Weather and Current Source Catalog
Rev: v2.1 · Updated: 2026-06-01
Every data source used in this project, plus the public ones wired into the automated pipeline. Verify all access is working before race week.
TL;DR
Three classes of data — never confuse them:
| Class |
What it is |
Sources here |
Horizon |
| FORECAST |
Model prediction of the future |
Open-Meteo (GFS/ECMWF/ICON), HRRR, NAM, ECMWF ENS, RTOFS forecast |
Useful to ~7 days; no model reaches race day until ~T-10/T-14 |
| REANALYSIS |
Best-estimate actuals (past / near-real-time), not a forecast |
ERA5 |
Past → ~5-day lag |
| OBSERVED |
Direct measurement of the present ocean/atmosphere |
CoastWatch/NESDIS SST, AVISO+ altimetry, ASCAT, RTOFS nowcast (assimilated) |
Now, minus latency |
- The forecast monitor (
scripts/forecast_monitor/) pulls Open-Meteo GFS+ECMWF+ICON wind/gust/MSLP/CAPE + Marine SST/current/waves — public, no key — and correctly declines to classify race day while it is >7 days out. See forecast_analog_matcher.md.
- The Gulf Stream monitor (
scripts/gulfstream_monitor/) fetches the OBSERVED ocean (SST + altimetry); ERA5 (REANALYSIS) backs scripts/analysis/weather_overlay.py.
- The Stream is the only genuinely predictive signal before the models converge — and for it, SST + altimetry beat RTOFS alone (see Gulf Stream Framework → RTOFS).
One click to every model, tool and data portal this project is built on. Details, horizons and caveats are in the tables below.
Forecast models
Open-Meteo (pipeline default — GFS·ECMWF·ICON + Marine) ·
NOAA NOMADS (GFS · NAM · HRRR · RTOFS GRIB) ·
ECMWF ·
DWD Open Data (ICON) ·
HRRR
Routing / GRIB tools
LuckGrib ·
PredictWind ·
Adrena ·
Expedition
Ocean — currents & SSH
RTOFS (NCEP Global) ·
HYCOM ·
Copernicus Marine (CMEMS) ·
AVISO+ altimetry ·
OSCAR (PO.DAAC) ·
NOAA OPC ocean products
SST & observed
NOAA CoastWatch ·
NESDIS STAR ·
Rutgers RUCOOL ·
NASA SPoRT ·
ASCAT (KNMI)
Reanalysis
ERA5 — Copernicus CDS ·
Open-Meteo Archive (ERA5)
Marine forecasts & expert read
NOAA NWS Marine ·
NOAA Ocean Prediction Center ·
Frank Bohlen's Gulf Stream notes (bermudarace.com)
FORECAST — Atmospheric Models (GRIB)
Open-Meteo (pipeline default — GFS + ECMWF + ICON)
| Field |
Detail |
| Provider |
Open-Meteo (re-serves NOAA GFS, ECMWF IFS, DWD ICON + Marine) |
| Resolution |
Native per model (GFS 0.25°, ECMWF 0.25°, ICON 13 km) |
| Forecast length |
~7 days usable horizon for this corridor |
| Access |
Public HTTP/JSON, no key; scripts/forecast_monitor/fetcher.py (stdlib urllib) |
| Race use |
Pre-race monitoring pipeline (scripts/daily_brief.py); not a race-period routing source |
| Key products |
Wind, gust, MSLP, CAPE (atmospheric) + Marine SST, surface current, waves |
| Horizon caveat |
Pipeline classifies periods P1/P2/P3 with model-agreement confidence and declines to classify race day (2026-06-19) while it is >7 days out — do not fabricate a race-day code |
GFS (Global Forecast System)
| Field |
Detail |
| Provider |
NOAA/NCEP |
| Resolution |
0.25° (~25 km) globally |
| Forecast length |
384h |
| Cycle frequency |
00z, 06z, 12z, 18z |
| Availability |
~4h after cycle |
| Access |
NOAA NOMADS, LuckGrib, PredictWind, Adrena, Expedition |
| Race use |
YES (2026 NOR confirmed) |
| Strengths / weaknesses |
Free, universal; sometimes overdevelops ridge; underperforms ECMWF at 5–7 days |
| Key products |
UGRD/VGRD (wind), PRMSL (pressure), APCP (precip), CAPE (convection) |
ECMWF
| Field |
Detail |
| Provider |
ECMWF via commercial services |
| Resolution |
0.25° (IFS), 9 km HRES |
| Forecast length |
240h (HRES), 360h (ENS) |
| Cycle frequency |
00z, 12z |
| Availability |
