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:

25 AUG 2019

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 W 18 7764 S 10 6898 S 13 8128 SW 20 6898 SW 20 6798 W 18 6898
Boomer Ridge W 26 7454 NW 21 7057 NW 21 7849 W 22 7652 W 22 7057 W 23 7256
9-Mile SW 20 8360 S 14 7771 SW 16 8556 S 20 8556 SW 21 7968 SW 18 7968
Flynns SW 9 8761 S 10 8419 SE 12 10258 S 13 9536 S 10 8419 S 10 8222
Gunter SW 9 6344 SE 10 7951 S 13 7468 S 14 5595 S 10 5595 S 9 6344
Paiute SW 10 8544 SE 12 9055 SE 12 8544 S 15 6272 S 14 6043 S 10 7114
Chalk Bluffs SE 7 9335 SE 10 9335 SE 14 9530 S 14 9530 S 12 9335 S 12 9335
McGee Creek W 13 9837 W 9 9291 S 9 8802 SW 13 5726 SW 12 7285 SW 14 8802
Bria Dog Ridge W 12 8545 SE 10 8036 S 10 8545 SW 14 5780 SW 14 5575 W 14 6585
Mammoth SW 14 4685 SW 10 5429 SW 12 5956 SW 16 2589 SW 15 2799 W 14 3008
Walts SE 14 5108 SE 13 4906 SE 15 5108 S 17 5728 S 15 4906 S 13 4906
Copper Mountain W 13 4855 NW 8 5957 W 9 5269 W 13 3805 W 13 4022 W 14 4439
Horseshoe SE 14 5108 SE 13 4906 SE 15 5108 S 17 5728 S 15 4906 S 13 4906
Wolf Peak W 14 6547 W 10 7166 W 10 7166 W 15 4176 W 14 4176 W 15 4924
Sweetwater W 13 6415 NW 10 7076 E 9 7076 W 13 4346 W 13 3927 W 15 4346
Lake Isabella Ground Launch Center W 22 6407 SE 16 6407 SE 17 6545 SW 20 6499 W 21 6314 W 22 6361

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