Matt Lanza

August 31, 2023 Outlook: Idalia off to Bermuda, Franklin out to sea, but what else is out there?

One-sentence summary

A much less intense Idalia should move toward Bermuda heading into this weekend, but there is a bit of uncertainty about what happens next week, while a couple other systems meander out to sea elsewhere.

Tropical Storm Idalia: 60 mph, moving ENE 21 mph

Idalia is moving off the coast of the Carolinas now, as it begins its march toward Bermuda.

Idalia’s track will take it east and then probably eventually southeast, nearing Bermuda by later in the weekend. (NOAA NHC)

Heavy rain continues from Idalia over far east North Carolina, with some flash flood warnings posted for the Outer Banks this morning. Some locally hefty rainfall amounts are occurring in that area. Wind gusts generally in the 40 to 50 mph range with a couple exceptions have also been occurring. A tropical storm impact in this region for sure.

Heavy rain continues over the Outer Banks, where flash flood warnings are posted. (RadarScope)

Idalia will continue eastward today and tomorrow with gradually improving weather over the Carolinas.

As Idalia heads out to sea it should hold its own or weaken a bit further, encountering a lot of wind shear. Because of Idalia’s size, tropical storm conditions or breezy rainfall could begin in Bermuda as early as later tomorrow or Saturday.

Through day 5, the forecast for Idalia is pretty straightforward. It will slow down as it approaches Bermuda and meander for a couple days, so by Monday it’s somewhere near or north of Bermuda.

From there, things get weird. On the map below I plotted the 500 mb pattern, or what would steer Idalia at about 20,000 feet up. Areas highlighted in red indicate warmer than normal, or what we’d refer to as “above normal heights.” Areas highlighted in blue are below normal. The yellow is an overlay I did of “spin” in the mid-levels of the atmosphere to identify Idalia relative to the 500 mb pattern. Confusing? A little, but it paints a picture I can use as a meteorologist.

As high pressure expands over the eastern Atlantic and without any real catalyst to “pick up” Idalia, the path may begin to get weird. (Tropical Tidbits)

The lack of blue color means there is a lack of lower heights or troughs that could pick up and move Idalia. Instead, Idalia on Monday night is stuck between a rock (high pressure over the Eastern U.S.) and a hard place (building high pressure from near the Cabo Verde Islands). This should produce erratic, uncertain movement early next week. And it’s plausible that Idalia has a lack of an exit, so whatever is left of it at this point would just sit and spin. This isn’t spectacular news as this could lead to an extended period of rough surf and rip tides on the East Coast that began this week and may extend into next week.

It also does open the door up for weird things like a track back toward the coast, except in the Northeast, not Florida. A couple things to note here: Idalia may or may not be a tropical system at this point. It surely should not be a strong tropical system if it is, but it may be a broad one size-wise, which means it would be capable of rough surf or offshore gale conditions. I think once we see how Hurricane Franklin’s exit goes, we’ll have higher confidence in the early next week period, hopefully in a day or two. But in general, we have a long way to go here, so we’ll keep an eye on things. Idalia should impact Bermuda in some fashion beginning by this weekend.

A busy Atlantic tropics continues, with 3 named storms, and a 4th area that may develop. (College of DuPage)

Elsewhere

Hurricane Franklin: 100 mph, moving ENE 15 mph

Franklin remains a category 2 hurricane, but it is beginning the process of accelerating out to sea.

Hurricane Franklin will pick up the pace out to sea over the next 2 to 3 days. (NOAA NHC)

No other impacts to land are expected as Franklin heads out.

Tropical Storm Jose: 40 mph, moving N 5 mph

As all the chaos broke with Idalia, Tropical Depression 11 formed out in the middle of the Atlantic this week. Overnight, that became Tropical Storm Jose. This will be a short-lived storm, and there’s no way Jose will impact land.

Invest 94L

Far out in the eastern Atlantic, we have Invest 94L , which is currently over the Cabo Verde Islands. This has about a 70 percent chance of becoming a tropical system over the next few days. But it will be heading northwest or due north away from any land impacts.

