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:

20 JUL 2018

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 12 7338 W 16 7338 SW 8 8374 W 8 8784 SW 12 9192 SW 10 9192
Boomer Ridge W 14 7490 W 14 7699 SW 12 8741 NW 12 9358 SW 10 8947 S 10 9563
9-Mile SE 15 7373 S 13 7373 N 10 7581 NW 12 7997 W 13 8619 W 13 9234
Flynns S 18 9105 S 15 8690 NW 10 8690 W 7 9105 SW 8 9929 W 9 10132
Gunter S 16 6943 SW 13 6108 SW 9 6108 SW 8 7150 SW 10 7357 SW 12 7564
Paiute S 17 7118 SW 14 6685 SW 10 6901 SW 10 7762 SW 13 8186 SW 14 8397
Chalk Bluffs S 16 9380 S 14 8554 N 9 8966 W 6 9380 W 6 10199 W 7 10401
McGee Creek S 13 6323 SW 10 5888 W 9 6323 SW 10 7606 W 14 8240 W 15 8240
Bria Dog Ridge S 15 7305 SW 12 6449 W 9 6879 SW 9 7518 SW 10 8149 W 12 8359
Mammoth SW 13 4593 SW 12 3832 W 12 4811 W 14 5677 W 18 6533 W 20 6746
Walts SE 20 7199 SE 17 6569 N 12 6990 NW 10 6990 NW 9 7408 NW 9 8236
Copper Mountain W 12 6528 W 10 5658 W 9 5876 W 9 6093 W 14 6956 W 14 7170
Horseshoe SE 20 7199 SE 17 6569 N 12 6990 NW 10 6990 NW 9 7408 NW 9 8236
Wolf Peak W 9 6116 W 10 5461 W 10 5680 W 13 6116 W 16 6976 W 16 6976
Sweetwater W 12 6456 W 10 6022 W 10 6022 W 13 6456 W 16 7314 W 16 7527
Lake Isabella Ground Launch Center W 14 7753 W 15 7341 S 13 7753 SW 14 8770 W 16 9376 S 13 9577

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