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

This week’s weatherSeattle, WA

Rain is likely in Seattle on Tuesday

Nearly all of NOAA’s 31 GEFS forecasts bring measurable rain to Seattle Mon 11 p.m.–5 a.m. PDT; 6 in 10 bring a tenth of an inch or more Tue 5–11 a.m.

NOAA GEFS, 31 forecasts · Mon 28 Sep 18Z run · updated Mon., Sept. 28, 4:03 p.m. PDT · times are Seattle’s (PDT)

See it on the globe Official National Weather Service forecast

Quick answers

Will it rain in Seattle this week?
The best chances of measurable rain: Tuesday (nearly all forecasts, 11 p.m.–5 a.m.); Wednesday (4 in 10 forecasts, 11 p.m.–5 a.m.). Drier: Thu, Fri, Sat, Sun (fewer than 2 in 10 forecasts in any six hours). Times are PDT.
How much rain will Seattle get this week?
By Mon., Oct. 5, 11 a.m. PDT (the end of the forecast), the middle forecast has 0.39 in of rain and melted snow, counting from Mon 5 p.m. 3 in 10 forecasts bring 0.5 in or more in total.
How windy will it get in Seattle?
No strong gusts: fewer than 1 in 10 forecasts have gusts over 30 mph at any of the six-hourly times. The middle forecast’s strongest gust is 27 mph, Tue 5 a.m. Checked every six hours, so a brief peak can fall between.
How warm or cold will it be in Seattle?
At the six-hourly times, the middle forecast runs from 48°F (Sat 5 a.m.) to 69°F (Sun., Oct. 4, 5 p.m.) PDT. The day’s real high and low can fall between those times.
Are any storms heading for Seattle?
No storm Stormlines tracks has 1 in 10 forecasts passing its centre within 100 miles of Seattle this week.

Chance of rain, six hours at a time

Mon 5–11 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneMon 11 p.m.–5 a.m.: nearly all forecasts with measurable rain; middle forecast 0.03 inTue 5–11 a.m.: nearly all forecasts with measurable rain; middle forecast 0.11 inTue 11 a.m.–5 p.m.: nearly all forecasts with measurable rain; middle forecast 0.09 inTue 5–11 p.m.: 8 in 10 forecasts with measurable rain; middle forecast 0.04 inTue 11 p.m.–5 a.m.: 4 in 10 forecasts with measurable rain; middle forecast almost noneWed 5–11 a.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneWed 11 a.m.–5 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneWed 5–11 p.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneWed 11 p.m.–5 a.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneThu 5–11 a.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneThu 11 a.m.–5 p.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneThu 5–11 p.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneThu 11 p.m.–5 a.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneFri 5–11 a.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneFri 11 a.m.–5 p.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneFri 5–11 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneFri 11 p.m.–5 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 5–11 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 11 a.m.–5 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 5–11 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSat 11 p.m.–5 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 5–11 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 11 a.m.–5 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 5–11 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 11 p.m.–5 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneMon 5–11 a.m.: fewer than 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, PDT.

The week, day by day

DayChance of rainA tenth of an inch or moreTotal by day’s endStrongest gustTemperature
Mon 28 (rest of day)<1 in 10<1 in 10almost none · <1 in 1024 mph57°F–64°F
Tue 29nearly all6 in 100.26 in · 1 in 1027 mph54°F–58°F
Wed 304 in 10<1 in 100.33 in · 1 in 108 mph51°F–61°F
Thu 12 in 101 in 100.38 in · 2 in 108 mph49°F–61°F
Fri 22 in 10<1 in 100.39 in · 3 in 106 mph51°F–64°F
Sat 3<1 in 10<1 in 100.39 in · 3 in 1014 mph48°F–65°F
Sun 4<1 in 10<1 in 100.39 in · 3 in 109 mph51°F–69°F
Mon 5 (part)<1 in 10<1 in 100.39 in · 3 in 106 mph52°F–64°F

Chances are the highest in any six hours of the day. “Total by day’s end” is the middle forecast’s running total since Mon 5 p.m., and the share of forecasts with 0.5 in 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 Seattle

No storm Stormlines tracks has 1 in 10 forecasts passing its centre near Seattle 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 Seattle’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: see the National Weather Service forecast for warnings and decisions. How the forecasts are read: how to read the maps and the glossary.

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