Tropical Storm Idalia: August 30-31, 2023

Overview

After making landfall in the Big Bend area of Florida as a Category 3 hurricane on August 30, Idalia weakened to a tropical storm as it moved across southeastern Georgia. The storm then moved off the northern South Carolina coast and just off the southeastern North Carolina coast early on August 31 causing flooding from heavy rain and storm surge, tropical storm-force wind gusts and 5 tornadoes.

IR satellite loop of Tropical Storm Idalia tracking through the Southeast U.S. on August 30-31, 2023

Winds

Tropical storm force wind gusts occurred across much of southeast NC and northeast SC with the highest gusts mainly near the coast and offshore. The combination of gusty winds and heavy rain led to some downed trees and power lines.

NHC Tropical Storm and Hurricane Force Wind Swaths of Idalia

Location	Peak Wind Gust (mph)	Peak Wind Gust (kt)
Wilmington, NC - KILM	52
N Myrtle Beach, SC - KCRE	48
Marion, SC - KMAO	47
Lumberton, NC - KLBT	46
Florence, SC - KFLO	43
Myrtle Beach, SC - KMYR	43
Southport, NC - KSUT	38
Frying Pan Shoals Buoy		53
Wrightsville Beach, NC - Offshore Buoy		53
Federal Point, NC (50 ft)		53
Wrightsville Beach, NC - Nearshore Buoy		49
Wrightsville Beach, NC - Johnnie Mercers Pier		48
Winyah Bay, SC		48
Sunset Beach, NC - Nearshore Buoy		45
Myrtle Beach, SC - Springmaid Pier		39

Rainfall

Widespread heavy rain fell across southeastern NC and northeastern SC with localized amounts over 10 inches which led to flash flooding, especially in Horry County, SC and Columbus County, NC.

Location	Rainfall (inches)
Mullins-0.8 mi SE	11.57
Mullins-4.9 mi ESE	10.70
Whiteville	9.46
Kingstree-7.9 mi NW	8.76
Loris-1.4 NE	8.64
Calabash-1.9 mi WNW	8.45
Longs-1.3 mi NW	8.08
Conway-9.2 mi NNE	7.90
Little River-4.7 mi WNW	7.41
Leland-5.5 mi WNW	7.03
St. James	6.90
Myrtle Beach-10 mi NE	6.86
Green Sea	6.64
Shallotte	6.34
Sunset Beach-1.7 mi WNW	6.24
Wrightsboro-2.9 mi ENE	6.10
Surf City-2.8 mi SW	6.07
Sunset Beach	5.91
Wilmington-KILM	5.31
Elizabethtown-6.2 mi NW	5.07
Southport-4 mi WNW	5.00
Georgetown-5.3 mi NNE	4.64
Florence-2.6 mi S	4.53
Darlington-7.3 mi SSW	4.50

NWS radar mosaic showing Idalia moving northeast across the Southeast U.S. from 0830 UTC (0430 EDT) on August 30, 2023 through 0830 UTC (0430 EDT) on August 31, 2023.

Tornadoes

5 tornadoes were confirmed: Horry County, SC (1 EF-0), Brunswick County, NC (1 EF-1 and 2 EF-0), New Hanover County, NC (1 EF-1).

NWS Wilmington, NC doppler radar reflectivity (left) and storm-relative velocity (right) showing 2 tornadoes touching down just south of Wilmington, NC.

Coastal Flooding

High tides led to several rounds of minor to moderate coastal flooding along the northern SC and southern NC coasts. Notice that the greatest anomalies (i.e., surge) occurred closer to a high tide at Myrtle Beach, SC which led to higher water levels compared to Wrightsville Beach/Wilmington, NC.


Water level observations (ft above MLLW) at the NOAA/NOS tide gage at Myrtle Beach, SC. The peak tide was 9.13 ft MLLW (3.53 ft MHHW) at 2348 UTC on 8/30/23.	Water level observations (ft above MLLW) at the NOAA/NOS tide gage at Wilmington, NC. The peak tide was 6.74 ft MLLW (2.05 ft MHHW) at 0224 UTC on 8/31/23.	Water level observations (ft above MLLW) at the NOAA/NOS tide gage at Wrightsville Beach, NC. The peak tide was 7.08 ft MLLW (2.6 ft MHHW) at 0012 UTC on 8/31/23.

Additional Links

Page Author: Bob Bright
Last Updated: May 4, 2024