News Brief by Kip Hansen – 27 September 2022

Hurricane Ian is projected to run right up the mouth of Florida’s Tampa Bay, making landfall as a Major Hurricane.  The threat presented by this hurricane depends on precisely where the eyewall hits which also determines which direction the strongest winds are blowing when it makes landfall.

If Hurricane Ian hits Tampa Bay, just north of the Lower Tampa Bay (see map below), the strongest winds, and thus the greatest amount of storm surge will be pushed up into the shallow Upper Bay, potentially causing widespread flooding for the portions of the surrounding cities, many of which are built on old flood plains just a few feet above Mean Higher High Water – the highest of Tampa Bay’s usual high tides.

NOAA’s projected tracks improve as the time window gets smaller. At 72 hours out, these projections are accurate to about 100 miles.   On Sunday, Ian was projected to hit Florida where the panhandle joins the main north-south body of the state.  Now it is targeted directly at Tampa Bay with just over 48 hours remaining to landfall.

As you can see, Tampa Bay is very shallow — 1 to 4 meters at the deepest.  [See this nautical chart] There are barrier islands along the Gulf shore, off Clearwater and Largo.  They will be entirely submerged by anything more of six feet of surge.   Large parts of Pinellas Park, single family homes most of it, will be flooded, along with almost all the bay-facing neighborhoods.

Using the NOAA Sea Level Rise viewer, first at Mean Higher High Water, then with five feet of storm surge and finally with an unlikely, but possible, ten feet of surge.  The very-light blue areas are inundation.

Only time will tell.  While a  50 mile shift north or south will make the world of difference for the Tampa/St Petersburg area, a major hurricane hitting this area, which has been spared a major hurricane event for nearly a century, will be a true disaster and create a real crisis as homes are destroyed and perhaps millions lose electrical power for a week or more.

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Author’s Comment:

I lived in this area long ago, and my first child was born there.  Somehow Tampa/St Pete was known as a hurricane safe area.   It had not suffered a direct hit since 1921. 

I hope the residents there will prepare well and follow evacuation advice early.

Praying for their safety.

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