Momentary interruptions of your power can last up to a few seconds and are usually caused by a temporary short circuit. Short circuits occur when something comes in contact with power lines, such as an animal or a tree limb.
When this happens, special electrical equipment is designed to quickly open and close the breaker two or three times automatically, in separate attempts, to clear the temporary short circuit. Each attempt may cause a momentary outage. These momentary interruptions actually work to prevent you from experiencing a longer outage.
To ensure your sensitive equipment, such as a computer or cable box, is not affected by a momentary outage, you may consider connecting it to an uninterrupted power supply (UPS) that includes a battery to maintain power in the event of a service interruption.