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)


2 OCT 2022

Temp/Wind data from:

NOAA Digital Forecast
Sun Mon Tue Wed Thu Fri
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Garlock SSW 16 4837 N 10 6016 NW 10 7204 NW 10 8982 NW 10 8221 NW 10 8221
Boomer Ridge S 15 12260 WSW 3 12059 S 6 12260
9-Mile S 15 11821 WSW 3 11620 S 6 11821
Flynns SSE 6 8025 NW 2 6127 NW 2 8025
Gunter SSE 6 13207 NW 2 12808 NW 2 13207
Paiute WSW 9 5473 NW 9 5473 SSE 8 6310 ESE 10 6310 SSE 10 5943 S 10 5943
Chalk Bluffs SE 12 4685 N 10 4989 ENE 11 7014 SE 11 7014 SSE 11 7014 SSE 12 5741
McGee Creek ESE 6 5806 ENE 5 5806 E 5 6164 NNE 6 6557 E 6 6557 ENE 6 6164
Bria Dog Ridge W 8 5472 NNE 9 5837 ENE 9 5837 NE 10 6197 E 9 6197 W 9 6197
Mammoth WSW 7 13985 NNE 8 14375 NNW 3 14763
Walts SE 12 3118 E 9 3118 SE 10 4166 ESE 10 4166 ESE 10 4166 SE 11 4166
Copper Mountain W 12 7514 NE 9 6620 NNE 8 7948
Horseshoe SE 12 3118 E 9 3118 SE 10 4166 ESE 10 4166 ESE 10 4166 SE 11 4166
Wolf Peak W 6 4025 NNE 5 5216 WNW 5 5216 WNW 5 5216 WNW 6 5577 WNW 8 5216
Sweetwater WNW 11 3832 N 11 4410 N 12 4782 N 12 5149 N 12 5149 NW 13 5149
Lake Isabella Ground Launch Center W 17 4658 WSW 13 5925 WSW 13 7030 WSW 13 8218 WSW 12 8218 WSW 12 8218

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