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 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 :-).

RASP and Windgrams should not be impacted

See the southern California RASP Model The detail grid covers the San Diego sites, but the 4km grid covers most of southern California.

Instructional video on reading the RASP Model

Check out the WINDGRAMS Windgrams are available for some Eastern Sierra sites from the more accurate RASP data



KVBG (alt)


15 JUN 2021

Temp/Wind data from:

NOAA Digital Forecast
Tue Wed Thu Fri Sat Sun
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Garlock SW 16 12021 WNW 14 15483 SW 17 15105 SW 18 15294 WSW 19 15294 WSW 21 14115
Boomer Ridge SSW 11 14805 WSW 12 16923 SSW 23 16732
9-Mile S 11 13185 SSW 10 16878 S 20 16878
Flynns WSW 12 10540 SSW 10 11356 SSW 12 12111
Gunter WSW 12 15735 SSW 10 15921 SSW 12 16106
Paiute SSW 18 17981 SSW 17 18168 SSW 16 17794 SW 16 16405 WSW 14 17606 WSW 13 18168
Chalk Bluffs SSW 18 18027 SSW 16 17648 WSW 14 17458 WSW 13 17648 WSW 17 17458 SW 13 18027
McGee Creek SSW 14 15133 SW 18 15329 SSW 10 14741 WSW 16 14938 WSW 14 15329 WSW 12 15329
Bria Dog Ridge WSW 16 15772 SW 19 15966 S 11 15966 WSW 18 15772 WSW 16 15578 WSW 13 16351
Mammoth SW 27 10148 SW 24 12293 SW 13 12293 WSW 18 12497 WSW 17 12700 WSW 14 13101
Walts SW 27 12525 S 18 12130 SSW 16 12130 WSW 17 11933 WSW 17 12525 SW 16 12130
Copper Mountain SSW 16 7064 SW 19 7064 WSW 13 9535 WSW 17 10243 WSW 17 9535 WSW 14 12071
Horseshoe SW 27 12525 S 18 12130 SSW 16 12130 WSW 17 11933 WSW 17 12525 SW 16 12130
Wolf Peak SW 13 9320 SW 14 13309 WSW 12 13512 WSW 13 13714 WSW 12 14117 WSW 11 13916
Sweetwater S 21 8461 WSW 19 13198 SSW 14 13401 WSW 18 13604 WSW 17 13198 W 14 13604
Lake Isabella Ground Launch Center WSW 19 8261 WSW 20 12280 W 21 12280 W 21 12280 W 23 12082 W 23 11687

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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or 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 website.

Wind Gust: This estimate is taken from the National Weather Service or 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