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)


24 JUL 2024

Temp/Wind data from:

NOAA Digital Forecast
Wed Thu Fri Sat Sun Mon
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Garlock W 14 10865 W 17 11064 W 18 10272 WSW 18 8052 SW 14 7533 SW 14 7533
Boomer Ridge WSW 18 11969 W 23 12167 WSW 25 12367
9-Mile W 18 9778 W 24 10587 WSW 27 9981 WSW 23 9164 SSW 18 9164 SSW 19 9371
Flynns WNW 10 9131 W 10 9840 SW 13 10046 WSW 13 9375 S 13 9375 SSE 13 9840
Gunter W 11 5414 WSW 10 6760 SW 13 7178 WSW 13 6760 S 13 6969 S 14 6969
Paiute SW 10 8635 WSW 10 6932 WSW 13 9062 SW 13 8635 S 13 8849 S 13 8849
Chalk Bluffs S 8 9181 WSW 9 10275 WSW 13 10275 SW 13 9864 S 12 9864 SSE 11 10070
McGee Creek NNW 6 6004 WSW 13 7781 SW 19 8211 WSW 14 6004 WSW 13 7781 WSW 12 7996
Bria Dog Ridge WNW 13 9800 WSW 17 9177 WSW 23 9384
Mammoth WSW 12 3837 WSW 20 3343 SW 28 6023 SSW 19 2748 SW 13 3837 SW 14 4097
Walts SW 10 5499 W 12 7230 SW 16 7650 WSW 14 7230 SSE 17 5499 SSE 18 7230
Copper Mountain SW 15 9330 WSW 19 9753 SW 19 9753
Horseshoe SW 10 5499 W 12 7230 SW 16 7650 WSW 14 7230 SSE 17 5499 SSE 18 7230
Wolf Peak WSW 6 7314 WSW 16 5459 SW 18 7745 SW 13 4534 WSW 11 7314 WSW 11 7530
Sweetwater W 12 4430 WSW 21 4430 SW 21 7302 SW 17 3338 WSW 13 5126 WSW 17 5409
Lake Isabella Ground Launch Center W 23 9376 W 26 9779 W 27 9376 W 25 5588 W 18 5588 W 19 7047

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]