NOAA’s National Weather Service issues a separate marine forecast for every coastal zone in the United States, four times a day. For Pacific Northwest cruisers the relevant products are: PZZ150-series for Puget Sound and the Strait of Juan de Fuca, PZZ100-series for the Washington and Oregon coastal waters, and PZZ200-series for the offshore waters out to 60 nautical miles. Each is a separate forecast for a separate water body. Reading the wrong one is the most common mistake.
This article explains what the marine forecast says, in working terms — the wind speed scale, the sea-state scale, the way fog gets predicted, and the difference between small craft advisory and gale warning. The PNW-specific patterns (Juneuary, summer fog, the autumn storm track, wind against current) are at the end.
The forecast you read
NOAA marine forecasts come in two formats: the technical text product issued for VHF broadcast and the prose forecast issued for the web. Both contain the same information; the prose is easier on the eye.
A typical Puget Sound forecast looks like this:
Coastal Waters Forecast for Puget Sound and Hood Canal — PZZ135
Issued by Seattle WFO at 1015 PDT Sat May 15 2026
SYNOPSIS:
Surface high pressure over the eastern Pacific will continue
to support a weak onshore flow through Sunday before a cold
front approaches the Washington coast Monday afternoon.
PUGET SOUND, NORTH OF ADMIRALTY INLET:
Tonight: West winds 10 to 15 kt becoming variable 5 kt or less
after midnight. Waves 2 ft or less. Patchy fog after midnight.
Sunday: Northwest winds 5 to 10 kt becoming west 10 to 15 kt
in the afternoon. Waves 1 to 2 ft.
Sunday Night: West winds 5 to 10 kt. Waves 1 ft or less.
Monday: South winds 10 to 15 kt becoming southwest 15 to 20 kt
with gusts to 25 kt by afternoon. Waves 2 to 3 ft.The header tells you which zone, which forecast office, when issued. The synopsis tells you what’s driving the weather (a high pressure system or a frontal passage). The detailed forecast tells you wind direction, wind speed, sea state, and any special phenomena (fog, thunderstorms, freezing spray) for each six-hour period.
Read the synopsis first. The detail is governed by the synopsis; understanding what’s coming through gives you the trajectory, not just the snapshot.
Wind
Wind in marine forecasts is described by direction it comes from (a west wind blows from the west toward the east) and sustained speed in knots.
The Beaufort-derived descriptive scale most NOAA forecasts use:
| Description | Knots |
|---|---|
| Calm | 0–1 |
| Light | 1–6 |
| Moderate | 7–15 |
| Fresh | 16–25 |
| Strong | 26–33 |
| Gale | 34–47 |
| Storm | 48–63 |
| Hurricane | 64+ |
A forecast of “15 knots gusting to 25” means a sustained wind of 15 knots with peaks up to 25 in the gust. Recreational sailors plan for the gust, not the average — “15 gusting 25” is a different sea state from “15 sustained, no gusts.”
For PNW cruising, the practical thresholds:
- Under 15 knots: comfortable sailing in any well-found cruising boat
- 15–25 knots: active sailing; reefs in mainsail, smaller jib
- 25–35 knots: small craft advisory range; experienced crews only; boats under 30 feet should be in shelter
- Above 35 knots: gale; recreational boats stay in
- Above 48 knots: storm; shelter and ride it out
Sea state
Wave heights in NOAA forecasts are reported in feet, measured from trough to crest. Two types of waves matter:
- Sea — waves generated by local wind, with short periods (3–7 seconds) and steep faces
- Swell — long-period waves (10+ seconds) propagated from distant systems, smoother and more predictable
A typical PNW summer day on Puget Sound has a 1- to 2-foot wind sea on top of a near-zero swell. A typical late-autumn day on the outer Washington coast has a 4-foot wind sea on top of a 10-foot Pacific swell. Both are in the forecast; both matter.
The descriptive scale:
| Description | Height (ft) |
|---|---|
| Calm / glassy | < 1 |
| Smooth | 1–3 |
| Moderate | 3–5 |
| Rough | 5–8 |
| Very rough | 8–13 |
| High | 13–20 |
| Very high | 20+ |
A 4-foot sea is a comfortable day in a 35-foot cruising sailboat. A 4-foot sea on a 6-second period in 25 knots of wind is uncomfortable and tiring. The same 4-foot sea on a 12-second period in 10 knots is comfortable. Sea state is wave height and period together; the height alone is insufficient.
Wind against current
The single most dangerous condition in the PNW is not strong wind. It is strong wind opposing strong current.
Wave height roughly doubles when wind blows against current. Wave period shortens, which means waves break rather than roll. A 15-knot southerly against a 3-knot ebb in Rosario Strait produces 4-foot short-period chop in less than an hour — uncomfortable in a 35-foot cruising boat, dangerous in anything smaller.
Always check both the wind forecast and the current prediction for the same time window. In the PNW the same 15 knots is two completely different sea states depending on its relationship to current. See Tides and Currents in the Pacific Northwest for the current side of the planning.
Visibility and fog
NOAA’s visibility scale:
| Description | Range |
|---|---|
| Excellent | 5+ nm |
| Good | 2–5 nm |
| Moderate | 1–2 nm |
| Poor | 0.5–1 nm |
| Very poor | < 0.5 nm (fog) |
PNW fog falls into three categories:
Advection fog — warm moist air moving over cold water. The dominant summer pattern. Forms in the Strait of Juan de Fuca and pushes east into Puget Sound on the morning land breeze. Burns off by mid-morning on most days.
