Agate Beach
Faces the big lake. Use the offshore wave record to see when the lake experienced stronger storm activity and how the waves changed afterward.
Burt Township beach information ↗Near-current measurements · No photos required
What's Lake Superior doing now?
Actual open-lake waves north of Grand Marais, plus independently checked NWS marine warnings. This describes offshore conditions, not rock exposure or beach safety.
Photo-free offshore storm readingChecking observation coverage
Checking the buoy and marine alerts…
Measured offshore conditions only; no photographs needed.
Agate Beach: exposed to open Lake Superior. Bayshore Park: sheltered harbor, not measured by this offshore buoy.
Important: A reported wave decline is not proof of newly exposed rocks or safe access. The remote Marquette water-level gauge cannot certify Grand Marais beach exposure.
Grand Marais buoy statusChecking sourceOriginal station timestamps
Last offshore wave height—Significant wave height · meters
Measured last 48h peak—Source-stamped offshore reading
NWS marine alert checkCheckingAlerts checked separately from buoy waves
What is the wind doing on shore?Independent NWS Grand Marais anemometer · not wave-derived wind
Measured wind speedCheckingNDBC GRMM4 · original station observations
Local wind-from direction—Compass degrees true north
Peak recent measured gust—Recent 3-hour station record · meters/second
GRMM4 reports actual wind but no measured wave heights. Offshore waves are independently observed by GLOS SPOT-1361. Wind and wave directions can differ because of swell and fetch.
NOAA GRMM4 original station ↗ · A stronger or calmer measured wind is not a prediction of newly exposed stones or a beach safety clearance.
When was the last sustained offshore wave activity?Up to 7 days · original Grand Marais buoy
Checking seven-day wave measurements…
This is the timing of measured offshore waves, not a prediction of fresh agates, safe access or beach wave height.
No photographs required; source gaps cannot be treated as calm conditions.
Has offshore wave activity changed since yesterday?Measured buoy height × mean period × time
Checking two 24-hour windows…
This is an observed offshore activity comparison, not wave power or measured movement of agates at the beach. Photographs are not required.
How unusual are today's offshore waves?
Compared with measured summer–fall 2026
Checking historical measurements…
This compares the buoy's latest complete 24-hour wave-activity measurement with its own 2026 June–October archive. A percentile is not the likelihood of finding agates or a safety rating.
Lake Superior level · Marquette gaugeCheckingNOAA measured water elevation, IGLD 1985
Measured change over 24 hours—Remote lake-level context, not beach height
What this tells usMarquette is not Grand Marais. Regional lake water level does not measure wave runup or exposed stones at Agate Beach.NOAA Marquette gauge ↗
What happens to Lake Superior water levels after a storm? Two distant NOAA gauges · dated source study
The current Marquette reading above is separate. The following side-by-side comparison is an archived October 16, 2026 original-source example from two Lake Superior water-level sensors. Neither gauge measures actual shoreline height, water runup, or new stones at Agate Beach.
Marquette C.G. · western context
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Observed six-hour level range
Dated source snapshot loading…
Point Iroquois · eastern context
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Observed six-hour level range
Dated source snapshot loading…
Checking original NOAA station/time provenance. This is not a current waterline reading at Grand Marais.
Why it matters: The lake can slosh after waves ease. A gauge reading hundreds of kilometers along the shore cannot tell us how many inches of pebble beach are exposed in Grand Marais. NOAA's Lake Superior seiche research ↗
Observed offshore wave trendUp to 48h of measured wave heights
Checking original Grand Marais Spotter observations. Gaps will not be filled.
What the measurements mean
Checking whether recent measurements are available.
Measured waves describe the open lake. The sheltered Bayshore Park harbor is not instrumented by this buoy.
What this does not claim: Offshore disturbance and wave decline can be detected without photos. Neither measurement proves fresh agates, wave height breaking on the beach, collecting permission, or a safe visit. Lower waves are not an all-clear.
Measured-source quality
Summer–fall 2026 · historical replay
How well does the wave tracker hold up?
We ran the photo-free environmental engine repeatedly across the original 2026 Grand Marais Spotter records. These figures describe how often sufficient buoy data were available—not whether stones appeared on the beach.
Original measured readings5,291GLOS offshore buoy
Past-only checks209Every 12 hours
Usable current wave data98.1%Source freshness and coverage
Complete two-day comparisons93.3%Two adequately sampled 24h windows
Fresh usable offshore observations98.1% of checkpoints
Both 24-hour wave windows complete93.3% of checkpoints
In this 2026 replay, three observation checkpoints showed renewed offshore waves; three had stale readings and one had a recent reporting gap. Those checks are not independent storms. Missing readings did not become calm-beach or safe-access claims.
