Analysis of the precipitation and cloudiness associated with COLs occurrence in the Iberian Peninsula

Nieto, Raquel; Añel, Juan Antonio; Torre, Laura de la; Gallego, David; Barriopedro, David; Gallego, M. C.; Gordillo, A.; Redaño, Á.; Delgado, G.

doi:10.1007/s00703-006-0223-6

Cited by 30 publications

(33 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In western areas with significant influence from the Atlantic, surface pressure patterns associated with westerly winds and fronts usually exhibit a closer relationship with precipitation extremes (Vincente‐Serrano and López‐Moreno, ; Fernández‐Montes et al , ; Seubert et al , ). During summer and transitional months, the interaction of circulations with the topography and thermodynamic conditions is essential for the formation of intense precipitation, with the appearance of cutoff lows in the mid to upper troposphere (Nieto et al , ).…”

Section: Introductionmentioning

confidence: 99%

Large-scale patterns of daily precipitation extremes on the Iberian Peninsula

et al. 2015

View full text Add to dashboard Cite

The study of weather extremes is critical because of their great impact on the environment, economy and society. The identification of areas at greater risk of extreme conditions, and of meteorological situations that give rise to such conditions, enhances the understanding of climate risks and helps establish measures to reduce adverse impacts. In the current paper, precipitation extreme events (PEEs) in Spain between 1960 and 2011 were analysed. Thresholds for determining event severity were defined using 99th percentiles. First, regions of extreme weather risk were identified and then trends of extreme precipitation index were analysed using the Mann–Kendall test. To better understand atmospheric processes associated with extreme weather events in each season, synoptic‐scale fields of events exceeding the 99th percentile were analysed. By applying non‐hierarchical K‐means clustering, we defined six large‐scale atmospheric patterns that largely explain the spatiotemporal distribution of PEEs in the study area. PEEs on the western Iberian Peninsula mainly occurred with zonal flow, with a long Atlantic fetch generating moisture advection towards that area. On the eastern peninsula, the most important pattern for PEE production is characterized by a cutoff low at mid‐levels together with easterly moisture flow. The relationship of PEEs with teleconnection patterns, such as the North Atlantic Oscillation (NAO), Mediterranean Oscillation (MO) and Western Mediterranean Oscillation (WeMO), showed that nearly all the events over the southwestern peninsula were during the NAO‐ and MO‐negative phases. However, on the Mediterranean coast, the negative WeMO phase had greater influence. By contrast, the northwestern peninsula and eastern Cantabrian coast showed weaker relationships between these indices and PEEs. The results show a clear ability to identify regions exposed to extreme precipitation hazards. The correct identification of synoptic patterns associated with each type of weather extreme will assist the prediction of such events, thereby providing useful information for decision making and warning systems.

show abstract

Section: Introductionmentioning

confidence: 99%

Large-scale patterns of daily precipitation extremes on the Iberian Peninsula

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In about 50% of cases, it is this precipitation that dominates. A scheme of the cloudiness and precipitation associated to a typical cut-off low pressure system is displayed in Nieto et al [55].…”

Section: Discussionmentioning

confidence: 99%

“…Placing the precipitation patterns associated to the cut-off low pressure system conceptual model over this area of high correlation, it is possible to view the likelihood of intense precipitation in the SE of the Iberian Peninsula and the Alborán Sea linked to cut-off low pressure systems over the Gulf of Cadiz. The study of Nieto et al [55] on precipitation over the Iberian Peninsula linked to cut-off low pressure systems [55] showed the important precipitation in the area associated with cut-off low pressure systems that occur over the Gulf of Cadiz. Returning to differences between NAO and AO indices, these results should be reflected in the correlations of these indices with precipitation in the SE Iberian Peninsula and the Alborán Sea.…”

Section: Discussionmentioning

confidence: 99%

Combined Effects of the North Atlantic Oscillation and the Arctic Oscillation on Sea Surface Temperature in the Alborán Sea

et al. 2013

View full text Add to dashboard Cite

We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Alborán Sea, both separately and combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Alborán watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.

show abstract

“…COLs in the southwestern quadrant of the IP and adjacent Atlantic and Morocco bring the largest precipitation amounts (30-40 mm) while COLs located in the northwestern quadrant and adjacent Atlantic bring less precipitation (20-30 mm) to the Valencia Province. About a third of COLs that affect the IP produce no rain while a third produce generalized rain over the entire [3]. Most COLs occur in Spring and Summer, with the fewest COLs occurring in the wintertime when the jetstream is located further south and Spain is in the cyclonically sheared side of the jet, inhibiting upper-level thinning troughs [4] and the formation of COLs.…”

Section: Introductionmentioning

confidence: 99%

“…Shallow COLs on the other hand produce weak convective precipitation near the center of the system, or no precipitation at all. A 41-year study [3] found that an average of 2.3 COLs affect the Iberian Peninsula each year. COL systems located in the western half of the Iberian Peninsula and adjacent Atlantic Ocean bring rainfall to a large portion of Spain, including the Valencia Province.…”

Section: Introductionmentioning

confidence: 99%

<strong>Pseudo global warming simulations of the effects of climate change on extreme precipitation events in the Iberian Peninsula</strong>

Ferreira

2017

Proceedings of First International Electronic Conference on the Hydrological Cycle

View full text Add to dashboard Cite

Abstract:A seasonal synoptic climatology of cut-off lows (COLs) that produced extreme precipitation in the Valencia region of Spain during 1998-2014 is presented. COLs were shown to be the main producer of extreme precipitation in the region, especially during the transition seasons. The strongest raining COL events occurred during September-November. Six-day composites of lower and upper tropospheric winds, geopotential, sea-level pressure and precipitation show that COLs that produce extreme rainfall in this region remain stationary over Spain for 2-3 days and produce rainfall over the Valencia region for at least two days. In the low levels these COLs are characterized by low pressure over the Mediterranean sea and winds with an easterly, onshore component. Another interesting aspect of the composites is that transition season COLs are characterized by the presence of a filament of moisture that extends from the tropical Atlantic to Spain suggesting a role for remote moisture transport to feed COL rainfall. Further analysis is needed to confirm this hypothesis.

show abstract

Analysis of the precipitation and cloudiness associated with COLs occurrence in the Iberian Peninsula

Cited by 30 publications

References 13 publications

Large-scale patterns of daily precipitation extremes on the Iberian Peninsula

Large-scale patterns of daily precipitation extremes on the Iberian Peninsula

Combined Effects of the North Atlantic Oscillation and the Arctic Oscillation on Sea Surface Temperature in the Alborán Sea

<strong>Pseudo global warming simulations of the effects of climate change on extreme precipitation events in the Iberian Peninsula</strong>

Contact Info

Product

Resources

About