Multifamily Tax Assessment after Sale

[Cole OHara]

Hello all!  Newbie real estate investor here. I am planning on making an offer on a small apartment building in Milwaukee and I am curious about others' experience with updated property tax assessment after the sale.   The current owner has flipped the property and the sales price will be significantly higher (like 400k more) than the current property tax valuation.  I have been doing my cash flow calculations based on the current property tax amount.  What are others' experience with a property being reassessed after the sale and how to I preemptively adjust my numbers to account for that happening?   Thanks!