Synoptic Causes of Torrential Rainfall in the Balearic Islands (1941–2010)

Abstract

This article determines the atmospheric situation for the 53 days where any weather station in the Balearic Islands detected torrential rain (equal to or above 200 mm in a single day) during the period 1941–2010. To do this, the synoptic charts for each day were analysed, classifying them in accordance with the types established by Martín Vide (1984) and, in addition, through the automatic synoptic classifications from Jenkinson and Collison (1977). The analysis results demonstrate the importance of cyclonic situations over the Western Mediterranean Basin linked to favourable altitude configurations (earlier presence of cut-off lows—DANA—or troughs). These atmospheric conditions contrast with those that predominate in nearby Mediterranean areas, such as the south-eastern coast of the Iberian Peninsula. Days with torrential rain on the Iberian coastline tend to coincide with easterly advections—a less common occurrence in the Balearics.

Are Atmospheric Situations Now More Favourable for Heavy Rainfall in the Spanish Mediterranean? Analysis of Episodes in the Alicante Province (1981–2020)

“…In Alicante, however, this type of situation is only represented in 12.2% of the days analysed. The results obtained by Martín Vide [29] partially coincided with those obtained by Grimalt-Gilabert et al [22] for the Balearic Isles, where the pure cyclonic type (C) stands out with 75.5%, while advection or hybrid advection (CE, E, NE, ASE) represents 20.7% of the 53 dates analysed in that study.…”

“…In the SE of Spain, for the dates on which over 200 mm rainfall was recorded (1941-2017), Martín Vide et al [21] also obtained a higher frequency of Advection from the E with DANA (52.9%), in second place the Trough type (17.6%), and, lastly, the Cold-core low (16.2%). Grimalt-Gilabert et al [22], however, for episodes with a threshold higher than 200 mm/day, for the Balearic Isles, obtained the highest frequencies in the dynamic Low type (26.4%), Troughs (24.5%), advections from the E with DANA (24.5%), and advections from the NE with DANA (11.3%). In another study for the coastal provinces of Catalonia, in the NE of the Iberian Peninsula, 304 days were analysed that presents a threshold similar to, or greater than, 100 mm/day , and the 7 most frequent patterns were identified by means of PCA analysis, among which can be highlighted the weak Cold-core low to the E, a blocking situation to the SE and advection from the SE, with differences in relation to the southeast [13].…”

“…The differences are much greater on comparing the results of the classification by J&C for the Peninsula and for the islands. According to the J&C classification, in Alicante the days with torrential rainfall present the circulation type from the E and NE (46.5%), whereas in the Balearic Isles, they are associated with pure cyclonic situations (C) (75.5%) [22]. In Alicante, however, this type of situation is only represented in 12.2% of the days analysed.…”

“…Among the most recent studies, applying manual (subjective) synoptic classification methods one can find those of Martín Vide et al [21] who applied the method proposed by Martín Vide [20] for 68 rainfall episodes of over 200 mm/day in the SE of Spain (Alicante and Murcia) for the 1941-2017 period. For the area of the Balearic Isles Grimalt-Gilabert et al [22] classify 53 episodes surpassing the threshold of 200 mm/day in the 1941-2010 period, according to the types established by Martín Vide [20] and combined with the automatic classification method of Jenkinson and Collison [23], hereinafter J&C. Likewise, Miró et al [24] combined Martín Vide's subjective classification [20] with the objective method of J&C. Other studies that have made use of subjective classifications, whether according to types of synoptic situations or types of climate for Spain and its regions, are those by Martín Vide [20], Gil Olcina and Olcina Cantos [25], Romero et al [26], Capel-Molina [27], and Martín Vide and Olcina [2].…”

Air Photo Interpretation for Spatial Analysis of Heritage Agrarian Structures in Mediterranean Settings as Sea-Breezes Proxy-Data. Application to the Island of Mallorca

“…To verify the climatic suitability of July 1956 for the formation of breezes, surface atmospheric circulation over the western Mediterranean area during that month and that year was analyzed using the Jenkinson and Collison automatic method of weather type classification [46][47][48]. The results indicate that the atmospheric circulation conditions were totally favorable to the formation of sea breezes on 24 days (77.4% of the days), while only 7 (22.6%) had advective situations that could have inhibited breezes.…”