Radiation fog — clear nights cool the land and adjacent water surface. Common in autumn. Disperses with the morning sun, sometimes lingers in protected coves until noon.
Frontal fog — forms along the boundary of an approaching warm front; persistent and thick. Less common in the PNW than the first two, but the most dangerous because it doesn’t burn off on schedule.
When the forecast says “patchy fog,” assume there will be fog and plan accordingly. Radar is not optional in a cruise that might encounter fog; see Marine Safety Equipment.
Warnings and advisories
NOAA issues four levels of marine warning:
- Small Craft Advisory: sustained winds 21–33 knots, or seas 6–9 feet that could be hazardous to recreational boats. Posted typically 12–24 hours in advance.
- Gale Warning: winds 34–47 knots expected.
- Storm Warning: winds 48–63 knots expected.
- Hurricane Warning: winds above 64 knots expected.
The PNW gets several Small Craft Advisories per month in winter, a handful per summer. Gale warnings are routine in the autumn storm track (October–March on the outer coast); rarer in summer. Storm warnings are uncommon — when they happen, they are the result of a deep low-pressure system tracking close to the coast. Hurricane warnings do not happen in the PNW.
A vessel under 33 feet should not depart in a Small Craft Advisory unless the skipper is experienced, the boat is well-found, and there is good shelter on the planned route. “Small craft” is the regulatory definition: under 33 feet of length. The advisory does not legally close the water — it warns recreational operators that the wind has crossed a threshold above which conditions are likely to be uncomfortable to dangerous.
NOAA Weather Radio
NOAA broadcasts continuous marine weather on dedicated VHF frequencies:
| Channel | Frequency | Coverage |
|---|---|---|
| WX-1 | 162.400 MHz | Outer coast Washington/Oregon |
| WX-2 | 162.425 MHz | Northern California |
| WX-3 | 162.450 MHz | Puget Sound, Strait of Juan de Fuca |
| WX-4 | 162.475 MHz | Columbia River, southern Washington coast |
| WX-5 | 162.500 MHz | Southern Puget Sound, Hood Canal |
Most modern VHF radios have a dedicated WX button that scans for the strongest local signal. Leave a weather radio running at the helm during any extended cruise; the broadcast updates every six hours.
The PNW patterns worth knowing
Juneuary. Persistent overcast and drizzle in early to mid-June. The marine layer holds; afternoon clearing happens later than in May. Settled summer weather usually arrives around July 4. Plan early-summer cruises with the expectation of grey rather than sun.
Summer fog. From mid-July through August, advection fog forms most mornings in the Strait of Juan de Fuca and pushes into the San Juans and northern Puget Sound. Forecast as “patchy fog after midnight, lifting by 1000.” Plan early starts to coincide with the fog burn-off window.
Autumn storm track. Starting late September, frontal systems begin tracking through the PNW on a weekly cadence. Strong southerly winds (40+ knots) on the outer coast become normal by mid-October. The Strait of Juan de Fuca and Strait of Georgia get the brunt of the wind; Puget Sound is somewhat sheltered but still exposed to fronts.
Williwaws. Cool air drains down the surrounding mountains in cool nights and accelerates over the water as a katabatic gust. Hood Canal, the Desolation Sound mainland inlets, and the BC fjords are williwaw country. Williwaws are not in the broad-area forecast — they are a microclimate effect. Plan accordingly when anchoring in a steep-sided fjord.
Pre-departure forecast process
The disciplined cruiser’s pre-departure forecast check, in order:
The night before: read the latest synopsis. Identify any incoming systems — fronts, lows, ridges. Check the extended forecast for the cruise duration.
The morning of: read the freshest forecast. Note any changes from last night. Check the wind direction and speed for the planned passage time, and the sea state for the planned passage zone. Cross-reference with the current prediction (see wind against current above).
Before casting off: check the current observed conditions at NOAA buoys near your route. Buoy 46087 (Neah Bay), 46211 (Grays Harbor), and 46029 (Columbia River Bar) are the relevant outer-coast stations. They report wind, wave height, and barometric pressure in real time.
Underway: keep WX-3 (or the relevant channel) audible at the helm. Conditions change. The forecast is a prediction, not a contract.
What the forecast cannot do
Marine forecasts predict the broad pattern. They do not predict:
- Exact gust timing in a passing front
- Williwaw events in mountain anchorages
- Local thermal effects on lee shores
- Fog development inside one or two hours
- The exact moment a frontal passage will arrive at your specific position
For all of those, the cruiser uses observation: barometer trend, wind shift direction, cloud development, sea state evolution. The forecast is the framework; the cruiser fills in the detail.
A line worth remembering
The forecast is what the atmosphere is probably going to do. The buoy is what the water is currently doing. The window outside the boat is what is happening now. All three matter.
The boat that left in 15 knots forecast and 35 knots actual is the boat that did not check the buoy, did not check the radar trend, did not look at the western horizon before casting off.
Related: Tides and Currents in the PNW · How to Cross the Columbia River Bar · PNW Weather Patterns · Marine Safety Equipment