Where a forecast comes from · from the data room's weather files only, as they stood at the reads given. Not a forecast of ours and not a warning: the warnings are IPMA's (layer 4). Each layer below is labelled: a fact was read from the body that measures, decides or warns; evidence is what others computed or reported; nothing here is our own prediction. Times are UTC (Lisbon is on UTC in November).
1. What was measured (observing systems)
Fact. IPMA's surface stations: eight stations in and next to Lisbon, hourly means, no gusts in this feed. Strongest hourly mean wind kept so far at each (IPMA observations, read 11:26 UTC, 11 Nov) · stations.json:
| Station | Strongest hourly mean wind | At | Latest hour: wind, rain, pressure |
|---|
| Lisboa (Geofísico) | 35.3 km/h | 05:00 Tue | 10:00 Wed: 13.7 km/h SE, ? mm, 1000.3 hPa |
| Lisboa, Relógio | 42.8 km/h | 04:00 Tue | 10:00 Wed: 16.2 km/h SE, 5.4 mm, no hPa |
| Lisboa, Tapada da Ajuda | 23.8 km/h | 13:00 Tue | 10:00 Wed: 9 km/h SE, 4.8 mm, no hPa |
| Lisboa, Amoreiras (LFCL) | 25.2 km/h | 04:00 Tue | 10:00 Wed: 10.8 km/h S, 3.8 mm, no hPa |
| Lisboa, Carnide (CML) | 29.9 km/h | 11:00 Tue | 10:00 Wed: 14.4 km/h S, 4.4 mm, 999.8 hPa |
| Oeiras / Vila Fria (CMO) | 37.1 km/h | 11:00 Tue | 10:00 Wed: 15.5 km/h SE, 5.9 mm, 999.7 hPa |
| Almada, P.Rainha | 24.5 km/h | 11:00 Tue | 10:00 Wed: 16.9 km/h SE, 5.6 mm, no hPa |
| Barreiro, Lavradio | 24.8 km/h | 23:00 Mon | 10:00 Wed: 18.4 km/h SE, 4.7 mm, no hPa |
Fact. Airport observations (METAR), Lisbon airport (LPPT), the only gust series we hold: 92 reports kept; strongest gust so far 67 km/h (36 kt) at 11:00 Tue (NOAA Aviation Weather Center, read 11:26 UTC, 11 Nov) · airport.json. The reports are issued in Portugal and redistributed by NOAA Aviation Weather Center data API: public domain as redistributed.
Fact. Madeira, IPMA's stations: the largest 6-hour rain at each (IPMA observations, read 11:26 UTC, 11 Nov) · madeira.json:
IPMA does not document whether an hour's label is the hour starting or ending; the data room's inference (hour ending) is labelled there.
Not in our data room: radar, satellite, radiosondes, buoys. They exist (IPMA's weather radars, Meteosat (geostationary), Radiosondes (weather balloons), Buoys and ships) and feed the models below; their licences decide whether we may show them (licences).
2. What the models computed
Fact (a model's output, published by IPMA). IPMA's hourly forecast for Lisbon (IPMA, read 11:26 UTC, 11 Nov) · forecast.json: strongest mean wind on Wednesday 40 km/h S at 14:00 Wed. IPMA does not say on that feed which model it is; IPMA's own pages say it runs AROME (Météo-France) and derives products from ECMWF IFS (see IPMA).
The same feed, earlier runs kept by the data room (the forecast changed under the same stamp):
Evidence (other bodies' models, never merged with IPMA's).
Six models side by side, after the official statement
The official statement first (fact). IPMA's warnings in force or still to come on Wednesday 11 November (IPMA, read 11:26 UTC, 11 Nov) · warnings.json:
- Lisbon district: red rain, 09:00 Wed to 18:00 Wed: "Precipitação forte e persistente."; orange rough sea, 12:00 Wed to 21:00 Wed: "Ondas de sudoeste com 5 a 7 metros e que poderão atingir até 13 metros de altura máxima."; orange wind, 09:00 Wed to 21:00 Wed: "Rajadas até 120 km/h."; yellow rough sea, 21:00 Wed to 03:00 Thu: "Ondas de sudoeste com 4 a 5 metros.".
- Madeira (red and orange only in our file): Madeira north coast: orange wind, 07:33 Wed to 12:00 Wed: "Rajadas até 100 km/h, em esepcial nos extremos leste e oeste."; Madeira south coast: orange wind, 07:33 Wed to 12:00 Wed: "Rajadas até 100 km/h."; Porto Santo: orange wind, 07:33 Wed to 12:00 Wed: "Rajadas até 100 km/h."; Madeira mountains: orange wind, 07:33 Wed to 12:00 Wed: "Rajadas até 130 km/h.".
