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:

23 JUN 2021

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 WSW 13 0 W 11 0 W 13 0 W 14 0 W 14 0 W 13 0
Mt Diablo WSW 13 1175 WNW 11 1175 W 16 1493 WSW 11 6225 WSW 12 6225 WSW 12 3390
Ed Levin WNW 12 1988 NW 10 1938 W 9 2092 WNW 9 3971 WNW 9 4839 W 9 3594
Mission Peak WNW 14 1811 WNW 12 1743 W 11 1912 W 10 2736 W 10 3323 W 10 2351
Potato Hill SSW 16 8757 ESE 13 9568 SSW 10 10573 SE 10 11752 SW 9 12335 SW 11 11946
Mt Tamalpais W 14 1636 W 14 1665 W 13 1665 W 11 1824 W 9 1824 W 9 1846
Tollhouse SSW 10 3063 SSW 13 1750 NW 6 2439 WSW 4 8723 WSW 4 9744 SW 4 9542
Elk Mountain WSW 9 9125 W 10 9936 W 10 10933
Big Sur SW 8 470 NNW 5 492 ENE 4 677 NW 5 970 WNW 4 1659 WNW 4 1018
Ft Funston WSW 12 0 W 11 0 W 12 0 W 14 0 W 14 0 W 13 0
Marina Beach WSW 14 0 W 10 0 W 9 0 WNW 10 0 WNW 11 0 WNW 11 0
Dunlap SW 10 1359 S 11 0 W 8 543 W 8 8397 W 8 9497 W 8 9189
Weaver Bally ESE 12 5957 NW 5 7070 NNE 5 11875 W 5 16059 SE 6 16247 SW 8 15871
Timberline ENE 10 7395 NE 8 7395 WSW 6 9956 W 9 16112 SW 8 17135 SW 8 15887
Burn Launch SW 12 10186 SSW 8 10800 ENE 8 11202
Hat Creek Rim W 12 9649 NE 12 9649 NW 10 11890 NW 11 12877 S 9 14461 WSW 12 14461
St John SE 9 13192 ESE 8 14159 E 7 15303
Noel Springs SE 12 8026 ESE 11 8945 ESE 9 14022 W 13 16743 WSW 10 17988 SSW 10 16964
Lake McClure NNW 9 4568 WSW 9 3919 W 8 5793 WNW 9 10078 WNW 9 11266 NW 10 11068
Sugar Hill W 9 9688 N 9 10090 NNE 6 10889 ENE 6 11718 ESE 10 12498 SE 10 13459
Goat Mountain SW 13 9945 WSW 8 10239 WNW 8 13271
Mt Vaca SW 9 1514 WSW 9 1760 SW 8 3480 WSW 6 9512 SW 8 9512 WSW 8 9105

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]