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 21 AUG 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
Torrey Pines Gliderport W 8 0 NW 9 0 W 9 0 W 9 0 W 8 0 W 8 0
Blossom Valley W 8 2227 W 9 2450 W 9 2227 W 10 2450 W 10 3367 W 10 4378
Horse Canyon W 8 6197 W 8 8101 W 9 7352 W 12 8814 W 14 9833 W 12 10243
Little Black W 9 1963 W 10 1984 W 10 1942 W 9 1984 W 10 2048 W 9 2070
Marshall SW 8 2766 SW 8 6222 SW 8 5229 N 8 5564 N 10 8235 NE 9 8648
Crestline SW 10 2609 SW 9 5216 SW 9 4208 N 12 4880 N 12 6037 S 10 8239
Mentone W 7 3906 W 9 6683 W 8 6352 W 8 6352 W 10 8256 W 12 9173
Kagel S 12 1024 S 12 5036 S 9 3265 SW 10 2919 SW 10 5719 SW 9 6707
Lake Elsinore SW 9 3976 W 7 7424 W 9 6117 W 9 7097 SW 13 9270 W 15 9475
Laguna S 7 5838 SW 7 8565 SW 13 7368 E 9 8565 E 9 9414 E 10 9856
Big Black W 7 2402 W 8 5234 W 8 4172 W 8 4910 W 9 6919 W 9 7447
Otay Mesa W 10 1686 NW 12 1867 W 12 1686 W 9 1764 W 9 2179 W 10 2290
Soboba SW 10 3442 SW 10 6600 SW 9 4488 SW 12 4870 SW 12 7248 SW 14 7573
Henninger Flats S 10 814 SW 9 3274 SW 8 2217 SW 9 2217 SW 8 3621 SW 8 6051
Palomar W 7 394 W 6 916 W 6 678 W 8 790 W 7 2817 W 8 3161
Thomas Mt SE 8 7528 SE 8 8968 W 9 7528 W 7 9403 E 9 10266 SE 8 10266
Winchester SW 12 3450 SW 10 6600 SW 12 4596 SW 12 4937 SW 13 7690 SW 15 8015
Blackhawk SE 15 9319 S 9 10174 E 7 10174 E 10 10590 E 12 10998 E 6 10998
Ord S 15 8216 S 14 9824 S 15 9405 S 9 10235 S 10 10668 SW 8 11510
Warner Springs SW 8 7979 SW 8 10682 SW 10 8649 W 12 10476 SW 13 11094 SW 12 11300

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