This study investigates the synoptic conditions associated with the heavy rainfall and flash flood event that affected Rafsanjan, Iran, on July 28–29, 2022. Multiple meteorological datasets were analyzed, including surface and upper-level synoptic charts (at 850 hPa and 500 hPa), omega and potential vorticity fields, moisture advection (specific humidity), and upper-air sounding data from Bandar Abbas station. The analysis revealed the simultaneous expansion of two low-pressure systems centered over Pakistan and the Red Sea across Iranian territory. At 500 hPa, the presence of a deep trough associated with the eastern flank of a Russian blocking pattern contributed to the intensification of the Indian monsoon flow. Moisture flux maps demonstrated substantial moisture transport toward eastern, southeastern, and central regions of Iran. Negative omega values confirmed strong upward vertical motion, particularly over Pakistan and the associated surface low-pressure center. Positive vorticity advection and instability signals were detected over central and northwestern Iran. Instability indices, including a K-Index of 39.90 and a Showalter Index of –2.85, indicated pronounced atmospheric instability. On July 29, Rafsanjan recorded 28.5 mm of precipitation, leading to significant damage to infrastructure in both urban and rural areas, including impacts on over 10,000 hectares of pistachio orchards and numerous vehicles.