~6–8h after cycle |
| Access |
PredictWind, LuckGrib, Adrena, Copernicus CDS |
| Race use |
YES (2026 NOR confirmed) |
| Strengths / weaknesses |
Generally superior to GFS at 5–10 days; requires subscription |
HRRR (High-Resolution Rapid Refresh)
| Field |
Detail |
| Provider |
NOAA/ESRL |
| Resolution |
3 km |
| Forecast length |
18h (standard), 48h (18z cycle) |
| Cycle frequency |
Hourly |
| Access |
NOAA NOMADS, LuckGrib |
| Race use |
Pre-race and start day coastal planning only |
| Note |
Best short-range convective detail; not useful south of ~35°N |
NAM (North American Mesoscale)
| Field |
Detail |
| Provider |
NOAA/NCEP |
| Resolution |
12 km |
| Forecast length |
84h |
| Cycle frequency |
00z, 06z, 12z, 18z |
| Access |
NOAA NOMADS, LuckGrib |
| Race use |
Pre-race coastal leg |
ICON (DWD)
| Field |
Detail |
| Provider |
German Met Service (DWD) |
| Resolution |
13 km global |
| Forecast length |
180h |
| Cycle frequency |
00z, 06z, 12z, 18z |
| Access |
LuckGrib, Adrena, DWD Open Data |
| Race use |
YES (2026 NOR confirmed); useful independent model check |
ECMWF ENS (Ensemble)
| Field |
Detail |
| Provider |
ECMWF |
| Resolution |
0.4° (51 members) |
| Forecast length |
360h |
| Access |
PredictWind, LuckGrib |
| Race use |
Analog comparison, confidence intervals, scenario planning; essential T-7 onwards |
OBSERVED + FORECAST — Ocean Current and Gulf Stream Products
RTOFS/HYCOM/CMEMS are forecast/nowcast models; AVISO+ and OSCAR are observed (altimetry). Validate models against observation.
RTOFS
| Field |
Detail |
| Provider |
NOAA/NCEP |
| Resolution |
1/12° (~8 km) |
| Forecast length |
8 days |
| Cycle frequency |
Daily (00z) |
| Availability |
~12h after cycle |
| Access |
NOAA NOMADS, LuckGrib (via HYCOM), Expedition plugin |
| Race use |
YES (2026 NOR confirmed) |
| Critical |
North wall position can be off 10–30 nm; always cross-check against SST. Do not route solely on RTOFS — see Gulf Stream Framework → RTOFS. |
HYCOM
| Field |
Detail |
| Provider |
COAPS/NRL |
| Resolution |
1/12° |
| Access |
hycom.org, LuckGrib |
| Note |
Often similar to RTOFS; useful cross-check |
CMEMS (Copernicus Marine Service)
| Field |
Detail |
| Provider |
EU Copernicus |
| Resolution |
1/12° (global physics) |
| Access |
marine.copernicus.eu (free registration) |
| Products |
Current, SSH anomaly, SST, mixed layer depth |
| Race use |
YES (2026 NOR confirmed) |
AVISO+ Altimetry (SSH Anomaly / ADT)
| Field |
Detail |
| Provider |
CNES/AVISO+ |
| Resolution |
0.25° (merged altimetry) |
| Update frequency |
Daily (2–3 day delay for best product) |
| Access |
aviso.altimetry.fr, CMEMS |
| Race use |
YES (2026 NOR confirmed) |
| Key products |
ADT (Absolute Dynamic Topography), SLA (Sea Level Anomaly) |
| Use |
SSH highs = warm core eddies/Stream meanders; SSH lows = cold core rings |
OSCAR
| Field |
Detail |
| Provider |
JPL/PO.DAAC |
| Resolution |
0.25° |
| Latency |
5 days |
| Access |
podaac.jpl.nasa.gov |
| Race use |
Pre-race context only; too delayed for tactical use |
REANALYSIS — Actuals (not forecast)
ERA5
| Field |
Detail |
| Provider |
ECMWF / Copernicus Climate Data Store (CDS) |
| Resolution |
0.25° hourly |
| Type |
Reanalysis — best-estimate past/near-real-time actuals, ~5-day lag; NOT a forecast |
| Access |
cdsapi (~/.cdsapirc credential); used by scripts/analysis/weather_overlay.py (with AVISO) |
| Race use |
Post-hoc verification, analog-year reconstruction, overlay basis — never as a forward forecast |
OBSERVED — SST and Thermal Imagery
NOAA CoastWatch SST
| Field |
Detail |
| Provider |
NOAA CoastWatch |
| Resolution |
1 km (GOES-R), 2 km (VIIRS) |
