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:

 30 MAY 2023

Temp/Wind data from:

 NOAA Digital Forecast
Tue Wed Thu Fri Sat Sun
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 16 0 W 17 0 W 13 0 W 13 0 W 13 0
Mt Diablo WSW 20 418 SW 16 647 WSW 18 2273 SW 13 3698 WSW 13 7181 WSW 13 6119
Ed Levin W 13 1566 W 11 1361 W 14 2813 W 11 4086 WNW 12 7628 WNW 11 6506
Mission Peak W 13 1211 W 13 1172 W 16 1744 W 12 2300 W 13 4301 W 12 3558
Potato Hill SSE 12 6282 SSE 9 6879 S 10 7622 SSE 10 8645 SSW 10 9452 SE 11 9851
Mt Tamalpais W 13 750 WNW 14 948 WNW 17 1080 W 13 1159 W 14 1274 WSW 13 969
Tollhouse SW 6 2300 WSW 8 6808 SW 8 7436
Elk Mountain W 10 6208 W 11 6491 W 12 6491 W 11 8116 W 11 9121 SSW 11 9520
Big Sur SW 5 0 W 11 0 WNW 13 0 WNW 10 37 WNW 12 254 WNW 10 134
Ft Funston WSW 13 0 W 17 0 W 18 0 W 13 0 W 14 0 W 13 0
Marina Beach W 11 0 W 13 0 W 13 0 WNW 11 0 WNW 13 0 W 11 0
Dunlap SW 8 0 W 8 691 WSW 10 2544 WSW 10 5550 WSW 9 6846 WSW 9 7050
Weaver Bally W 12 3626 W 13 4723 W 13 5145 W 11 6397 W 11 7017 ESE 12 7629
Timberline SW 9 3973 WNW 11 5455 W 12 5455 SW 10 6699 SSW 10 7936 S 11 8344
Burn Launch WSW 10 5197 WSW 9 4288 W 13 5197 WSW 9 7108 ESE 9 7942 E 11 7734
Hat Creek Rim W 12 5838 WNW 13 5955 NW 16 5955 NNW 10 8250 N 10 9469 ENE 11 9469
St John S 11 0 W 9 260 S 10 2744 SSE 10 5260 SE 9 6297 SE 10 6504
Noel Springs SSE 11 4826 SE 9 5360 S 11 5447 ESE 10 7761 ESE 10 8790 ESE 11 8994
Lake McClure W 8 2058 WSW 8 7693 W 9 8744
Sugar Hill NW 10 5633 WNW 12 5272 NW 10 5134 WSW 9 6945 NE 10 8168 E 11 8573
Goat Mountain W 10 2858 WNW 11 8235 W 13 8235 WNW 11 9053 WNW 11 10261 W 12 10261
Mt Vaca WSW 17 667 SW 12 1682 SW 13 4281 SW 12 6893 SW 13 7637 SW 13 7551
Hull Mountain NW 12 4580 WNW 13 6379 W 12 6379 SW 10 7649 WSW 11 8894 S 11 8483

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]