Windy.com is the latest and greatest to add to our forecasting tool box.
This page was prepared for the VSA Seminar Series, January 12, 2019.
You may download the App – called Windy.com – to your device or, more simply, go to the Williams Soaring Center home page – https://www.williamssoaring.com/ Select the Weather icon, then select the Windy.com icon – https://www.windy.com/39.155/-122.149?800h,38.177,-122.149,7,i:pressure,m:eKqacLA There is no need to load the app onto your phone, or computer, since it is set up to open from the WSC site, and it is centered on WSC.
Although I highlight a few of the many features below, you will discover there are several tutorials on You Tube which are readily available, and there are thousands of reviews which highlight the many features of this helpful App. This is a boon to pilots of all types.
After you open Windy.com via the link provided by Williams Soaring Center, you will see it shows the wind flag centered on the gliderport, but you can move it to anywhere on the page with your mouse, zoom in and out, put it anywhere. When zooming, you may find it easier if you use the + and – buttons in the top right corner, rather than the scroll wheel on your mouse.
I’ll walk you around this first page in the next few images…
In the lower part of the screen – see the Forecast Box (enlarged below in the next image). The slider along the top of the box is on the current time, but you can slide it to the right to see several days in advance, for the fcst for the location under the wind flag. Read the info vertically. In this illustration, I moved the slider to teh left about 12 hours and we are at displaying the map for conditions at 12 PM (noon) on Friday 21 Dec, 2018. Cloudy, partial sun, 58 deg F, no rain, wind is 5 kts, gusts to 11, from the NNE:
The bottom line of the above forecast initializes on “Basic”, but move to the right of “Basic” along that bottom line and click on “Wind”, as forecasted by each of the available weather models, of which there are four (note links to the wiki pages are provided):
Each model has a different resolution in the modeling programs (they resolve the input data with more geographic refinement), and vary in the amount of time they project forward. I just stick with the European model on this system, since I mostly use this Windy.com tool for more than two days before flying. As you can see, it is a bit of alphabet soup trying to keep these model names sorted. Although Windy .com can be very helpful for showing you a generalized forecast, particularly several days in advance, the short range soaring forecast for a specific flying area is best provided by Dr Jack’s RASP.
A side bar on the RASP
RASP is THE BEST source you have for a specific area forecast. It is important to have an understanding of what the RASP is offering to you. I recommend that every pilot prepare for each new soaring season with a review of the info pages published by Dr Jack. They are easy to understand and will assist you immensely in putting the RASP fcst into perspective. Here are two quotes from the “parameters page“. The first relates to the models and the second to the map display:
The parameters are averages over grid squares as forecast by the WRF (Weather Research and Forecasting) model. …
….The model topography is plotted as black contours, to assist in location identification but also to emphasize the smoothed nature of the model topography.
Back to Windy.com
Still on the bottom line of that box select Meteogram. You can see all the items listed in the left column, including the clouds, over that spot where you have your wind flag located. Remember to use the big red X (white x in a red circle) to close each new display, rather than using the back arrow, so you don’t lose your page.
Shows the winds over the selected spot at all levels up past 30,000 ft
MB key (FYI) ( In case you are not familiar with MB levels):
1000 mb (approx sea level pressure) (1012 = 29.92 on the baro)
850 = 5,000 ft
700 = 10,000 ft
500 = 18,000 ft
300 = 30,000 ft
To the right of the “NEMS” selection is the “Compare” key and can see how the forecasts vary, according to which model you are using.
Now direct your attention to the right margin of that first screen you pulled up. That vertical menu tree allows you to display various elements on the map.
See the right hand margin menu
Note it usually starts with “Wind” button on, and lower down you see the level / altitude of those winds. The start up default from the WSC page is 2,000 m or 6,400 ft. BTW – if you want to change your display setting to Meters vs feet, Degrees C vs F, MPH vs kts, etc, use the setting menu, found on the top left corner of the main screen (the three lines next to the search box)
Move you mouse pointer around on the map. Right click on any location and it allows to to see forecast for that particular spot, or a sounding, etc. This is what appears on the right mouse click…
If you look at a sounding, be sure to use the magnifier in the lower right to zoom into the lower altitudes….
See a Meteogram for the location you have selected with your points…
Change to Airgram and see the winds and clouds that are forecasted for any time in that spot…
On that right menu tree you may select “Flying”at the top and then display multitude of things – clouds at various levels, freezing level, temps, rain,etc. It is really amazing, but you must be aware of what location and altitude level you have selected….
I could go on and on with examples, but you will soon become familiar with it by simply by experimenting on your own.
Validate the usefulness of this App and these models. Compare it to actual conditions. Walk out side, examine the sky, then see what the models say about the clouds and the wind above. You’ll be amazed.
When you see on the Forum that Kempton, Russ, or Ed are high in the wave somewhere, go to their tracking device, and note their location and altitude. Switch back to Windy.com, place the cursor on their current location and you may observe wind direction and strength at various altitudes above and below them, see clouds that may be below or above them, see the ambient air temp they are “enjoying”, etc..
I encourage pilots to use this App to gain a perspective of the atmosphere that has previously been difficult to gain. Review the location and strength of the Pacific High and the Alaskan Lows as they move towards our gliding area. See how the Lows are sometimes blocked or deflected and either weakened or strengthened as they move towards us. Becoming more aware of the dynamics that are occurring 24 hours prior to your flight will help you to understand why the forecast may vary, or underscore why it is sometimes acutely accurate.