THE WEATHER BEAT · OCT 22

The St. Johns River at Astor, Florida, reaches moderate flood stage on days of northeast wind, with stronger wind due this weekend

No rain required: northeast wind has pushed the St. Johns at Astor to 3.2 ft against a 2.3 ft flood stage, and Melbourne expects 20 to 30 mph winds this.

By the Weather Rock October 22, 2026, 1:05 p.m. · 6 min read

Astor Bridge over the St. Johns River, Florida — The Astor Bridge over the St. Johns River between Lake County and Volusia County, Florida, photographed on 22 January 2012. Photo: Leonard J. DeFrancisci, Wikimedia Commons, CC BY-SA 3.0. This crop carries the same licence.

Key points

At 8:30 a.m. EDT Thursday, the St. Johns River near Astor, Florida, measured 3.2 feet. Flood stage there is 2.3 feet. NWS Melbourne calls this moderate flooding and blames "persistent northeast winds", not rain.
The warning covers Lake and Volusia counties and runs until further notice. It says the river is forecast to keep climbing slowly through moderate flood stage over the weekend. Next week, after the northeast wind picks up again, levels could approach major flood stage.
Melbourne's morning discussion expects northeast winds of 20 to 30 mph this weekend, arriving with high astronomical tides. It says beach erosion and minor coastal flooding are increasingly likely from Saturday into early next week.

Astor, Florida : St. Johns River — The St. Johns River at Astor, Florida, looking north, photographed on 24 April 2010. Photo: Ebyabe, Wikimedia Commons, CC BY-SA 3.0. This crop carries the same licence.

A river pushed by the wind

Most river floods start with rain. This one started with wind. The St. Johns is one of the few big rivers in the country that flows north, and it falls only a few feet over its whole length. When a northeast wind blows up it for days, the water backs up. NWS Melbourne's Flood Warning says that is what happened at Astor: "Persistent northeast winds have caused river levels on the St Johns at Astor to rise into Moderate Flood Stage."

The gauge read 3.2 feet at 8:30 a.m. EDT Thursday. Bankfull is 2.0 feet and flood stage is 2.3 feet. In the 24 hours before that reading, 3.2 feet was also the highest the river reached. The office expects it to hold there for now. It also lists what happens at 3.5 feet. Canals overflow into yards. Homes on and near Wildhog and Bonnet Roads can only be reached through water, and several inches of water get inside homes along the river and canals. Docks at the Astor Bridge marina and throughout Astor go completely under, and Bartram Road, Holiday Circle and Clair Street cannot be driven.

Georgia also has a slow river. NWS Jacksonville has the Satilla River at Atkinson, in Brantley County, at 13.8 feet as of 7:45 a.m. EDT, with flood stage at 13.0. At that level Warners Landing, Louis Landing and the secondary roads around the KOA campgrounds begin to flood. River Rock Road takes water at 14.0 feet. That warning calls the flooding minor and gives no cause.

On the Outer Banks, the nor'easter's long tail is still showing. NWS Newport/Morehead City kept the Coastal Flood Warning for Hatteras Island in force until 8 p.m. EDT Thursday. It calls for up to 2 to 4 feet of inundation in low-lying areas near shorelines and tidal waterways, and breaking waves of 8 to 12 feet in the surf zone.

Product	Office	Where	Measured	Flood stage	Category	Issued	In force until
Flood Warning	Melbourne FL	St. Johns River near Astor, Lake and Volusia	3.2 ft at 8:30 a.m. EDT Thu	2.3 ft (bankfull 2.0 ft)	moderate	9:36 a.m. EDT Thu	further notice; next statement 11 a.m. EDT Fri
Flood Warning	Jacksonville FL	Satilla River at Atkinson, Brantley GA	13.8 ft at 7:45 a.m. EDT Thu	13.0 ft	minor	8:51 a.m. EDT Thu	further notice; next statement 9 a.m. EDT Fri
Coastal Flood Warning	Newport/Morehead City NC	Hatteras Island	up to 2 to 4 ft inundation forecast; surf 8 to 12 ft	n/a	n/a	4:03 a.m. EDT Thu	8 p.m. EDT Thu

*Source: NWS alert products on api.weather.gov, read at 17:05Z October 22. Stages, flood stages and categories are quoted from each warning. The Astor warning gives no moderate-stage figure, so none is printed here.*

Today, officially

NWS Melbourne's Area Forecast Discussion was issued at 7 a.m. EDT, and its forecast sections were written at 2:57 a.m. It expects the northeast wind to continue at 10 to 15 mph today, with gusts to 20 to 25 mph, and to get a little stronger Friday. From Saturday it describes a "highly unsettled weather pattern." Low pressure is expected to form along an old frontal boundary near or northeast of the Bahamas. High pressure to the north is expected to strengthen. Between the two, the office expects northeast to east-northeast winds of 20 to 30 mph sustained this weekend, with frequent higher gusts. It says Wind Advisories may be needed, at least for the coast.

The office says those winds "will coincide with high astronomical tides and help produce another hazardous coastal event". It lists beach erosion, rough surf, minor coastal flooding and dangerous rip currents this weekend into early next week. Offshore, it expects seas to build to 12 to 15 feet by late Saturday, and says Gale Watches or Warnings will likely be needed starting sometime Saturday. For the St. Johns, the Flood Warning itself says the river "is forecast to climb slowly through Moderate Flood Stage through the weekend," with the potential to approach Major Flood Stage next week.

Element	Melbourne's forecast	Window
Northeast wind	10 to 15 mph, gusts 20 to 25 mph	Thursday
Northeast to east-northeast wind	20 to 30 mph sustained, frequent higher gusts	Saturday to Monday
Seas offshore	building to 12 to 15 ft	late Saturday into Saturday night
Coastal hazards	beach erosion, rough surf, minor coastal flooding, rip currents	this weekend into early next week

*Source: NWS Melbourne Area Forecast Discussion, 700 a.m. EDT October 22 (discussion and marine sections issued 257 a.m. EDT), and the NWS Melbourne Flood Warning for the St. Johns River near Astor, 9:36 a.m. EDT October 22.*

What the reader can check

The St. Johns at Astor is an experiment you can follow from home. If Melbourne's discussion is right, nothing about the rain will explain the next few days of that gauge. The wind will. The Weather School lesson on why the wind blows covers the pressure gradient the office describes. Friday's 11 a.m. statement will show whether the river held at 3.2 feet or started its weekend climb.

This is a summary, not emergency information. For live warnings see weather.gov and your local officials.