Musings and forecasts of Andalusian weather and climate, from a veteran meteorologist.
By: esteban9, 8:11 AM GMT on December 09, 2010
While there are still showers over Portugal, these should move north and give way to partly cloudy skies and the long-advertised break from the heavy rains of the last week. This was a truly prodigious event, which caused severe flooding along the Guadalquivir. The latest event occurred yesterday in Lora del Rio (a little northeast of Seville), which was also a victim of the February floods
So today we should begin a few days of drying out. The cyclone currently producing the showers in Portugal should retreat from Iberia (a somewhat odd process that we meteorologists call "retrogression") and weak high pressure should take its place. Temperatures will be seasonal to above average until the middle of next week, when cold but dry air may invade from the north. For now, however, enjoy the respite!
PS, I learned a new term. The recent unusually sultry and humid weather that we just experienced is called a "bochorno." This old dog is learning new tricks.
Updated: 8:12 AM GMT on December 09, 2010
By: esteban9, 7:17 PM GMT on December 08, 2010
Yet again the train of echoes has appeared in the Sierra north of Seville and Cordoba. These echoes are being produced by intense thunderstorms with numerous lightning flashes. This is exactly what is not needed - more runoff into the Guadalquivir. More flooding likely on the river between the two aforementioned cities.
As the child's death near Ciudad Real shows, crossing an flooded arroyo in even an SUV can be fatal. Be careful out there!
By: esteban9, 7:23 AM GMT on December 08, 2010
At this time yesterday, I mentioned the possibility of flooding, and by afternoon I suggested that this may be a repeat of the severe inundations of last winter. Mother Nature has brought this about, in spades. Only this time, the rains didn't take as long to do the job.
Yesterday numerous thunderstorms traveled from west-southwest to east-northeast within a band that mainly lay in the Sierra Morena and Sierra del Norte, north of Cordoba and Seville, respectively. These storms therefore repeatedly struck the same areas, dumping torrential rains there. This "stuck" pattern is referred to as one with "train echoes," referring to its appearance on the radar - see this example from yesterday at 1610 hours. When a lot of rain falls in a short time (more than 200 mm in some places, over two days), the soil has little time to absorb it and most of it runs off into the rivers. In this case, much of the runoff went into the main stem of the Guadalquivir.
The following are just some news stories on the flooding:
Evacuations in Lora del Rio (between Cordoba and Seville)
Flooding of the Genil River at Écija (record 7.3 meters river height)
Córdoba drowns again
As I commented yesterday, the rain will begin to move north today. Unfortunately, it will be with us long enough today to create more problems. A peek at the current radar image shows that there are already lines of echoes with similar orientation and location as yesterday (over the northern Sierras).
Ay ay ay! Stay tuned for updates.
PS the high winds I predicted yesterday also occurred. I saw reports of gusts in excess of 90 km/hour.
By: esteban9, 9:16 PM GMT on December 07, 2010
The rains of today have swelled the Guadalquivir river, and the high water mentioned in the last post is reaching Seville. The flow there is over 3200 cubic meters per second; compare to the maximum flow last winter on 17 February of 3400 cubic meters per second. There has already been flooding in low-lying areas of the valley and this will continue tonight. Wow!
By: esteban9, 2:41 PM GMT on December 07, 2010
I recently raised the question of whether Autumn is picking up where Spring left off, in terms of flooding in Andalucia. There are signs that this may be happening.
The line of thunderstorms described this morning weakened into smaller but widespread thundershowers, which have impacted mainly the Sierra del Norte, to the north of Sevilla and Cordoba. Nevertheless, these storms have formed a "train" of radar echoes that have been dumping rain over the same area north of Cordoba, and this runs off into the Guadalquivir. Here is a live webcam from Montoro, just upstream of Cordoba. One can see the river at bank full. The reservoir Martin Gonzalo, just north of this point, has recorded 188 mm of rain since yesterday. This will have to be watched!
Tip 'o the hat to Emilio of Digitalmeteo for the webcam link.
By: esteban9, 7:06 AM GMT on December 07, 2010
Well, some thunderstorms developed after all yesterday, mostly in the late afternoon. And, as anticipated, an even stronger round of storms is on the way today. In fact, the most impressive and organized line of thunderstorms thus far has just crossed the Portuguese/Spanish border, extending from Huelva well into Badajoz province. This line will continue to move east into Sevilla and Cordoba provinces this morning, bringing with it torrential rain and strong winds. The Gibraltar sounding from 1 AM is more unstable than yesterday, further supporting the forecast of stronger storms.
Once again, most of this activity will be centered on the western half of Andalucia. AEMET has raised an orange alert for heavy rains (30-40 mm per hour) in Sevilla, Cordoba, Cadiz, and western Malaga provinces. In areas already saturated areas by previous rains, some flooding (especially in urban areas) could result. With the strongest storms, again, beware also of high winds. We will monitor the line of thunderstorms in the west for changes.
Tomorrow, much (but not all) precipitation should shift to the north of Andalucia, and Thursday looks warm and dry.
By: esteban9, 7:07 AM GMT on December 06, 2010
There were lots of thunderstorms overnight in western Andalucia and the Straits. While the threat of thunderstorms is less today (as indicated by the Gibraltar sounding), there is still ample moisture for rain showers today. However, there will be more sunshine in between showers as compared to yesterday. Tomorrow, however, rain and clouds will increase in coverage again. The best bet for clearing skies will wait until Thursday. And it will remain warm. So, good news for those looking for a break in the active weather pattern of the last week.
By: esteban9, 8:24 AM GMT on December 05, 2010
There is good news and bad news for those that like sunny and warm weather.
The good news is that temperatures will be several degrees warmer than the last week. The bad news is that rain showers will plague the land. Already light to moderate rain is entering the mouth of the Guadalquivir valley (Huelva and Sevilla provinces). This will set the tone for the next couple days, i.e., clouds and showers.
The culprit is a large storm that has been spinning off the coast for a while. It was an open question if and when this storm would move inland and, if so, how much rain it would produce in Andalucia (the focus for heavier precipitation was, and still is, northwest Spain). Nonetheless, it now appears that the rain in the south will be significant in quantity.
It seems that warm AND sunny is not on the menu this late fall season in the south. Well, as has been said many a time, it could be worse - one could be in the frozen tundra of the rest of Europe right now!
By: esteban9, 3:02 PM GMT on December 01, 2010
A line of thunderstorms is entering Seville. The echoes don't look that impressive, but since the lightning maps show quite a few flashes, the convection is real and the areas impacted by this line should see a short-lived dousing of at least moderate rain.