ashley haworth-roberts]

I've seen a blog by Liam Dutton and an article from Sky News. The latter refers to a Depresion Aislada en Niveles Alto or DANA without offering a translation. Wikipedia suggests 'isolated depression at high levels'. A cut-off depression or low. DANA was discussed (with saying what it stood for) on the BBC News at One. And gota fria seems to be Cold Pool in English. 

[jack.h...@gmail.com]

Excellent explanation here:

https://news.sky.com/video/what-caused-the-extreme-weather-that-led-to-flooding-in-spain-13244968

Jack

[Tudor Hughes]

It was what proper meteorologists call a cut-off cold pool but the translation is a bit laborious.  This one seems to be somewhat more marked than normal and the Mediterranean is a little warmer than usual so the potential for vigorous convection was there.  The rain fell inland from Valencia and was extremely intense though quite large parts of the city were not flooded at all.

    Some of the media (e.g. the Guardian) have been running around like headless chickens over this, saying that Global Warming is a threat to us all.  I don't see this.  There seems little reason why heavy downpours such as this should become more frequent in a warmer world.  It's all very well to say that warmer air can contain more moisture but it needs a mechanism to release it and that depends on the synoptics.  We shall have to wait for an article in Weather for a proper meteorological assessment.

Tudor Hughes, Warlingham, Surrey.

[jack.h...@gmail.com]

Seems fairly obvious that a lot of the flooding problems came from too much concrete in urban areas with no proper drainage.

I notice that new housing estates in UK often have ponds these days.  Some lessons might have been learned.

Jack

[jack.h...@gmail.com]

I have just been reading an hourly history (good series) about the Great Fire of London.  The catastrophe was apparently a case of not if but when - in other words inevitable.  Lessons learned translated into planning regulations such as greater spacing between buildings, establishment of Fire Brigades and so on.

The Valencia floods are in some respects a parallel.  Again, not if but when.  I spent some time in Singapore - where it rains! - and streets have storm drains.  They got things right decades ago.  So Europe needs to adapt and adapt quickly.  The Valencia floods - as has been pointed out - are not necessarily a consequence of climate change but more likely due to poor planning and infrastructure: in other words, too much concrete, uncontrolled building, too many people crowded into small areas.

Another book I have just read in the hourly history is about Native Americans.  They lived for millennia in harmony with the land.  Then Europeans arrived and knew better!  We 21st century humans need a take a long, hard look in many areas not just concentrate on man-made climate change.  We need to live with nature and not keep trying to fight it.

Jack

[Graham Easterling]

I'd go along with that. There's is no doubt that global warming is very concerning & will bring about changes we should be very keen to avoid. However this need to blame it for every event is doing more harm than good. Down here in windy Cornwall every gale is blamed on climate change, even though the gale frequency has been low this centuary (Perhaps because the temperature gradient in the bearby north Atlantic has reduced slightly because of the warming of the Arctic) This allows councils and government (and indeed the NT) to say that every sea wall collapse is down to 'increased storminess', which is b*ll*cks, poor maintenance is the reason.

The only practical route into Mousehole is slowly sliding into the sea, nothing has been done for decades, except replace the fence as is slides into the sea and repair one bit they had to do as half the road disappeared. I await an appropriate global warming event. 

Strange that everything is blamed on global warming, but global CO2 emissions keep rising, unless there's a lockdown. 

Graham

Penzance  - even more worrying, the addiction to vast quantities totally uneccessary plasic, especially in TesMorBurys. (Good word Andrew)