The Eyewall

Editor’s note: Idalia made landfall with estimated 125 mph winds, making it a category 3 major hurricane

One-sentence summary

Idalia is about to make landfall as a category 4 hurricane in Taylor County, FL, with catastrophic storm surge in the Big Bend and wind, tide, and rain impacts spreading north into Georgia and the Carolinas later.

Hurricane Idalia: 130 mph, moving north-northeast at 18 mph

Idalia looks prepared to make landfall on the eastern side of Apalachee Bay in Taylor County or on the Taylor/Dixie County line.

What’s changed since late last night?

Idalia is now a category 4 major hurricane with 130 mph maximum sustained winds. It is nearing landfall. Because of Idalia’s fast forward speed, hurricane warnings are now in effect on the East Coast from just north of St. Simons Island, GA to Edisto Beach, SC. Storm Surge Warnings are also posted from St. Catherine’s Sound in Georgia to the South Santee River in South Carolina. Tropical Storm Warnings are in effect north from Surf City, NC to the North Carolina and Virginia border.

Forecast tides in South Carolina are a little higher today.

An extreme wind warning is in effect for Taylor and portions of Dixie County, FL as Idalia approaches landfall.

Idalia’s surge

The storm surge forecast remains on track in Florida, with a little expansion of surge this morning forecast for the South Carolina coast, now up to 3 to 5 feet in the Charleston area.

With Idalia coming ashore in Taylor County in all likelihood, surge may be a bit under the forecast west of the Taylor/Jefferson County line. This is accounted for in the map above, but it may even drop off a bit faster than shown. Still, as much as 12 to 16 feet of surge should be in the process of rolling ashore in the Big Bend. Charleston’s forecast is now up to 8.5 foot tidal levels in the harbor.

This is now forecast to be up to about November 2021 levels and close to cracking Charleston’s top 10 list.

There has not been much change in Savannah this morning, with a 10.3 foot crest expected.

Idalia’s wind

The core of Idalia’s category 4 winds, the real catastrophic winds will push into Taylor County, FL and right toward Perry, FL over the next hour or two. Those will cross I-10 near or west of Live Oak in all likelihood. Strong winds are likely in a secondary eyewall forming to expand Idalia’s wind field this morning. That will push inland on the west side of Apalachee Bay and come very close to Tallahassee.

Idalia’s wind field is expanding but the intensity will gradually lessen as Idalia push inland and weakens. Still, this storm will be capable of big wind and many power outages as it comes north and east.

The strongest winds will hopefully avoid Valdosta, but much of southeast Georgia will see very strong winds as Idalia races northeast. Hurricane-force winds will also be possible in southeast South Carolina.

Idalia’s tornadoes

A Tornado Watch is posted for most of North Florida and southeast Georgia through mid-afternoon.

Tropical systems do produce isolated tornadoes, so this will be a possibility anywhere in the watch area.

Idalia’s rain

Idalia is expected to produce a narrow but lengthy corridor of 6 to 10 inches of rain into southeast North Carolina.

Flash flooding is likely in spots as it comes northward.

Our next update will be posted around Noon ET with the latest on Idalia as it comes northeast.

One-sentence summary

Hurricane Idalia is expected to make landfall in the morning as a category 4 major hurricane, bringing catastrophic storm surge to the Florida Big Bend region and Apalachee Bay, an unprecedented storm in modern history for this region.

Hurricane Idalia: 110 mph, moving North at 18 mph

As of the 11 PM ET advisory, Idalia is on the cusp of becoming a major category 3 hurricane. Idalia is beginning to take on “the look” when you look at satellite imagery. Unfortunately, if you’ve watched the Gulf since 2017, when a storm takes on “the look,” it usually means the forecast of a major storm with major impacts will verify. We’re in that boat tonight.

What’s changed since late afternoon?

A few notable changes: First the storm track has shifted the landfall point even a little farther west, now in the middle of Apalachee Bay. This has implications on Tallahassee discussed below.

Second, storm surge heights have increased. They are now as high as 12 to 16 feet above ground level in the eastern portion of Apalachee Bay and the Big Bend. Basically St. Marks to Yankeetown is likely to be completely inundated with deep water. Surge heights are slowly being trimmed back on the southwest coast of Florida up through Tampa as Idalia accelerates north.

