A representative-point Level 1 metocean desktop study, end-to-end
⏱ ~5 min read
This page summarises a methodology sample produced by PF Tech Services Ltd. Full PDF download at the bottom of this page.
Within the 2019–2023 analysis window at the representative offshore Changhua selection point, the strongest sea states were driven by sustained northeast-monsoon events — not by direct typhoon passage.
Site location
Selection point 24.05°N, 119.80°E (centre marker on map) — approximately 50 km off the Changhua coast.
▶ Executive Summary
At a glance
Five-number snapshot
What we found
The five top significant-wave-height (Hs) timestamps in the 2019–2023 5-year window — all between 5.95 m and 6.25 m — were direction-verified and partition-energy-confirmed as northeast-monsoon events. They correspond to three independent storm events (one storm on 2023-10-05 contributes three consecutive 3-hourly samples). By comparison, the strongest named-typhoon site impact in the same window (Typhoon DOKSURI, July 2023) generated a peak Hs of 5.14 m.
This is a within-window finding from a low-typhoon-activity sample, not a long-run climatological claim: the 2019–2023 window was a period of below-average landfalling typhoon activity for Taiwan, and happens to contain no Cat 4+ typhoon passing the site at near-peak intensity. A longer (15–30 yr) analysis is recommended before drawing climatological conclusions about whether winter monsoon or direct-pass typhoons dominate extreme Hs at this site.
For operability planning within the analysed window, sustained winter NE-monsoon conditions are at least as significant a constraint on offshore-wind installation, operations, and maintenance planning as direct typhoon passage was.
How we know
Seasonal cycle is dominated by the NE monsoon (2019–2023)
Calendar heatmap of daily-mean 100 m wind speed at site 24.05°N 119.80°E, 2019–2023. Each year is one panel; columns within each panel represent week-of-year (labeled with month abbreviations); rows represent day-of-week. Deeper colour = stronger wind. The Oct–Mar NE-monsoon dominance appears as the dark band recurring every year.
Typhoons in the 2019–2023 window did NOT directly drive the top Hs events
Tracks of the six IBTrACS-catalogued tropical cyclones (lifetime peak intensity ≥ Tropical Storm) that passed within 200 km of the site during 2019–2023. None of them generated a site Hs higher than the NE-monsoon top-five timestamps.
Joint Hs–Tp distribution (2019–2023) shows the wind-sea regime
Joint distribution of Hs and peak wave period at the site (2019–2023). Bulk of samples cluster at short period (5–7 s), consistent with locally-driven wind sea. The top-five Hs timestamps sit at the upper-right of the wind-sea cluster — high-Hs events with wind-sea spectral signatures, not long-period remote-typhoon swell.
Cross-validation against alternative-source 10-year wave hindcast
Monthly Hs at site: WAVERYS 2019–2023 (5 yr) vs CWA WW3 2008–2017 (10 yr). Seasonal-cycle shape is consistent (12-month Pearson r ≈ 0.97) — supporting evidence that the WAVERYS site climatology used in this study captures the regional seasonal pattern.
ⓘ How to read this sample
This is a methodology sample, not a project deliverable. Intended for prospective customers evaluating PF Tech's Level 1 Metocean Desktop Study service:
- What this report shows — the analytical depth, framing, and limitations discipline of a PF Tech early-stage desktop study, demonstrated end-to-end on a representative point off Changhua. The methodology and report structure are the durable contribution; specific values are illustrative.
- What it is good for — early-phase site screening, technology selection, feasibility-stage scoping, and weather-window planning discussions with internal stakeholders.
- What it is not — a project-specific engineering input. The selection point is a methodology demonstrator, not an actual project location; values shown are not site-specific design figures.
The full report — methodology, complete data sources, full caveats, partition-energy analysis, and reproducibility manifest — PDF download below.
📄 See the full deliverable
The complete bilingual report — methodology, data sources, partition-energy analysis, reproducibility manifest.
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CONTACT
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Disclaimer
This page summarises a methodology sample. It does not constitute a design basis for any specific wind farm, port facility, or coastal asset. PF Tech makes no representation about whether the selection point falls within any specific operating or planned project area. The full Disclaimer is on page 3 of the PDF.
PF Tech Services Ltd. — 沛風科技服務有限公司. © 2026 PF Tech Services Ltd. All rights reserved.
Data attribution: ERA5 (CC-BY 4.0 Copernicus Climate Change Service), Copernicus Marine WAVERYS (CMEMS Licence), IBTrACS (NOAA NCEI public domain), CWA OpenData (Open Government Data License v1). Full attribution and DOIs in §9 of the PDF.