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 SEP 2017

Temp/Wind data from:

NOAA Digital Forecast
Mon Tue Wed Thu Fri Sat
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Garlock N 18 4326 NE 22 4857 NE 12 5732 NE 9 6018 N 8 6584 NW 8 6864
Boomer Ridge N 20 3745 NE 21 4636 N 13 5217 N 8 5217 N 7 5790 NW 7 6355
9-Mile N 18 4705 N 23 5574 N 17 6142 N 12 6703 SE 9 7738 NW 8 7738
Flynns N 12 3949 N 13 4548 N 8 5715 SE 6 6569 S 7 7128 NW 6 7479
Gunter N 8 0 NW 8 1751 NW 5 1751 SE 6 2916 S 6 3202 NW 6 3202
Paiute N 10 2029 N 12 3259 N 5 3860 E 6 5036 S 6 7842 SW 7 7842
Chalk Bluffs N 14 5625 N 13 6494 NW 8 7623 SW 3 8451 S 6 9132 S 6 10045
McGee Creek N 10 2058 NE 9 3263 E 7 3559 SE 5 6603 W 5 7059 NW 7 7505
Bria Dog Ridge N 12 2183 NW 9 3684 E 8 4559 SE 6 7338 S 5 7785 N 8 7338
Mammoth N 12 434 NE 12 1644 NE 7 3671 E 5 5162 W 6 5162 S 7 4701
Walts NW 17 1518 NW 20 2117 NW 13 3290 NW 8 3865 SE 9 6564 NW 8 7012
Copper Mountain NE 10 1627 NE 8 2846 NE 7 5867 S 5 6795 NW 6 7249 N 7 7249
Horseshoe NW 17 1518 NW 20 2117 NW 13 3290 NW 8 3865 SE 9 6564 NW 8 7012
Wolf Peak E 8 553 NE 9 2101 E 6 3297 NW 6 3653 W 6 4738 NW 7 3653
Sweetwater NE 8 167 NE 12 2041 E 7 2944 NW 7 3536 NW 7 5579 N 9 4549
Lake Isabella Ground Launch Center E 7 3985 NE 10 4504 E 8 5647 S 6 5364 N 6 5929 W 7 5929

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  If a front comes through, the sounding is no longer valid.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