Gusts stronger than forecast
On Monday 26 October in Zumaia, the models forecast gusts of 28 km/h and gusts of 64 km/h were measured
With what we measure, we cannot tell why.
Zumaia station (AEMET), 1 km from Zumaia.
What happened
- Only the ECMWF IFS saw it coming: it gave 49 km/h.
- This station usually measures gusts 7 km/h stronger than forecast; that day they were 36 km/h stronger.
- With what we measure, we cannot tell why.
- The Atlas Forecast missed too: 9.3 km/h average error each hour (the median of the models, 8.5 km/h).
What each model gave
| Model | For that day (0–24 h) | A day earlier (24–48 h) |
|---|---|---|
| ECMWF IFS (saw it) | 49 km/h | — |
| GFS | 28 km/h | 28 km/h |
| ICON | 25 km/h | 27 km/h |
| UKMO | 27 km/h | 19 km/h |
| Median | 28 km/h | 27 km/h |
| Measured | 64 km/h | |
Hour by hour
Maximum gust at the Zumaia station, with each model's forecast for that same day (0–24 h). Spanish mainland time.
- Measured
- Median of the models
- ECMWF IFS (saw it)
- Each of the other models
Show the data in a table
| Time | Measured | ECMWF IFS | ECMWF AIFS | GFS | ICON | ARPEGE | UKMO |
|---|---|---|---|---|---|---|---|
| 02:00 | 8.6 | 15.8 | — | 9.4 | 10.8 | — | 14.4 |
| 03:00 | 11.9 | 16.9 | — | 11.5 | 12.6 | — | 17.6 |
| 04:00 | 13.3 | 18 | — | 10.8 | 16.2 | — | 19.4 |
| 05:00 | 17.3 | 19.1 | — | 14 | 15.1 | — | 22.7 |
| 06:00 | 18 | 20.2 | — | 13.7 | 15.5 | — | 18.4 |
| 07:00 | 13 | 20.9 | — | 8.6 | 15.1 | — | 15.5 |
| 08:00 | 14.8 | 20.9 | — | 10.1 | 14.4 | — | 11.9 |
| 09:00 | 15.5 | 20.5 | — | 9 | 14.4 | — | 10.8 |
| 10:00 | 13.7 | 19.8 | — | 6.8 | 10.4 | — | 9 |
| 11:00 | 9 | 18 | — | 3.6 | 8.6 | — | 7.6 |
| 12:00 | 10.4 | 15.8 | — | 5.4 | 11.2 | — | 5.4 |
| 13:00 | 13.3 | 14.4 | — | 7.9 | 11.5 | — | 8.3 |
| 14:00 | 14 | 14.8 | — | 10.1 | 14.8 | — | 11.9 |
| 15:00 | 15.1 | 16.6 | — | 11.2 | 16.6 | — | 13.7 |
| 16:00 | 19.1 | 17.6 | — | 11.2 | 15.5 | — | 16.2 |
| 17:00 | 19.8 | 17.3 | — | 7.9 | 15.8 | — | 14.8 |
| 18:00 | 14.8 | 16.6 | — | 6.8 | 9.7 | — | 12.6 |
| 19:00 | 13 | 18.4 | — | 9.7 | 12.6 | — | 11.2 |
| 20:00 | 11.5 | 24.5 | — | 18.7 | 19.8 | — | 14 |
| 21:00 | 30.2 | 32.8 | — | 24.5 | 22.3 | — | 19.4 |
| 22:00 | 34.9 | 40 | — | 25.9 | 22.3 | — | 19.1 |
| 23:00 | 50 | 44.6 | — | 26.3 | 24.1 | — | 14.4 |
| 00:00 | 64.1 | 47.9 | — | 27.4 | 24.5 | — | 5.8 |
| 01:00 | 62.6 | 49.3 | — | 28.4 | 23.4 | — | 27.4 |
Weather in Zumaia · Model accuracy · The model league · Other misses
How we spot them
Every day we compare what the Meteocat (in Catalonia) and AEMET weather stations measured the day before with what each model had forecast for that same day (0–24 h ahead). It counts as a notable miss if 15 mm or more fell and the median of the models gave less than 3; if it gave 15 mm or more and less than 1 fell; if the high was off by 4 °C or more (and by at least 4 °C more than that station usually is); or if a gust went over 60 km/h and was 25 km/h or more above the forecast. Stations within 40 km with the same miss count as one episode, and we show at most 5 per day.
The explanations come from the same data: which model saw it, whether the rain came earlier or later, whether it fell (or was forecast) a few kilometres away, whether it was very concentrated… When none of that fits, we say so. Days run from midnight to midnight UTC (2 am to 2 am in summer and 1 am to 1 am in winter, Spanish mainland time).
Missing now and then is unavoidable: the weather is chaotic and every model has its days. How often each one gets it right, on average, is in Accuracy and in the model league.