Green’s Dictionary of Slang

(Aus./US) an umbrella.

1905		Indianapolis News 13 June 16/5: ‘Gentlemen, you’ll have to make use of your own storm stick’.
1911		St Johns Review (Portland, OR) 15 Dec. 5/4: [advert] We have an elegant assotment of Ladies’ and Men’s storm sticks.
1925		Dly Notes (Canonsbyurg, PA) 15 June 2/3: The deserted storm sticks that had seen [...] better days did not remain neglected for long.
1941		Baker Popular Dict. Aus. Sl.
1950		Sydney Morn. Herald 5 June 5/7: [advert] Right now the ‘S. for M.’ will see you to a light-weight storm-stick that can take anything Pluvius might send on down.
2000		Hartford Courant (CT) sect. D 5 Sept. 27/4: G’Day from Down Under [...] Stormstick — umbrella.