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:

1 AUG 2021

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 11 0 W 10 0 W 12 0 W 14 0 WNW 18 0 W 16 0
Mt Diablo WSW 13 410 WSW 10 256 WSW 12 659 WSW 14 0 WSW 12 256 WSW 13 907
Ed Levin WSW 8 567 W 5 567 W 8 718 W 8 123 W 9 334 W 9 567
Mission Peak W 10 37 WSW 6 37 W 9 106 W 10 0 W 10 0 W 10 106
Potato Hill SE 14 9832 ESE 12 9523 WSW 12 9675 SW 12 9523 NW 9 9242 WSW 10 9523
Mt Tamalpais WSW 9 0 W 8 0 W 9 0 W 10 0 WNW 12 0 W 13 0
Tollhouse SW 10 7025 SW 9 7025 W 5 7675 WSW 5 7025 WSW 5 1178 SW 4 1178
Elk Mountain W 10 9037 SW 9 7956 S 8 8809 SSW 6 8885 SW 6 8403 W 8 3571
Big Sur SSW 10 440 W 4 1910 W 7 8368
Ft Funston WSW 11 0 W 11 0 W 12 0 WNW 14 0 W 18 0 W 16 0
Marina Beach W 8 0 WNW 8 0 WNW 10 0
Dunlap SW 10 6939 W 10 6939 W 9 7521 WSW 9 6939 W 9 2915 WSW 8 2915
Weaver Bally WNW 10 7022 W 9 6648 SE 10 6268 SSE 6 6268 SW 9 6081 W 9 4481
Timberline SW 10 7305 SSW 8 7149 ENE 8 7149 S 9 7149 SSW 9 6994 W 9 5162
Burn Launch SW 11 6923 SSW 12 7236 SW 10 7992 SW 14 6923 WSW 11 6686 WSW 11 6923
Hat Creek Rim W 10 8464 W 11 8544 W 11 9284 SW 13 8464 W 8 7387 W 10 7884
St John SE 14 5583 ESE 11 5583 WSW 10 5583 SW 11 4962 NW 9 3000 W 9 5583
Noel Springs SE 13 8163 ESE 11 8008 SSE 9 8163 SSE 9 7852 NW 8 6978 WNW 8 7930
Lake McClure SE 11 9798 WNW 10 9174 W 8 10071 WNW 10 9174 WNW 10 2994 W 8 6828
Sugar Hill W 5 5902 WSW 6 10681 WSW 9 11182 WSW 23 12035 W 11 5745 W 10 6180
Goat Mountain S 12 9503 SSE 8 9503 WNW 8 10225 WNW 10 9135 WNW 10 8978 W 9 8978
Mt Vaca SW 8 1036 SW 4 788 SW 5 2181 SW 8 557 SW 5 1036 SW 6 2181

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