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:

31 MAY 2023

Temp/Wind data from:

NOAA Digital Forecast
Wed Thu Fri Sat Sun Mon
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Dumps W 12 0 W 13 0 WNW 13 0 WNW 14 0 W 12 0 SW 13 0
Mt Diablo WSW 12 674 WSW 13 1268 W 14 1953 WSW 13 4994 W 13 6679 WSW 16 1513
Ed Levin WNW 10 1366 WNW 12 1804 NW 13 2413 W 12 3360 WNW 11 6732 W 11 2654
Mission Peak W 11 923 W 12 1349 WNW 11 1804 W 12 2476 W 12 5614 W 12 1804
Potato Hill ENE 9 5102 W 10 6754 WSW 9 8950 WSW 10 10784 SW 11 10388 SW 11 9986
Mt Tamalpais W 12 731 W 12 818 WNW 13 818 WNW 16 899 WSW 12 818 SW 13 681
Tollhouse W 9 1831 W 9 6064 W 11 7522 WSW 10 10987 SW 9 10987 SW 10 8022
Elk Mountain W 9 11366 W 9 11709 W 8 14043
Big Sur WSW 9 0 WSW 9 0 NW 11 0 WNW 13 105 W 10 0 SW 8 0
Ft Funston W 12 0 WNW 16 0 WNW 13 0 WNW 14 0 W 12 0 SW 13 0
Marina Beach W 11 0 W 12 0 WNW 11 0 WNW 13 0 W 11 0 WSW 11 0
Dunlap W 9 0 W 9 611 W 10 3342 WSW 9 5683 NNW 10 5794 WSW 9 3711
Weaver Bally W 10 4153 W 14 4767 W 13 6610 W 11 9265 W 11 10603 SE 11 10603
Timberline WSW 8 11942 WSW 8 12140 WSW 7 13163
Burn Launch W 9 4690 WSW 11 2812 N 5 7114 E 6 10278 S 9 10278 E 9 9265
Hat Creek Rim WNW 12 5528 WNW 13 4648 NNW 11 9816 W 10 11303 NW 11 12305 N 11 11881
St John E 8 0 NW 10 1597 NW 10 3715 W 10 6939 ESE 10 8327 SSW 11 7503
Noel Springs ESE 7 14991 ESE 8 15568 E 6 16700
Lake McClure W 9 3349 WNW 10 6443 WNW 12 7856 W 11 9770 W 10 9970 W 10 8221
Sugar Hill WNW 8 4277 E 5 2975 WNW 9 7826 E 9 9252 NE 10 9656 NE 11 9049
Goat Mountain N 10 6232 W 11 6232 WNW 10 8830 NW 12 11799 W 12 12844 WNW 12 9402
Mt Vaca WSW 12 1386 SW 12 2087 WSW 12 5413 SW 13 7177 SW 13 7472 SW 14 2577
Hull Mountain WNW 9 4516 WNW 13 6158 W 11 8040 W 11 10922 SSW 11 11328 W 11 10922

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]