While it blasted through central Napier it missed the coastal areas of Te Awanga, as well as Taradale and Hastings — although they received rain.
Keyser said the thunderstorm, which developed from the northwest built up fast over Napier and that was where it "exploded".
He described it as a fast-passing low which charged in around 6pm, with 27mm of rain being recorded at Hawke's Bay Airport.
"That is a lot," he said.
Added to the earlier bands of rain Napier took 40.8mm for the day, with Hastings getting 23.3mm.
A peak wind blast of 61km/h was recorded at Hawke's Bay Airport during the 45-minute stormy blast.
Firefighters responded to four calls during the event, three to Westshore and one to Ahuriri, where residents were fearful of rising waters around their homes.
A spokesperson for the service said the flooding was "minor", with rain getting in, or threatening to get in, after rushing down driveways.
Crews had to be cautious using pumps "as that pushes the water somewhere else" and in some cases assisted with sandbagging.
"Nothing major though."
One Ahuriri man who spoke to Hawke's Bay Today, who gave his name as David, said the brief blast washed "half my front garden" onto the road.
It had also dashed barbecue plans for a mate in Napier South.
"It cleared nicely during the day so he decided that yep, he could get away with it — but he didn't."
Visitors, including campers, at Kennedy Park Resort did however get away with it, as while there were a few branches snapped from trees there was no flooding across the grounds a spokesperson said.
The MetService said weather for the region was now on the up as the unstable low pressure systems drifted away.
"It is looking good right up to New Year," Keyser said.
While there was a new system set to approach the country around that time, it was too early to determine exactly what affect it would have.