Mt Hood · Aug 28-30 · -3 days out Updated Mon Aug 31, 5:00 AM · refreshes daily at 5am

Everything is fine.

9 in 10chance the weekend is fine - clear or lightly hazy

First, a flag on the dates: today is August 31 and the trip window was August 28 through 30, so this is a look back, not a look ahead — the answer is already sitting in the monitor archive. Everything in the packet points to easy air over that weekend: the big fire east of Mt Hood was 83% wrapped up and sits behind the mountain anyway, the winds were light and coming off the ocean rather than off the fires, rain was arriving Tuesday, and the monitor 8.7 miles from the house reads 14 today, solidly in the 'Good' range with no smoke alerts, no closures, and no evacuation zone touching Welches.

The one real hazard was the Austin fire, about 18 miles south at zero containment and on the same side of the crest as the house, which under a southerly night breeze could have put one hazy day on the board — but nothing in the record suggests it did.

Known now5 of 5 forecast sources already cover your dates

No horizonFire size and containment are observations, not forecasts — they can move this on any day

Decide byAug 26

What would change this

Evacuation zone at the housenone
US-26 open, Portland to Welchesopen
Air at Multorpor14 · Clear
Nearest fire outside 10 miles13.9 mi · The Narrows
Wind pushing smoke our wayno - SSE at 3 mph

So what are the odds?

If we ran this weekend 100 times, here is how they would split. Hover a row to pick it out of the dots.

7 in 1072%	Clear weekend AQI 0-50 Blue sky over the Salmon River valley, Mt Hood sharp-edged all three days, maybe a thin milky layer at the horizon in the afternoon. Nobody mentions smoke.	nothing
2 in 1021%	Hazy but fine AQI 50-100 Flat white light, the ridgelines toward Government Camp softened, a faint campfire smell in the morning that burns off by noon. Fine for hiking; kids and anyone with asthma take it easy in the afternoon.	Austin fire (18 mi S, 0% contained) or The Narrows puts up a smoke column and light southerly drainage flow settles it in the valley overnight.
1 in 106%	One smoky day AQI 100-150 Sun is an orange disc, you can taste it, the far side of the golf course goes gray. One day of indoor plans; the other two days recover.	Austin makes a wind-driven run under a thermal trough with sustained S/SSE flow up the Sandy and Salmon drainages, plus an inversion that traps it overnight.
0 in 102%	Real smoke episode AQI 150+ Visibility under a mile, headlights on US-26 midday, ash on the car. The trip is effectively indoors.	A new ignition west of the crest within ~20 miles during the lead time, or a multi-day east-wind event pushing Grasshopper's residual smoke over the Cascade gaps and down the west slope.

Clear AQI 0-50

You can see the mountain. Nobody notices anything.

Hazy AQI 50-100

Visible haze, ridgelines soften, faint campfire smell.

Smoky AQI 100-150

Distinctly smoky, orange sun, eyes sting a little.

Bad AQI over 150

Mountain invisible. You smell it indoors.

Where the fires are

Fires near the house, drawn at their real shape from the federal perimeter data, over USGS terrain. Dashed rings are distance from the house; the shaded wedge is the only direction an east wind could carry smoke here from. Point at a fire for its details.

Solid dots are fires too small to draw at this scale but whose size is known. A dashed circle would mean a fire that has been located but has no published perimeter - size unknown, not small.

Beyond this frame, and too far to threaten the house but close enough to add regional haze: Bench (67,071 acres, 45.5 mi SSE), Ten Mile (4,834 acres, 56.7 mi SE), High Lava (2,894 acres, 37.0 mi N), Beachcomb (2,346 acres, 49.5 mi SSE).

An outline is only as current as the last mapping flight, which is not the same as when this page refreshed. Outlines flown — Grasshopper Aug 30 · Austin Aug 30 · The Narrows Aug 30. The oldest is Austin, 0 days behind. Acreage and containment are refreshed far more often than the outlines are re-flown — those figures were last updated Aug 31, 4:01 AM, so a fire may already be larger than the shape drawn for it.

Terrain: USGS 3DEP (public domain). Roads and water: © OpenStreetMap contributors (ODbL). Fire perimeters: NIFC.

Want to check it yourself, or see the rest of the state? The Oregonian's wildfire tracker is live and updates every 15 minutes.

