NEWS:

June 29, 2009: This site is running the code developed by Tad Hurst.

I've done some tuning to make the estimates for Marshall, Crestline and Soboba a bit less optimistic. 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


Site Forecasts

Sounding

Station:

KNKX (alt)

Date/Time:

12Z 24 APR 2014

Temp/Wind data from:

NOAA Digital Forecast
Thu Fri Sat Sun Mon Tue
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Torrey Pines Gliderport W 12 0 SW 16 0 W 21 0 NW 10 0 NW 8 0 NE 12 1754
Blossom Valley W 14 3541 SW 16 2131 W 18 757 W 10 2626 NE 6 5442 E 18 7633
Horse Canyon SW 13 4255 W 17 2316 W 26 0 SW 10 448 E 10 5231 NE 17 6813
Little Black W 13 1420 SW 16 81 W 17 0 W 10 329 W 7 2005 NE 14 5184
Marshall S 12 4289 SW 15 909 SW 14 0 N 9 909 NE 9 5055 NE 16 6819
Crestline S 14 1617 S 17 0 NW 12 0 N 9 0 NE 9 2987 NE 17 3789
Mentone SW 10 5107 SW 14 1569 W 15 0 W 9 1434 NE 6 5701 NE 14 7236
Kagel N 14 4209 SW 15 0 N 15 0 N 21 1557 N 13 5181 NE 22 7298
Lake Elsinore SW 15 5191 SW 20 1890 W 17 101 W 10 1890 NE 6 5971 NE 14 8357
Laguna SW 12 3801 W 36 1726 W 39 0 W 14 0 E 10 4832 NE 21 5204
Big Black SW 13 2518 SW 18 528 W 22 0 W 10 30 E 9 4144 E 21 5131
Otay Mesa W 13 3049 SW 16 1078 W 18 364 W 12 1257 W 7 3483 NE 17 7211
Soboba SW 14 5659 SW 17 2257 W 18 608 W 10 2257 E 8 6241 E 15 7732
Henninger Flats SW 9 4459 SW 12 0 W 14 0 W 10 1640 N 8 5615 NE 18 8449
Palomar W 12 1586 SW 15 75 W 17 0 W 12 0 E 6 2734 NE 17 5270
Thomas Mt SW 12 3256 W 26 829 W 25 0 W 12 69 E 9 3900 NE 18 5152
Winchester S 15 5906 SW 18 2622 W 16 1056 W 12 2674 E 7 6476 E 15 8587

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  If a front comes through, the sounding is no longer valid.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