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

This week’s weatherPortland, OR

Little or no rain in the forecasts for Portland this week

Fewer than 3 in 10 of NOAA’s 31 GEFS forecasts bring measurable rain in any six hours through Mon., Oct. 5.

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

See it on the globe Official National Weather Service forecast

Quick answers

Will it rain in Portland this week?
Probably not much: in no six-hour period do 3 in 10 forecasts bring measurable rain. Times are PDT.
How much rain will Portland get this week?
By Mon., Oct. 5, 11 a.m. PDT (the end of the forecast), the middle forecast has 0.04 in of rain and melted snow, counting from Mon 5 p.m. Fewer than 1 in 10 forecasts bring 0.5 in in total.
How windy will it get in Portland?
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 13 mph, Sat 5 p.m. Checked every six hours, so a brief peak can fall between.
How warm or cold will it be in Portland?
At the six-hourly times, the middle forecast runs from 52°F (Thu 5 a.m.) to 78°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 Portland?
No storm Stormlines tracks has 1 in 10 forecasts passing its centre within 100 miles of Portland 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.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneTue 5–11 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneTue 11 a.m.–5 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneTue 5–11 p.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneTue 11 p.m.–5 a.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneWed 5–11 a.m.: fewer than 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.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneWed 11 p.m.–5 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneThu 5–11 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneThu 11 a.m.–5 p.m.: 1 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.: 1 in 10 forecasts with measurable rain; middle forecast almost noneFri 5–11 a.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneFri 11 a.m.–5 p.m.: 1 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 105 mph53°F–67°F
Tue 292 in 10<1 in 10almost none · <1 in 109 mph53°F–63°F
Wed 302 in 10<1 in 100.02 in · <1 in 106 mph55°F–68°F
Thu 11 in 10<1 in 100.02 in · <1 in 104 mph52°F–71°F
Fri 21 in 10<1 in 100.04 in · <1 in 107 mph55°F–71°F
Sat 3<1 in 10<1 in 100.04 in · <1 in 1013 mph52°F–76°F
Sun 4<1 in 10<1 in 100.04 in · <1 in 107 mph55°F–78°F
Mon 5 (part)<1 in 10<1 in 100.04 in · <1 in 104 mph55°F–66°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 Portland

No storm Stormlines tracks has 1 in 10 forecasts passing its centre near Portland 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 Portland’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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