Invest 94L may become a lower-end tropical system in the coming days as it moves northwest in the open Atlantic. The next name on the list is Katia. (Tropical Tidbits)

Looking ahead

Other than monitoring Idalia, it will be a relatively quiet weekend into early next week. There are some signals of another Cabo Verde type system that could get going later next week or next weekend, but that’s far out there, and given the high uncertainty in the northern half of the Atlantic, I don’t really want to speculate on what might happen with that one.

That’s about it at the moment. We have a couple days to catch our breath and focus on hopefully lower-end impacts of Idalia in Bermuda. We’ll then see what happens next week and keep tabs on the next system emerging off Africa later next week.

Idalia gradually winding itself down as it races to the coast

One-sentence summary

Idalia is heading to the ocean again, and it will continue offshore with diminishing rain and wind in the Carolinas overnight and a potential date with Bermuda late Friday or Saturday as a tropical storm.

Idalia should move offshore overnight and begin to head east, ending the rain and wind in the Carolinas. (NOAA NHC)

Tropical Storm Idalia: 60 mph maximum winds, moving NE 21 mph

What’s changed since early evening?

Idalia is headed for the exits with no real forecast changes of note.

Charleston, SC recorded their 5th highest tide on record, maxing out at 9.23 feet tonight, about a half-foot higher than forecast.

Charleston preliminarily has established their 5th highest tide observation on record at 9.23 feet. (NOAA)

Myrtle Beach managed a 9.13 foot tide, which, if confirmed, is their sixth highest on record.

What’s next? Idalia and Bermuda

Idalia’s rain continues over northeast South Carolina and much of eastern North Carolina, where flash flooding remains a possibility into the overnight hours. (College of DuPage)

Idalia is on its way out to sea. Heavy rain will continue over eastern North Carolina and northeast South Carolina into the night. Localized flash flooding remains a concern. Otherwise, the wind and surge aspect of Idalia should begin to level off. Rough surf, beach erosion, and rip currents will continue along much of the East Coast due to both Idalia and Hurricane Franklin. If you’re kicking off Labor Day weekend early, please keep that in mind on the Eastern Seaboard.

Again, to emphasize, Idalia is heading out to sea. It is unlikely to pivot back west toward Florida again. And even if it did do that, Idalia is not the same Idalia that it was this morning. This is a much more disheveled and disorganized storm. Conditions in the Atlantic are going to be absolutely raging with wind shear over the next few days, so we’ll see if it can even survive that. Bottom line: You don’t need to worry about a second act of Idalia right now.

For Bermuda? Idalia is worth watching over the next few days to see how it manages to navigate the Atlantic wind shear. A tropical storm impact could occur there as early as late Friday and linger into the weekend. I’m more concerned about the length of time and proximity Idalia may spend near Bermuda than the intensity of the storm right now, so we’ll see how this unfolds. Interests in Bermuda need to monitor this over the next few days.

After early next week, I cannot tell you where Idalia will go, except to say probably out to sea eventually. We’ll stay on top of it.

Our next update will be our regularly scheduled morning outlook on Thursday, where we’ll catch you up on what’s happening elsewhere in the Atlantic.

Evening Update on Idalia as it hustles toward the coast to get offshore

One-sentence summary

Idalia is now a tropical storm, racing off to the northeast and should emerge offshore tonight, where it will head east for several days before possibly impacting Bermuda.

Tropical Storm Idalia: 70 mph, moving NE at 21 mph

Idalia is no longer a hurricane, now a tropical storm, but still causing plenty of headaches as it comes northeast across Georgia and just about into South Carolina.

Idalia will head out to sea over the next few days. (NOAA NHC)

What’s changed since late morning

Idalia is now a tropical storm.

All warnings for Florida’s Gulf Coast have been discontinued.