Surge forecasts have been added for North Carolina now, with perhaps as much as 2 to 4 feet in some of the mainland shores of Pamlico Sound, as well as near Cape Lookout.

Surge update

Catastrophic surge is expected in the Florida Big Bend. Not much else to say here. There’s been little change since earlier this evening in terms of this impact. The forecast has shuffled a bit with 12 to 16 feet of surge now as far west as the Wakulla/Jefferson County line, just east of St. Marks. We continue to believe this will come into an area with no real modern historic precedent of this level of hurricane hitting (best comp perhaps being in the late 1800s).

This is the last warning folks in the relatively rural Big Bend have to get out. These smaller communities will need a lot of help in the days ahead.

Wind update

The core of strongest wind is expected to be just east of Tallahassee across much of the Big Bend into much of north-central Florida and far south Georgia. Live Oak, Lake City, Alachua, and Valdosta may all see significant hurricane-force winds. Considerable wind will also be possible as Idalia moves into Georgia, so communities like Waycross, Kingsland, or even Brunswick could see strong winds.

The exact location of these strong winds may maneuver a little west if Idalia’s track shifts any farther that direction.

Tallahassee

For the city of Tallahassee, the track of Idalia has not trended kindly today. The slight nudge west today has kept Tallahassee in play for the western eyewall of Idalia as it comes ashore. What does this mean? It means that most of the city will either see generic damaging winds (hurricane-force gusts, mostly) or sustained hurricane-force winds and widespread damage potential. There may even be a relatively noticeable east to west gradient of damage, with more of it on the east side and less to the west. We’ve gotten no real additional clarity tonight on exactly how close that will come, but suffice to say, it will be close.

Rainfall from Idalia

Idalia is expected to be a pretty healthy rainmaker as it comes north. Flood watches extend from Florida into North Carolina now. There will be corridor of 6 to 10 inches of rain up the coast, just inland, basically along and west of I-95, depending on exactly how Idalia tracks.

I think North Carolina bears some watching, as there is a sign in some modeling for an area of enhanced rainfall from about Cape Hatteras south and west onto the mainland near New Bern where amounts toward the higher end of the forecast range are possible. The Weather Prediction Center has a “moderate” risk (level 3/4) for this region for excessive rainfall and flooding for Wednesday.

Thankfully, Idalia should be moving offshore by Thursday morning, ending the rain threat in the Carolinas and Georgia.

As is always the case, isolated tornadoes do occur with landfalling tropical cyclones, and Idalia should be no different. The highest chances of a tornado would be in North Florida, coastal Georgia or coastal South Carolina.

Charleston, Savannah, and Jacksonville

We continue to monitor the risk of storm surge and coastal flooding in some of the larger metro areas on the Atlantic coast, in particular Charleston, Savannah, and Jacksonville.

For JAX, this should be hopefully mostly a nuisance event, with wind gusts to 50 mph and about 1 to 3 feet of surge. This would produce mostly minor to moderate flooding in the Jacksonville area.

In Savannah, winds could be stronger, as it will be closer to Idalia’s center when it comes by, so gusts of up to 70 mph are possible there. In addition, up to 4 feet of water above ground level is possible.

The 10.3 foot forecast at the Fort Pulaski tide gage would be the highest since last November’s 10.41 foot level. This is associated with moderate coastal flooding.

In Charleston, the Harbor is still forecast to get to 8.3 feet, which qualifies as “major” tidal flooding. Of course, coastal flooding is a scourge in Charleston, and this level was achieved as recently as June of this summer.

Charleston should see wind gusts as high as 60 mph with Idalia as it passes by, which may in combination with heavy rain complicate drainage of water a bit, making this tidal level a little worse than what would normally be expected with 8.3 foot tides.

The second act

Once again, I just want to close out on this: Don’t worry about the second act of Idalia, as some models show it looping back toward Florida heading into next week. It’s simply not a relevant concern at the moment and the storm would likely be a shell of itself if it happened that way. We are not concerned right now about this coming to fruition in a serious manner. The focus should be on impacts tonight and tomorrow.

Our next post will aim to come at you around 7:30 AM ET Wednesday.

One-sentence summary

Idalia is steadily strengthening today and is expected to come ashore as a major hurricane tomorrow morning somewhere in the Big Bend of Florida or Apalachee Bay with catastrophic storm surge and damaging wind potential increasing for Tallahassee.

