The jet stream, which typically forms in the upper levels of the troposphere, plays a crucial role in guiding the movement of rain-producing systems. This study identified and introduced the dominant synoptic patterns associated with severe wet year in the northern of Iran. Then, Daily precipitation data from selected stations the northern region of Iran, (the provinces of Guilan, Mazandaran, and Golestan), has been collected in a 33-year period corresponding to three solar cycles (22, 23 and 24). Based on the annual average precipitation and SPI index, and using DIP software, severe wet years were extracted. After identifying wet years, atmospheric data for heavy and super heavy precipitation days, including data on orbital and meridional wind speed components, specific humidity, and omega levels of 1000 to 500 hpa, were obtained from the NCEP/NCAR and ECMWF websites. Then, using factor analysis and repeated visual inspections, the most frequent patterns were selected for synoptic analysis. results of the study showed that migratory high, Sudanese low pressure/migratory high, African high, vortex, vortex/migratory high, Siberian high /migratory high, Sudanese low pressure/Mediterranean cyclone, monsoon, monsoon/migratory high, and Sudanese low pressure/vortex are the dominant synoptic patterns on days of heavy rainfall in the northern region of Iran. results of the study showed that Migrant High is the dominant synoptic pattern on heavy rainfall in the northern of Iran. On heavy rainfall days in northern Iran. it show that the moisture source at lower and middle levels of the troposphere primarily comes from the Caspian Sea. At higher levels, moisture originates from the convergence zone and is transported to northern Iran. the best and most suitable location of the central core of the jet to intensify instabilities in the northern region of Iran, is the northern region of Iraq to East Azerbaijan province