NEWS:

March 24, 2013: This site is running the code developed by Tad Hurst.

This section created with the help of Aaron Colby.
Why not submit your favorite site? I need site name, lat, long, LZ and launch altitudes and the zipcode.

- Alan

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

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


Sounding

Station:

KVBG (alt)

Date/Time:

19 AUG 2018

Temp/Wind data from:

NOAA Digital Forecast
Sun Mon Tue Wed Thu Fri
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Garlock SW 13 9709 SW 21 8513 SW 20 7313 SW 20 7313 SW 21 7313 W 22 7313
Boomer Ridge W 26 9705 W 24 9193 SW 22 7388 W 22 7388 W 23 7388 W 24 6727
9-Mile W 15 10968 SW 20 10571 SW 17 8533 SW 23 9681 SW 23 9681 SW 22 9118
Flynns S 14 11078 S 9 11311 S 12 9473 S 12 9959 S 8 9959 S 8 9473
Gunter S 13 7635 S 13 9205 S 14 8626 S 9 7635 S 7 7635 SW 8 7160
Paiute S 13 8463 S 15 8981 S 17 8981 SE 9 8737 SW 7 8981 SW 7 8463
Chalk Bluffs S 12 12609 SW 13 12380 S 8 11810 S 8 12150 SW 7 11810 SW 7 11810
McGee Creek SW 12 9581 SW 16 7828 SW 13 7828 SW 9 8072 SW 7 8072 SW 9 7828
Bria Dog Ridge SW 12 10882 SW 16 8743 SW 15 7963 SW 12 7038 SW 7 7506 SW 10 7506
Mammoth SW 14 4890 SW 21 3156 SW 16 1119 SW 17 4890 SW 9 4890 SW 10 4407
Walts SE 15 8568 SW 14 8568 SW 10 7207 S 21 7565 SE 16 7565 SE 16 7207
Copper Mountain SW 12 10357 SW 16 8239 SW 14 7415 SW 13 5887 SW 9 5256 SW 10 5887
Horseshoe SE 15 8568 SW 14 8568 SW 10 7207 S 21 7565 SE 16 7565 SE 16 7207
Wolf Peak SW 14 8910 SW 18 7302 SW 17 5589 S 13 3625 SW 10 2897 SW 12 3625
Sweetwater SW 14 8809 SW 20 7259 SW 17 5476 SW 14 5476 W 8 4846 SW 12 4846
Lake Isabella Ground Launch Center W 20 8587 W 17 7971 W 21 6937 W 20 6937 W 20 6625 W 20 6625

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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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 ac_soaring@yahoo.com