UPDATE 4.45PM: Homes in Mooloolaba have been inundated after rapid downpours in the past two hours, while Mudjimba streets have flooded, Petrie Creek has broken its banks and Mount Coolum has become a waterfall.
Buderim backyards were turned into swimming pools as some sites recorded more than 100mm of rain in just a few hours.
Thankfully Bureau of Meteorology forecaster Lauren Murphy said the worst of the rain had passed now, with patchy, lighter falls possible through the evening and early tomorrow morning.
Since 9am the Bureau recorded falls of 120mm in the Sippy Downs and Mountain Creek areas, while Parrearra Weir recorded 112mm.
Ms Murphy said depending on the response times it can take up to a day for rainfall to make its way down into the lower reaches of creeks and rivers, which means waters may still rise.
She said the upper trough will shift offshore and conditions will start clearing tomorrow.
UPDATE 2.30PM: More than 30mm dropped in the last hour in suburbs across the Coast, as floodwaters have closed cafes and sent torrents of water cascading down unit block stairwells.
Parts of Caloundra copped more than 30mm between 1pm and 2pm today, while heavy rain continued to pound Mountain Creek.
Popular Mooloolaba restaurant The Velo Project has had to close its doors today, as floodwaters lap the building, and edge alongside the neighbouring childcare centre.
Rain radars show a large system now clearing off the Coast, but there is still some significant patches of rain making their way south-east from Maryborough and Gympie areas which may affect the region.
Meanwhile unit blocks in Alexandra Headland have had their garages turned into wading pools and floodwaters have created waterfalls as they cascade down stairwells.
UPDATE 1.30PM: A fresh thunderstorm warning has been issued with Caloundra next in the firing line.
The slow-moving system is making its way towards Caloundra and coastal waters in that area have been identified as at risk of flash flooding with more heavy rainfall to come.
Maroochydore copped nearly 40mm in the last hour.
The Queensland Fire and Emergency Service has warned parents against letting children play in floodwaters, as culverts fill and roads go underwater across the region.
Kids and drains are never a good combination. Heavy rainfall and flash flooding can send fast-moving water through drains and causeways with enough force to suck children in. Play it safe and make sure your children understand the dangers. Remember: if it’s flooded, forget it. pic.twitter.com/ootIRwRnBp— Qld Fire & Emergency (@QldFES) December 3, 2017
UPDATE 12.30PM: The Coast is copping it as a slow-moving storm cell dumps on the region.
In the past hour 69mm fell in Parrearra, while Tanawha copped 60mm, and Bundilla (58mm), Mountain Creek (57mm), West Woombye (24mm), Maroochydore (28mm) and Mount Tinbeerwah (35mm) were all heavily hit.
Sippy Downs has copped 93mm of rain since 9am.
Sunshine Coast SES local area controller Janet Scott said they weren't receiving many call outs at the moment, but the few they had been to were for localised flooding.
She expected more callouts as people returned home from work later this afternoon.
Cedar Pocket Dam outflows have now been increased, and the same measures have already been in place at Borumba Dam since yesterday evening.
BREAKING: A severe thunderstorm warning has been issued moments ago for the Sunshine Coast, Noosa and Gympie, as a slow-moving depression dumps heavily on the region.
The Bureau of Meteorology just released the severe storm warning after 62mm of rain hammered down west of Tewantin in only an hour.
The storms are set to batter the region for several hours.
Flood warnings have been issued for the lower Mary River, with the river rising in Tiaro and expected to cause flooding there.
The rain has been widespread in the past hour, with Sippy Downs (35mm), Tanawha (25mm), Mount Tinbeerwah (25mm), Lake Macdonald (56mm) and Jimna (37mm) among the hardest hit.
Bureau forecaster David Bernard said the worst of the system was hitting and would continue to do so this afternoon and into the evening.
He said up to 70mm could fall across the region, with heavier isolated patches.
A large system is moving our way from the Wide Bay and Gympie regions, blanketing the radar in rainfall.
High tides are aiding the rapid rise in waters, as well as the already-drenched grounds after more than a week of downpours.
Mr Bernard said the upper and surface troughs wouldn't clear out until probably early tomorrow morning, before a sunny shift in the weather.
Traffic issues are beginning to surface, with motorists advising if water across the road on Parklands Boulevard at Meridan Plains, while the traffic lights are reportedly not working properly at the Maroochydore Road-Broadmeadows Road intersection in Maroochydore.