Detailed Predictions for: Calabasas
Launch Altitude (f): 1640
LZ Altitude (f): 770
Sounding

Station:

KVBG

Date/Time:

19 AUG 2018

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Sun 70 70 E 2 1677 1645 5 Blue 7
6 AM Sun 69 69 E 2 1666 1640 0 Blue 6
7 AM Sun 69 69 E 2 1666 1640 0 Blue 6
8 AM Sun 74 74 NW 2 1730 1687 47 Blue 11
9 AM Sun 79 81 NW 2 1864 1794 154 Blue 18
10 AM Sun 84 88 NW 2 2234 1958 318 Blue 25
11 AM Sun 87 92 SW 5 2895 2368 728 Blue 29
12 Noon Sun 90 97 SW 5 7469 4142 2502 Blue 34
1 PM Sun 90 97 SW 5 7469 4142 2502 Blue 34
2 PM Sun 91 98 SW 5 8076 5182 3542 Blue 35
3 PM Sun 91 97 SW 5 7469 4142 2502 Blue 34
4 PM Sun 90 94 SW 5 4228 2681 1041 Blue 31
5 PM Sun 90 92 S 5 2895 2368 728 Blue 29
6 PM Sun 87 88 S 5 2234 1958 318 Blue 25
7 PM Sun 83 83 S 5 1911 1841 201 Blue 20
8 PM Sun 80 80 S 5 1841 1775 135 Blue 17
9 PM Sun 77 77 S 5 1775 1730 90 Blue 14
10 PM Sun 76 76 S 5 1760 1715 75 Blue 13
11 PM Sun 75 75 SE 5 1745 1700 60 Blue 12
12 Midnight Mon 74 74 SE 5 1730 1687 47 Blue 11
1 AM Mon 72 72 SE 5 1700 1666 26 Blue 9
2 AM Mon 71 71 SE 5 1687 1656 16 Blue 8
3 AM Mon 71 71 SE 5 1687 1656 16 Blue 8
4 AM Mon 71 71 SE 5 1687 1656 16 Blue 8
5 AM Mon 70 70 E 2 1677 1645 5 Blue 7
6 AM Mon 69 69 E 2 1666 1640 0 Blue 6
7 AM Mon 69 69 E 2 1666 1640 0 Blue 6
8 AM Mon 73 73 SE 3 1715 1677 37 Blue 10
9 AM Mon 78 80 SE 3 1841 1775 135 Blue 17
10 AM Mon 82 86 SE 3 1981 1911 271 Blue 23
11 AM Mon 85 90 S 8 2509 2068 428 Blue 27
12 Noon Mon 87 94 S 8 4228 2681 1041 Blue 31
1 PM Mon 87 94 S 8 4228 2681 1041 Blue 31
2 PM Mon 88 95 S 7 5349 2886 1246 Blue 32
3 PM Mon 88 94 S 7 4228 2681 1041 Blue 31
4 PM Mon 87 91 S 7 2689 2231 591 Blue 28
5 PM Mon 87 89 S 7 2372 1981 341 Blue 26
6 PM Mon 84 85 S 7 1958 1887 247 Blue 22
7 PM Mon 81 81 S 7 1864 1794 154 Blue 18
8 PM Mon 78 78 S 7 1794 1745 105 Blue 15
9 PM Mon 76 76 S 7 1760 1715 75 Blue 13
10 PM Mon 74 74 S 7 1730 1687 47 Blue 11
11 PM Mon 73 73 SE 3 1715 1677 37 Blue 10
12 Midnight Tue 72 72 SE 3 1700 1666 26 Blue 9
1 AM Tue 71 71 SE 3 1687 1656 16 Blue 8
2 AM Tue 70 70 SE 3 1677 1645 5 Blue 7
3 AM Tue 70 70 SE 3 1677 1645 5 Blue 7
4 AM Tue 70 70 SE 3 1677 1645 5 Blue 7
5 AM Tue 69 69 E 2 1666 1640 0 Blue 6
6 AM Tue 68 68 E 2 1656 1640 0 Blue 5
7 AM Tue 68 68 E 2 1656 1640 0 Blue 5
8 AM Tue 72 72 E 2 1700 1666 26 Blue 9
9 AM Tue 78 80 E 2 1841 1775 135 Blue 17
10 AM Tue 82 85 E 2 1958 1887 247 Blue 22
11 AM Tue 86 91 SW 9 2689 2231 591 Blue 28
12 Noon Tue 88 94 SW 9 4228 2681 1041 Blue 31
1 PM Tue 88 94 SW 9 4228 2681 1041 Blue 31
2 PM Tue 89 95 SW 9 5349 2886 1246 Blue 32
3 PM Tue 89 94 SW 9 4228 2681 1041 Blue 31
4 PM Tue 88 91 SW 9 2689 2231 591 Blue 28
5 PM Tue 88 90 SW 7 2509 2068 428 Blue 27
6 PM Tue 85 85 SW 7 1958 1887 247 Blue 22
7 PM Tue 82 82 SW 7 1888 1817 177 Blue 19
8 PM Tue 79 79 SW 7 1818 1760 120 Blue 16
9 PM Tue 77 77 SW 7 1775 1730 90 Blue 14
10 PM Tue 75 75 SW 7 1745 1700 60 Blue 12
11 PM Tue 74 74 SE 2 1730 1687 47 Blue 11
12 Midnight Wed 73 73 SE 2 1715 1677 37 Blue 10
1 AM Wed 72 72 SE 2 1700 1666 26 Blue 9
2 AM Wed 71 71 SE 2 1687 1656 16 Blue 8
3 AM Wed 71 71 SE 2 1687 1656 16 Blue 8
