Hurricane Idalia peak wind / surge forecasts increase slightly

The latest NHC update on hurricane Idalia shows a further slight increase in the peak wind speeds expected from the storm as it approaches a major category landfall on Florida’s Gulf Coast, while the peak storm surge forecast height has also risen.

As time passes the NHC is becoming more confident in the forecast, with its main message for Florida still being that hurricane Idalia will strengthen right up to landfall, with a Category 3 extremely dangerous major hurricane still expected.

The results of which will be “life-threatening storm surge and hurricane conditions” along portion of the Gulf Coast of Florida tonight and into Wednesday.

Hurricane Idalia has maximum sustained winds of 85 mph currently, with higher gusts.

The NHC says, “Rapid intensification is expected before landfall, and Idalia is forecast to be a major hurricane when it reaches the Gulf coast of Florida Wednesday morning.”

The peak sustained wind speed forecast before hurricane Idalia’s landfall has now been increased to close to 127 mph.

At the same time the peak wind gusts from Idalia are now forecast to reach as much as 155 mph, according to the latest NHC advisory.

You can see the latest location for Idalia below, using Tomer Burg’s excellent map which shows wind speed forecasts in increments and sea surface temperatures as well, using the NHC data:

For the insurance, reinsurance and insurance-linked securities (ILS) community, it’s important to note that the track has not changed too much, with hurricane Idalia still forecast to come ashore somewhere in the Big Bend region.

Here, the coastal population is less dense than further south, or north, meaning the insured value exposure concentration is lower in parts, making the landfall location critical in determining the eventual insurance and any reinsurance market loss from hurricane Idalia.

Also critical, could be the size of Idalia, as it remains a relatively compact hurricane, with hurricane wind speeds only extending 15 miles from the center of the storm and tropical storm winds 160 miles.

But, with rapid intensification forecast potentially right up to landfall, there is a likelihood hurricane Idalia will grow. But it could still be a much smaller storm than we saw last year with Ian, which will have ramifications for the eventual insurance and reinsurance market impact as well.

Storm surge is seen as a significant threat with hurricane Idalia, with the peak storm surge heights now also having increased at the latest NHC forecast update.

Now, the NHC is calling for storm surges to reach as much as 10 to 15 feet for the region of Aucilla River, FL to Yankeetown, FL.

Storm surges of 7 to 11 feet are anticipated for Yankeetown to Chassahowitzka, FL, while the coastal regions of Chassahowitzka, FL to Anclote River, FL and Ochlockonee River, FL to Aucilla River, FL are expected to see 6 to 9 feet of storm surge. Tampa Bay continues to be forecast to see 4 to 7 foot of surge.

“Life-threatening” coastal inundation by storm surges are possible with hurricane Idalia and the NHC urges people to prepare, while evacuations are ongoing in coastal areas.

The main messages have not changed, but in some cases they have worsened, and with hurricane Idalia moving relatively quickly north, the rush to prepare, move out of harms way and protect property and lives is urgent for those in the path of Idalia.

Inland, hurricane Idalia is still forecast to near or reach Georgia still at hurricane strength, while the Carolina’s face tropical storm conditions.

Once Idalia emerges into the Atlantic off the southeast coast of the Carolina’s things become a little less certain again, with some models opting for a recurving storm that could threaten the Atlantic coast of Florida. Right now those are outliers, but worth keeping an eye on, in case other models also opt for a similar steering pattern.

As we reported earlier, ILS asset manager Plenum Investments said that the impact to the catastrophe bond market is not expected to be overly significant, while modelled loss runs continue to point to mid or high single digit billions of dollars up to something into the double-digits, perhaps approaching $20 billion. Still a wide range and with the eventual landfall location key in determining the eventual insurance and reinsurance industry loss.

Track storm or hurricane Idalia and the entire 2023 Atlantic tropical storm and hurricane season on our dedicated page and we’ll update you as new information emerges.