Currently in the Atlantic - September 27th, 2022

The weather, currently.

Ian strengthening & moving toward Gulf

Tampa. Tampa. Tampa. It seems that's all I'm seeing and hearing about. But before we talk about Tampa, let me emphasize this: because of the size, strength, and track predictions, the ENTIRE WEST COAST OF FLORIDA WILL GET SIGNIFICANT FLOODING. The worst area of flooding will be determined by the exact track, which is not (and cannot be) a certainty so far in advance.

The west coast of Florida is much different than the East. First of all, direct hits are rare. The last major hurricane that threatened the Tampa area (Charley in 2004) turned east in the last hours and was small enough to limit the damaged area. Very few folks along the west coast have had a true hurricane experience.

But the most important difference is the shallow water off the west coast vs. deep water off the east coast. Storm surges build up much higher with shallow water out there. For example, the same storm that would produce a 10-foot storm surge on the east coast could produce a near 20-foot surge on the west coast!

Storm surge flood threat ENTIRE west coast of Florida

The predicted surge from NHC at the time of this writing ranged from 2 to 10 feet from the Florida Keys to well north of Tampa (surge forecasts will come later for the coast up to the Panhandle).

Now for the Tampa area. They haven't had a direct major hurricane hit since 1921! Their population is more than 20 TIMES HIGHER now! A storm track just offshore and then making landfall just north of Tampa would be a worst-case scenario. But even if Ian stays offshore there will be a huge storm surge. The water in the Gulf will keep building up EVEN WHEN THE STORM MOVES NORTH OF THE AREA!

Predicted track + amount of surge

Aside from the rarity, population explosion, low elevations, and shallow water offshore, the geography causes more potential for disaster. Look at the map above. A wind from the southwest or west will funnel water all the way into Tampa Bay. There's nowhere for that water to go except to flood even more land.

A few days ago, I mentioned Elena in 1985. The eye never came within 100 miles of the coast, but it was large and slow-moving. The Tampa area flooded for DAYS. Elena was never more than a Category 3. Never made landfall in Florida. But it didn't matter enough to spare Florida.

Intensity changes and forward speed will be just as important as the exact track. Will it indeed intensify into a Category 4? Will it slow to a crawl as it tracks west of Tampa?

One measure of potential intensification is known as the "Max Potential Index" first developed by Dr. Kerry Emanuel of MIT. He has done pioneering research which showed how much future hurricanes could intensify as climate change keeps warming the oceans.

"Max Potential Intensity" - Category 3 or 4 up to Tampa

Those reddish colors show max potential to Category before Ian moves past (or over) Cuba. The major hurricane potential continues almost all the way north to Tampa, but definitely drops farther north. That's one of the reasons weakening is expected eventually.

The wind shear currently is very low, part of the reason Ian is expected to intensify rapidly. But it has already been increasing over the Gulf of Mexico. One of the best things we can hope for is for that trend to continue, and the combination of cooler waters and higher shear leading to a quicker weakening of Ian in the Gulf. But even if that happens it will take a LONG time for the water to calm down.

Wind shear increasing in the Gulf. hope the trend continues!

The 5pm EDT update from NHC paints about as bad a picture as possible. If you are in an area asked to evacuate, please do. And if you have friends or relatives in the hurricane warning area, please advise them to follow official advisories. This is not a storm to be taken lightly. A worst-case scenario would be catastrophic.

Glenn "Hurricane" Schwartz    thehurricaneschwartz@gmail.com

What you need to know, currently.

Hurricane Ian rapidly intensifying as it heads toward Cuba and Florida
Hurricane Ian barrels towards western Cuba. Then, it’s on track to make landfall in Florida, just north of Tampa Bay.

Evacuations are underway in Florida as Hurricane Ian moves in. Hurricane Ian, which is now a Category 3 hurricane, is expected to grow to a Category 4 by Tuesday afternoon, before making landfall in Florida’s Gulf Coast on Wednesday. Thousands across the state are under mandatory evacuation orders.

Since leaving Cuba, the storm’s track has moved slightly east — dangerous Hurricane weather is still expected along the West coast. Threats include flooding, hurricane force winds, tornadoes, power outages and storm surges. Storm surges south of Tampa Bay in Sarasota are now expected to reach up to 12 feet.

According to Currently’s Hurricane expert, Glenn Schwartz, with the hurricane’s new path, there is a smaller chance of the storm weakening before landfall. This will cause the storm to make landfall faster than previously expected.

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—Aarohi Sheth

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What you can do, currently.

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