When the weather forecast predicts winds from the South West, for example, will that mean that sailors on the river surface will experience a South Westerly wind? In general, the unobstructed winds of weather forecasts and high in the air will differ from what sailors find. The reason is that these winds are deflected by hill, ridges and tall buildings around the Point. So wind at the water's surface can differ significantly from the forecast winds, even if the forecast is correct.
After several seasons sailing on the rivers around the point, I have collected enough experience with different wind conditions to know which which wind conditions arise at the river surface from the various unobstructed winds. They are summarized in the table below. For more details on how I determined the wind conditions on the surface, see "Decoding the Winds." The major finding is that hills and buildings on the river shores tend to redirect winds to blow along the rivers, either directly upstream or downstream. Hence they are often reported in that way in the table.
The rivers around the point have been divided into four regions indicated on the map below.
A few rules of thumb will answer many questions:
The best wind on each segment of the river comes when the unobstructed winds blow exactly along the length of the river.
The section of the Allegheny river marked above is aligned roughly West-South-West to East-North-East. A West-South-West wind will give the best sailing since it will blow unobstructed along its length.
There are wind shadows in the lee of anything big.
The same West-South-West winds will be obstructed by the high ridge along the Western shore of the Ohio and Mon, so that winds will be erratic close to that shore.
Sailing works best with unobstructed winds over 5 mph.
Below that speed, obstructions and natural variations in the wind will leave a lot of periods of calm. The conditions I like best come at 10 mph for unobstructed winds. By 15 mph (when whitecaps form), there are likely to be erratic and strong gusts that make sailing hard work.
| Unobstructed winds | Ohio River | The Point | Allegheny River | Monongahela River | Sailing day with (near) matching wind | |
|---|---|---|---|---|---|---|
| North N | Winds blow upstream. Experience includes steady winds and erratic winds. | Winds can be erratic; obstruction from buildings on North shore. | Winds can be erratic; obstruction from buildings on North shore | Winds generally blow upstream, but can be erratic in places. |
August 27, 2011 N July 21, 2012 N |
|
| June 27, 2009 NNW September 13, 2009 NNW June 17, 2010 NNW July 30, 2011 NNW |
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| North West NW | Best overall wind conditions for sailing on all regions. | Winds blow steadily upstream. | Winds blow steadily upstream, dividing at point. | Erratic winds blow upstream; periods of calm possible | Winds blow steadily upstream. |
August 11, 2011 NW August 16, 2011 NW June 26, 2012 NW August 1, 2012 NW September 9, 2012 NW |
| July 8, 2009 WNW August 6, 2010 WNW August 16, 2010 WNW June 13, 2011 WNW August 7, 2011 WNW |
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| West W | Variable. Winds may be blocked by hills on southern shore. | Winds blow steadily upstream, dividing at point. | Winds blow steadily upstream | Winds tend to blow upstream; some erratic wind possible. | August 21, 2011 W | |
| August 9, 2009 WSW August 29, 2009 WSW June 27, 2010 WSW July 24, 2010 WSW September 5, 2010 WSW |
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| South West SW | Best sailing is on the Allegheny. | Winds blocked by hills on southern shore; erratic. Winds can be funneled into rivercourse through valley at West End Bridge and spread from there into upstream and downstream directions. | Erratic winds; obstruction from hills on southern shore. | Winds blow steadily upstream | Erratic winds; significant obstruction from hills on Southern shore. Winds may even blow momentarily from NE! | July 17, 2010 SW July 18, 2011 SW August 13, 2011 SW September 4, 2011 SW June 30, 2012 SW August 17, 2012 SW |
| June 22, 2011 SSW August 6, 2011 SSW |
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| South S | ||||||
| South East SE | Best sailing on the Ohio and Mon. | Winds blow steadily downstream. | Winds blow steadily downstream. | Erratic; obstructions from buildings on Southern shore. Winds become more erratic farther upstream. | Winds blow steadily downstream. | September 11, 2010 SE September 3, 2012 SE |
| September 6, 2009 ESE | ||||||
| East E* | Winds blow downstream | Winds blow downstream | Winds blow downstream | July 14, 2011 E August 26, 2012 E (and SE) |
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| North East NE | ||||||
| Unobstructed winds | Ohio River | The Point | Allegheny River | Monongahela River | Sailing day with (near) matching wind |
*Experience on several days suggests that the forecast of Easterly winds is unreliable. These winds tend to arise only for a short time while wind direction changes. The forecasters seem to have trouble locating accurately the window in which the Easterly winds come. See July 14, 2011 and July 21, 2012.