Hurricane Idalia: 100 mph, moving N 16 mph

The bottom line on Idalia this evening: A catastrophic storm surge impact is expected in the Big Bend and Apalachee Bay from a major hurricane tomorrow morning. In addition, strong winds will buffet the west coast of Florida along with surge up through Tampa to the Big Bend as well. Tallahassee is now going to come close to getting into the western eyewall of Idalia as it moves inland, which could lead to wind damage and widespread power outages. Idalia will continue producing wind and rain impacts into south Georgia with coastal flooding up the Georgia and South Carolina coasts as well.

What’s changed since this morning?

A few things. First, the general forecast remains on track. The landfall point has nudged a bit farther to the west, which introduces the risk of catastrophic surge to a wider portion of Apalachee Bay. We are now looking at 3 to 7 feet on the west side of the bay and 10 to 15 feet on the east side into the Big Bend.

More on surge in a moment.

Tropical Storm Warnings extend up into North Carolina (Surf City) now with TS Watches posted north of there to the Virginia border. Hurricane Watches remain for the coast of Georgia and South Carolina up to Edisto Beach. Hurricane Watches were dropped on the west coast from Englwood to Longboat Key, and the Storm Surge Watch was dropped south of Bonita Beach, FL.

Another big change today has been the westward nudge likely putting Tallahassee in play for potential eyewall winds tomorrow morning as Idalia comes ashore. Using the GFS operational model as our guide, we can annotate roughly where the strongest winds *should* go at present.

Tallahassee is currently right on the edge of the stronger winds as Idalia comes ashore. This will probably be a close call between hurricane-force gusts and widespread hurricane-force winds with significant damage. Prepare accordingly. Anywhere that sees the strongest wind could see multi-day power outages.

Other notes on Idalia in Florida and South Georgia

We discussed Tallahassee above. Tampa Bay will likely see 4 to 7 feet of surge and at least tropical storm force winds. This will cause serious flooding around the bay and along the coast. Please heed the advice of local officials tonight and tomorrow.

For interior and eastern Florida, this actually looks a bit less impactful now. We are seeing bands with isolated tornadoes and gusty winds. But for places like Orlando and Miami, it should not get too much worse. For Jacksonville, that area will see winds pick up tonight and tomorrow as Idalia passes by to the north and west. Wind impacts will be most significant west toward Lake City and north toward Waycross, GA and Brunswick, GA. Minor surge impacts are possible on the First Coast, with slightly higher surge impacts in Georgia (2 to 4 feet).

For Savannah moderate flooding is expected, but for Charleston, SC major flooding is forecast.

Along the Georgia and South Carolina coasts, as well as near where Idalia comes ashore in Florida, water levels could be locally higher than forecast due to heavy rainfall as Idalia comes in, preventing water from being able to drain.

More on surge

The amount of water that is expected to inundate portions of Citrus, Levy, Dixie, and Taylor Counties is catastrophic. The National Hurricane Center spends a lot of time deliberating when to use that word, but they chose it for this storm. Given that there is no modern history of a storm of this magnitude coming ashore in this area, there is no precedent for what is going to occur here. That’s a terrifying inundation map from this morning, which shows surge possibly going *well* inland from the coast in the Big Bend.

The map above shows the scenario that has a 10% chance of being exceeded. This is somewhat of a worst-case scenario type map, but it gives you the right idea. You do not want to be on the coast or a few miles inland in the Big Bend. Surge impacts west of here will also be bad for Apalachee Bay, but less severe than this. Regardless, this is truly catastrophic surge coming to the Big Bend and east side of the bay.

Idalia’s exit

We still anticipate that Idalia will weaken to a tropical storm over Georgia and South Carolina, and it should exit the coast somewhere between Wilmington, NC and Savannah, GA depending on the exact track of the storm. From there, all bets are off in terms of track. We do expect wind shear to become a severe issue off the East Coast, so that should keep any reintensification of Idalia in check. I would not spend much time worrying over a second act of Idalia at this time. We’ll keep you posted. We’ll update once more later this evening and again in the morning. Look for a video update on our social channels this evening.

Editor’s Note:

I neglected to discuss rain before hitting publish. Here’s the latest rain forecast. Our late evening post will take a closer look at this.