1. Tropical storm conditions are expected within the warning area along the northeastern coast of South Carolina this morning and will spread northeastward within the warning area along the North Carolina coast this afternoon into Sunday.

2. Areas of heavy rainfall may result in localized flash flooding across portions of coastal South and North Carolina through Sunday morning.

CHANGES WITH THIS ADVISORY: A Tropical Storm Warning has been issued from South Santee River, South Carolina, to Duck, North Carolina, including Pamlico Sound. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for...
- South Santee River, South Carolina, to Duck, North Carolina
- Pamlico Sound A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office.

WIND: Tropical storm conditions are expected within the warning area in South Carolina this morning and will spread northward to the warning area in North Carolina this afternoon through Sunday.

RAINFALL: Colin will continue to produce locally heavy rainfall across portions of coastal South and North Carolina through Sunday morning. An additional 1 to 2 inches of rainfall, with isolated amounts up to 4 inches, is expected. This rainfall may result in localized areas of flash flooding.

At 500 AM EDT (0900 UTC), the center of Tropical Storm Colin was located just inland over South Carolina near latitude 33.2 North, longitude 79.5 West. Colin is moving toward the northeast near 8 mph (13 km/h), and this general motion is expected to continue through Sunday. A turn toward the east northeast with an increase in forward speed is expected late Sunday and Sunday night. On the forecast track, the center of Colin is expected to move northeastward along or just inland of the South Carolina and North Carolina coasts through Sunday, and then emerge over the western Atlantic Ocean late Sunday. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Little change in strength is forecast during the next couple of days. Colin is expected to dissipate over the western Atlantic on Monday. Tropical storm force winds extend outward up to 70 miles (110 km) mainly to the southeast of the center. The estimated minimum central pressure is 1011 mb (29.86 inches).

A small area of low pressure formed along a surface trough just offshore of Savannah, Georgia, yesterday morning and moved inland across the Lowcountry of South Carolina by the evening. Deep convection formed near the low center as it was moving inland and has persisted and become better organized over the past 6 to 12 hours. In addition, surface observations and ASCAT data from 02-03 UTC indicated that an area of sustained 35-kt winds had developed offshore and near the coast of South Carolina. As a result, and rather unexpectedly, Tropical Storm Colin has formed near the South Carolina coast, centered just inland a bit to the northeast of Charleston.

Colin is moving northeastward just inland of the coast with a motion of 045/7 kt. A low- to mid-level area of high pressure is located over the western Atlantic, and Colin is expected to move northeastward and then east-northeastward around that high during the next 48 hours. The bulk of the available track guidance suggests that Colin's center will move along or just inland of the coasts of South and North Carolina during the next 36 hours, and the NHC track forecast is generally a blend of the GFEX and HCCA consensus aids.

Northwesterly shear of roughly 15-20 kt is expected to continue affecting Colin during the next 36 hours or so, with that shear increasing to 30 kt or more by 48 hours. As a result, strengthening is not anticipated, and Colin is expected to remain a sheared tropical storm while it moves across coastal areas of the Carolinas, with tropical-storm-force winds primarily limited to the southeast of the center. Colin is likely to dissipate over the western Atlantic soon after 48 hours.