A powerful cold front diving to the south across the Middle East will bring one of the first widespread and heavy rainfalls of the season from the eastern Mediterranean coast to the Caspian Sea.
On Sunday, heavy rain will fall across the mountains of northern Iraq and northwestern Iran. In excess of 50 mm (2 inches) of rain is expected to fall. This will lead to a rapid rise in rivers and could lead to isolated flooding.
Over the summer months, this region is typical dry as the jet stream remains across northern Asia, well to the north of the area. As the jet stream begins to drop to the south in the autumn, rounds of rain begin to affect the region.
Rain is expected to continue across the region through Monday as the result of a slow-moving area of low pressure. This will only further the flooding threat as additional rainfall could exceed 25 mm (1 inch) on Monday.
While it is not out of the ordinary for the region to see bouts of rainfall this time of year, receiving 2-4 inches of rain from one of the first storms of the season could be considered somewhat unusual.
The heaviest of the rain will fall in the mountains, however, showers and thunderstorms will soak areas across Syria, Jordan and Lebanon as well. A few showers and thunderstorms will extend as far south as Baghdad.
Into Tuesday, the steadiest of the rain will shift into western Iran, giving rain-drenched parts of northern Iraq a chance to dry out.