Isaias forecast to regain hurricane status before Carolinas landfall

Tropical storm Isaias had a close brush with Florida as a low category hurricane and is now heading north for an expected landfall in the Carolinas, with forecasters expecting the storm to regain weak hurricane status before coming ashore in North Carolina.

As we explained last week, Isaias is the first Florida and U.S. east coast hurricane threat of the season.

Storm Isaias proved a challenging one for the insurance and reinsurance sector to predict, having looked as if it might make a Florida landfall, but then passed the state with its main wind and rain bands offshore.

Wind shear reduced Isaias’ chances of becoming a much stronger hurricane and eventually meant that the storm caused little in the way of meaningful impacts as it passed by Florida.

Currently, tropical storm Isaias has 70 mph sustained winds and higher gusts and is heading north-north east for a landfall around the South Carolina to North Carolina border region.

NOAA forecasters said that they expect Isaias will regain its hurricane status over the coming hours before it draws near to the Carolinas coast, so there is a chance of a low category 1 hurricane landfall which at the moment is expected to be right at the southern edge of the North Carolina coast (although that could change).

Hurricane Isaias did not experience the environmental conditions most conducive to intensification on its travels, despite the warm sea surface temperatures it has moved across, as wind shear remained relatively high and the storm found itself remaining lop-sided as a result.

The storm has been fed drier air from high pressure to its east, which also affected its ability to intensify and actually resulted in a little weakening.

Once alongside Florida and as it moved further north storm Isaias continued to experience wind shear that prevented it taking full advantage of the very warm Gulf Stream. Hence the storm did not live up to forecasters expectations and has resulted in a less powerful threat to the U.S. than the insurance, reinsurance and insurance-linked securities (ILS) community had feared over the weekend.

Whenever a hurricane comes close to Florida it puts the insurance-linked securities (ILS) and catastrophe bond market on watch, given the significant concentration of reinsurance exposure in the state.

Coming soon after a mid-year renewal season when rates were very attractive to underwrite Florida reinsurance business, but hedging capacity wasn’t always readily available, it will be interesting to see whether some quoting activity breaks out for instruments such as industry loss warranties (ILW’s) or last minute parametric reinsurance and retro coverage.

However, we’re told live cat quoting activity was incredibly quiet, as the forecast didn’t suggest the significant intensification and the market appeared to be focusing on the potential for a relatively low, perhaps in the low single digit billions of dollars, industry loss, our sources said on Saturday.

Expectations dropped further on Sunday and as of today the market believes it is looking at another hurricane industry loss in the hundreds of millions of dollars, we’re told today.

In its latest update the NHC said:

…ISAIAS FORECAST TO MAKE LANDFALL TONIGHT AS A HURRICANE…
…EXPECTED TO BRING STRONG WINDS AND HEAVY RAINFALL FROM THE EASTERN CAROLINAS TO THE MID-ATLANTIC COAST TONIGHT AND TUESDAY…

SUMMARY OF 1100 AM EDT…1500 UTC…INFORMATION
———————————————–
LOCATION…30.7N 80.1W
ABOUT 90 MI…145 KM ESE OF BRUNSWICK GEORGIA
ABOUT 220 MI…350 KM SSW OF MYRTLE BEACH SOUTH CAROLINA
MAXIMUM SUSTAINED WINDS…70 MPH…110 KM/H
PRESENT MOVEMENT…N OR 360 DEGREES AT 13 MPH…20 KM/H
MINIMUM CENTRAL PRESSURE…998 MB…29.47 INCHES

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for…
* Edisto Beach South Carolina to Cape Fear North Carolina
* Pamlico and Albemarle Sounds, including the Neuse and Pamlico Rivers
* Oregon Inlet North Carolina to the North Carolina/Virginia border

A Storm Surge Watch is in effect for…
* Cape Fear to Oregon Inlet North Carolina

A Hurricane Warning is in effect for…
* South Santee River South Carolina to Surf City North Carolina