Day by day

Fri Aug 28

Clear

likely 26 - could reach 62

5% chance of a smoky day

Sat Aug 29

Clear

likely 28 - could reach 58

4% chance of a smoky day

Sun Aug 30

Clear

likely 23 - could reach 55

4% chance of a smoky day

The specific odds

All three days clear72%

At least one smoky day (100+)7%

Two or more smoky days3%

At least one bad day (150+)2%

US-26 closed during the trip1%

Evacuation level at Welches2%

The one thing that would bring smoke here

Long-range wind signal unavailable this run.

When we'll actually know more

It is not one cut-off. Five sources arrive on five different dates, and the darker the strip, the more of them cover your weekend. Hover any day for the count.

Hover a dayto see the forecast we logged that morning and how much was known.

▼ Since 2026-08-10 the forecast has moved better (-11 on the likely worst day) across 22 daily updates. Shading above shows source coverage, not this movement - hover a past day to see what we said that morning.

now	Fire size & containment how big the fires are and whether they are being held
now	Long-range ensembles (GEFS 0.5 + GEM) wind direction, 52 members · reaches 32 days out
now	ECMWF ensemble (51 members) wind direction, the sharpest ensemble · reaches 13 days out
now	Deterministic weather (16-day) day-by-day wind and temperature · reaches 15 days out
now	Air-quality / smoke model (CAMS) actual AQI at the house · reaches 6 days out

Why we think this

Start with the geometry, because it does most of the work: the one genuinely large fire, Grasshopper at 93,961 acres, is 17 miles east with an 11,250-ft volcano between it and the house AND is 83% contained, so it needs a sustained east-wind event through the Cascade gaps to matter — and the actual wind forecast shows light westerly/WNW flow with rain arriving. The fires that are NOT shielded are the west-side ones — Austin at 18.4 mi S and 0% containment, and The Narrows at 13.9 mi SSW — and those are the real mechanism here; but at 11,682 and 301 acres they are an order of magnitude too small to load a 24-hour average at 14-18 miles unless a night inversion concentrates the plume in the Salmon River valley, which requires the stable, stagnant, southerly-drainage setup rather than the ventilated onshore one the packet describes. The east-wind ensemble field is null, so I have no departure signal to weigh — I fall back on the 31% climatological offshore rate and on the observed synoptic pattern, which argues against reversal. On calibration: the anchor is a median daily max of 12, I multiply by the locally measured season ratio of 2.0 for 24, and I refuse to stack a second 'record year' factor on top because the packet explicitly says that ratio already contains 2026's severity as it manifested here; the statewide 2.34-million-acre number is dominated by east-side fires that do not transport to this address.

A normal late August here is Clear - median AQI 12 across the last 4 years. On these exact dates: 2025: 16 · 2024: 10 · 2023: 11 · 2022: 11.

We are forecasting a worst day of 31, 19 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.

What the bad version needs:
The Austin fire (11,682 acres, 0% contained, 18.4 mi due south and on the WEST side of the crest, so Mt Hood shields nothing) gets an afternoon of low humidity and wind and makes a run. → Overnight the valley goes stable and drainage flow turns S/SSE — exactly the direction the packet shows for tonight — carrying the plume down the Clackamas and into the Sandy/Salmon River corridor. → The smoke pools under an inversion at Welches through the night and does not mix out until late morning, so the 24-hour average — not just a smoky hour — clears 100.
First visible signal: The Multorpor / Government Camp sensor on the AirNow or PurpleAir map climbing out of the teens into the 60s-80s between about 10pm and 6am, paired with a woodsmoke smell at dawn near the river. The overnight climb is the tell — a daytime bump alone usually washes out of the 24-hour number. - about 1 days ahead

Key drivers, and what would change our minds

Grasshopper, the only large nearby fire, is 83% contained AND behind Mt Hood — it needs a sustained east-wind event to reach the house, and the forecast shows onshore flow instead
Austin (18 mi S, 0% contained) and The Narrows (14 mi SSW) are on the SAME side of the crest — no terrain shielding — but both are far too small to load a 24-hour average without an overnight valley inversion
Observed PM2.5 at the monitor 8.7 miles away is 14 (Good) right now, with no NWS alerts and no evacuation zone touching the house
Light rain likely Tuesday with W/WNW flow — a ventilating, season-softening pattern rather than a smoke-trapping one
Season anomaly ratio of 2.0, measured locally, is the entire multiplier I apply — nothing further stacked on top
Climatology archive starts in 2022 and excludes 2017/2018/2020/2021, so the 0% historical exceedance rate is an under-sampled tail, not a measured zero

