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:

16 SEP 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 18 7273 W 17 7273 W 21 6783 W 13 6783 W 9 7749 SW 17 7273
Boomer Ridge SW 15 7598 SW 16 7598 W 17 7134 W 13 6172 S 10 7134 SW 15 7134
9-Mile SW 23 9368 SW 25 9368 W 25 9368 SW 20 8060 SW 14 8505 SW 22 8505
Flynns S 16 8743 S 14 8743 S 10 8743 NW 12 7846 S 12 8300 SW 10 8300
Gunter SE 13 7562 E 10 7562 N 10 6854 NW 7 4346 S 10 4803 S 8 4346
Paiute SE 14 8426 E 12 8048 N 12 8426 NW 9 7225 S 10 6775 S 9 7225
Chalk Bluffs SE 12 10171 SE 12 10593 W 8 10171 N 6 8849 S 8 10593 SW 7 10171
McGee Creek SW 12 7211 S 9 7211 W 12 6420 W 7 6827 SW 7 6827 SW 9 6420
Bria Dog Ridge SW 12 6738 S 9 6289 W 13 6289 W 7 5362 SW 8 6289 SW 12 5362
Mammoth S 15 1100 S 14 1100 SW 15 556 SW 12 2640 SW 9 3126 SW 12 2640
Walts W 25 7710 W 17 7710 W 12 7710 E 18 5996 S 13 6431 SE 16 6431
Copper Mountain S 12 7014 SW 12 7014 SW 13 5712 SW 8 3777 W 9 5712 SW 14 4768
Horseshoe W 25 7710 W 17 7710 W 12 7710 E 18 5996 S 13 6431 SE 16 6431
Wolf Peak SW 14 3910 SW 13 3910 SW 15 3409 SW 7 2365 SW 10 3409 SW 16 2365
Sweetwater SW 13 4299 SW 13 4778 SW 14 4299 SW 10 2783 SW 9 4299 SW 16 3302
Lake Isabella Ground Launch Center W 13 5637 W 14 5637 W 16 5426 W 12 5016 NW 9 6290 W 12 5847

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