GREAT LAKES SURF REPORT: WAVES, MOONLIGHT, AND THE FRESHWATER NIGHT DESK NITETIME.NET // October 18, 2026 Some stations cover oceans. NITETIME has five inland seas, a moon fixation, and a weather desk with more enthusiasm than furniture. Great Lakes Surf Report brings Superior, Michigan, Huron, Erie, and Ontario into one place: https://surf.nitetime.net/ . It combines marine wave forecasts, recent station observations, and an astronomical night desk. The attitude belongs to NITETIME. The measurements and forecasts have named sources and timestamps. The original dispatch introduced a wave-and-moon forecast. The site has since grown into a surf-weather hub, with a station leaderboard, shoreline weather, daylight and moon calculations, water temperatures, and the original forecast timeline. This article describes those tools and the distinctions that make their numbers useful. START WITH THE LAKE, THEN THE SHORELINE Five clickable lake outlines lead into thirteen selected U.S. shoreline forecast desks. Choose a lake and a point, then choose feet or metres and a 24-, 48-, 72-hour, or coming-week view. The hourly plot and slider let you inspect a particular forecast hour. Daily peak controls jump to the larger forecast windows, and an hourly table provides the same information without requiring you to read the graph. These points sample a large region. They do not claim to describe every beach or every part of a lake. The shoreline selection matters because the page associates its forecast, local clock, weather observations, and astronomical calculations with that place. FORECASTS HAVE A SOURCE AND AN EXPIRATION DATE The wave guidance comes from NOAA / National Weather Service marine forecast grids. The report displays source issue and retrieval times, marine alerts, and missing or stale states. Its wave watch ranks eligible forecast windows by wave height, period, and then lighter wind. That is a way to sort available guidance, not a universal rating of surf quality. There is roughly a week of wave guidance when the provider supplies it. The long-range desk links separately to NOAA's broader outlooks. Those outlooks do not become invented hourly wave heights for a second week. If a future moon event lies beyond the available forecast, the site can show the moon date while leaving the corresponding wave forecast absent. The collection system excludes failed or cached grids from the wave watch. Its documented freshness rules also exclude NOAA issue times older than eighteen hours or retrievals older than two hours. A retained snapshot can still explain what the system last knew; it must not quietly become a new observation. A marine-grid wave height is not a promise of a clean breaking wave at a particular beach. Local shoreline shape, exposure, and conditions are outside that single number. The forecast is useful evidence to read alongside warnings and local knowledge. THE GNARLIEST PLACES RIGHT NOW The station leaderboard answers a different question from the forecast: what are selected reporting stations measuring? It can sort by observed wave height, the maximum reported sustained wind or gust, coldest air, coldest water, or lowest visibility. It does not merge these into a supposedly scientific danger score. The documented catalog contains 111 selected marine and coastal stations identified from NOAA's National Data Buoy Center metadata. It includes Canadian-partner observations relayed by NDBC. That is a curated catalog, not exhaustive coverage, and the number reporting usable values changes with availability and seasonal deployment. The board follows the selected lake. It does not inherit the forecast horizon or night and moon filters. Each metric excludes missing readings, failed refreshes, and observations or fetches older than two hours, with a small allowance for clock differences. Each card identifies the station, source, and time. Calculated moon context is displayed separately from the measured conditions. This distinction is the heart of the page: an observation describes a reporting station at a recorded time; a forecast describes expected conditions; an astronomical calculation describes the sky's geometry. Putting them on one screen does not make them interchangeable. THREE DESKS FOR THE SHORELINE FOG OFFICE uses nearby land-station observations to show reported visibility and weather, air temperature and dew point, wind and gusts, station distance, and observation time. Low visibility alone does not establish that fog caused it. The shoreline weather lookup rejects stations more than 75 kilometres away rather than treating any available reading as local. LAST LIGHT lists sunset, the end of civil twilight, dawn, sunrise, moonrise and moonset, along with current calculated sun and moon positions and estimated lunar illumination. These are SunCalc calculations for the selected shoreline coordinates. Times are displayed in that shoreline's local time, with daylight-saving handling, rather than assuming the visitor's computer is beside the lake. Civil twilight ends when the sun is six degrees below the horizon. WATER DOES NOT LOVE YOU finds a station on the same lake with a fresh water-temperature reading within 80 kilometres. It names the station and gives distance and time. Air temperature is never substituted for water temperature. A nearby instrument is still not an exact measurement at the reader's beach, and the page keeps that limitation visible. THE MOON GETS ITS OWN SHIFT NIGHT SHIFT selects 20:00 through 06:00 on the local shoreline clock. That is an explicit clock-time filter, not a claim that the entire interval is dark in every season. LAST LIGHT provides the separate astronomical context. The combined timeline places wave height beside estimated lunar disc illumination using separate labelled axes. The selected-hour readout and hourly table include moon information; daily moon values refer to the same hour as that day's selected wave peak. Above- and below-horizon estimates indicate whether the moon is geometrically up at that location and hour. The lunar calendar uses official U.S. Naval Observatory timestamps for primary phases. Full- and new-moon filters select the twenty-four hours on either side of the event, then intersect that window with the overnight hours. Local calculations supply illumination and position; USNO supplies the exact primary-phase event dates used by the calendar. FLOODLIT and LIGHTS OUT are the night desk's labels. They are not predictions of actual illumination on the water. Clouds and observed sky brightness are not supplied by these calculations. Lunar phase does not produce a wave-size estimate or a danger score. The moon provides context, not permission. A SMALL COLLECTOR BEHIND THE PAGE The public interface reads a server-produced JSON snapshot. A Python collector retrieves forecast grids and marine alerts, NDBC observations, NWS station weather, and USNO phase data. The existing refresh timer runs about every thirty minutes, with a small scheduling variation. Provider requests happen on the server; the browser does not need weather API credentials. Successful updates publish the snapshot atomically so readers receive a complete version. On failure, retained data keeps its original timestamps and is marked as cached. Missing values stay missing. The browser refreshes snapshots every five minutes while visible and rechecks observation freshness and astronomy every minute. Frequent screen updates do not imply that a remote buoy has issued a new measurement. The interface includes a readable hourly table and was checked on desktop and narrow phone layouts. Source and time labels travel with the numbers. The old main-domain /surf/ address redirects to the dedicated subdomain. The page links back to NITETIME.NET and the Gopher shelves; the station's homepage now also provides a direct entrance. FRESHWATER, HEAVY CONSEQUENCES The desk's unofficial line is that the big ones mostly come out at night. That is newsroom atmosphere, not a meteorological result. The actual forecast gets the vote, and missing measurements do not become excitement just because the page has a loud voice. The site's warning is direct: this sport is dangerous, and entering the water is at your own risk. Read marine warnings and consider local access, cold water, currents, and ice. Night coverage is for studying the conditions; a moon icon is not an assurance that entering the lake is safe. The value of this report is the ability to look across several kinds of evidence without hiding where each came from. Pick a lake. Read the timestamp. Inspect the forecast. Check what nearby stations actually report. Then let the night desk provide the commentary while the sources supply the facts. Technical basis: NITETIME server's Great Lakes Surf Weather deployment and observation-hub records, updated October 14, 2026. This is an independent NITETIME publication; NOAA and USNO provide source information, not endorsement. This article describes the service, not current water conditions.