(This article, first published Wednesday evening, was updated Thursday afternoon.)

The outer bands of Hurricane Florence have begun to batter the eastern Carolinas, and ocean water is rising along the coast. “Catastrophic” flooding from both this rise in ocean water and tremendous rainfall, which will extend far inland, is feared. More than 15 million people are under storm watches and warnings.

Here’s a guide to what key cities in the impact zone can expect, bearing in mind that forecasts may change.

Virginia

Norfolk: Gusty showers begin Thursday, becoming heavy squalls overnight Thursday into Friday. They are accompanied by onshore easterly winds gusting to 45 mph. The rain will taper off gradually by Saturday evening, with winds slackening Saturday afternoon. Two to four inches of rain is possible. The storm surge may raise water levels up to one to three feet above normally dry land at the coast.

North Carolina

Wilmington: Tropical storm conditions will arrive as early as midafternoon Thursday, with rain and gusty winds increasing. Conditions will deteriorate overnight as winds start to gust over 70 mph.

By the predawn hours of Friday, expect destructive winds of 70 to 90 mph, gusting over 100 mph. The wind will be accompanied by blinding rain. The storm surge may cause the water at the coast to rise four to six feet above normally dry land.

Winds will start to slowly ease late Friday but are expected to remain tropical-storm-force Saturday in the range of 40 to 60 mph before subsiding Sunday.

Total rainfall of 15 to 20 inches with isolated 30-inch amounts is possible. Widespread, possibly catastrophic, flooding is expected.

Raleigh: Tropical storm conditions possible beginning late Thursday night and lasting through Saturday. On Friday, winds become sustained around 30 mph, with gusts to 45 mph, before tapering off Saturday afternoon or evening. At least six inches of rain is possible, and some flooding is likely.

Charlotte: Cloudy, breezy summertime weather through Saturday, with showers possible at times. Winds pick up Saturday night into Sunday, gusting up to 30 to 40 mph, when rain is likely to move in. Rain could continue at times into early next week, with at least three to six inches possible, which could cause flooding.


Seven-day rainfall forecast for Mid-Atlantic from Hurricane Florence. (PivotalWeather.com)

South Carolina

Myrtle Beach: Tropical storm conditions arrive by late Thursday, intensifying overnight as winds become sustained at 40 to 50 mph and gust to 65 mph.

Steady, moderate squalls will rotate in throughout the day on Friday. Florence’s slow movement will result in a significant, prolonged period of onshore damaging winds through the weekend.

The worst conditions will be felt Friday afternoon into the night, with winds becoming northerly and sustained at 60 to 70 mph, gusting to 80 to 90 mph. The storm surge may cause the water at the coast to rise four to six feet above normally dry land.

Tropical-storm-force winds of around 40 mph, gusting to 50 mph into Saturday, are likely before they gradually taper at night. Total rainfall may exceed a foot.

Charleston: Winds start to become gusty late Thursday into Friday but may increase substantially Friday night into early Saturday, with gusts to 50 mph and possibly higher, depending on the storm track. Winds should ease some Saturday night. Rain totals reach three to six inches, and the storm surge could reach two to four feet. This remains an uncertain forecast, and the model trends bear watching for Charleston.

Columbia: Relatively calm into Friday morning, before winds gradually start to increase. The best chance of rainy and windy (gusts up to 40 mph) weather develops Saturday. While winds slowly diminish, rain, possibly heavy, could linger into Monday, pushing totals up to around eight inches.

Georgia

Savannah: It may lie on the southern periphery of storm conditions, so the forecast here is uncertain. Tropical storm conditions could develop here Friday night into Saturday, with a period of heavy rain and strong winds. Wind gusts to 50 mph and one to two inches of rain are possible.

Atlanta: Sinking air on the periphery of Florence will result in mostly clear skies Friday and Saturday. The city sits along the very southwestern edge of where the storm’s wind and rain might reach possibly for a period Sunday into Monday. The forecast here is also very uncertain.