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:

2 OCT 2022

Temp/Wind data from:

NOAA Digital Forecast
Sun Mon Tue Wed Thu Fri
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Dumps WSW 9 158 WNW 12 158 WNW 10 158
Mt Diablo WSW 14 482 W 13 482 SW 9 575 SW 8 2169 W 6 2547 W 8 2547
Ed Levin NW 6 2296 NW 7 3278 NW 7 4295
Mission Peak NW 8 2467 WNW 7 3491 WNW 7 4409
Potato Hill S 5 4719 WSW 6 5884 WSW 7 6173
Mt Tamalpais SW 9 930 W 6 1380 W 8 2335 WNW 5 3324 W 4 3550 W 4 2589
Tollhouse SW 5 620 WSW 5 1049 WSW 5 1476 WSW 5 2395 WSW 5 2592 WSW 5 2395
Elk Mountain S 5 2444 W 9 2804 W 5 2804 W 5 3685 WSW 5 3875 WSW 5 3875
Big Sur NW 10 2291 NW 10 2853 NW 9 3297
Ft Funston WSW 9 0 WNW 12 0 WNW 10 0
Marina Beach WNW 8 0 NW 9 0 NW 8 0
Dunlap WSW 5 134 W 5 458 WSW 5 993 WSW 5 1910 ENE 5 2015 ENE 5 1471
Weaver Bally ENE 5 1002 S 8 1002 N 4 1199 N 3 1388 NNE 3 1199 NNE 3 1199
Timberline NNE 8 1653 NNE 9 1653 SW 8 1653 N 5 2239 N 6 2044 N 6 2044
Burn Launch SW 7 6981 SW 3 8434 SW 5 9018
Hat Creek Rim WNW 8 2325 NW 6 3512 WNW 6 3512 WNW 5 4388 W 5 3698 WNW 5 3512
St John E 5 0 N 4 0 WNW 5 0 WNW 5 74 ESE 6 74 S 6 173
Noel Springs ESE 5 429 E 5 1466 SE 5 1566 E 5 2705 ESE 6 2509 ESE 6 1666
Lake McClure W 6 2632 WNW 8 3477 WNW 6 3589 WSW 5 4484 WSW 6 4581 WNW 8 4581
Sugar Hill SSE 8 574 SE 8 1588 SSE 4 1891 WNW 5 2490 SE 4 2191 W 5 2191
Goat Mountain NNE 9 3998 NNE 10 4189 N 6 5104 NW 5 5971 E 6 6573 NE 6 6573
Mt Vaca W 5 406 WSW 5 779 W 5 779 WNW 4 2188 NNE 4 2745 SW 5 2383
Hull Mountain WSW 7 7682 W 7 9356 W 7 11322

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