Gusty northerly winds will switch to southerly with the strongest winds overnight on Friday, with a drop in temperature.
“The strongest winds line up with the period of more persistent, heavier showers,” Hillyer said.
“There will be a very noticeable drop in temperatures from tonight and into tomorrow.”
The temperatures are forecast to drop from a high of 16C on Friday to a high of 12C on Saturday and Sunday, accompanied by lows of 4C to 6C.
However, Hillyer expected it would feel colder than 12C.
“I’d say the average daytime temperature will feel much colder. So it’s not like the mornings will be really chilly and then warm up through the day, it’s just going to be a very cold, blustery-feeling weekend,” she said.
After Saturday morning, the weather conditions are forecast to gradually calm throughout the weekend.
“The showers will ever so gradually weaken and ease into Sunday, eventually clearing as the system turns southeasterly and Whanganui becomes more sheltered,” Hillyer said.
“Very similarly to the showers, the wind very gradually eases over the weekend and towards Monday.”
MetService has issued a road snowfall warning for Desert Road State Highway 1 from 2am to 10am on Saturday, August 9.
Between 1cm and 3cm of snow may accumulate above 800m, with lesser amounts down to 600m.
Updates on weather warnings can be found at metservice.com/warnings
Olivia Reid is a multimedia journalist based in Whanganui.