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)


26 SEP 2022

Temp/Wind data from:

NOAA Digital Forecast
Mon Tue Wed Thu Fri Sat
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Garlock N 10 9884 N 9 9677 SW 13 9468 SSW 14 5607 SSW 13 5607 SSW 13 4653
Boomer Ridge ESE 10 8349 SE 10 8140 SW 13 7932 SSW 16 3928 S 13 3082 S 13 2154
9-Mile SE 12 9106 SSE 14 8903 S 16 8903 S 14 8485 S 14 8275 S 14 8275
Flynns S 11 9080 SW 11 8452 S 13 9080 S 11 8452 SSE 10 8664 S 12 8452
Gunter SW 11 6886 SSW 11 6886 S 13 6472 SSW 10 6263 S 11 6472 S 12 6055
Paiute SSW 11 9308 SSW 11 9308 SSW 14 8674 SSW 10 8462 SSE 10 8674 S 12 8462
Chalk Bluffs S 13 9280 S 12 6017 SSW 14 9489 SSW 12 6017 SE 12 9280 SSE 13 9280
McGee Creek E 8 8338 S 9 8127 WSW 25 8338 WSW 9 8338 E 6 8127 S 8 8127
Bria Dog Ridge SE 10 8269 S 10 8691 WSW 17 8269 WSW 10 7847 SE 9 8269 S 10 8059
Mammoth SE 4 11774 SW 11 11567 SW 17 11567
Walts SSE 11 6370 SE 12 6370 S 14 6789 SSE 12 6580 SE 11 6580 SSE 12 6580
Copper Mountain SW 9 8988 WSW 13 8570 SW 17 8779
Horseshoe SSE 11 6370 SE 12 6370 S 14 6789 SSE 12 6580 SE 11 6580 SSE 12 6580
Wolf Peak SW 8 7929 SW 12 7717 SW 27 6860 W 9 7075 WNW 6 7717 W 6 7289
Sweetwater WSW 10 7523 SW 14 7948 SW 28 7093 SSW 12 7093 N 11 7523 NW 12 7093
Lake Isabella Ground Launch Center SSE 11 9991 WSW 12 9597 W 18 9189 WSW 16 4836 SSW 13 5486 S 13 4836

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 [email protected]