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

Date/Time UTC:

260911/1200

Temp/Wind data from:

NOAA Digital Forecast
Fri Sat Sun Mon Tue Wed
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Dumps W 11 0 W 20 0 NW 18 0 WNW 16 0 W 11 0 W 10 0
Mt Diablo WSW 11 0 WSW 18 0 W 9 0 WSW 9 0 WSW 9 0 W 9 0
Ed Levin W 8 276 W 14 0 WNW 11 0 W 9 0 W 8 0 WNW 6 0
Mission Peak W 9 0 W 14 0 WNW 11 0 WNW 9 0 W 9 0 WNW 8 0
Potato Hill WSW 6 3024 W 20 0 NNE 5 0 ENE 4 0 E 5 0 E 5 0
Mt Tamalpais W 10 0 WNW 19 0 NW 12 0 WNW 11 0 W 6 0 W 5 0
Tollhouse SW 5 4419 WSW 5 3737 WSW 5 0 WSW 4 0 SW 4 0 WSW 4 0
Elk Mountain W 10 3864 W 13 0 NNW 8 0 W 6 263 WSW 6 733 SW 6 263
Big Sur N 3 0 W 6 0 N 6 0 N 3 0 W 3 0 W 2 0
Ft Funston W 12 0 W 20 0 NW 18 0 WNW 16 0 W 11 0 WSW 9 0
Marina Beach WNW 10 0 WNW 16 0 WNW 17 0 WNW 12 0 WNW 10 0 W 8 0
Dunlap WSW 6 413 WSW 6 0 W 5 0 WSW 5 0 WSW 5 0 WSW 5 0
Weaver Bally W 12 782 W 16 0 WNW 12 0 NNW 5 0 SSW 8 0 ESE 9 0
Timberline W 11 627 W 16 0 NW 16 0 WSW 6 0 SW 5 0 S 5 0
Burn Launch SW 9 2116 SW 14 0 W 4 0 NE 11 0 SW 6 0 SW 4 0
Hat Creek Rim WSW 11 3157 SW 18 0 N 6 0 E 6 0 W 8 99 W 6 0
St John WNW 6 0 W 18 0 N 6 0 W 6 0 ESE 5 0 E 6 0
Noel Springs SSW 5 1483 WSW 14 0 WNW 6 0 WNW 9 0 SE 5 0 ESE 5 0
Lake McClure W 8 4279 WNW 10 1503 WNW 10 190 W 6 669 WSW 6 669 W 6 669
Sugar Hill WSW 16 1493 WSW 19 522 W 5 0 ENE 5 0 W 4 0 ENE 5 0
Goat Mountain W 9 8743 WNW 9 4192 NNW 9 0 NW 6 459 SW 6 743 SW 5 266
Mt Vaca WSW 8 453 WSW 13 0 WNW 8 0 SW 6 0 SW 5 0 SW 5 0
Hull Mountain W 11 1970 W 17 218 NW 17 218 NW 6 218 SW 5 218 NE 5 218

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]