The Multorpor sensor on the AirNow app reading above 60 at 5am — an overnight number, not an afternoon one, is what shows the valley is trapping smoke
A new fire appearing on the InciWeb or Watch Duty map WEST or SOUTHWEST of Welches, closer than about 20 miles
A weather app showing east or southeast wind at the house for two days running instead of the westerly flow currently forecast
The Austin fire's acreage jumping on consecutive daily updates while containment stays at 0%
Any evacuation level posted for the Welches-Rhododendron area, or a TripCheck closure on US-26 east of Sandy
You can no longer see Mt Hood clearly from the deck in the morning — the simplest check there is

Fires within 60 miles

13.9 mi	The Narrows SSW	301 acres · 11% contained
17.4 mi	Grasshopper E	93,961 acres · 83% contained
18.4 mi	Austin S	11,682 acres · 0% contained
37.0 mi	High Lava N	2,894 acres · 30% contained
45.5 mi	Bench SSE	67,071 acres · 90% contained
48.8 mi	Section 12 SW	size not yet reported
49.5 mi	Beachcomb SSE	2,346 acres · 100% contained

The biggest hole in this forecast: 1 of the nearby fires (Section 12) have no size reported yet. Whether those are 300-acre creepers or 20,000-acre runners is most of the answer.

Pack this regardless

A box of N95 or KN95 respirators — one per person, plus spares; bandanas and surgical masks do nothing for PM2.5
One or two portable HEPA air purifiers sized for the main room, or the materials for a box-fan-plus-MERV-13-filter build (~$40 at any hardware store in Sandy)
Inhalers, allergy meds, and eye drops for anyone with asthma, COPD, or a heart condition — and make sure the group knows who those people are
A rain layer and a warm layer: the same fronts that clear smoke bring 45-degree wet mornings on the west slope in early September
A downloaded offline map plus one printed alternate route out (Lolo Pass Rd / OR-35 or west to Sandy) in case US-26 is restricted
An indoor plan the group would actually enjoy — cards, a projector, a cooking night — so a hazy day is a change of plan and not a ruined trip

If the weekend is clean you carried masks for nothing. If it is not, this is the difference between a bad weekend and a ruined one.

Watch list, and getting there

PM2.5 at the Multorpor / Government Camp monitor, 8.7 mi from the house — and specifically the overnight hours - Any overnight hour above 60, or a 24-hour value above 75, means the valley is trapping smoke — move plans indoors for the next day. (fire.airnow.gov (or the AirNow app; PurpleAir map as a backup for finer spacing))
Austin fire acreage and containment — the one uncontained fire on the house's side of the crest - Acreage growing more than ~50% in a day while containment stays at 0%, or any new evacuation level published for the Clackamas corridor. (inciweb.wildfire.gov and the Oregon Smoke Information blog (oregonsmoke.blogspot.com))
Evacuation levels for Clackamas County / Welches - Level 1 (BE READY) posted anywhere in the Welches-Rhododendron area — that is the point to shorten the trip, not to wait. (clackamas.us or the Clackamas County Sheriff / RapidSOS evacuation map)
US-26 status between Sandy and Welches - Any closure or pilot-car control on US-26 east of Sandy. (TripCheck.com (ODOT))
Wind direction at the house - Two or more consecutive days forecast with sustained E or SSE wind — that is the pattern that both carries Grasshopper smoke over the gaps and pulls Austin's plume north. (weather.gov point forecast for 45.32, -121.96, or any phone weather app's wind field)

Sandy	19.4 mi
Brightwood	15.5 mi
Welches	14.8 mi

Distance from each point on the drive in to the nearest fire. TripCheck is the authority on closures.

If we wanted cleaner air, where would we go?

Ranked by how bad these dates have historically been at each place. The coast is not just cleaner today — it sits upwind of everything burning, so it only smokes during an east-wind reversal, which is the same event that would smoke out the house.

“Bad day / typical” is what the air actually did on Aug 26 – Sep 1 in 2022, 2023, 2024 and 2025 — 28 days per place. The first number is the bad day: one day in ten was worse than this. The second is the typical day, the middle of the range. We rank on the bad day rather than the typical one, because the bad day is what would spoil a weekend.

Both are converted onto the same scale as the “now” column, so every AQI figure in this table is comparable. That conversion matters more than it sounds: the model these come from runs about 2.5× high on the coast but close to true inland, so before correcting it the coast looked far worse than it is.