Original-source walk-forward verification and tests. The replay did not use photos, pretend to know historic NWS warnings, validate gravel movement, or estimate odds of finding agates. Current lake conditions appear in the live observations above, not these dated percentages.
Observed lake conditions · Historical research
2026 summer–fall observations
Read the lake's storm story
How high did the waves get? Did they ease off, or rise again? Explore the measured wave history that helps explain when Lake Superior has been active around Grand Marais.
Original wave readings5,243Grand Marais Spotter
Days in the record111June to October 2026
Well-sampled wave episodes8Grouped from actual measurements
Waves built again2Multiple elevated-wave pulses
Measured offshore wave peaksSignificant wave height · meters
Eight observed wave episodes between July and October 2026, grouped from original buoy readings.
Storm and recovery
Pick a measured episode to follow the lake's rise and recovery.
Wave observations are shown with their recorded UTC dates.
Wave direction snapshot
October 14 buoy waves traveled from roughly NNW, near the historical Agate Beach shoreline-facing direction.
Which storm stayed active the longest?
Measured height × period × time · historical comparison
Peak height isn't the whole story. This comparison uses observed wave height, mean period, direction and duration from the same Grand Marais buoy. It's not a chance of finding agates, a beach-wave prediction, or a safe-visit signal.
Reading the actual 2026 wave measurements…
Only original buoy readings, with observation gaps excluded.
Compare all eight storms by measured activity
Loading archived research data.
Relative to the strongest sufficiently sampled 2026 offshore episode only. The index integrates Hs² × recorded mean period over observed intervals of 90 minutes or less; it is not absolute wave power (kW/m), sediment transport, or agate exposure. The historical shoreline-facing direction is not a surveyed modern beach bearing.
Bayshore Park
Inside the Grand Marais harbor. Its protected setting makes local marine conditions and harbor-specific information especially useful to check.
Burt Township park information ↗Historical wave observations through October 14, 2026, not a live beach reading. Use the current forecast, posted access conditions and local collecting rules when planning a visit.
Explore the research archive, charts and original source studies
INTERACTIVE DESIGN DEMO — NOT LIVE WEATHER. The interactive storm picker uses illustrative scenarios; the separately labeled GLOS and NOAA observation panels below use dated authentic measurements. No beach has been declared safe, newly exposed, or legally cleared for collection.
Choose shoreline
Explore example conditions
EXAMPLE · RESEARCH SIGNAL
Waves have settled from a recent peak.
The simulated open-coast wave record shows recent disturbance followed by a sustained decline. A real result would still require verified shoreline exposure, hazards, and observations.
Illustrative candidate · not a visit recommendationRecent peak6.1 ftSimulated offshore height
Current modeled1.4 ftSimulated · not at shore
Since the peak−77%Illustrative wave height drop
Next 12 hoursLowerSimulated directional outlook
What changed in the water?
72-hour example history and following 12-hour example forecast
Past wave heightExample outlook
Three questions, in order
The engine must clear each stage before showing an opportunity.
- Did a meaningful disturbance happen?Compare recent wave forcing to a seasonal site baseline, using direction and period—not height alone.
- Have conditions moderated?Check the time since the peak and whether the next forecast period is rebuilding.
- Is it sensible to consider a visit?Marine warnings, ice, access changes and insufficient evidence can veto the decision.
What we won't claim: A storm does not guarantee fresh stones. No buoy or offshore model alone establishes safe shoreline access.
Two beaches, different wave exposure
Documented public sites around Grand Marais. Location roles are evidence-based; the wave readouts above are simulations.
Open Lake Superior · Search leadDocumented destination
Agate Beach
Burt Township identifies this as a public rockhounding beach and documents parking by the boardwalk. Open-lake exposure makes it the primary site for future storm research.
Township beach details ↗Protected harbor · ComparisonPublic beach
Bayshore Park
Public swimming beach inside Grand Marais harbor. Useful to demonstrate why the same offshore waves cannot automatically be assigned to a sheltered shoreline. Not an independently documented agate deposit.
Township park details ↗Shoreline comparison
A simple orientation sketch, not a navigable map.
Schematic, not geographic coastline geometry. The NOAA regional grid may not resolve the harbor.
Exposed research siteSheltered comparison
What this screen will show later
The live version must make uncertainty visible rather than hide it.
- Real source timestampsArchived NOAA analysis versus upcoming modeled forecasts.
- A site-specific evidence labelOffshore reference, modeled nearby water, or unverified harbor shelter.
- A useful verdict—or no verdictDisturbance detected, still active, settling, rebounding, hazard veto or insufficient information.
