1. As Elsa moves across the Carolinas Thursday, heavy rainfall may result in limited flash and urban flooding. Heavy rainfall from the Mid-Atlantic into New England Thursday and Friday could lead to considerable flash and urban flooding.

2. Tropical storm conditions are expected along portions of the coasts of Georgia and South Carolina this morning. Tropical storm conditions are also expected along the coasts of North Carolina starting later today and the mid-Atlantic by this afternoon or tonight. Tropical storm conditions are expected in portions of the southern New England states and New York by Friday. Gale winds are expected over the portions of the New Hampshire and Maine coasts by late Friday or Friday night, and those conditions are possible over portions of Atlantic Canada Friday night and Saturday.

CHANGES WITH THIS ADVISORY: A Tropical Storm Warning is now in effect north of Great Egg Inlet, New Jersey to Sandy Hook, New Jersey, and for the coast of Long Island from East Rockaway Inlet to the eastern tip along the south shore and from Port Jefferson Harbor eastward on the north shore. A Tropical Storm Warning is also in effect from New Haven, Connecticut to Sagamore Beach, Massachusetts including Cape Cod, Block Island, Martha's Vineyard, and Nantucket. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for...
- Little River Inlet, South Carolina to Sandy Hook, New Jersey
- Pamlico and Albemarle Sounds
- Chesapeake Bay south of North Beach and the tidal Potomac south of Cobb Island
- Delaware Bay south of Slaughter Beach
- Long Island from East Rockaway Inlet to the eastern tip along the south shore and from Port Jefferson Harbor eastward on the north shore
- New Haven, Connecticut to Sagamore Beach, Massachusetts including Cape Cod, Block Island, Martha's Vineyard, and Nantucket A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. Interests elsewhere in the northeastern United States and the Canadian Maritimes should monitor the progress of Elsa. 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.

Key messages for Elsa can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT5, WMO header WTNT45 KNHC and on the web at www.hurricanes.gov/graphics_at5.shtml?key_messages.

WIND: Tropical storm conditions are expected in the Tropical Storm Warning area along the Georgia coast for the next few hours, along the South Carolina coast this morning, along the North Carolina coast later today, and along the mid Atlantic coast by this afternoon. Tropical storm conditions are expected in the warning area in the mid Atlantic and northeastern states by Friday and Friday night. Non tropical gale warnings are in effect for portions of the U. S. coast north of the Tropical Storm Warning area, and gale conditions are expected in this area late Friday and Friday night.

RAINFALL: Elsa is expected to produce the following rainfall amounts and impacts the rest of this week: Across portions of South Carolina, storm totals of 3 to 5 inches with isolated maximum amounts up to 8 inches are likely through Thursday, which may result in limited flash and urban flooding. Across central and eastern North Carolina into southeastern Virginia and from the Mid Atlantic into New England...2 to 4 inches of rain with isolated totals up to 6 inches on Thursday through Friday are possible, which could result in limited to considerable flash and urban flooding, as well as isolated minor river flooding.

TORNADOES: A few tornadoes are possible across the eastern Carolinas into southeast Virginia through this afternoon. The threat for a tornado or two may continue tonight into Friday morning across coastal portions of the Mid Atlantic to southern New England.

At 500 AM EDT (0900 UTC), the center of Tropical Storm Elsa was located near latitude 33.4 North, longitude 81.3 West. Elsa is moving toward the northeast near 18 mph (30 km/h), and this general motion is expected to continue with an increase in forward speed during the next couple of days. On the forecast track, Elsa will move over South Carolina and North Carolina today, pass near the eastern mid Atlantic states by tonight, and move near or over the northeastern United States on Friday and Friday night. The system should move over Atlantic Canada by Friday night and Saturday. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Some re strengthening is possible tonight and Friday while the system moves close to the northeastern United States. Elsa is forecast to become a post tropical cyclone Friday night or Saturday. Tropical storm force winds extend outward up to 115 miles (185 km) mainly over water to the southeast of the center. The NOAA station at Folly Island, South Carolina, recently reported sustained winds of 38 mph (61 km/h) and a wind gust of 46 mph (74 km/h). The estimated minimum central pressure is 1007 mb (29.74 inches).

Doppler radar and surface observation indicate that the center of Elsa is moving into southern South Carolina at this time. The organization of the storm has changed little during the past several hours, with a complex of bands in the eastern semicircle. The initial intensity is 35 kt, and these winds are occurring along an area of the coast and coastal waters well southeast of the center.

The initial motion is now 035/16. The track guidance is in good agreement that Elsa should accelerate northeastward during the next few days as it becomes entrained into the mid-latitude southwesterly flow, with the track carrying the system across the Carolinas and the mid-Atlantic states during the next 24 hours, then near or over southeastern New England and Atlantic Canada. The new forecast track is basically an update of the previous track, and it is very close to the consensus models.

Rawinsonde data and GOES-16 RGB airmass imagery show an upper-level shortwave trough over the southeastern United States to the west of Elsa, and the global models forecast this system to follow the cyclone northeastward and take on a negative tilt. This should result in increasing upper-level divergence over Elsa, which in turn should lead to some strengthening as the storm moves near or over the east coast of the United States. The 00Z ECMWF model is not as bullish on intensification as its previous run, but it and the 00Z UKMET still call for strengthening, and even the weaker GFS forecasts the favorable upper-air pattern. Based on this, the new intensity forecast shows a little more strengthening than the previous forecast.

Based on the new forecast track, the tropical storm warning has been extended northward along the United States east coast to Massachusetts. Non-tropical gale warnings are in effect for the coastal areas to the north of the tropical storm warning due to the likelihood that Elsa will become extratropical as it reaches that area.