You checked for Saturday — 25 knots showing.
You cancelled the plan.
Saturday came — flat calm.
We should have
gone.Or: glad we didn't.
Or the reverse: the forecast looks good, then falls apart as the date closes in. The problem isn't the forecast — it's how we look at it. A forecast is not a fixed thing — it keeps changing as the target date approaches, but we only ever see the latest version. Windtrack records every step in between: which model said what and when, which way the forecast drifted, whether the models converged. It doesn't just show the weather; it analyses how the forecast for a future date is changing.
A sample track. The models start scattered between 9 and 26 knots; as the target approaches they converge around 19 knots. The narrower the spread, the more the forecast can be trusted.
How it works
Most sailors — charter crews especially — plan a passage weeks, sometimes months ahead. With a charter the dates are fixed from the start and won't move; the weather only comes into focus as it approaches. First the route is planned, then the eyes turn to the sky. That is where Windtrack comes in.
Mark your points now
With five or six days still to go, pick your departure day and the points along your route straight from the map: position, day and hour. For every point the system creates four more satellite points 20 nautical miles N/S/E/W of it; any point that lands on an island or ashore is moved out to open water automatically.
Windtrack keeps watch for you
While you get on with your day, ECMWF, ICON, GFS, MeteoFrance and UKMO are queried every day at 05:00, 11:00, 17:00 and 23:00. Three days from the target the 5 km Greek POSEIDON model joins in — it can resolve channel funnelling and lee shadows. No record is ever deleted.
The change is analysed for you
At every update the system works out model agreement, direction stability and how far the forecast has drifted; the result is compared against five years of history for the same point and turned into a short skipper's comment — in the language of the app. A notification reaches your phone as soon as it is ready.
The closer it gets, the easier the plan
As the date approaches you see whether the forecast has settled; you review your route without being squeezed into the last day. If you need to, you move a point or put an alternative bay on watch.
The gap between models: "spread"
Other apps give you the latest forecast at this moment. What Windtrack tracks is spread: the gap between the highest and the lowest model in the same update. Windtrack doesn't tell you "18 knots on Saturday"; it says "five models are converging around 18 knots and haven't changed their minds for three days". That difference is the difference between a passage cancelled and a passage made.
Historical context: "Is this wind normal?"
"14 knots on Saturday, 6 knots between the models." Is that good or bad? The answer doesn't come from the forecast alone; you need to know what normal looks like for that place on that date. In every comment the forecast is compared against the same location's past five years within the same date window (±7 days, same hour). Inside the historical band it is ordinary seasonal variation; past the top 10% of the record it really is unusual — and it will be said so.
In a sailor's language, without deciding for you
Everything gathered — trend, spread, direction stability, spatial pattern, POSEIDON, past years, pressure tendency, atmospheric instability — is handed to the AI as structured data and turned into a short skipper's comment. What follows is not invented; it is what the system produced for a real tracked point:
This forecast has been rock solid: all five models have sat in the "agreed" band through every one of the ten updates we've tracked — the strongest confidence signal this tool gives. Latest average is 16.5 kt from the N, gusting around 20.8 kt, spread just 2.1 kt, and direction is locked into a tight 22° arc between N and NNE. POSEIDON's high-resolution view backs it up at 15.2 kt.
For this date and spot, that's slightly above the usual — typical is around 13.8 kt — but well within what past years have delivered here. Nothing unusual.
The striking feature is spatial: 20 miles east the wind drops to 10.3 kt, while north (18.6 kt), west and south all hold 17+ kt. The eastern sector is a clearly softer zone; your target point sits on the windier side of that divide.
Hour by hour, 09:00 is unremarkable — the day builds to its peak of 18.2 kt around 17:00, and 06:00 is the calmest at 14.4 kt. Shifting your time there earlier buys you a slightly quieter picture; later afternoon is the firmest. The atmosphere shows moderate instability, so limited potential for local development, but pressure is steady.
Real system comment · 18 hours to target
Why it can be trusted
First-rate sources
The data comes from the world's reference global models (ECMWF chief among them) and, for the Aegean, from HCMR's operational POSEIDON model. Actual measurements from 18 Aegean METAR stations are also collected and compared with the forecasts on the same convention.
Maths that follows seamanship
Wind direction is a circular quantity; the average of 350° and 010° is not 180°. Everywhere in the system a vector mean and circular spread are used — in the Aegean, where the meltemi swings around 0°, that detail is the difference between "the models are scattered" and "the models agree on northerly". Satellite points are computed with spherical trigonometry.
Thresholds are not left to the AI
Judgements like "is the spread narrowing, is the pressure falling" are computed by the system; the AI only puts them into words. If the data is thin, no comment is made; if it is uncertain, it says "uncertain". No "no risk" assurance is ever given for something unknown.
It states its limits
Windtrack does not produce forecasts; it watches the existing ones — and all five models can be wrong together. The historical archive is model output; there is no wave or current data yet; high resolution is for now limited to the Aegean. A system that does not hide these is easier to trust.
The difference, briefly
| Other forecast apps | Windtrack |
|---|---|
| The latest forecast at this moment | How the forecast changes over time and what that means |
| A single model or a single map | Six models' agreement and divergence |
| A single point | Centre + 4 satellites for the structure of the wind field |
| Numbers without context | Compared against 5 years of history for the same place and date |
| You stop checking | Checks four times a day in your place — and forgets nothing |
Who is it for?
Windtrack was built for skippers sailing the Mediterranean and the Aegean, by a skipper, and is in active use by sailors in these waters. It installs as an app on iOS and Android phones; with notifications enabled it lets you know when a comment is ready or when something changes sharply.
Questions and suggestions: info@windtrack.tr