Another system would affect similar regions on Thursday and was “likely to be significant and impactful”, MetService said.
MetService would be “keeping a close eye on things for Thursday” with strong winds expected around the Wellington region, Pawley said.
There was a possibility of those winds picking up around Whanganui, he said.
Cloud cover would increase through Monday and turn into rain on Tuesday in Whanganui. The rain brought by northwesterlies connected to the severe wind watch may become heavy at times, especially on Tuesday afternoon and evening.
Wednesday would likely have some scattered showers.
“Towards Thursday evening, we’re going to see another decent period of rain coming through ... hopefully clearing up [on] Friday,” Pawley said.
Daytime highs for the week will be 22C on Monday and Tuesday, 19C on Wednesday, 23C on Thursday and 19C on Friday.
Overnight lows will be 16C on Monday, 12C on Tuesday, 13C on Wednesday and Thursday, and 10C on Friday.
“What is happening tomorrow, there will be a repeat pretty much coming in on Thursday as well,” Pawley said.