2026 Atlantic season · WPC advisory 20 · Sun 11 a.m. ET, Oct 11

Post-Tropical Cyclone Isaias

Flash Flood Threat from Isaias Is Decreasing But Some Risk Continues Today Across Portions of the Appalachians and Mid-Atlantic. About 180 mi NE of Nashville Tennessee. In effect inland: Flood Watches and Wind Advisory.

Where the remnants of Isaias are headed

Isaias is now a post-tropical cyclone, the remnants of the storm, with top winds of 25 mph, below tropical-storm strength. The threat now is heavy rain and flash flooding: see How much rain? The map starts from WPC’s position now and follows the hurricane center’s last forecast track (advisory 18).

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Where did Isaias come ashore?

Hurricane Isaias made landfall near Destin, Florida, around 830 PM CDT (0130 UTC) with maximum sustained winds of 105 mph (165 km/h). Our last odds before landfall (advisory 013A) gave Okaloosa County 96%, the most of any county.

OUR ODDS139 forecast tracks from 8 p.m., started from Isaias's position; each dot is one place the center comes ashore. The coast is shaded by the chance of landfall per 10 miles; the big numbers are each county's chance.

Landfall chance per 10 miles0.512346811%+Where one track comes ashoreForecast trackHurricane center track

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How we get these odds: every forecast track we receive for Isaias (139: ensembles of 30, 51, 47 members plus 11 single runs, the newest of each), each started from the hurricane center's 8 p.m. position. Each of the four groups counts the same. Model tracks bunch together more than storms do, so we widen the spread by the amount measured on every Atlantic storm from 2023 to 2026; run that way on those storms, the area that should hold the center 9 times in 10 held it 9 times in 10.

The hurricane center's forecast is the official one. These odds are about the center only. Hurricane winds, surge and flooding rain reach well beyond it, so go by your local NWS office's warnings.

Source: our odds from public forecast tracks (NOAA/NHC guidance, ECMWF open data, CC BY 4.0), started from NHC advisory 013A. Kept as the record since landfall.

How much rain?

Our forecast has less than 2 inches of rain across most of the area through 8 a.m. Wednesday, locally more.

OUR BLENDTotal rain from 2 p.m. Sunday to 8 a.m. Wednesday.

0.10–0.25″0.25–0.50″0.50–1″1–1.5″1.5–2″2–3″3–5″5″ or moreIsaias forecast track

Forecasts come in low in the wettest spots: in this year's three U.S. landfalls (Arthur, Bertha, Edouard), the wettest place got about twice what the forecast showed there. Flooding rain can fall far inland and well after the wind has dropped.

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Source: our blend (2 p.m. Sunday run), the same run as the Rain map on Weather Hazards; NOAA Weather Prediction Center for days 4–7 and the flash-flood risk. Updated with each run.

Could it bring tornadoes?

The Storm Prediction Center gives a 2% chance of a tornado within 25 miles of any point around Virginia Beach, VA, and Salisbury, MD, from 9 p.m. Sunday to 8 a.m. Monday. For Tuesday, SPC has only its outlook for any severe storm so far: 5% around Buffalo and Syracuse, NY. No tornado watches or warnings are in effect in the area right now.

NOAA SPCChance of a tornado within 25 miles of any point, 9 p.m. Sunday to 8 a.m. Monday.

2% tornadoIsaias forecast track

Tornadoes in a landfalling tropical storm are usually brief and weak, and can spin up with little warning. Most form in rain bands to the right of the track, and they can keep forming a day or two after landfall, well inland. Tornado watches and warnings are drawn on the map while they are in effect.

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Source: NOAA Storm Prediction Center convective outlooks (Day 1 issued 8:47 p.m. Sunday; Day 3 issued 3:09 p.m. Sunday); NWS tornado watches and warnings; SPC storm reports. Updated with each outlook.

The forecast

The Weather Prediction Center's position now (advisory 20), then the hurricane center's last forecast points still ahead (advisory 18), times Eastern.