Denver averages 10.7 inches of snow in March, making it the city’s snowiest month. But if it seems like all parts of the Mile High City don’t get dumped on equally, that’s because they don’t. The metro area’s heaviest snowfalls are concentrated in the southwest suburbs and in northeast neighborhoods such as Park Hill and Stapleton. The latter sit within the Denver Convergence Vorticity Zone (DCVZ), a roughly 10-mile-wide swath of land on a diagonal line between the state Capitol and DIA. The DCVZ is precisely where moisture headed north from the Gulf of Mexico collides with weather patterns striking from Colorado’s northeast plains, according to Jeff Weber, program manager at the University Corporation for Atmospheric Research in Boulder. Result: powder.

There’s another reason for the disparate fall of fluffy stuff, too. Sudden temperature shifts—like when a cold front rolls into a pocket of warmer air—create more convection storms throughout the city in transitional months such as March. This is the same phenomenon that causes summer thunderstorms, by the way, except in winter you get thundersnow. These minisystems can sometimes drop up to six inches of snow an hour on small areas throughout the city. And don’t be fooled into thinking April will bring a whole lot of relief: It’s Denver’s second snowiest month.