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 22 NOV 2014

Temp/Wind data from:

NOAA Digital Forecast
Sat Sun Mon Tue Wed Thu
Site
Name
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Wind Above
Launch
Torrey Pines Gliderport W 7 0 NW 8 0 NE 12 205 NE 10 218 NE 8 218 E 6 205
Blossom Valley W 8 2106 E 6 2667 E 22 3922 E 21 4757 E 20 5586 E 15 5165
Horse Canyon W 10 2400 NE 20 1530 NE 22 1530 NE 18 2400 NE 15 4252 NE 9 4534
Little Black W 8 0 SE 7 819 NE 15 1742 E 14 2488 E 13 2954 E 10 2090
Marshall N 7 1913 N 36 1484 N 31 2779 N 23 4068 N 18 4991 N 12 4850
Crestline N 8 845 N 35 0 N 28 845 N 23 2606 NE 18 3593 NE 12 3027
Mentone W 6 735 S 5 983 W 5 1783 E 6 3108 NE 8 5204 E 5 4405
Kagel N 18 800 NE 26 800 NE 25 2866 NE 22 4574 NE 25 5620 NE 17 3724
Lake Elsinore W 10 2684 NW 21 3542 N 14 4397 NE 12 5958 NE 13 6445 E 8 6168
Laguna W 21 2678 W 20 460 E 16 460 E 16 2678 E 14 3487 E 9 3621
Big Black W 9 0 E 22 79 E 29 79 E 26 1402 E 24 3142 E 16 3142
Otay Mesa W 8 757 NE 5 2476 E 24 3858 E 22 4691 E 20 5382 E 15 4274
Soboba SW 8 1816 SW 6 3323 E 26 3323 E 22 3742 E 20 5439 E 14 5439
Henninger Flats W 12 2024 NE 17 2878 NE 9 3304 NE 13 5423 NE 13 5954 NE 10 4948
Palomar NE 6 0 NE 8 745 E 18 864 E 17 1910 E 17 3177 E 14 2753
Thomas Mt NW 15 914 NE 24 0 NE 21 12 NE 18 1816 NE 16 3163 E 8 3163
Winchester SW 8 1135 W 5 2243 NE 8 2243 E 10 3780 E 13 5044 E 9 4626

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