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This paper examines temporal and spatial variability and trends of annual and seasonal precipitation in Slovenia and their relationship with three atmospheric circulation patterns represented by their indices: North Atlantic Oscillation index (NAOi), Mediterranean Oscillation index (MOi) and Western Mediterranean Oscillation index (WeMOi). Data from 45 precipitation stations were used for the period 1963-2012. Mean annual precipitation varies from 736 mm in eastern Slovenia to 2,518 mm in northwestern Slovenia. A significant annual precipitation decrease (from −3% to −6% per decade) is observed in western Slovenia. Significant negative trends are observed in southwestern Slovenia in summer (from −4% to −10% per decade) and near the Adriatic coast in spring (from −6% to −10% per decade). Non-significant negative and positive trends are observed in winter and autumn, respectively. Results indicate significant correlations between winter precipitation and MOi (from −0.3 to −0.7), NAOi (from −0.3 to −0.6) and WeMOi (from 0.3 to 0.6). Significant WeMOi influence is observed in spring and autumn, while NAOi and MOi influence has not been detected. Annual precipitation and WeMOi are significantly correlated in central and eastern Slovenia, while significant NAOi and MOi influence is observed in western Slovenia (with the larger area covered by MOi influence).

The use of weather satellite recordings has been growing rapidly over the last three decades. Determining the patterns between meteorological and topographical features is an important scientific job. Cloud cover analysis and properties can be of the utmost significance for potential cloud seeding. Here, the analysis of the cloud properties was conducted by means of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite recordings. The resolution of used data was 1 km2 within the period of 30 years (1989–2019). This research showed moderate changing of cloudiness in the territory of Serbia with a high cloudiness in February, followed by cloudiness in January and November. For the past three decades, May has been the month with the highest cloudiness. The regions in the east and south-west, and particularly in the west, have a high absolute cloudiness, which is connected with the high elevation of the country. By means of long term monitoring, the whole territory of Serbia was analyzed for the first time, in terms of cloudiness. Apart from the statistical and numerical results obtained, this research showed a connection between relief and clouds, especially in the winter season. Linear regression MK (Mann–Kendall test) has proven this theory right, connecting high elevation sides with high absolute cloudiness through the year.

This paper examines temporal and spatial patterns of annual and seasonal maximum temperatures (Tmax) in Slovenia and their relationship with atmospheric circulation patterns. A significant increase in maximum temperature (Tmax; from 0.3°C to 0.5°C·decade-1) was observed throughout the country at the annual scale in the period 1963–2014. Significant positive trends are observed on all stations in summer (from 0.4°C to 0.7°C·decade-1) and spring (from 0.4°C to 0.6°C·decade-1). The results indicate significant correlations between the mean annual maximum temperature (Tmax) and the East Atlantic Oscillation (EA) (from 0.5 to 0.7), the Arctic Oscillation (AO) (from 0.4 to 0.7) and the Scandinavian Oscillation (SCAND) (from −0.3 to −0.4) throughout the country. A significant EA influence is observed in all seasons, while the AO influence is noticed in winter and spring, SCAND in spring and summer, the North Atlantic Oscillation (NAO) and the Mediterranean Oscillation (MO) in winter, the East Atlantic/Western Russia Oscillation (EA/WR) in summer and the El Nino Southern Oscillation (ENSO) in autumn.

This paper represents an analysis of the time series of selected meteorological parameters: mean, maximum and minimum air temperatures, sums of effective air temperature values with the temperature thresholds 5ºC and 10ºC, average precipitation quantities, number of days with frost, potential evapotranspiration and water balance. Study included data from 10 meteorological stations located on the territory of the Republic of Slovenia for the period 1961-2011. Analyzes were performed on a seasonal and annual basis. The obtained results showed a statistically significant positive trends of temperature parameters and potential evapotranspiration, while average precipitation quantities and water balance had a negative trend on the seasonal and annual basis. Positive trend of number of days with frost is present on most stations. In the second part of this paper, the obtained results were associated with the phenological data (data about the development of plants) in order to determine the intensity of correlation between them