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:

15 AUG 2022

Temp/Wind data from:

NOAA Digital Forecast
Mon Tue Wed Thu Fri Sat
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Dumps W 8 144 WSW 7 144 WSW 10 144
Mt Diablo W 17 4043 WSW 16 6250 WSW 21 3683 WSW 12 902 SW 11 902 SW 12 0
Ed Levin WNW 10 3178 WNW 8 4705 SSW 8 3178 W 9 221 W 9 221 W 10 0
Mission Peak W 11 206 W 11 2648 SSW 11 206 SW 10 0 W 10 0 W 11 0
Potato Hill WNW 9 4099 ESE 8 6173 SSW 10 7761 SW 9 5170 SSW 9 7761 SSW 10 3740
Mt Tamalpais NW 13 4772 SW 5 4407 WSW 8 498 WSW 5 183 W 6 244 W 9 62
Tollhouse WSW 6 3107 SW 5 3472 WSW 5 3107 W 6 2363 WSW 6 2737 WSW 6 2737
Elk Mountain WSW 9 12325 WSW 10 15524 SW 11 15524
Big Sur SW 9 818 SW 9 1901 WSW 10 0 WNW 9 571 WNW 9 0 W 6 0
Ft Funston W 11 0 WSW 11 0 W 13 0 W 13 0 W 13 0 W 13 0
Marina Beach WNW 11 0 W 10 0 WNW 11 0 WNW 10 0 WNW 11 0 WNW 10 0
Dunlap WSW 6 11724 W 7 12396 W 7 14760
Weaver Bally WSW 9 0 S 8 4727 SSE 10 6452 W 9 8495 W 9 6986 SE 12 2225
Timberline NW 10 4901 SSW 10 8409 S 12 9400 SSW 9 8912 SSW 6 6227 SSW 10 1382
Burn Launch WSW 9 8040 WSW 8 8554 WSW 5 6959 WSW 8 5156 SW 8 6959 SSW 10 6390
Hat Creek Rim WSW 9 14446 WSW 11 16210 SSW 9 12483
St John WNW 6 4384 ESE 6 5698 SSE 9 6269 S 8 5091 NW 6 5698 SSE 10 1598
Noel Springs WSW 9 15857 WSW 10 18985 SW 11 18985
Lake McClure W 7 10455 WSW 6 12231 WNW 8 12429
Sugar Hill NNE 5 16660 NNE 4 18537 WSW 7 11823
Goat Mountain ENE 3 17052 SW 9 17052 SW 17 18741
Mt Vaca WSW 6 4250 WSW 16 5438 WSW 19 4250 W 14 2464 SW 8 2034 SW 9 0

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 ac_soaring@yahoo.com