The Analysis of Moisture Flux Convergence Frequency Affected the Heavy Rainfall in Northwest of Iran

In this study, frequency and location of Moisture Flux Convergence (MFC) related to heavy rainfall have been analyzed using environmental to circulation approach. Based on the threshold of upper 99 percent, we selected 106 days of the super and overall heavy rainfall from IRIMO data base. MFC’s frequency and their locations have been detected from 0  to 120 E and 0to 80 N in the five levels (1000, 925, 850, 700, 600 and 500 HPa level) at 00:00, 06:00, 12:00 and 18:00 UTC. Analysis of MFC indicated that among upper levels, frequency of MFC in 850 hPa, due to high frequency is very important