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 AUG 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 W 11 11406 E 10 11406 SW 12 11221 SW 13 11221 SSW 12 11221 SSW 16 10665
Boomer Ridge ESE 6 15041 SSW 7 16536 S 10 17549
9-Mile W 16 10427 ESE 14 10427 W 13 10611 W 16 10611 WSW 16 10611 SSW 17 9686
Flynns S 11 10084 N 13 9709 SSE 15 9709
Gunter S 11 13785 N 13 13387 SSE 15 13387
Paiute S 11 15210 N 13 14705 SSE 15 14705
Chalk Bluffs SSE 13 11228 WSW 16 10673 SW 13 10673 W 13 10858 S 12 10673 S 13 10858
McGee Creek WSW 9 12307 S 10 6538 WSW 9 6538 W 10 6733 WSW 10 8074 WSW 10 6929
Bria Dog Ridge ESE 7 9160 SW 10 7222 E 7 7222
Mammoth SW 13 13680 E 8 12253 NW 11 12253
Walts ESE 10 6576 E 10 6576 S 11 6384 SSW 11 6576 S 10 6767 S 12 6576
Copper Mountain W 10 11798 S 10 7957 SW 6 11226
Horseshoe ESE 10 6576 E 10 6576 S 11 6384 SSW 11 6576 S 10 6767 S 12 6576
Wolf Peak W 9 10502 S 5 6219 WSW 6 5825 W 11 6219 W 10 6416 WSW 13 6219
Sweetwater W 10 10397 NNW 10 5984 W 10 4173 W 11 5787 W 11 6182 WSW 14 5984
Lake Isabella Ground Launch Center WSW 17 10993 WSW 13 10993 W 14 10633 W 17 10633 W 16 10813 W 16 10452

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