Hokitika and Greymouth would be the first areas to get hit by the severe weather followed three or four hours later by places like Greymouth and Westport.
"We've got some thunderstorms sparking off down there that are quite isolated but heavy. And if this front stalls over them this evening they could see quite a lot of rain and then the thunderstorm activity could be quite severe."
The same front is affecting the lower North Island there was a moderate risk of thunderstorms in Manawatu and Kapiti Coast tomorrow morning.
"All the thunderstorm activity really is expected to be south of Whanganui tomorrow in the western part.
There was also a moderate risk of thunderstorms in the Manawatu and Horowhenua regions tomorrow afternoon.
Showers could also fall over parts of the central North Island, but the weather would be nowhere near as dramatic as had it had been in the past two days where the dramatic weather saw four Hamilton teachers and an Auckland cleaner struck by lightning.
"As we get into the late hours of this evening and the early hours of this morning we will see some more showers, but they are not expected to be anywhere as near as severe as what happened today. So we don't have a thunderstorm risk associated with that.
"All the thunderstorm activity really is expected to be south of Whanganui tomorrow in the western part."
