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:

15 OCT 2018

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 NE 13 275 W 14 140 W 12 0 W 10 140 NE 9 140 NE 7 177
Blossom Valley NE 18 4782 NE 16 3312 NE 12 3763 NW 12 5617 NE 9 5824 E 8 6240
Horse Canyon NE 25 943 NE 28 3725 NE 28 4802 NE 15 6729 NE 18 6935 NE 14 6935
Little Black NE 18 1058 E 18 988 NE 15 988 E 12 1058 W 12 1243 E 8 2706
Marshall N 45 0 N 30 817 N 29 2433 N 23 6673 N 24 6880 N 21 6880
Crestline N 44 0 N 36 0 N 29 0 N 23 0 NE 25 1667 N 22 4127
Mentone NE 36 0 NE 25 1624 E 8 1624 NE 17 7300 NE 21 7507 NE 20 7507
Kagel NE 40 5519 NE 26 8304 NE 21 7078 NE 12 7693 NE 13 8304 NE 16 7898
Lake Elsinore N 29 2490 N 20 5897 N 9 7706 N 9 8528 NE 13 8732 N 10 8528
Laguna NE 22 0 NE 18 0 E 16 0 NE 13 5731 NE 17 6156 NE 13 6366
Big Black NE 30 856 NE 28 856 NE 29 1199 E 14 6992 NE 18 7198 NE 14 7198
Otay Mesa W 8 3710 E 17 3262 E 14 3262 W 13 5235 W 13 5235 NW 8 5442
Soboba NE 40 1088 NE 33 2323 E 25 3234 E 18 5154 NE 22 5575 NE 21 5154
Henninger Flats NE 30 6249 NE 21 7505 N 10 6456 NE 7 7097 N 6 7706 N 9 7301
Palomar NE 28 999 NE 22 1515 NE 17 1515 NE 13 3769 NE 16 4189 NE 15 3560
Thomas Mt NE 38 0 NE 36 3144 NE 25 3873 NE 18 6136 NE 23 6346 NE 21 6136
Winchester NE 30 2900 E 12 3216 NE 16 4871 NE 8 5713 NE 18 6131 NE 15 5923
Blackhawk NE 20 0 NE 12 943 NE 8 3777 NE 10 5774 NE 15 5774 E 12 5774
Ord NE 28 0 NE 21 0 NE 16 937 NE 13 5500 NE 16 5921 NE 16 5921
Warner Springs NE 32 2903 NE 12 3391 E 14 4650 NE 13 9347 NE 16 9552 NE 13 9552

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