| Coverage |
Daily (cloud-dependent) |
| Access |
coastwatch.noaa.gov |
| Race use |
YES (2026 NOR confirmed) |
| Key use |
North wall position, eddy identification, SST gradient sharpness |
NOAA NESDIS SST Composites
| Field |
Detail |
| Provider |
NOAA NESDIS/STAR |
| Resolution |
2 km (daily and 7-day composite) |
| Access |
star.nesdis.noaa.gov |
| Race use |
YES (2026 NOR confirmed) |
| Key use |
7-day composite fills cloud gaps; good for eddy position confirmation |
PredictWind SST
| Field |
Detail |
| Access |
predictwind.com or iOS/Android app |
| Note |
Subscription service — verify personalized data during race is permitted |
OBSERVED — Wind Validation
ASCAT (Advanced Scatterometer)
| Field |
Detail |
| Provider |
KNMI/EUMETSAT |
| Resolution |
12.5 km, 25 km |
| Coverage |
Polar orbiting, ~12h global |
| Access |
knmi.nl/research/ASCAT, PODAAC |
| Race use |
Pre-race model validation; validate GFS/ECMWF wind field against actual surface |
Public Forecast Services
NOAA Ocean Prediction Center (OPC)
| Product |
Access |
Race use |
| Surface analysis charts |
ocean.weather.gov |
Category A — YES |
| 24h/48h/96h/120h surface prognosis |
ocean.weather.gov |
Category A — YES |
| High Seas forecast (text) |
ocean.weather.gov |
Category A — YES |
| Significant wave height charts |
ocean.weather.gov |
Category A — YES |
NOAA NWS Marine Forecasts
| Product |
Access |
Race use |
| Offshore marine zone forecasts |
weather.gov |
Category A — YES |
| VHF weather radio (WX) |
Onboard VHF |
Category A — YES |
| Tropical weather outlook |
nhc.noaa.gov |
Category A — YES |
Commercial Services - Routing
Personalized routing advice during the race is Category D (prohibited). Pre-race use unrestricted.
| Service |
Notes |
| PredictWind |
Routing, GRIB, SST, offshore weather |
| FastSeas |
Offshore routing |
| LuckGrib |
GRIB downloader (Mac/iOS); excellent multi-model access |
| Weather4D |
GRIB viewer, iOS/Android |
| Passage Weather |
Visualization only |
| Windy.com |
Visualization only — do not use as routing source |
Access Verification Checklist (Complete Before Race Week)
- [ ] LuckGrib subscription active; ECMWF, GFS, ICON accessible
- [ ] PredictWind subscription active; GRIB download tested
- [ ] Adrena or Expedition GRIB plugin configured; test download successful
- [ ] NOAA CoastWatch SST access confirmed; latest product available
- [ ] RTOFS current overlay working in routing software
- [ ] AVISO or CMEMS ADT access confirmed
- [ ] OPC charts bookmarked and accessible
- [ ] NWS offshore forecast zones for race corridor bookmarked
- [ ] Offshore hardware (Iridium, SSB) configured; GRIB download tested
- [ ] Open-Meteo pipeline reachable (
scripts/forecast_monitor/fetcher.py — no key)
- [ ] ERA5 CDS credential present (
~/.cdsapirc); AVISO Copernicus Marine credential present
Sources
- Pipeline code (FORECAST) —
scripts/forecast_monitor/fetcher.py, scripts/forecast_monitor/classify.py, scripts/daily_brief.py (Open-Meteo GFS+ECMWF+ICON, public, no key).
- Gulf Stream monitor (OBSERVED) —
scripts/gulfstream_monitor/fetcher.py (SST + altimetry sources).
- Reanalysis / overlay —
scripts/analysis/weather_overlay.py (ERA5 via cdsapi + AVISO).
- RTOFS limitations & SST-first rule — gulf_stream_framework.md.
- Pipeline / matcher overview — forecast_analog_matcher.md.
- External providers — NOAA NOMADS/NCEP, ECMWF, DWD, Copernicus (CDS + Marine), AVISO+, JPL PO.DAAC, NOAA CoastWatch/NESDIS, KNMI/EUMETSAT, NOAA OPC/NWS; commercial: PredictWind, LuckGrib, Adrena, Expedition, FastSeas, Weather4D.
PRE-RACE RESEARCH — not race-period routing advice. Updated 2026-05-29.