Measured waves near Grand Marais
A closer source than East Superior: GLOS Seagull Grand Marais Spotter SPOT-1361, operated by Superior Watershed Partnership. These are real offshore observations, not beach surf or predicted exposed stones.
Observation freshness: The original 2026 source sample ended October 14 at 23:46 UTC. It was stale at the October 15 research check. Storm completion remains unverified; missing or delayed observations cannot be interpreted as calm water.
Highest observed height in study window2.57 mOct 12 · 14:46 UTC · not Agate surf
Last observed height0.95 m2026-10-14 23:46 UTC
Last observed wave-from direction329°Wave direction, not wind direction
A new source-verified rolling archive retained 142 original readings from October 12–14, including one sustained elevated-wave episode (83 related measurements, not 83 separate storms). This offshore wave change is promising input for the future post-storm engine, not a validated collecting opportunity, a protected-harbor wave estimate, or a current shore hazard assessment.
GLOS Grand Marais Spotter original data ↗ · Original source verification ↗
Which measured storms worked the lake hardest?
Compare observed offshore wave activity using height, mean period, and sustained duration rather than just the tallest wave. No photographs needed. This ranks what the buoy measured—not agate discoveries or measured movement on the beach.
Original 2026 wave observations5,291GLOS SPOT-1361 · archived
Coverage-qualified episodes811 original offshore episode groups
Independent measured pebble outcomes0Wave signal alone cannot verify agates
Historical source: Computed from original wave records available October 16, 2026 at 12:27 UTC. The buoy was stale and the independent NWS alert check was active at that research time. This is not a live shore-condition or safety clearance.
Checking source-stamped relative offshore wave observations…
What the numbers mean: We integrate actual observations of significant wave height squared × observed mean wave period × measured elapsed hours. The output is a relative wave-activity proxy, not calibrated wave power or beach sediment movement. Gaps larger than 90 minutes are not filled; sparse episodes are not ranked. The 2014 charted shore direction is not a surveyed current wave-exposure factor.
Why duration changes the ranking: The October 5 offshore peak reached 2.51 m, yet accumulated more measured wave activity over its episode than the October 12 event that peaked at 2.57 m. Neither result predicts exposed agates, safe access or protected Bayshore Park waves.
Original Grand Marais buoy ↗ · 5,291-reading calculation and tests ↗
2026 Lake Superior storm history
Research-only wave history from 5,243 original Grand Marais Spotter readings across 111 UTC days, June 26 to October 14. These are open-lake measurements, not conditions at a collecting beach.
Original GLOS observations5,243Sixteen source-verified time windows
Elevated-wave episode groups11At least 48h separation needed for new groups
Episodes with enough measurements8Independently measured offshore, not rock finds
Interpretation: An episode means related elevated buoy readings, not a separate meteorological storm. A peak, falling wave height, or 48-hour observation record does not establish beach safety, shoreline changes or fresh agates.
- The historical event table is loading. No rock exposure is inferred.
Two Grand Marais beaches. Very different evidence.
Burt Township confirms both public waterfront destinations. That does not make both agate-producing beaches, allow rock removal, or establish safe post-storm conditions. This research gate keeps each claim separate.
Open Lake Superior shoreline
Agate Beach
Township public beach and historic boardwalk; the Chamber describes the town's traditional rockhounding destination.
Beach exists: Township documented
Measured wave history: 5,243 regional offshore readings—not surf at the beach
Newly exposed stones: Not verified
Township collecting permission: Unverified
Exact parking route: Not independently mapped
Sheltered Grand Marais harbor
Bayshore Park
Township swimming beach with bathhouse, parking and playground. Not an independently verified agate deposit.
Public park: Township documented
Measured harbor waves: No verified harbor data—cannot reuse open-lake buoy heights
Agate-bearing substrate: Not verified
Township collecting permission: Unverified
Exact parking route: Not independently mapped
Collecting rules ≠ public beach access:
EGLE's 25-pound annual limit for applicable state-owned/public-trust lands does not automatically grant permission to collect rocks at either township beach. Local/posted restrictions and separate NWS hazard checks are still required.
Loading locally sourced pilot readiness audit. No current surf, collecting clearance or rock-exposure claim is made.
Research priority: A same-view beach photo from just before the July 21, 2026 observed offshore event. That event has an uncertain later photo date but no comparable earlier frame.
These are historical, noindex research disclosures. A shoreline or legal-collecting clearance will not appear until independently verified; no wave or photo status here is a current invitation to enter the water.
Which measured storms have matching beach photographs?
