They were likely to continue into this morning - with some severe storms producing downpours with localised rain rates of 25 to 40mm/hr.
Rainfall of this intensity could cause flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and could also lead to slips.
While the severe weather was expected to be over by tonight, Mr Glassey said over the rest of the long weekend "Hawke's Bay isn't looking quite as good as other parts of the country".
With southerlies, on-shore winds, and temperatures not expected to go past 20C, Mr Glassey said temperatures would be cooler than recently.
As well as heavy rain in northern parts of the region, there would be scattered rain in southern areas, gradually clearing this afternoon.
Cloudy periods were expected tomorrow, with a few showers clearing in the evening. The southerlies would be dying out, with a high of 18C.
Labour Day was expected to bring the highest temperatures of the long weekend, with 20C the high in Hastings, and 19C in Waipukurau.
There would also be cloud increasing and northerlies developing, but little chance of rain.
Until the storms ease this evening, driving conditions could also become hazardous with surface flooding and poor visibility in heavy rain.
Police were reminding drivers to be safe, and using the long weekend to launch their 'Buckle up buttercup' campaign to encourage everyone to wear their seatbelt.
During Labour Weekend 2015, five people died and 21 people were seriously
injured in crashes on our roads.
This year, police would have a highly visible and active presence on the road during the weekend, focusing on high risk driving behaviour using a mixture of enforcement activities.