Climate change

Hothouse Rains for Florida — 40 Year Old Record Smashed by 8 Inch Downpour in Daytona Beach

Robertscribbler,

24 September, 2014

Increasingly, due to global atmospheric heating, this is the kind of event we’ve seen –

An atmosphere hotter than at any time in at least the past 120,000 years develops a powerful thermal lift. The dense clouds build higher and higher, drawing in moisture from a hydrological cycle that has been intensified by at least 6 percent due to a 0.8 C global heating since the 1880s. Eventually, the heavy moisture loading within the cloud comes crashing downward in a collapsing inundation, resulting in record rainfall.

Almost daily, now, we see new record rainfall events due to this set of hothouse warming heightened atmospheric dynamics. Just one of the increasingly severe weather impacts predicted by climate scientists. And for a broad region of Eastern and Central Florida sitting under a pattern of rainfall that has now persisted for 8 days, yesterday witnessed just such a major inundation.

(Powerful storms close in on Central and Eastern Florida yesterday afternoon just prior to another record rainfall event. Image source: LANCE-MODIS.)

Towering storms swept in, puffed up by the hotter than normal waters of the Atlantic and Gulf of Mexico spreading dense, white cloud tops up toward the stratosphere. By late evening, Central and Eastern Florida were hemmed in by the towering cloud deck.

The heavy rains began last night around midnight and continued on until around 7 AM this morning. Dousing sheets of rain swept through Volusia County cities focusing in on Orlando, Port Orange, New Smyrna Beach and Daytona. For Daytona, the previous rainfall record for the day, set in the 1970s at 4.22 inches was shattered as 7.98 inches of rain fell over a seven hour period.

The massive downpour left ten homes flooded and entire neighborhoods shut down as city residents pushed water-logged vehicles to higher ground or gingerly waded through knee to waist deep waters. Nearby Port Orange found itself in a similar situation after a 7 inch deluge flooded numerous roads and neighborhoods even as it completely buried a section of railroad track in flood waters. The flooding storms also uprooted trees and knocked down power lines in the affected region.

As of about 1 PM this afternoon more storms were riding in off the Atlantic Ocean heightening the risk of continued flooding for the already storm-plagued region. River levels were rapidly rising and a flood warning was issued for the larger St. John’s River.

(Southeast Water Vapor Imagery. Image source: NOAA.)

As of 4 PM Eastern Time, water vapor imagery and radar showed strong thunderstorm cells just to the southeast of Volusia county and traveling toward the northwest — threatening a second inundation for an already flooded region.

Links:

Heavy Rains Flood Parts of Central Florida

LANCE MODIS

NOAA

Top Climate Scientists Explain How Global Warming Wrecks the Jet Stream and Amps Up the Hydrological Cycle to Spur Dangerous Weather

Global Warming to Drive Increase in Severe Thunderstorm Risk

(Hat Tip to Colorado Bob)

Severe thunderstorms lash Sydney

SMH,

September, 2014

The cluster of storms passed rapidly from west to east and dumped pea-sized hail in areas from Homebush to Bondi.

Twenty millimetres of rain were recorded in Kings Langley, in Sydney's north-west, while 11mm fell at Rose Bay and 10mm at Mona Vale, the Bureau of Meteorology said.

said.

Small hailstones of about 1 centimetre in diameter were seen at Beecroft and Plumpton.

Meteorologist Rebecca Kamitakahara said the line of thunderstorms had now moved out to sea, but showers were likely to continue through the afternoon.

"There's still a fair amount of shower activity coming off the ranges into the basin," she said.

Weatherzone: Sydney radar

"I'd say the worst of it has passed by now."

Winds are also forecast to pick up when a southerly change arrives later in the afternoon.

Herald columnist Sam de Brito said he observed 10 minutes of heavy, pea-sized hail at Bondi. 

"The whole of the Bondi sky just went dark, it was like the apocalypse was approaching," he said. 

"You literally couldn't see for more than about 20 metres."

Twitter user Ben Shepherd reported small hailstones falling at Homebush.

Some flights in and out of Sydney Airport were delayed because ground crews on the tarmac are affected by the wet weather, a spokeswoman said.

A severe thunderstorm warning is still in place for the state's north-west slopes and plains and Northern Tablelands.