Fellow Flyers,
Since we have many newer pilots flying Woodrat which implies new wind forecasters, I'd like to remind all to really think of the two flows you always must consider when you fly in the mountains. First, as you make your forecast for the days flying always divide the winds into two separate forecasts. You have the valley winds forecast (think 1000 ft or so thick) and the general flow forecast (or synoptic flow). The best place to get an accurate forecast for the valley winds around here is right where the NWS office is which is next to the airport right in the middle of our biggest valley. If you have an idea of the valley winds here you will know what the valley winds are doing in the rest of the area. Doing point forecasts for winds at a specific spot, like Ruch or any small valley, should be taken with some scepticism. The other accurate valley winds forecast by NWS is the Grants Pass valley. Again, the other big valley in the area that helps you predict what the smaller valleys are doing. Both of these forecasts are easily accessible on the RVHPA wx site or Scotts wx site. For those that use the weather models for forecasting valley wind flows, the RUC, GFS, etc., always keep in mind that it will give you a general idea of the valley flow but they are not capable of accurately predicting valley flow. Weather model winds forecasts for around here become much more accurate at around 5000 ft and above in this area.
Once you have an idea of the valley winds in your mind, next build your general flow forecast. This is always easier because there is so much good information using the weather models. But first always check to see what our local professionals think by seeing what winds they are forecasting for the high ground which is up in the general flow. And by high ground I mean at the 6000 to 7000 ft level, which means the Siskiyou ridge area SW of Woodrat 15 to 20 miles. On rvhpa wx this area is listed as NWS cascade/siskiyou mountain. Once you see what our locals think then go to the weather models (RUC, GFS, NAM) on xc skies or rvhpa wx and pay special attention to the 4000 ft to 8000ft forecast winds.
Now that you have your two wind flow forecasts in mind, you must figure out how the two interact for your days flying. This is the complicated part and often comes from your own experiences and, better, listening to others experiences under similar conditions. Just keep in mind that wind flow in mountains is complex and varied but somewhat predicatable if you have all the information. Always give yourself a bigger margin for error at a site where the valleys are narrow because constriction effects can really make the wind speed up and surge. Woodrat is a site with many constrictions nearby-- the LZ area being one. For all you paraglider pilots out there, as a general rule, any wind forecast you see that goes over 10 mph should give you pause to study the forecasts in more detail before you fly. And if you do fly, fly with more awareness. 10 mph wind can easily become 20 mph or more in mountain/valley dynamics.
Most of my valley flow and general flow education came from not only flying in it, but studying the many wind recording sites in the area and the mfr ballon release wind data for 5 pm (the mfr skew-t on RVPA wx), especially after I have just flown. For high terrain wind information (gives an idea of general flow) look at Squaw Peak (15 miles S), Parker Mt.(38 mi ESE), Sexton(32 mi NW), and Onion (34 mi W). For valley flow I look at Medford airport, Ashland airport, Provolt, and Grants Pass.
All these wind recording sites are visible on the Mesowest site under Current Winds. Just hover the pointer over the recording station and click it to see the last 24 hrs of wind data. I'll soon change the RVHP wx site to make it eaiser to just click on these weather stations.
Hayden
Since we have many newer pilots flying Woodrat which implies new wind forecasters, I'd like to remind all to really think of the two flows you always must consider when you fly in the mountains. First, as you make your forecast for the days flying always divide the winds into two separate forecasts. You have the valley winds forecast (think 1000 ft or so thick) and the general flow forecast (or synoptic flow). The best place to get an accurate forecast for the valley winds around here is right where the NWS office is which is next to the airport right in the middle of our biggest valley. If you have an idea of the valley winds here you will know what the valley winds are doing in the rest of the area. Doing point forecasts for winds at a specific spot, like Ruch or any small valley, should be taken with some scepticism. The other accurate valley winds forecast by NWS is the Grants Pass valley. Again, the other big valley in the area that helps you predict what the smaller valleys are doing. Both of these forecasts are easily accessible on the RVHPA wx site or Scotts wx site. For those that use the weather models for forecasting valley wind flows, the RUC, GFS, etc., always keep in mind that it will give you a general idea of the valley flow but they are not capable of accurately predicting valley flow. Weather model winds forecasts for around here become much more accurate at around 5000 ft and above in this area.
Once you have an idea of the valley winds in your mind, next build your general flow forecast. This is always easier because there is so much good information using the weather models. But first always check to see what our local professionals think by seeing what winds they are forecasting for the high ground which is up in the general flow. And by high ground I mean at the 6000 to 7000 ft level, which means the Siskiyou ridge area SW of Woodrat 15 to 20 miles. On rvhpa wx this area is listed as NWS cascade/siskiyou mountain. Once you see what our locals think then go to the weather models (RUC, GFS, NAM) on xc skies or rvhpa wx and pay special attention to the 4000 ft to 8000ft forecast winds.
Now that you have your two wind flow forecasts in mind, you must figure out how the two interact for your days flying. This is the complicated part and often comes from your own experiences and, better, listening to others experiences under similar conditions. Just keep in mind that wind flow in mountains is complex and varied but somewhat predicatable if you have all the information. Always give yourself a bigger margin for error at a site where the valleys are narrow because constriction effects can really make the wind speed up and surge. Woodrat is a site with many constrictions nearby-- the LZ area being one. For all you paraglider pilots out there, as a general rule, any wind forecast you see that goes over 10 mph should give you pause to study the forecasts in more detail before you fly. And if you do fly, fly with more awareness. 10 mph wind can easily become 20 mph or more in mountain/valley dynamics.
Most of my valley flow and general flow education came from not only flying in it, but studying the many wind recording sites in the area and the mfr ballon release wind data for 5 pm (the mfr skew-t on RVPA wx), especially after I have just flown. For high terrain wind information (gives an idea of general flow) look at Squaw Peak (15 miles S), Parker Mt.(38 mi ESE), Sexton(32 mi NW), and Onion (34 mi W). For valley flow I look at Medford airport, Ashland airport, Provolt, and Grants Pass.
All these wind recording sites are visible on the Mesowest site under Current Winds. Just hover the pointer over the recording station and click it to see the last 24 hrs of wind data. I'll soon change the RVHP wx site to make it eaiser to just click on these weather stations.
Hayden
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