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:

24 AUG 2019

Temp/Wind data from:

NOAA Digital Forecast
Sat Sun Mon Tue Wed Thu
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Garlock SW 18 5153 W 18 6740 S 10 5842 S 12 7082 SW 18 6740 SW 20 5842
Boomer Ridge S 21 5660 W 25 6181 W 23 5834 NW 22 6355 W 22 6355 W 22 5834
9-Mile SW 14 6484 SW 18 6812 SW 14 6484 S 15 7936 S 20 6952 S 21 6812
Flynns S 17 9346 S 10 8704 S 13 8704 SE 10 9957 S 13 7368 S 12 7368
Gunter S 15 5432 S 10 6667 S 10 7316 S 13 6064 S 14 5432 S 15 3224
Paiute S 16 6298 SW 13 8258 S 10 8941 S 12 8258 S 14 6985 SW 15 4623
Chalk Bluffs SE 17 8111 S 10 7972 SE 10 8111 SE 14 9570 S 13 8111 S 14 7827
McGee Creek SW 13 8439 W 12 8592 SW 10 8592 S 10 8592 SW 10 8439 SW 14 6937
Bria Dog Ridge W 15 7122 SE 12 7742 S 9 8941 S 10 8375 SW 12 7122 SW 15 5786
Mammoth W 16 2836 W 14 3714 W 12 4396 SW 12 3714 SW 13 1594 SW 16 1090
Walts SE 18 3362 SE 13 4936 SE 13 3362 SE 15 5635 S 17 5635 S 17 3506
Copper Mountain W 12 3657 NW 13 5150 NW 10 3657 SW 9 3657 W 12 2984 W 14 2801
Horseshoe SE 18 3362 SE 13 4936 SE 13 3362 SE 15 5635 S 17 5635 S 17 3506
Wolf Peak W 16 6220 W 15 5563 W 12 6847 W 12 6847 W 12 6220 W 15 3003
Sweetwater W 15 6096 W 14 5430 NW 12 6096 W 10 6096 W 13 4726 W 15 2633
Lake Isabella Ground Launch Center SW 17 4492 W 21 4492 W 16 3677 SE 16 5363 SW 18 5363 W 20 4202

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