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:

21 JUL 2018

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 8248 SW 10 9286 SW 9 9900 SW 12 10905 SW 13 11105 W 15 10706
Boomer Ridge W 17 7810 NW 14 8650 NW 12 9266 SW 10 10282 SW 12 10485 W 14 10081
9-Mile SE 12 8503 SE 9 8713 NW 12 9125 W 15 10349 SW 15 10952 W 16 10349
Flynns S 13 8689 NW 7 8266 W 8 9309 W 9 9926 W 10 10537 W 10 10131
Gunter S 14 5161 W 10 4736 SW 8 6420 SW 8 6420 SW 10 6628 SW 10 7042
Paiute S 15 7485 W 10 7269 SW 10 8766 SW 8 8977 SW 13 9397 SW 13 10242
Chalk Bluffs SW 14 10813 NW 7 10813 W 7 11623 SW 6 12225 SW 6 12822 W 6 12425
McGee Creek SW 10 7337 W 9 7337 SW 10 8405 W 8 8832 W 13 9474 W 14 10116
Bria Dog Ridge SW 13 6588 W 10 6372 SW 9 8075 W 7 7864 W 10 8285 W 13 8912
Mammoth SW 14 4775 W 10 5197 W 14 6300 W 10 7160 W 17 7812 W 18 8244
Walts SE 17 5134 N 9 5563 NW 12 5775 N 10 6619 NW 10 7245 NW 10 6619
Copper Mountain W 10 6804 W 10 6587 W 9 8089 W 10 7663 W 13 8513 W 14 9152
Horseshoe SE 17 5134 N 9 5563 NW 12 5775 N 10 6619 NW 10 7245 NW 10 6619
Wolf Peak W 8 6510 SW 10 5871 W 13 7883 W 9 7486 W 15 8360 W 20 9009
Sweetwater W 10 6815 W 12 5794 W 13 7847 W 10 7847 W 14 8988 W 20 9419
Lake Isabella Ground Launch Center W 16 9230 SW 16 7930 SW 14 10241 W 16 11234 S 13 11431 W 13 11431

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