Debby Strengthening, Winding Up for Big Impact

UPDATES:

Tropical Storm #Debby is wrapping up and intensifying as it approaches the Big Bend region of #Florida on Sunday night. This area is no stranger to hurricanes and to big storm surges. The shape of the coast is ideal for generating big storm surges. https://t.co/pK3EMVTVvY pic.twitter.com/vYgIaQcpu2

— Brian McNoldy (@BMcNoldy) August 4, 2024

The Howard Franklin bridge over Tampa Bay is being battered by waves and gusts in the 50 mph range.

I’ve gotta say…The amount of people out driving today is a little surprising to me. #flwx #tropics #TropicalStormDebby #wxtwitter pic.twitter.com/OiRl07phhU

— CollinRL (@CollinRLwx) August 4, 2024

This will not end well. Potentially historic rain is forecast that will lead to areas of catastrophic flooding. In terms of impact severity, it brings to mind the terrible flood event in South Carolina on October 1-5, 2015.

Stalling tropical systems are the worst pic.twitter.com/eu0l4vzLay

— Greg Diamond (@gdimeweather) August 4, 2024

NPR, Sunday August 4, 12:53 ET:

“It’s going to be far beyond the center of the storm. So just prepare for that,” Florida Gov. Ron DeSantis said of the rainfall forecast during a Sunday morning press conference. “Just because you’re not in the eye of the storm, it does not mean you are not going to have major, major impacts from the storm.”

The National Hurricane Center says Debby could unleash catastrophic conditions in Florida as well as in parts of Georgia and South Carolina later in the week, dropping potentially record-breaking rainfall amounts in those two states.

“There are some really amazing rainfall totals being forecast — and amazing in a very bad way,” National Hurricane Center director Michael Brennan saidduring a Sunday briefing.

Florida could see six to 12 inches of rain, with isolated amounts as high as 18 inches, and coastal areas in Georgia and South Carolina could be hit even harder. Brennan said communities near Savannah and Charleston could see between 10 and 20 inches of widespread rainfall, with isolated totals as high as 30 inches in some areas.

As someone who has seen serious flooding Houston multiple times, I cannot stress enough how serious a flooding threat Debby will be between Charleston and Savannah. These are historic rain totals that will test some records. Please make sure anyone you know is prepared there. https://t.co/WjRZF6t2uq

— Matt Lanza 🤌🏼 (@mattlanza) August 4, 2024

“Not explosive” due to some dry air to the west, but Debby strengthening and grinding on toward an landfall in Florida’s Big Bend region.
Already impacts from outer bands, but the big story is going to be the rains that a slow, dawdling storm is going to bring to North Florida, Georgia and South Carolina. We no longer need a major hurricane to have major hurricane impacts.

Forecast Cone below shows a big “Bubble” in the area where the storm is expected to linger, dumping rain and pulling warm, moist air from the Gulf Stream onshore.

Michael Lowry in Eye on the Tropics:

Tropical Storm Debby, which formed Saturday afternoon, continues to strengthen this morning and is expected to become a hurricane before making landfall in Florida’s Big Bend tomorrow. Conditions will quickly deteriorate today along Florida’s Gulf Coast, with up to 10 feet of storm surge flooding possible into many of the same areas affected by Hurricane Idalia last August.
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National Weather Service Sunday morning bulletin underlines the emerging consensus on the storm.