Complex sentence: The highest rainfall is found instead in upland places on the border with Lazio, are especially vulnerable to disturbances Atlantic, and are around (Pescara in 2010 showed a value close to 2800 mm).
Split into simpler sentences: The highest rainfall occurs in upland areas on the border with Lazio; they are especially vulnerable to Atlantic disturbances. Around of precipitation is typical (Pescara in 2010 showed a value close to 2800 mm).