Complex sentence: To the north at Philadelphia, the tempest was the most intense in 30 years, with its high tides engulfing every wharf in the city; a total of of rain was measured at Pennsylvania Hospital.
Split into simpler sentences: To the north at Philadelphia, the tempest was of an intensity not seen in the past 30 years, with its high tides engulfing every wharf in the city. A total of of rain was measured at Pennsylvania Hospital.