Typhoon Lan isn't expected to hit Japan until late on Sunday evening after the regatta finishes but it should see stronger breezes than the sailors have had to contend with over the first four days.
Many have struggled with the light conditions, not least of those in the highly-competitive Laser fleet where many classy sailors have banked some big scores among some good ones.
McKenzie, who was third in the recent European championships, is among that group. He easily won the first race of the day but also finished 30th in the last race and is now eighth overall, one place ahead of fellow Kiwi Tom Saunders.
"It's been a really challenging week so far," he said. "I was really happy to get a race win today but it's been hard to find any consistency - along with much of the fleet.
"There are three races scheduled for tomorrow so it's going to be about getting off the start line cleanly and scoring keepers. Being such a high-scoring event means the medals still aren't out of reach."
The Kiwis are well poised in the 49er, with Logan Dunning Beck and Oscar Gunn (61 points) fifth, Josh Porebski and Trent Rippey (61) sixth and Isaac McHardie and William McKenzie (65) seventh.
The British crews of Dylan Fletcher-Scott and Stuart Bithell (33 points) and James Peters and Fynn Sterritt (38), who were first and second at this year's world championships, continue to set the pace.
Snow-Hansen and Willcox made up ground in the men's 470, climbing three spots to be second overall. They are 10 points behind multiple world champions Mathew Belcher and Will Ryan and were first, 15th and fourth in yesterday's three races.
Susannah Pyatt is 32nd in the women's Laser Radial.
Results and standings after day four of the World Cup regatta in Gamagori, Japan, yesterday:
Laser (50 boats)
1st: Pavlos Kontides (CYP) (7) 4 3 2 (51 DSQ) 14 2 - 32 points
2nd: Sam Meech (NZL) 4 13 15 1 (51 BFD) 1 1 - 35 pts
3rd: Lorenzo Brando Chiavarini (GBR) 3 8 5 6 16 (20) 16 - 54 pts
8th: Andrew McKenzie (NZL) 23 (32) 16 4 1 6 30 - 80 pts
9th: Tom Saunders (NZL) 13 39 2 30 20 12 9 - 86 pts
Laser Radial (35 boats)
1st: Vasileia Karachaliou (GRE) 4 4 1 9 (14) 8 5 - 31 pts
2nd: Josefin Olsson (SWE) (30) 3 9 18 1 1 1 - 33 pts
3rd: Emma Plasschaert (BEL) (16) 1 4 6 12 6 12 - 41 pts
32nd: Susannah Pyatt (NZL) 14 32 32 30 32 18 (33) - 157 pts
49er (20 boats)
1st: Dylan Fletcher-Scott / Stuart Bithell (GBR) 4 1 8 5 1 1 (12) 1 12 - 33 pts
2nd: James Peters / Fynn Sterritt (GBR) 2 5 1 9 8 (17) 3 9 1 - 38 pts
3rd: Lukasz Przybytek / Pawel Kolodzinski (POL) (13) 3 6 8 4 6 2 4 10 - 43 pts
5th: Logan Dunning Beck / Oscar Gunn (NZL) 6 (21 UFD) 9 1 3 8 11 12 11 - 61 pts
6th: Josh Porebski / Trent Rippey (NZL) 10 4 13 2 14 10 4 (16) 4 - 61 pts
7th: Isaac McHardie / William McKenzie (NZL) 1 6 10 15 6 4 13 10 (18) - 65 pts
Men's 470 (24 boats)
1st: Mathew Belcher / William Ryan (AUS) 3 2 (11) 3 11 2 - 21 pts
2nd: Paul Snow-Hansen / Dan Willcox (NZL) 2 (22) 9 1 15 4 - 31 pts
3rd: Tetsuya Isozaki / Akira Takayanagi (JPN) 1 7 2 12 (16) 10 - 32 pts