Areas highlighted in orange have the best chance at tropical storm-force winds, while yellow areas may see some gusts up to tropical-storm force. (NOAA)

Idalia’s wind

Wind gusts up near 70 mph were recently reported near Savannah, GA, so Idalia still has some punch left. Power outage numbers are now up to around 500,000 in Florida and Georgia per poweroutage.us. Idalia will weaken a bit further as it moves northeast before getting back out over the Atlantic, but it will still be capable of 50 to 70 mph wind gusts over a wide area of Georgia, South Carolina, and parts of North Carolina.

Charleston is expected to record its highest tide level since November 2018 this evening. (NOAA)

Idalia’s surge

Major coastal flooding is expected in parts of South Carolina, with Charleston forecast to see their highest tidal level since November 2018 this evening, peaking near 8.7 feet. If that is achieved, it would be the seventh highest level recorded in Charleston since records have been kept.

Farther up the coast, Myrtle Beach is expecting moderate coastal flooding, while Wilmington, NC is expecting minor coastal flooding. Additional moderate flooding may occur on the mainland side of Pamlico Sound in North Carolina.

Peak storm surge expected this evening in the Carolinas, with residual high tides in Florida and Georgia. (NOAA NHC)

Idalia’s rainfall

Heavy rains continue along the path of Idalia.

Tropical Storm Idalia is spreading heavy rain north and east through the Carolinas now. Conditions will improve in Georgia this evening. (College of DuPage)

Pockets of flash flooding should occur in spots across the Carolinas this evening, with 6 to 8 inches possible in North Carolina and another 2 to 6 inches in South Carolina. River flood warnings will be needed for some of the hardest hit basins. A moderate (level 3 of 4) risk of excessive rainfall remains in effect for the Carolinas.

A tornado watch is in effect for the coastal plain of South Carolina and southeast North Carolina through 10 PM ET this evening. (NOAA SPC)

Idalia’s tornadoes

Isolated tornadoes remain possible, particularly south and east of where Idalia ventures, hence a tornado watch is in effect tonight for coastal South Carolina and a portion of North Carolina.

Idalia’s future track: Loop looks less likely

The forecast track for Idalia is coming into better focus now, and we can stop talking about the possible loop de loop back to Florida. Models are unanimous in taking Idalia out to sea for now, slowly but steadily.

Idalia is going to head out to sea. It may tap the brakes southwest of Bermuda, but it will eventually get there. (Tropical Tidbits)

If there is a risk with Idalia, it would be to Bermuda or for the very, very, very outside chance that it were to get pushed back toward the Northeast U.S. at some point. The latter seems highly unlikely right now, and the former (risk to Bermuda) is a low risk right now. Modeling agrees that Idalia should remain below hurricane intensity for now while it meanders offshore. We’ll keep eyes on this over the coming days however.

Regardless, Idalia will help keep surf rough and probably enhance the risk of rip currents up and down the U.S. East Coast, in concert with what’s left from Franklin.

Our next update will be a brief one after the 11 PM ET advisory package.

Idalia approaches landfall in Florida’s Big Bend as a category 4 hurricane

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.

Idalia will track into Georgia and South Carolina today before exiting offshore. (NOAA NHC)

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.

Catastrophic storm surge is expected this morning in the Big Bend of Florida. (NOAA NHC)

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.

Charleston should see tides into major flood levels, peaking around 8.5 feet. (NOAA)

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 catastrophic category 4 winds will be in a small area but drive right into Perry, FL, while strong winds are likely to extend out from there into a secondary eyewall that will likely graze Tallahassee. (RadarScope)

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.

Because of Idalia’s forward speed, strong damaging winds will expand into southeast Georgia, likely just east of Valdosta. Hurricane-force winds are possible into coastal Georgia and south of Charleston, SC. (NOAA)

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.

Isolated tornadoes are possible on the east side of Idalia’s track. (NOAA SPC)

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.

Idalia will produce a swath of 6 to 10 inches of rain into southeast North Carolina, likely causing flash flooding in spots as it comes northeast (NOAA)

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.