Why is the NDP seemingly much more popular at the provincial level than nationally?

Not a Canadian, so there might be something obvious I'm missing, but I was just curious as to why provincial NDP parties have so much strength compared to the federal NDP. Federally the NDP only has 5 seats in Parliament, and got around 7%~ of the vote in last election, however they hold government in two provinces (Manitoba, British Columbia), and the official opposition status in four provinces.

And while I understand that the last federal election was especially bad for the NDP, in previous elections they've only held 3rd or 4th place (except 2011).