Protest-battered Hong Kong should also brace itself for an "economic typhoon" caused by the U.S.-China trade war and recent political unrest in the city, Financial Secretary Paul Chan wrote in a blog post Sunday.

The warning from the city's top budget official came after Hong Kong last week slashed its 2019 growth forecast to as little as zero, down from a previous range of 2 percent to 3 percent. The government also adopted a $2.4 billion spending package to try to buoy the economy — a move that Chen likened to the food stockpiles that households gather to gird themselves against a typhoon.

Two months of protests that have shut the airport, blocked streets and sent stocks sliding have hit the local economy at a time when the U.S.-China trade war was already chipping away at exports, Chan wrote.

Chan called the economic storm a level 3 danger, invoking the terminology that the Hong Kong observatory uses to issue storm warnings. A level 8 basically shuts the city down.