What is Forecast Replay?
Forecast Replay lets you step back in time up to 3 months and see how the synoptic weather overview evolved on a global map, based on the ECMWF 8km initial conditions. It shows familiar weather layers like wind, gusts, rain and waves in hourly timesteps, so you can see what the big picture looked like when you were actually out sailing.
With a Basic, Standard or Professional Forecast subscription, you can use Forecast Replay to review memorable passages or after weather events to see if what happened matched what you expected from reviewing the forecast.
Winter Storm Hernando "Blizzard of 2026" - Feb 22 - 24, 2026
What are ECMWF Initial Conditions?
ECMWF initial conditions are high‑resolution, best‑estimate snapshots of the current atmosphere, land and ocean state used to start the ECMWF forecast model. These are created by combining millions of quality‑checked observations from satellites, aircraft, ships and weather stations with short‑range model forecasts into a single, consistent analysis.
How to use Forecast Replay on the Forecast Website
How to use Forecast Replay on the Forecast website:
Log in to the PredictWind website.
From the main menu, select Forecast > Forecast Replay.
Select Wind in the bottom right corner of the map to open Forecast Options.
Select the weather layer you want to view, e.g. Wind, Gust, Waves or Rain.
Use the time slider to choose a day and time in the past 3 months.
On the map timeline, select the Play Arrow to watch the Forecast Replay evolve or drag the time slider to move to a specific hour.
What Forecast Options does Forecast Replay include?
Weather Variables visible in Forecast Replay are:
Wind and Gust
Rain and Cape
Cloud and Isobar
Air Temp and Sea Temp
Currents and Wave
Display - Forecast Replay display options are the same as in Maps, i.e. Streamlines, Feathers and Directional Arrows.
Grid Size - The map uses a 100 km grid. It is limited to a broad, synoptic‑scale view, so small‑scale local effects such as land breezes and harbour gusts will not appear.
Important: Forecast Replay is for reviewing past conditions, not predicting future weather. Always rely on current forecasts, Weather Routing and official warnings for decision‑making.
How is Forecast Replay helpful?
You can use Forecast Replay to look back at strong winds, squalls or heavy seas you experienced and see how the synoptic pattern developed around your route. You might debrief a passage with the crew by replaying the weather from a multi‑day coastal or offshore trip to discuss which features you spotted early, which you missed, and how you might adjust routing or reefing calls next time.
During Winter Storm Hernando, the “Blizzard of 2026” pictured above, a rapidly deepening coastal low brought hurricane‑force gusts, heavy snow and coastal flooding from New Jersey to New England. With Forecast Replay, you could step back through those two days, watch the low deepen and track up the Eastern Seaboard, and compare the evolving wind and pressure pattern with the conditions you logged in ports and anchorages along the U.S. Northeast coast.
Frequently Asked Questions
Do I need a PredictWind Forecast subscription to view the Forecast Replay?
Yes. To view Forecast Replay, you need a Basic, Standard or Professional Forecast subscription.
Can I view future weather in Forecast Replay?
No. Forecast Replay lets you review how the ECMWF forecast looked at the time. It does not show future weather. Use Forecast Maps for weather forecasts.
Where can I view Forecast Replay?
Forecast Replay is available on the PredictWind Forecast Website, in the PredictWind app, and on your GPS Tracking page, where it appears as weather history.