Extended Abstract
Introduction
One of the primary climatic problems in arid and semi-arid areas is drought, which has a big effect on ecosystems, agriculture, and water supplies. The fall and winter droughts are especially significant in the province of Khuzestan. This study uses the Standardized Precipitation Index (SPI) to quantify the intensity and length of droughts in Khuzestan through both regional and synoptic analysis. According to research, the length of the drought varies from 7 to 12 years in different stations of this province, with shorter return periods in the eastern parts resulting in more severe droughts. Numerous research have examined drought in various regions of the world using the SPI index. According to a synoptic analysis, Siberian and subtropical high-pressure systems are two of the main causes of Khuzestan's ongoing droughts. Furthermore, according to some research, the absence of moisture transfer from important sources like the Mediterranean Sea and the Red Sea has made the drought in this area worse .
Methodology
For this study, daily rainfall data from 11 sites in Khuzestan Province for a 29-year period (1995–2023) were provided by the national meteorological organization. The data were first organized in Excel and then analyzed using the SPI index. This tool makes analyzing long-term trends in precipitation easier. In the United States, upper-atmospheric data from the National Oceanic and Atmospheric Administration (NOAA) were analyzed using sea-level pressure, vertical air velocity, geopotential height data at the 500 hPa level, and other relevant factors. The data were analyzed using ArcGIS and GRADS software to identify and investigate the effective synoptic patterns associated with droughts throughout the cold season.
 
Results and Discussion
The results of this study show a direct correlation between certain synoptic patterns and cold-season droughts in Khuzestan Province. The depth of the western wind trough, the direction and speed of these winds, the existence of the Siberian and subtropical highs, and blocking events are some of the recognized atmospheric patterns. There is less precipitation and more dry days as a result of these patterns' ability to stabilize the weather and keep systems that bring rain from entering the area. These results can be useful in developing management plans to lessen the effects of drought and as indicators for anticipating droughts in this area.
Conclusion
One major climatic issue that has a big effect on economies, ecosystems, and communities is drought. Khuzestan Province experiences drought conditions on a regular basis because of its distinct climatic features. Meteorological data analyzed between 1995 and 2023 shows the occurrence of severe droughts, including the ones that happened in 2010. The Arabian high, the Siberian high, the subtropical high, wind flow, and the absence of westerly winds all play a significant role in reducing precipitation and increasing the number of dry days in the region, according to the Standardized Precipitation Index (SPI) and geographic and spatial data. The study's findings are in line with earlier studies, like that of Masoudi et al. (2019), with the exception that this research employs upper-atmospheric models and daily precipitation data to identify synoptic patterns as markers for drought prediction. To minimize negative effects and maximize the utilization of available water resources, management plans and drought mitigation techniques must take these trends into account.