An event-by-event review of eight real Grand Marais offshore wave episodes. Photo dates come from independent sources; this panel does not estimate exposed stones, safe shoreline conditions, or visit windows.
Sampling-qualified offshore episodes8Measured GLOS buoy data, not forecasts
Possible dated post-scene links1July 21 wave event; capture time uncertain
Validated repeated camera pairs0No measured beach sediment outcome
Source review only; no photo can certify a fresh-agate opportunity.
Location trap: Another Agate Beach is near Toivola in Stanton Township. A July 2026 photo was explicitly identified there, not at Grand Marais. It is excluded from this evidence queue. Photos shot during a storm cannot be labeled “after.”
Evidence audit uses existing publicly dated images and the archived GLOS Grand Marais Spotter records. The weekly Wikimedia check uses one bounded metadata request and preserves newly discovered source details in a source-stamped photo review inbox, without additional visitor requests. Missing photos, unverified beach views and source-metadata revisions never create a fresh-agate or safety recommendation.
A storm doesn't always put more stones on the beach
Local Grand Marais reporting gives us a critical reality check: Lake Superior waves and shore ice can uncover rocks, but they can also carry rocks away or bury them under sand. These are firsthand historical accounts—not a measured 2026 Agate Beach outcome.
Rocks exposed or redeposited
A March 2012 Grand Marais area shoreline report describes shore ice bringing loose rocks up and leaving them as it melted. Conditions differed by beach segment.
Rocks washed out or buried
In a November 2013 report, a longtime local rockhound documented stretches of formerly rocky shore with little exposed rock—including Woodland Park during August—after repeated storms.
A separate 2009–2014 spring-beach comparison shows that shore ice can also keep rocks inaccessible into late March in some years. Conclusion: Offshore waves alone tell us a disturbance happened—not whether the right pebbles will be exposed at Agate Beach. These historical observations have not been calibrated against the 2026 GLOS events.
Historical observer evidence is dated and geographically broader than the Agate Beach study point. No current beach condition, collecting window, or fresh-agate probability is inferred.
Did the storm change the actual beach?
Independent dated photographs are the missing piece. We can now document a real Agate Beach scene and investigate a later report, but we cannot yet verify new stones were exposed by a particular storm.
Independently dated beach media3July 2026 source records
Possible storm-to-photo date links1Capture time and viewpoint unverified
Verified same-vantage change pairs0No measured new-agate exposure
What the evidence actually shows
July 4–5 · beforeTwo independent Agate Beach photos from Flickr and Wikimedia Commons. Too old and not same-camera registered to serve as a July 21 storm baseline.
July 21–22 · measured lake disturbanceThe Grand Marais Spotter recorded a 1.62 m offshore peak July 21 at 23:46 UTC. Wave height is not a measurement of beach sediment movement.
Approximately July 24 · possible later beach mediaA July 26 public post described Agate Beach two days earlier. The precise capture timestamp, GPS, exact shoreline segment, and comparable camera framing are unverified.
Current conclusion: One tentative post-event media date, but zero validated before/after shoreline-change pairs and zero verified newly exposed agates. We will not transform a photo date or general satellite pixel into a collecting probability.
Source-audit registry: independent photo metadata, exact GLOS July event timestamps, unreviewed OSM pilot geometry, and separate marine hazard controls. Loading local verification summary.
Why 10 m satellite images cannot resolve new pebbles ↗ · Why NAIP cannot capture every storm ↗
Repeat-view research: could we compare the same beach?
Two independently dated photographs show a broadly similar Grand Marais coastal landscape, twelve years apart. Similar-looking bluffs are not proof of a shared camera position. This visual is a candidate review, not a before-and-after storm result.
Licensed dated views3May 2014 and July 2026
Candidate bluff-silhouette comparison1Not camera matched
Verified post-storm repeat photos0No visible sediment change measured
Not an aligned photo pair: The 2014 camera position and both photographs' viewing bearings are unknown. Different lenses and seasons also change apparent beach width and perspective. No waterline shift, new rock exposure, or storm causality has been measured.
Why a second 2014 photo is a useful negative control
The same photographer also took a Grand Marais photo toward the open Lake Superior horizon around 10:36 on May 31, 2014, only six minutes after the coastal scene. That frame lacks the same bluffs and trees. Same date, photographer and named town do not mean the images share the same view.
Checking the local licensed-source comparison audit. No additional image matching or live-wave claims are supplied if it is unavailable.
Repeat-photo target, for future remotely sourced imagery: match the 2026 camera's position, identifiable bluffs/tree landmarks and view direction; verify both capture clocks, water level, lighting and wave runup. A historical landscape match cannot replace a storm-bracketing pair.
