To answer the question in the description, the outbreak Pokémon you can find in White (along with their Route numbers) are:
Paras (11), Mankey (15), Farfetch'd (1), Doduo (12), Exeggcute (18), Sentret (7), Yanma (16), Smeargle (5), Tyrogue (10), Poochyena (9), Minun (6), Illumise (3), Shuppet (13), Wynaut (2), Hippopotas (4), Croagunk (8; not in winter)
However, the title mentions Unova, which seems to imply all Gen 5 games. So ask and ye shall recieve.
Black and White
All outbreak Pokémon have a level range of 15-55 in these games.
Paras - Route 11, White-exclusive
Mankey - Route 15
Farfetch'd - Route 1
Doduo - Route 12
Exeggcute - Route 18
Sentret - Route 7
Yanma - Route 14
Pineco - Route 16
Houndour - Route 9, Black-exclusive
Smeargle - Route 5
Tyrogue - Route 10
Poochyena - Route 9, White-exclusive
Shroomish - Route 11, Black-exclusive
Plusle - Route 6, Black-exclusive
Minun - Route 6, White-exclusive
Volbeat - Route 3, Black-exclusive
Illumise - Route 3, White-exclusive
Shuppet - Route 13
Wynaut - Route 2
Hippopotas - Route 4
Croagunk - Route 8 (if it occurs in winter, there will appear to be no outbreak, as Route 8 is inaccessible in winter)
Black 2 and White 2
All outbreak Pokémon have a level range of 40-55 and an encounter rate of 40% in these games.
Fearow - Route 15
Slowpoke - Abundant Shrine
Farfetch'd - Route 1
Doduo - Route 12
Hypno - Dreamyard
Mr. Mime - Route 20, White 2-exclusive
Furret - Route 7
Ledian - Route 22, White 2-exclusive
Ariados - Route 22, Black 2-exclusive
Natu - Route 5
Sudowoodo - Route 20, Black 2-exclusive
Hoppip - Route 18
Quagsire - Route 8
Pineco - Route 16
Swellow - Route 13
Masquerain - Route 11
Plusle - Route 6, Black 2-exclusive
Minun - Route 6, White 2-exclusive
Volbeat - Route 3, Black 2-exclusive
Illumise - Route 3, White 2-exclusive
Swalot - Route 9
Cacturne - Reversal Mountain
Hippowdon - Desert Resort
Source: Bulbapedia