A Tropical Storm Warning is in effect for…
* Altamaha Sound Georgia to South Santee River South Carolina
* North of Surf City North Carolina to the Mouth of the Merrimack River
* Pamlico and Albemarle Sounds
* Chesapeake Bay
* Tidal Potomac River
* Delaware Bay
* Long Island and Long Island Sound
* Martha’s Vineyard, Nantucket, and Block Island

A Tropical Storm Watch is in effect for…
* Mouth of the Merrimack River to Eastport Maine

DISCUSSION AND OUTLOOK
———————-
At 1100 AM EDT (1500 UTC), the center of Tropical Storm Isaias was located by an Air Force Reserve reconnaissance aircraft and NOAA Doppler weather radars near latitude 30.7 North, longitude 80.1 West. Isaias is moving toward the north near 13 mph (20 km/h), and this general motion is expected to continue today. A turn toward the north-northeast along with an increase in forward speed is expected by this late afternoon or early evening, followed by a faster
northeastward motion tonight and Tuesday. On the forecast track, the center of Isaias will pass well east of the Georgia coast through this afternoon. The center of Isaias will then approach the coasts of northeastern South Carolina and southern North Carolina within the hurricane warning area this evening. The center will then move inland over eastern North Carolina tonight, and move along the coast of the mid-Atlantic states on Tuesday and into the northeastern United States Tuesday night.

Data from the reconnaissance aircraft and NOAA Doppler weather radars indicate that maximum sustained winds remain near 70 mph (110 km/h) with higher gusts. Some strengthening is forecast this afternoon, and Isaias is expected to regain hurricane strength just before it reaches the coast of northeastern South Carolina or southern North Carolina tonight. Only slow weakening is anticipated after Isaias makes landfall in the Carolinas and moves across the U.S. mid-Atlantic region tonight and Tuesday.

Tropical-storm-force winds extend outward up to 125 miles (205 km) from the center.

The estimated minimum central pressure based on reports from the aircraft is 998 mb (29.47 inches).

HAZARDS AFFECTING LAND
———————-

STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide…

South Santee River SC to Cape Fear NC…3-5 ft
Edisto Beach SC to South Santee River SC…2-4 ft
Cape Fear NC to the North Carolina/Virginia border including Pamlico Sound, Albemarle Sound, Neuse and Pamlico Rivers…2-4 ft
Altamaha Sound GA to Edisto Beach SC…1-3 ft
North of the North Carolina/Virginia border to Martha’s Vineyard including the Chesapeake Bay, the Tidal Potomac River, and Delaware Bay…1-3 ft

WIND: Hurricane conditions are expected within the hurricane warning area in South and North Carolina this evening through tonight, with tropical storm conditions beginning later today.

Widespread tropical-storm-conditions are expected in the tropical storm warning area from coastal North Carolina to the mid-Atlantic states tonight and Tuesday, with wind gusts to hurricane force possible. These winds could cause tree damage and power outages.

Tropical storm conditions are expected to reach southern New England late Tuesday and are possible along the northern New England coast Tuesday night and early Wednesday.

RAINFALL: The following rainfall accumulations are expected alongand near the track of Isaias:

Carolinas and the Mid-Atlantic: 3 to 6 inches, isolated maximum totals 8 inches.

Southeast New York and much of New England: 2 to 4 inches, isolated maximum totals 6 inches.

TORNADOES: A few tornadoes will be possible over coastal South Carolina beginning this evening, spreading across eastern North Carolina tonight into Tuesday morning. A couple tornadoes will be possible on Tuesday from eastern Virginia northeastward into southern New England.

You can see a forecast intensity model run for tropical storm or hurricane Isaias from TropicalTidbits.com below:

Track the 2020 Atlantic tropical storm and hurricane season on our dedicated page and we’ll update you as new information emerges and any meaningful storms form.