A severe thunderstorm has hit Hawke’s Bay, bringing some surface flooding to several communities already reeling in the wake of Cyclone Gabrielle.
A MetService meteorologist said its sophisticated technology detected the “cells” about 2.15pm and a warning was issued, but it was all over in an hour, with rainfall of more than 20mm, surface flooding in the twin cities, and about 1000 lightning strikes, around 300 of them ground strikes and mainly focused on the Hastings area.
The igniting of a tree in Windsor Ave, Hastings, appeared to have been caused by lightning but by late afternoon, and despite the associated strong winds, there appeared to be no significant damage.
The storm came at the same time as school pick-ups and rattled residents rushed to pick up their children, or get to ground they felt was safer, causing large traffic jams.
There was torrential rain and in Napier people could hear loud thunderclaps as the black clouds formed over Hastings. Hawke’s Bay Today reporter Doug Laing said from Napier: “It’s sounding like a paint shop exploding in a fire.”
Lighthouse Rd resident Mario Schmidt said some people on the Bluff Hill street in Napier had to fight to prevent water from entering their homes.
“Ten minutes later the water receded again - all this happened within only 15 minutes, just as well the rain stopped again.
“These drains are no longer adequate for these sorts of weather events. These are changing times.
“This job was supposed to be done by now but obviously the cyclone changed priorities for council, who can blame them.”
MetService meteorologist John Law said at the storm’s peak between 2pm and 3pm the forecaster was recording 22 millimetres of rainfall in the space of two minutes.
But by 3.15pm the band had moved out to sea with the heaviest thunderstorms cleared. The rest of the afternoon would consist of light showers, he said.
Its brevity was highlighted by rainfall figures of 27mm at Chesterhope for the day up to 4pm, 25.5mm at a Farndon Rd recording station between Napier and Hastings, and 25mm at Hawke’s Bay Airport, all thought to have fallen just through the storm, driven increasingly by gusts from the southwest.
The MetService weather radar detected severe thunderstorms moving east near Sherenden at 2.07pm on Friday.
“These severe thunderstorms are moving towards the east, and are expected to lie near Napier, Hastings, Fernhill and Haumoana at 2.37pm and near offshore Hawke’s Bay and Cape Kidnappers at 3.07pm.”
“These thunderstorms are expected to be accompanied by very heavy rain.”
MetService said the very heavy rain could cause surface and/or flash flooding about streams, gullies and urban areas, and make driving conditions extremely hazardous.
At 2.15pm it detected severe thunderstorms near Rissington, Sherenden, Napier, Hastings, Fernhill, Bridge Pa and Maraekakaho.
“These thunderstorms are expected to be accompanied by very heavy rain and damaging wind gusts.
“Very heavy rain can cause surface and/or flash flooding about streams, gullies and urban areas, and make driving conditions extremely hazardous.
“Very strong wind gusts can break branches from trees, damage roofing, and make driving hazardous, especially for high-sided vehicles and motorcycles.
“The National Emergency Management Agency advises that as storms approach you should:
- Take shelter, preferably indoors away from windows;
- Avoid sheltering under trees, if outside;
- Get back to land, if outdoors on the water;
- Move cars under cover or away from trees;
- Secure any loose objects around your property;
- Check that drains and gutters are clear;
- Be ready to slow down or stop, if driving. During and after the storm, you should also:
- Beware of fallen trees and power lines;
- Avoid streams and drains as you may be swept away in flash flooding.