NEWS:

Feb 16, 2021
- Problems getting data from National Weather Service began on Feb 11 impacting operation of the Soaring Predictor software.
The service seems to be working again at about 75% as of this morning, Feb 16.


Backup data is being sourced from WeatherAPI.com however, their free service is limited to 3 days. If you see a three day forecast for your favorite site, thank the WeatherAPI folks. The full 5-day forecasts are receiving input data from the National Weather service (thank them too :-).

Sounding

Station:

KOAK (alt)

Date/Time:

21 SEP 2021

Temp/Wind data from:

NOAA Digital Forecast
Tue Wed Thu Fri Sat Sun
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Dumps E 12 0 W 11 0 W 6 0 WSW 10 0 WSW 13 0 W 13 0
Mt Diablo SE 8 2815 S 12 1169 NNE 11 2042 W 9 2042 WSW 13 1169 WSW 12 0
Ed Levin SSE 9 2974 S 9 1741 N 8 2411 WNW 6 2411 WNW 8 1134 W 8 0
Mission Peak WNW 10 2738 S 10 0 N 6 1653 S 8 1728 W 9 0 W 9 0
Potato Hill N 13 2205 S 10 2205 SW 10 3629 NE 10 4279 NE 6 4842 SSW 6 4034
Mt Tamalpais NE 16 2301 WNW 9 0 NW 12 0 WSW 6 0 WSW 9 0 WSW 9 0
Tollhouse N 10 1264 SW 11 1102 SW 3 729 W 4 1102 WSW 4 729 SW 3 143
Elk Mountain SSW 8 3557 SSW 5 1336 NNE 10 3557 WSW 5 3801 W 5 2923 WSW 5 1336
Big Sur ESE 9 0 SSE 4 0 NNE 4 0 E 6 0 WSW 3 0 NW 3 0
Ft Funston SSW 12 0 W 10 0 W 6 0 WSW 10 0 WSW 14 0 W 14 0
Marina Beach WSW 13 0 W 8 0 NW 6 0 WSW 8 0 W 10 0 W 11 0
Dunlap W 9 274 SW 10 274 W 6 0 WSW 8 163 WSW 8 0 WSW 6 0
Weaver Bally ENE 9 0 W 11 0 NE 12 0 NE 6 669 W 6 226 W 4 0
Timberline SW 8 12214 W 8 10126 W 7 13479
Burn Launch SSW 13 1512 SW 17 830 ENE 10 0 NE 9 1839 SW 10 1512 SW 10 421
Hat Creek Rim WNW 10 2554 W 10 729 ENE 10 1288 W 8 3242 W 9 2760 W 9 1830
St John S 9 0 SE 11 0 NNW 12 0 NE 10 739 SW 6 0 S 6 0
Noel Springs SSE 10 2332 SE 11 1815 NNW 14 1815 E 10 2804 S 6 2332 S 6 721
Lake McClure NNE 9 3741 ENE 11 3097 W 6 2840 W 6 3097 W 6 2840 W 6 2186
Sugar Hill E 14 718 WSW 18 0 ENE 11 0 E 11 718 W 10 823 WSW 9 26
Goat Mountain SE 14 5729 S 11 4080 ENE 8 3845 E 8 5078 W 9 3978 W 10 3161
Mt Vaca NE 8 2862 WSW 8 1619 N 8 2328 WSW 5 2268 SW 5 1779 SW 6 1019

DISCLAIMER: These estimates are intended to assist in daily site selection only.  No warranty is made concerning the accuracy of these estimates.  These estimates cannot be used to determine if conditions are safe for flying.  Conditions should be evaluated at the launch site by experienced pilots before launching.

Sounding: This is the site at which the weather balloon was released.  If the flying site predicted is far from the sounding site, the estimate is not valid.  Also, the sounding is done at 12Z (4AM PST).  If a front comes through, the sounding is no longer valid. The sounding becomes less valid later in the day.

Thermal Ceiling: the lower of the height at which the thermal stops rising and the cloud level.  We can't fly into the clouds, so it doesn't matter how much higher the thermal goes.  Remember that we can't get to the top of the thermal because of our sink rate.  Our upper limit will be lower than the reported ceiling.

Soaring Ceiling: We will stop going up when the thermal is rising just fast enough to offset our sink.  It is estimated that this happens when the temperature difference between the thermal and the surrounding air is about 2 degrees F. This number is an estimate of the maximum altitude we might reach if we start at launch height, and should be more reflective of our chances of soaring than the thermal top. Please let me know how this compares with actually flying, and I will adjust it as necessary.

Above Launch: The difference between how high we might get and how high we start. This estimate does not account for ridge lift.

High Temp: This estimate is taken from the National Weather Service or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com estimate of cloudiness, and the angle of the sun.  When the sun is directly overhead on a sunny day, the puddle temp is esimated to be 25 degrees warmer than the high ambient temperature. This estimate now includes a rigorous calculation of the Sun Angle, and accounts for the seasonal differences in zenith and daylight hours.

Wind: This estimate is taken from the National Weather Service or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com website.

Thermal Type: Blue (no cloud formation) or White (Cloud formation)

Thermal Index: This is the maximum difference in temperature between the rising packet of air (the thermal) and the surrounding air.  The difference in temperature is responsible for the buoyancy of the thermal, and larger temperature differences mean faster rising thermals.  A value of about 10 F or greater often means that the conditions are soarable.  Values above 20 could indicate rowdy thermals.

Validity of estimate: Many factors (including strong wind, fronts, cloud shadows, incorrectly predicted temperatures, etc) can affect the validity of the estimates. 

Author: Tad Hurst

Supported By: Alan Crouse [email protected]