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 MAY 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 5396 SW 25 0 W 21 3876 W 13 5811 SW 14 5396 SW 15 6640
Boomer Ridge W 21 4981 W 26 0 W 20 3888 W 14 5615 SW 16 4981 SW 16 6245
9-Mile W 23 5280 W 33 0 W 21 4194 W 17 5700 S 25 6327 SW 26 6950
Flynns S 12 5678 S 16 3280 NW 14 5040 NW 13 6102 N 13 6524 N 14 7357
Gunter S 12 3427 SE 15 0 NW 13 1739 NW 15 3854 SE 10 4699 S 9 5116
Paiute S 14 6479 S 17 867 NW 15 3994 NW 18 6907 S 12 7335 S 13 7759
Chalk Bluffs W 8 5762 S 10 3575 NW 12 5096 N 9 6182 N 8 6809 S 8 7435
McGee Creek SW 15 6275 SW 14 557 NW 12 4976 N 12 7126 N 9 7126 S 8 8384
Bria Dog Ridge SW 14 5978 S 13 0 NW 14 3281 N 14 5978 N 10 6404 S 8 7041
Mammoth SW 20 0 S 23 0 N 15 0 N 14 376 SW 10 900 SW 9 3081
Walts W 14 2377 SW 24 0 NW 22 2122 NW 21 4453 SE 24 4239 S 24 5091
Copper Mountain SW 16 2209 S 15 0 W 15 755 N 15 2728 N 13 2986 NW 10 5907
Horseshoe W 14 2377 SW 24 0 NW 22 2122 NW 21 4453 SE 24 4239 S 24 5091
Wolf Peak SW 20 4396 S 23 0 W 14 1999 N 16 4678 N 14 6265 W 12 6479
Sweetwater SW 18 4635 S 21 0 NW 15 1685 N 15 4635 N 12 5002 NW 10 6543
Lake Isabella Ground Launch Center W 16 4823 W 21 0 W 22 0 NW 16 5061 NW 13 4823 W 15 6089

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  If a front comes through, the sounding is no longer valid.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