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:

22 MAY 2018

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 W 15 7444 SW 16 8705 SW 20 9113 SW 23 7683 W 25 6311 W 15 8501
Boomer Ridge W 16 6626 SW 13 8028 SW 17 8439 SW 24 6868 W 24 5626 W 16 8028
9-Mile NW 12 7195 S 14 8663 SW 17 9274 W 25 8049 W 23 7195 NW 14 8663
Flynns SW 7 7552 S 17 8591 S 25 9207 S 14 8384 NW 22 6579 NW 20 8384
Gunter S 10 3113 S 14 6961 SE 14 7794 S 13 6961 NW 13 2863 NW 13 6260
Paiute S 9 5012 S 15 7815 S 16 9176 S 14 9176 NW 15 5012 NW 16 8750
Chalk Bluffs W 6 9151 S 14 10169 SE 24 10169 SW 15 9559 NW 17 7901 N 18 9559
McGee Creek E 8 5003 SW 10 6203 S 14 8417 SW 14 7613 W 10 3446 N 14 8203
Bria Dog Ridge SE 6 5776 S 12 6954 S 12 8176 SW 14 7750 NW 14 3635 N 18 7750
Mammoth NE 8 1793 SW 10 3094 S 17 4700 S 17 3094 W 12 473 N 14 4308
Walts SW 12 2950 SE 14 6685 SE 20 7315 SW 23 6474 W 16 4661 N 14 6685
Copper Mountain NE 5 3880 SW 9 5603 S 13 6779 SW 14 3880 W 10 1318 N 12 3880
Horseshoe SW 12 2950 SE 14 6685 SE 20 7315 SW 23 6474 W 16 4661 N 14 6685
Wolf Peak NW 7 2899 SW 8 3157 S 13 5201 S 12 2200 W 9 0 N 12 3157
Sweetwater N 8 3361 SW 8 4300 S 18 6304 S 13 3361 W 15 804 NW 16 5522
Lake Isabella Ground Launch Center W 15 5065 W 14 7172 SW 14 7987 W 18 5863 W 22 3913 W 16 6636

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