Can we compare the same shoreline view? Historical camera-location audit
Nearby geotagged Commons files6Within 2 km of Agate Beach
Two shore-labeled camera points192 m apartFar too different for a matched frame
Reviewed same-view before/after pairs0No certified beach sediment shift
October 5, 2016 · nearby Lake Superior shore
Original camera geotag, CC BY-SA 2.0. A dated earlier lake-coast photograph, not the same surveyed viewpoint. View original Wikimedia photo ↗
July 5, 2026 · Agate Beach
Original camera geotag, CC BY 4.0. Both sources have upload dates later than their original photo dates. View original Agate photo ↗
The source data were checked in October 2026. Neither photograph brackets a measured 2026 wave event from the same fixed camera location. Dated source ≠ documented exposed rocks.
Observed offshore wave events
Three dated wave episodes from NOAA buoy 45004 in eastern Lake Superior. These are actual observations—not simulated data and not waves measured at Agate Beach.
Location warning: The buoy is approximately 111 km from Grand Marais. This data confirms offshore disturbances only; it cannot establish shoreline conditions, newly exposed rocks, or safe collecting.
Measured offshore event · Not a beach verdict
Loading observed wave evidence
All data points were sampled from NOAA's archived East Superior station record.
Observed peak—
Later wave height—
Checking observation coverage.
NOAA buoy source ↗Historical source: NOAA NDBC THREDDS 45004h9999, significant wave height (meters), sampled approximately every 3 hours. Missing readings omitted and shown as gaps. Wave direction and local stone observations are not included in this dataset.
Why the shoreline matters
Actual NOAA charted geography checked against independent Great Lakes water/land mapping. These findings are not live surf or a rock-finding forecast.
AGATE BEACH · OPEN LAKE
337° NNW
Historic NOAA coastline tangent suggests a northwest-facing research shoreline. Six independent water/land tests agreed with the lakeward side.
2014 chart source · research bearing only, not a surveyed 2026 shoreline normal.BAYSHORE PARK · PROTECTED HARBOR
2 charted piers
NOAA charts two substantial harbor-entrance piers. A mapped pier does not tell us how much the waves diminish behind it.
Pier geometry dates to 2004–2014. NOAA soundings cover the harbor, but current depths, structure condition and wave attenuation remain unverified.What NOAA actually charts beneath the harbor
Verified source coverage, not a live depth survey or harbor-wave forecast. These geographic areas overlap, so their record counts cannot be added together.
| Study area | Soundings | Depth contours |
|---|---|---|
| Inner southwest harbor | 17 | 6 |
| Harbor center | 41 | 12 |
| Entrance piers | 38 | 12 |
| Lake approach | 42 | 2 |
Underlying NOAA ENC sounding source dates: 2004–2020. The contour records provide no individual survey dates. Charts cannot establish current harbor depths, navigable clearance, wave shelter, or whether rocks have been exposed.
New research: where current harbor observations could come from
A recent USACE harbor survey record is now confirmed, while none of these sources establishes measured waves inside Grand Marais Harbor.
- USACE eHydro SurveyJob — authoritative survey catalog metadata, not a live wave gauge. Live source lookup confirmed 10 Grand Marais survey jobs, with the most recent survey dated July 30, 2026. The original 2026 USACE survey chart is publicly available. The chart documents multibeam soundings in feet relative to IGLD 1985. Original data verified: the 2026 USACE ZIP contains 17,804 numerical XYZ elevations in US survey feet relative to IGLD 1985; these are elevations, not current water depths. New survey coverage check: the surveyed entrance-channel area lies outside both Agate Beach and Bayshore Park research footprints. These soundings cannot establish water depth or wave exposure at either beach. It is not a wave gauge.
- GRMM4 — nearby observed wind; available station rows do not show measured wave heights.
- 45172 Grand Marais buoy — offshore seasonal station, reported recovered for winter as of October 15, 2026. Not a sheltered-harbor wave measurement.
Decision-engine status: historic harbor structures documented; actual harbor wave heights, wave transmission, beach safety and new-stone exposure not verified. This prototype does not convert wind or survey dates into wave predictions.
Source: NOAA ENC Direct, checked against GLAHF mapped water. Neither beach has a validated wave or safety verdict.
Rock collecting and public access: Public beach access does not by itself authorize removing rocks from every segment. Check posted township rules and seasonal access notices. National Park Service beaches can prohibit collection. This design does not provide directions to unverified parking gates.
Prototype only. Simulated wave scenarios are embedded in this page; the separate historical buoy chart loads dated NOAA observations. The shoreline summary is historic NOAA chart research, not live beach weather. No device location, personal data, account, tracking, or map key is needed.