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:

17 OCT 2017

Temp/Wind data from:

NOAA Digital Forecast
Tue Wed Thu Fri Sat Sun
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Garlock SW 9 0 SW 8 495 W 22 0 W 23 0 W 12 0 NE 10 0
Boomer Ridge W 10 961 W 18 1812 W 21 0 W 21 0 NW 12 0 E 9 0
9-Mile SW 14 1667 NW 10 0 W 28 0 W 36 0 N 14 0 N 12 792
Flynns N 7 4664 S 7 4664 S 8 2057 NW 15 0 N 7 0 N 5 1205
Gunter N 6 4413 NW 7 4166 S 15 4166 W 12 0 N 7 0 E 5 2513
Paiute NW 13 6590 NW 6 6387 S 22 5922 NW 16 240 NW 8 2403 NE 6 6174
Chalk Bluffs NW 6 4310 W 6 5609 SW 9 2247 NW 10 0 NW 3 0 N 3 2247
McGee Creek SW 21 5234 SW 7 5439 SW 20 4050 SW 24 0 NW 6 4050 NE 6 5937
Bria Dog Ridge W 12 5708 SW 6 6126 SW 21 5708 SW 17 0 NW 6 1930 NE 7 5923
Mammoth SW 26 3330 S 7 3744 SW 33 0 SW 44 0 W 12 2078 N 7 4029
Walts NW 8 4267 SE 9 1894 W 13 1894 W 35 0 N 12 0 NW 10 2519
Copper Mountain SW 17 4304 SW 8 4920 SW 20 0 SW 24 0 NW 7 0 NE 7 4920
Horseshoe NW 8 4267 SE 9 1894 W 13 1894 W 35 0 N 12 0 NW 10 2519
Wolf Peak SW 22 1545 SW 8 2252 SW 28 0 SW 26 0 W 7 0 NE 6 4046
Sweetwater SW 25 3000 SW 9 4401 SW 37 645 SW 37 0 W 14 0 SW 8 4656
Lake Isabella Ground Launch Center W 15 0 W 12 0 W 15 0 W 18 0 NW 12 0 N 6 0

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  If a front comes through, the sounding is no longer valid.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