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:

15 JUL 2019

Temp/Wind data from:

NOAA Digital Forecast
Mon Tue Wed Thu Fri Sat
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Garlock W 23 10538 SW 23 10323 SW 24 9147 SW 23 8510 SW 22 8510 S 21 8510
Boomer Ridge W 33 10336 W 32 9905 SW 30 9688 SW 29 9688 SW 28 9252 S 26 9470
9-Mile W 25 10977 W 30 10977 SW 26 10224 SW 24 10009 SW 24 10224 SW 22 10224
Flynns NW 12 14294 SW 10 14097 S 16 11017 S 17 10850 S 18 13656 S 17 11017
Gunter SW 13 10804 SW 13 10876 S 13 10876 S 14 10876 S 13 11355 SE 13 11021
Paiute W 14 12535 SW 14 12461 SE 14 12388 S 13 12388 S 15 12535 SE 12 12388
Chalk Bluffs NW 9 13549 SW 8 13549 S 10 12138 S 14 11616 SE 15 12303 S 16 11973
McGee Creek SW 13 11646 SW 12 11646 SW 9 11829 S 7 11371 SW 8 11519 SE 9 11445
Bria Dog Ridge W 17 12003 W 15 12003 SW 13 10643 S 12 12003 S 13 12076 SE 13 11930
Mammoth SW 20 5464 SW 22 5065 SW 12 5818 SW 10 5641 SW 10 5287 NE 10 5065
Walts SE 14 11362 SE 17 11362 SE 22 7366 SE 22 7195 SE 22 7538 S 23 7538
Copper Mountain SW 17 7132 W 13 7132 W 14 7345 W 12 7869 W 12 7695 E 10 7345
Horseshoe SE 14 11362 SE 17 11362 SE 22 7366 SE 22 7195 SE 22 7538 S 23 7538
Wolf Peak SW 18 7207 SW 14 6855 W 14 7207 SW 12 6663 W 12 6663 E 12 6663
Sweetwater SW 22 9803 SW 16 6997 SW 14 10907 SW 12 9803 NW 12 7174 NE 13 6821
Lake Isabella Ground Launch Center W 22 9230 W 22 7976 SW 18 7299 SW 18 8619 SW 18 6578 SW 18 7299

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