Cuilo fire, 31 July 2026 –
- Burned area
- 12,668ha
- VIIRS hotspots in the film
- 276
- Passes with fire
- 18
- Highest FRP of a hotspot
- 338MW
Fire front film
How it spread, pass by pass, and what the wind was doing
Each dot is a hotspot the satellite detected as it flew over. The hourly wind flows underneath.
Upper-level wind (850 and 700 hPa) is only available for fires from the last two weeks: the ERA5 archive we use has no pressure levels.
| Pass (local time) | Satellite | Hotspots | Total FRP | Spread | Heading | ERA5 wind between passes | Front and wind |
|---|---|---|---|---|---|---|---|
| Fri 31 Jul · 13:49 | Suomi NPP | 12 | 76 MW | start | — | — | — |
| Sat 1 Aug · 00:52 | Suomi NPP | 8 | 55 MW | 2.0 km | NNW 348° | from ESE at 4 km/h | crosswind (61°) |
| Sat 1 Aug · 13:27 | Suomi NPP | 18 | 122 MW | 2.4 km | S 185° | from SE at 6 km/h | against (139°) |
| Mon 3 Aug · 13:10 | NOAA-20 | 9 | 138 MW | 5.0 km | E 85° | from ESE at 6 km/h | against (146°) |
| Tue 4 Aug · 12:51 | NOAA-20 | 1 | 12 MW | 0.7 km | no clear spread | — | — |
| Wed 5 Aug · 13:53 | Suomi NPP | 12 | 516 MW | 5.2 km | ESE 111° | from ESE at 4 km/h | against (174°) |
| Thu 6 Aug · 13:36 | Suomi NPP | 2 | 12 MW | 0.8 km | no clear spread | — | — |
| Fri 7 Aug · 13:17 | Suomi NPP | 63 | 2,013 MW | 4.7 km | SSE 167° | from SE at 7 km/h | against (145°) |
| Sat 8 Aug · 12:57 | Suomi NPP | 11 | 79 MW | 1.8 km | W 266° | from SE at 4 km/h | with the wind (38°) |
| Mon 10 Aug · 13:59 | Suomi NPP | 11 | 231 MW | 2.8 km | SE 130° | from E at 4 km/h | against (150°) |
| Tue 11 Aug · 01:05 | Suomi NPP | 8 | 51 MW | 1.2 km | ENE 73° | from NE at 3 km/h | against (158°) |
| Tue 11 Aug · 13:42 | Suomi NPP | 16 | 567 MW | 1.0 km | no clear spread | — | — |
| Wed 12 Aug · 00:46 | Suomi NPP | 1 | 1 MW | 7.6 km | no clear spread | — | — |
| Wed 12 Aug · 13:21 | Suomi NPP | 47 | 458 MW | 3.7 km | SSE 163° | from SE at 8 km/h | against (161°) |
| Thu 13 Aug · 13:04 | Suomi NPP | 47 | 1,675 MW | 3.7 km | SSE 149° | from ESE at 7 km/h | against (143°) |
| Fri 14 Aug · 12:47 | Suomi NPP | 5 | 224 MW | 1.6 km | no clear spread | — | — |
| Sat 15 Aug · 14:06 | Suomi NPP | 4 | 60 MW | 3.8 km | no clear spread | — | — |
| Sun 16 Aug · 13:49 | Suomi NPP | 1 | 19 MW | 2.8 km | no clear spread | — | — |
How it is calculated (for anyone who wants to check)
Pass: the hotspots from one satellite with less than 20 minutes between them. Spread: the distance from each new hotspot to the nearest earlier hotspot; we take the 90th percentile so a single stray hotspot cannot inflate the figure, and we only count the pass if at least 5 hotspots fall more than 750 m from what had already been seen (those more than 15 km away are another fire and do not count). Speed: the spread divided by the hours since the previous pass, only if 6 hours or more have gone by; it is a minimum, because the front may have moved faster and then stopped. Wind: the vector mean of the hours between the two passes, interpolated between the model grid points around the hotspots that moved. “With the wind” if the heading of the spread and the direction the wind blows towards differ by less than 60°, “crosswind” up to 120° and “against” beyond that.
Cuilo fire, 31 July 2026 Wildfires in Angola worldfires methodology