4 AM Wed 71 71 SE 2 1687 1656 16 Blue 8
5 AM Wed 70 70 E 2 1677 1645 5 Blue 7
6 AM Wed 69 69 E 2 1666 1640 0 Blue 6
7 AM Wed 69 69 E 2 1666 1640 0 Blue 6
8 AM Wed 73 73 E 2 1715 1677 37 Blue 10
9 AM Wed 79 81 E 2 1864 1794 154 Blue 18
10 AM Wed 83 87 E 2 2072 1934 294 Blue 24
11 AM Wed 87 92 SW 14 2895 2368 728 Blue 29
12 Noon Wed 89 95 SW 14 5349 2886 1246 Blue 32
1 PM Wed 89 95 SW 14 5349 2886 1246 Blue 32
2 PM Wed 90 96 SW 14 6649 3090 1450 Blue 33
3 PM Wed 90 95 SW 14 5349 2886 1246 Blue 32
4 PM Wed 89 92 SW 14 2895 2368 728 Blue 29
5 PM Wed 89 91 SW 14 2689 2231 591 Blue 28
6 PM Wed 86 86 SW 14 1981 1911 271 Blue 23
7 PM Wed 82 82 SW 14 1888 1817 177 Blue 19
8 PM Wed 79 79 SW 14 1818 1760 120 Blue 16
9 PM Wed 76 76 SW 14 1760 1715 75 Blue 13
10 PM Wed 75 75 SW 14 1745 1700 60 Blue 12
11 PM Wed 74 74 W 2 1730 1687 47 Blue 11
12 Midnight Thu 73 73 W 2 1715 1677 37 Blue 10
1 AM Thu 71 71 W 2 1687 1656 16 Blue 8
2 AM Thu 70 70 W 2 1677 1645 5 Blue 7
3 AM Thu 70 70 W 2 1677 1645 5 Blue 7
4 AM Thu 70 70 W 2 1677 1645 5 Blue 7
5 AM Thu 69 69 NE 2 1666 1640 0 Blue 6
6 AM Thu 68 68 NE 2 1656 1640 0 Blue 5
7 AM Thu 68 68 NE 2 1656 1640 0 Blue 5
8 AM Thu 73 73 NE 2 1715 1677 37 Blue 10
9 AM Thu 78 80 NE 2 1841 1775 135 Blue 17
10 AM Thu 83 86 NE 2 1981 1911 271 Blue 23
11 AM Thu 86 91 SW 8 2689 2231 591 Blue 28
12 Noon Thu 89 96 SW 8 6649 3090 1450 Blue 33
1 PM Thu 89 96 SW 8 6649 3090 1450 Blue 33
2 PM Thu 90 97 SW 8 7469 4142 2502 Blue 34
3 PM Thu 90 96 SW 8 6649 3090 1450 Blue 33
4 PM Thu 89 93 SW 8 3100 2505 865 Blue 30
5 PM Thu 89 91 SW 8 2689 2231 591 Blue 28
6 PM Thu 86 87 SW 8 2072 1934 294 Blue 24
7 PM Thu 82 82 SW 8 1888 1817 177 Blue 19
8 PM Thu 79 79 SW 8 1818 1760 120 Blue 16
9 PM Thu 76 76 SW 8 1760 1715 75 Blue 13
10 PM Thu 75 75 SW 8 1745 1700 60 Blue 12
11 PM Thu 74 74 SW 3 1730 1687 47 Blue 11
12 Midnight Fri 73 73 SW 3 1715 1677 37 Blue 10
1 AM Fri 71 71 SW 3 1687 1656 16 Blue 8
2 AM Fri 70 70 SW 3 1677 1645 5 Blue 7
3 AM Fri 70 70 SW 3 1677 1645 5 Blue 7
4 AM Fri 70 70 SW 3 1677 1645 5 Blue 7
5 AM Fri 69 69 SW 2 1666 1640 0 Blue 6
6 AM Fri 68 68 SW 2 1656 1640 0 Blue 5
7 AM Fri 68 68 SW 2 1656 1640 0 Blue 5
8 AM Fri 72 72 SW 2 1700 1666 26 Blue 9
9 AM Fri 78 80 SW 2 1841 1775 135 Blue 17
10 AM Fri 82 85 SW 2 1958 1887 247 Blue 22
11 AM Fri 86 91 SW 9 2689 2231 591 Blue 28
12 Noon Fri 88 95 SW 9 5349 2886 1246 Blue 32
1 PM Fri 88 95 SW 9 5349 2886 1246 Blue 32
2 PM Fri 89 96 SW 9 6649 3090 1450 Blue 33
3 PM Fri 89 95 SW 9 5349 2886 1246 Blue 32
4 PM Fri 88 92 SW 9 2895 2368 728 Blue 29
5 PM Fri 88 90 SW 8 2509 2068 428 Blue 27
6 PM Fri 85 86 SW 8 1981 1911 271 Blue 23
7 PM Fri 82 82 SW 8 1888 1817 177 Blue 19
8 PM Fri 79 79 SW 8 1818 1760 120 Blue 16
9 PM Fri 76 76 SW 8 1760 1715 75 Blue 13
10 PM Fri 74 74 SW 8 1730 1687 47 Blue 11
11 PM Fri 73 73 NW 1 1715 1677 37 Blue 10
12 Midnight Sat 72 72 NW 1 1700 1666 26 Blue 9
1 AM Sat 71 71 NW 1 1687 1656 16 Blue 8
2 AM Sat 70 70 NW 1 1677 1645 5 Blue 7
3 AM Sat 70 70 NW 1 1677 1645 5 Blue 7
4 AM Sat 70 70 NW 1 1677 1645 5 Blue 7

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