These warnings are the statement that counts. What follows is not a forecast and not ours.
Evidence. Each row is a model's output, read at Open-Meteo (our sample, as returned, read 02:49 UTC, 11 Nov), for the grid cell nearest each place; attribution: Weather data by Open-Meteo.com, CC BY 4.0. The figure is the highest gust value in that model's series for the hours of 11 November, with its hour. No average is taken and no model is preferred.
A grid cell some 10 to 25 km wide is not a headland or a bridge, and a model's gust for a cell is not what IPMA's warning describes ("the most exposed places"). The models differ from each other. This site is not a warning service and does not forecast: for what to do, IPMA's warnings above and ANEPC.
3. The forecaster's product for pilots (TAF)
Fact. The aerodrome forecast for Lisbon airport, issued 11:00 Wed (NOAA Aviation Weather Center, read 11:26 UTC, 11 Nov): strongest group 74 km/h gusting 102 km/h (40G55 kt, probability 30%), 12:00 Wed to 16:00 Wed. 6 issues kept. A point forecast for one runway, written by a forecaster from the models above: quoted beside IPMA's warning, never instead of it.
TAF LPPT 111100Z 1112/1218 14015KT 4000 RADZ BR SCT004 BKN008 TEMPO 1112/1116 14020G35KT 2000 RA BR SCT002 BKN004 FEW016CB PROB30 TEMPO 1112/1116 14040G55KT 1200 +TSRA SCT015CB BECMG 1116/1118 29012KT 9999 NSW SCT020 TEMPO 1118/1121 29017G27KT TEMPO 1200/1218 4000 SHRA BKN018 FEW020CB BECMG 1200/1202 23013KT
4. The warning (IPMA decides)
Fact. IPMA's weather warnings (avisos meteorológicos) for the Lisbon district (IPMA, read 11:26 UTC, 11 Nov) · warnings.json. Highest level: red.
| Hazard | IPMA's level | From | To | IPMA's words | Sent by IPMA |
|---|
| rough sea | orange | 12:00 Wed | 21:00 Wed | Ondas de sudoeste com 5 a 7 metros e que poderão atingir até 13 metros de altura máxima. | 12:09 Tue |
| rough sea | yellow | 21:00 Wed | 03:00 Thu | Ondas de sudoeste com 4 a 5 metros. | 07:18 Tue |
| rain | red | 09:00 Wed | 18:00 Wed | Precipitação forte e persistente. | 21:23 Tue |
| wind | orange | 09:00 Wed | 21:00 Wed | Rajadas até 120 km/h. | 07:16 Wed |
Which model stands behind a warning? IPMA's weather warnings (avisos meteorológicos): IPMA's page on its warning system gives thresholds, not models. A warning is a forecaster's decision over all of the above; that step is not published as data.
Fact. IPMA's communiqués kept: "Chuva, vento e agitação marítima - Depressão CHARLES - Continente e Madeira - Comunicado nº2" (issued 17:07 Tue); "Depressão BRUNA - Açores - COMUNICADO Nº3" (issued 08:30 Sat) (IPMA communiqués, read 11:26 UTC, 11 Nov) · communiques.json.
Fact. The same warnings as CAP messages through MeteoAlarm: 18 messages for Lisbon kept, sent between 12:58 Thu (2026-11-05) and 07:16 Wed (2026-11-11); 43 more for Madeira and other red areas (MeteoAlarm feed for Portugal, read 11:26 UTC, 11 Nov) · cap.json. The CAP message carries the time IPMA sent it; IPMA's own open data does not, and lagged the CAP feed by two hours or more on 10 November (the data room's finding, in warnings.json → history).
6. What people looked at (sites and apps)
Evidence (incident.weatherwatch@'s reading). On 10 November, IPMA's own local forecast page, Yr and BBC Weather each printed an automatic wind for Lisbon far below the gusts of IPMA's red warning, with no explanation on the page: research/weather-sites. The chain explains why without anyone being wrong: those pages draw layer 2 (a model's mean wind for a grid cell), the warning is layer 4 (a forecaster's decision about the worst gusts in the most exposed places). Which model each site draws, where the site says: IPMA, Yr (MET Norway and NRK), BBC Weather, Windy, Ventusky, MeteoPT.
Not a warning service. For warnings follow IPMA and ANEPC.