Place	Bad day / typical	Now	Official forecast	Next 5 days	Nearest fire
Newport coast	20 / 16	18 Clear	Good	– steady	101 mi · Austin
Cannon Beach coast	23 / 20	26 Clear	—	– steady	88 mi · High Lava
Manzanita coast	23 / 21	26 Clear	—	– steady	87 mi · High Lava
Pacific City coast	23 / 21	26 Clear	—	– steady	91 mi · The Narrows
Welches / Mt Hood booked	25 / 18	59 Hazy	Good	– steady	14 mi · The Narrows
Hood River east of crest	28 / 18	26 Clear	Good	– steady	21 mi · Grasshopper
Astoria coast	29 / 26	24 Clear	Good	– steady	84 mi · High Lava
Long Beach, WA coast	30 / 26	24 Clear	Good	– steady	97 mi · High Lava
Silver Falls valley	42 / 31	24 Clear	—	– steady	31 mi · Austin
Portland valley	46 / 37	51 Hazy	Good	– steady	36 mi · High Lava
McMinnville valley	48 / 34	33 Clear	Good	▼ clearing	54 mi · The Narrows
Bend east of crest	90 / 53	122 Smoky	—	– steady	22 mi · Akawa Butte

What each column covers, and where it comes from

Field	Period it covers	What it is
Air right now	08/31/26 4:00 PDT	Nearest EPA/AirNow ground monitor to each place, within 45 miles airnow.gov
Official forecast	issued 08/31/26 by Washington Department of Ecology	Next published outlook for that reporting area — a human forecaster's call Oregon DEQ via AirNow
Next 5 days	today's model run, covering 2026-09-04	Direction only. Copernicus CAMS global air-quality model open-meteo.com
Bad day / typical	Aug 26 – Sep 1 in 2022, 2023, 2024, 2025 (28 days each)	CAMS reanalysis for those exact dates, then converted to the monitor scale open-meteo.com
Scale conversion	median of 14 daily model-vs-monitor pairs, 2026-08-16 to 2026-08-29	Median of daily model-vs-monitor ratios — the bias differs by place, from 0.362 on the coast to 0.799 inland AirNow daily archive
Nearest fire	queried Aug 31 5:00 AM	Perimeter polygons of fires over 100 acres, distance to the burned edge NIFC WFIGS

Every AQI figure above is on the ground-monitor scale — the same thing your phone shows. n/a means the model and the monitors disagree so sharply at that spot that we cannot honestly place it on that scale (steep terrain inside a coarse model grid cell — the Gorge is the usual culprit); those rows are sorted by today’s reading instead.

How this is made, and what it cannot do

Fire perimeters from NIFC, evacuation zones from Oregon OEM, weather and alerts from NWS, air quality from AirNow (Multorpor, 8.7 mi away). The forecast is judged by Claude Opus 5 on the live data above, sampled 5 times and pooled conservatively.

It is a judgement, never scored against an outcome. Nobody forecasts smoke this far out: NOAA's smoke model runs 48 hours and the EPA's air-quality forecast is for tomorrow. Two-to-six weeks ahead is what meteorologists call the predictability desert. Anyone giving you a number for the trip right now - us included - is giving you a base rate with a story attached.

How thin the history is. The air-quality record for this spot begins in 2022, so "normal" here is built from just 4 years (2022, 2023, 2024, 2025). In those 28 sampled days the worst single day was AQI 22, and none reached 100.

That record has never seen a bad Oregon smoke year — not 2020, when Portland sat above AQI 500 for days, nor 2017, 2018 or 2021. So the base rate below is drawn entirely from calm years, and the upper end of our range is an estimate rather than something history has shown us. It is the main reason not to read the good news too confidently.

Are these forecasts any good? Across 80 scored forecast-days, the air-quality model beat both simple baselines at 1 of 5 lead times. Where it does not, this page should not be trusted to out-guess them either.

AQI here means the highest 24-hour PM2.5 value touching a day, at the house, on the local monitor scale - the same thing your phone shows. The model's own restatement of the target: “I am forecasting the US EPA AQI for PM2.5 — a 24-hour-average quantity — at the house at 45.320, -121.956 in Welches, Oregon. For each calendar day I give the highest 24-hour AQI value touching that day, and the trip's worst-day figure is the maximum of those three daily values, not their average. All numbers are on the local monitor scale, i.e. what a phone app at the Multorpor station would display, using the calibration already supplied in the pack (factor 0.2); I have applied no additional bias correction of my own. One flag on the inputs: the trip dates are 2026-08-28 through 2026-08-30 and today is 2026-08-31, so days_until_trip is -3 — this window has already closed, and these figures are a reconstruction of days that have passed rather than a forecast of days ahead. The group should simply look up the Multorpor monitor's history for those three dates, which will beat any estimate I can give.”

Updated daily at 5am. A convenience, not an authority -
if officials issue an evacuation order, follow it.