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:

260316/1200

Temp/Wind data from:

NOAA Digital Forecast
Mon Tue Wed Thu Fri Sat
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Dumps NW 9 0 NW 10 0 WNW 9 0 NW 10 0 WNW 11 0 WNW 13 0
Mt Diablo NNE 8 4721 NE 6 6039 NE 6 5653 NNW 8 6662 WNW 10 6937 W 13 3792
Ed Levin N 9 983 NNW 8 2968 NNW 8 3342 NNW 10 3815 NW 11 3815 WNW 11 748
Mission Peak N 10 755 NNW 9 2122 NW 9 2761 NW 11 3091 NW 11 2761 WNW 13 520
Potato Hill WNW 4 1455 S 4 2725 S 4 2210 ESE 4 2725 WSW 6 2725 NW 8 0
Mt Tamalpais NW 5 583 NW 5 869 WNW 5 869 WNW 6 985 WNW 8 869 WNW 10 0
Tollhouse SW 5 1270 W 4 3651 WSW 5 5007 WSW 5 5007 SW 5 5326 WSW 6 3651
Elk Mountain NNE 6 3320 W 6 4709 W 5 4230 WNW 5 4230 WNW 6 4709 W 6 0
Big Sur NNE 6 0 NE 6 111 NE 6 111 NNE 5 1166 NNE 6 1166 NW 8 0
Ft Funston NW 8 0 WNW 9 0 WNW 9 0 NW 9 0 WNW 11 0 WNW 13 0
Marina Beach NNW 6 0 NNW 6 0 WNW 6 0 NW 8 0 NW 8 0 NW 9 0
Dunlap WSW 4 0 W 4 407 WSW 4 1153 W 4 1665 WSW 4 1665 WSW 5 407
Weaver Bally WNW 9 360 W 11 1313 WSW 9 1313 W 10 1313 W 11 360 W 13 0
Timberline N 8 2772 W 9 3515 W 10 3192 N 9 3835 WNW 10 3515 WNW 11 0
Burn Launch NNE 5 2279 WSW 9 3077 SW 12 3859 WSW 9 4152 WSW 13 4002 WSW 13 1301
Hat Creek Rim NNW 3 2706 W 6 4130 W 8 4500 W 6 4819 W 9 4819 WNW 10 771
St John NNW 11 0 WNW 10 0 WSW 10 0 NW 10 814 W 13 814 WNW 14 0
Noel Springs NNW 10 3128 WNW 8 4368 S 8 4368 WNW 8 4687 W 10 4687 NW 12 1695
Lake McClure SW 4 825 WSW 3 2884 WSW 4 2884 W 5 2884 WSW 5 3606 W 8 2212
Sugar Hill W 8 0 WSW 10 2052 WSW 12 2377 WSW 10 2377 W 9 2052 WNW 13 0
Goat Mountain N 8 6101 E 6 7591 E 5 9772 N 8 10675 N 8 10983 NNW 10 6551
Mt Vaca N 12 2866 N 9 2457 NNW 8 3377 NNW 9 4329 NW 9 3858 W 12 594
Hull Mountain NW 10 4088 W 12 4236 W 13 4236 WNW 12 4528 WNW 13 4236 WNW 14 637

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]