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:

18 OCT 2019

Temp/Wind data from:

NOAA Digital Forecast
Fri Sat Sun Mon Tue Wed
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Garlock SW 14 2462 NW 9 2976 NW 10 2720 N 9 3837 N 9 5688 N 9 6003
Boomer Ridge W 22 2115 NW 22 2361 NW 20 2115 NW 15 3233 N 15 5172 NW 16 5260
9-Mile SW 17 2709 W 17 3207 N 12 2476 N 12 4989 N 13 5610 SE 12 5697
Flynns N 9 2929 NW 16 5132 N 13 4015 NW 8 5509 NE 6 5772 N 9 5509
Gunter S 8 801 NW 18 1579 N 13 1132 NW 6 1758 E 6 1937 NW 5 1848
Paiute NW 9 2587 NW 22 3315 N 16 3041 NW 8 3315 W 6 3589 N 6 3406
Chalk Bluffs SE 8 3422 NW 16 5543 N 14 3949 N 8 6490 N 7 6664 N 10 6490
McGee Creek W 9 2026 W 21 2393 N 12 2301 N 6 2848 SW 6 4571 N 7 2848
Bria Dog Ridge SW 10 2132 W 22 2680 N 15 2132 NW 8 3134 W 6 3404 N 9 3134
Mammoth W 14 0 W 30 0 NW 14 0 NE 12 589 SW 10 954 W 9 681
Walts NW 12 683 SW 15 1961 N 10 683 NE 10 2141 N 10 2411 E 12 2321
Copper Mountain W 14 0 W 23 100 N 14 100 NW 8 2182 W 8 2548 N 9 2090
Horseshoe NW 12 683 SW 15 1961 N 10 683 NE 10 2141 N 10 2411 E 12 2321
Wolf Peak W 15 0 W 25 294 N 15 1098 NE 9 2022 SW 8 3157 N 9 2205
Sweetwater W 16 0 W 33 678 NW 17 0 N 14 1818 SW 12 2368 NW 10 2003
Lake Isabella Ground Launch Center W 22 1213 SW 25 1291 W 15 1291 SE 15 2885 SW 15 4909 W 15 4404

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  If a front comes through, the sounding is no longer valid.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