Alpena Harbor Light
Live NOAA readings, Lake Huron, MI, station APNM4
Alpena Harbor Light is reading 5 kt from the NW, gusting 7, measured 27 minutes ago.
Over the last 12 hours it has run 1–13 kt on the hour, and its strongest single reading was 13 kt 5 hours ago.
All readings
Knots, newest on the right, never interpolated — a gap is a gap in the record.
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APNM4, the morning after, Mon 12 Oct
What last night's forecast was worth
Yesterday the Alpena Harbor Light meter topped out at 14 kt at 5 pm. The night before, NWS said 7 kt, Forecast Lab — what Premium is served — 8.6, the other 4 models 6.9–8.4 kt. That morning’s lake-breeze watch expected no lake breeze, and none came.
How this was measured
One day is an illustration, not a record — a model that reads low every day will still land one. The number that means anything is the scored one over 90 days, in how our calls are graded.
Each model row is the highest wind it forecast for the 6am–6pm window at this meter, taken from the freshest run that existed before midnight the night before — between 10 and 23 hours ahead, depending on the hour. A model with no run in that window shows no call; it is never filled in from a closer-range forecast. Raw rows are the provider's own numbers; NWS + this meter's bias is that forecast shaded by this station's own measured error. That correction is Premium: a Premium rider is served the corrected row, and a free or signed-out rider is served the raw NWS row above it. The meter's figure is the strongest reading of each hour from this station's stored observations. Hours over your floor are counted from those readings alone; rideable is the nightly scorer's verdict and also weighs gust, direction and waves, so the two numbers are not the same measurement and are never added. Knots throughout.
LAKE-BREEZE CALLS · ALPENA HARBOR LIGHT
A lake breeze (thermal wind) is the onshore wind that fills in on a hot afternoon. No forecast model predicts it. WindStoke tells you the morning it’s coming, so you get more days on the water.
Since June 6 we’ve called it 42 mornings at Alpena Harbor Light and it showed 20 times. The forecast had those afternoons at 9 kt. They blew 15.
- Sat Aug 15Came in 4 pm
- Tue Aug 11Came in 5 pm
- Fri Aug 7Came in 11 am
- Sat Aug 1No lake breeze
- Fri Jul 31Came in 4 pm
How this was measured
Called: our morning lake-breeze watch flagged that afternoon at Alpena Harbor Light. Came in: the wind at the meter (APNM4) turned onshore and built. Forecast: the model forecast’s afternoon peak for the spot as of that morning (HRRR). Blew: the afternoon’s peak sustained wind at the meter. 10 kt is about the least you can ride, on a big kite or a foil. The 9 and 15 kt above are averages over the called days it showed with a forecast on file (10). The last 5 calls are listed, misses included; 2 calls when the meter was down are left out. On the 29 mornings we stayed quiet, a lake breeze showed 10 times (every other graded morning, including the ones the watch saw primed but held back). Only spots where the call has beaten the quiet mornings get this card, and those are the spots it goes out from, by push or email.
APNM4, where the wind comes from, 40 days
Which way the working wind blows here
40% of the hours over 12 kt came from SE–S in the last 40 days, though the wind sat most often in the NW — that is the lighter wind. The dark wedges are the ones to read.
How this was measured
Floor is the 12 kt default; set a wind floor on an alert here and the rose is cut at yours. Hours the meter read at or over the floor: 239 of 869 (28%). Over the floor at the meter is not a rideable hour: gust, your direction window and the meter's own siting are not in it.
One reading per hour, the hour's strongest sample, from this meter's own readings over the last 40 days. Sixteen sectors. The two roses are each drawn to their own total: a light wedge is that sector's share of ALL hours, a dark wedge its share of the hours at or over the floor, and the rings are marked in the dark set's percentages. They are two distributions, not one inside the other. Direction is where the wind blows FROM.