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Nerd mode: every forecast, readouts, filters and range & bearing for weather enthusiasts

This week’s weatherBrest, France

Rain is likely in Brest on Tuesday

Nearly all of NOAA’s 31 GEFS forecasts bring measurable rain to Brest Tue 8 p.m.–2 a.m. CEST; 9 in 10 bring 2.5 mm or more.

NOAA GEFS, 31 forecasts · Mon 28 Sep 18Z run · updated Tues., Sept. 29, 1:03 a.m. CEST · times are Brest’s (CEST)

See it on the globe For warnings, follow your national weather service.

Quick answers

Will it rain in Brest this week?
The best chances of measurable rain: Tuesday (nearly all forecasts, 8 p.m.–2 a.m.); Wednesday (9 in 10 forecasts, 2–8 a.m.). Drier: Fri, Sat, Sun (fewer than 2 in 10 forecasts in any six hours). Times are CEST.
How much rain will Brest get this week?
By Mon., Oct. 5, 8 p.m. CEST (the end of the forecast), the middle forecast has 11 mm of rain and melted snow, counting from Tue 2 a.m. 5 in 10 forecasts bring 13 mm or more in total.
How windy will it get in Brest?
Gusts over 64 km/h: 5 in 10 forecasts at Wed 2 a.m. CEST. The middle forecast’s strongest gust is 64 km/h, Wed 2 a.m. Checked every six hours, so a brief peak can fall between.
How warm or cold will it be in Brest?
At the six-hourly times, the middle forecast runs from 11°C (Fri 8 a.m.) to 23°C (Tue 2 p.m.) CEST. The day’s real high and low can fall between those times.
Are any storms heading for Brest?
No storm Stormlines tracks has 1 in 10 forecasts passing its centre within 160 kilometres of Brest this week.

Chance of rain, six hours at a time

Tue 2–8 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneTue 8 a.m.–2 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneTue 2–8 p.m.: 8 in 10 forecasts with measurable rain; middle forecast 1.2 mmTue 8 p.m.–2 a.m.: nearly all forecasts with measurable rain; middle forecast 5.3 mmWed 2–8 a.m.: 9 in 10 forecasts with measurable rain; middle forecast 1.2 mmWed 8 a.m.–2 p.m.: 3 in 10 forecasts with measurable rain; middle forecast almost noneWed 2–8 p.m.: 7 in 10 forecasts with measurable rain; middle forecast 0.7 mmWed 8 p.m.–2 a.m.: 7 in 10 forecasts with measurable rain; middle forecast 1.0 mmThu 2–8 a.m.: 3 in 10 forecasts with measurable rain; middle forecast almost noneThu 8 a.m.–2 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneThu 2–8 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneThu 8 p.m.–2 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneFri 2–8 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneFri 8 a.m.–2 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneFri 2–8 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneFri 8 p.m.–2 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 2–8 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 8 a.m.–2 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 2–8 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 8 p.m.–2 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 2–8 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 8 a.m.–2 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 2–8 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 8 p.m.–2 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneMon 2–8 a.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneMon 8 a.m.–2 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneMon 2–8 p.m.: 1 in 10 forecasts with measurable rain; middle forecast almost none

Each bar is the share of the 31 forecasts with measurable rain or melted snow in that six hours; the darker the bar, the more forecasts agree. Local days, CEST.

The week, day by day

DayChance of rain2.5 mm or moreTotal by day’s endStrongest gustTemperature
Tue 29nearly all9 in 107.1 mm · 1 in 1058 km/h · 2 in 10 >64 km/h14°C–23°C
Wed 309 in 103 in 1010 mm · 4 in 1064 km/h · 5 in 10 >64 km/h16°C–19°C
Thu 13 in 10<1 in 1011 mm · 4 in 1027 km/h13°C–18°C
Fri 2<1 in 10<1 in 1011 mm · 4 in 1017 km/h11°C–19°C
Sat 3<1 in 10<1 in 1011 mm · 4 in 1031 km/h12°C–20°C
Sun 4<1 in 10<1 in 1011 mm · 4 in 1034 km/h13°C–20°C
Mon 5 (part)1 in 101 in 1011 mm · 5 in 1035 km/h14°C–21°C

Chances are the highest in any six hours of the day. “Total by day’s end” is the middle forecast’s running total since Tue 2 a.m., and the share of forecasts with 13 mm or more by then; totals aren’t added up day by day, because the middle forecast of each day isn’t the same forecast. Gusts and temperatures are read every six hours.

Storms near Brest

No storm Stormlines tracks has 1 in 10 forecasts passing its centre near Brest this week. Every storm we’re tracking →

About these numbers

They come from one source, NOAA’s Global Ensemble Forecast System (GEFS): 31 runs of the same model, each started slightly differently, read at Brest’s coordinates on a grid about 55 km (35 miles) apart. “8 in 10 forecasts” means 8 in 10 of those runs. Nothing is adjusted for local effects such as coasts, lakes, hills or city heat, so the numbers can differ from your local official forecast, especially for snow and showers.

“Measurable rain” counts rain or melted snow in a six-hour period. Not an official forecast: follow your national weather service for warnings and decisions. How the forecasts are read: how to read the maps and the glossary.

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