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

Station:

KVBG

Date/Time:

20 AUG 2019

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 Tue 60 60 E 2 2054 1640 0 Blue 0
6 AM Tue 59 59 E 2 1861 1640 0 Blue 0
7 AM Tue 59 59 E 2 1861 1640 0 Blue 0
8 AM Tue 65 65 N 2 2758 2433 793 Blue 2
9 AM Tue 70 72 N 2 3377 3107 1467 Blue 9
10 AM Tue 76 80 N 2 4085 3813 2173 Blue 17
11 AM Tue 81 87 SW 6 4707 4432 2792 Blue 24
12 Noon Tue 85 92 SW 6 5867 4875 3235 Blue 29
1 PM Tue 87 95 SW 6 6907 5818 4178 Blue 32
2 PM Tue 88 95 SW 7 6907 5818 4178 Blue 32
3 PM Tue 89 95 SW 7 6907 5818 4178 Blue 32
4 PM Tue 89 93 SW 7 6217 5112 3472 Blue 30
5 PM Tue 87 89 SW 10 4884 4609 2969 Blue 26
6 PM Tue 85 86 SW 10 4618 4343 2703 Blue 23
7 PM Tue 81 81 SW 10 4174 3901 2261 Blue 18
8 PM Tue 76 76 E 10 3731 3459 1819 Blue 13
9 PM Tue 72 72 E 10 3377 3107 1467 Blue 9
10 PM Tue 69 69 E 10 3111 2842 1202 Blue 6
11 PM Tue 68 68 N 3 3023 2754 1114 Blue 5
12 Midnight Wed 67 67 N 3 2935 2666 1026 Blue 4
1 AM Wed 66 66 N 3 2846 2578 938 Blue 3
2 AM Wed 64 64 N 3 2670 2242 602 Blue 1
3 AM Wed 64 64 N 3 2670 2242 602 Blue 1
4 AM Wed 63 63 N 3 2581 2051 411 Blue 0
5 AM Wed 62 62 N 5 2439 1859 219 Blue 0
6 AM Wed 61 61 N 5 2247 1667 27 Blue 0
7 AM Wed 61 61 N 5 2247 1667 27 Blue 0
8 AM Wed 67 67 NE 3 2935 2666 1026 Blue 4
9 AM Wed 73 75 NE 3 3642 3371 1731 Blue 12
10 AM Wed 79 83 NE 3 4351 4078 2438 Blue 20
11 AM Wed 84 90 SW 10 5154 4698 3058 Blue 27
12 Noon Wed 88 95 SW 10 6907 5818 4178 Blue 32
1 PM Wed 90 98 SW 10 7915 6848 5208 Blue 35
2 PM Wed 91 98 SW 9 7915 6848 5208 Blue 35
3 PM Wed 92 98 SW 9 7915 6848 5208 Blue 35
4 PM Wed 92 96 SW 9 7246 6165 4525 Blue 33
5 PM Wed 90 92 SW 2 5867 4875 3235 Blue 29
6 PM Wed 88 89 SW 2 4884 4609 2969 Blue 26
7 PM Wed 83 83 SW 2 4351 4078 2438 Blue 20
8 PM Wed 78 78 SW 2 3908 3636 1996 Blue 15
9 PM Wed 74 74 SW 2 3554 3283 1643 Blue 11
10 PM Wed 71 71 SW 2 3288 3019 1379 Blue 8
11 PM Wed 69 69 SE 7 3111 2842 1202 Blue 6
12 Midnight Thu 68 68 SE 7 3023 2754 1114 Blue 5
1 AM Thu 67 67 SE 7 2935 2666 1026 Blue 4
2 AM Thu 65 65 SE 7 2758 2433 793 Blue 2
3 AM Thu 65 65 SE 7 2758 2433 793 Blue 2
4 AM Thu 64 64 SE 7 2670 2242 602 Blue 1
5 AM Thu 63 63 SE 3 2581 2051 411 Blue 0
6 AM Thu 62 62 SE 3 2439 1859 219 Blue 0
7 AM Thu 62 62 SE 3 2439 1859 219 Blue 0
8 AM Thu 67 67 SE 3 2935 2666 1026 Blue 4
9 AM Thu 72 74 SE 3 3554 3283 1643 Blue 11
10 AM Thu 78 82 SE 3 4263 3989 2349 Blue 19
11 AM Thu 82 88 S 9 4796 4520 2880 Blue 25
12 Noon Thu 85 92 S 9 5867 4875 3235 Blue 29
1 PM Thu 87 95 S 9 6907 5818 4178 Blue 32
2 PM Thu 88 95 S 9 6907 5818 4178 Blue 32
3 PM Thu 89 95 S 9 6907 5818 4178 Blue 32
4 PM Thu 89 93 S 9 6217 5112 3472 Blue 30
5 PM Thu 87 89 S 6 4884 4609 2969 Blue 26
6 PM Thu 85 86 S 6 4618 4343 2703 Blue 23
7 PM Thu 80 80 S 6 4085 3813 2173 Blue 17
8 PM Thu 75 75 S 6 3642 3371 1731 Blue 12
9 PM Thu 71 71 S 6 3288 3019 1379 Blue 8
10 PM Thu 68 68 S 6 3023 2754 1114 Blue 5
11 PM Thu 66 66 SE 5 2846 2578 938 Blue 3
12 Midnight Fri 65 65 SE 5 2758 2433 793 Blue 2
1 AM Fri 64 64 SE 5 2670 2242 602 Blue 1
2 AM Fri 62 62 SE 5 2439 1859 219 Blue 0
3 AM Fri 62 62 SE 5 2439 1859 219 Blue 0
4 AM Fri 61 61 SE 5 2247 1667 27 Blue 0
5 AM Fri 60 60 SE 6 2054 1640 0 Blue 0
6 AM Fri 59 59 SE 6 1861 1640 0 Blue 0
7 AM Fri 59 59 SE 6 1861 1640 0 Blue 0
8 AM Fri 64 64 SE 6 2670 2242 602 Blue 1
9 AM Fri 69 71 SE 6 3288 3019 1379 Blue 8
10 AM Fri 75 79 SE 6 3996 3724 2084 Blue 16
11 AM Fri 79 85 S 12 4529 4255 2615 Blue 22
12 Noon Fri 82 89 S 12 4884 4609 2969 Blue 26
1 PM Fri 84 92 S 12 5867 4875 3235 Blue 29
2 PM Fri 85 92 S 12 5867 4875 3235 Blue 29
3 PM Fri 86 92 S 12 5867 4875 3235 Blue 29
4 PM Fri 86 90 S 12 5154 4698 3058 Blue 27
5 PM Fri 84 86 S 12 4618 4343 2703 Blue 23
6 PM Fri 82 83 S 12 4351 4078 2438 Blue 20
7 PM Fri 78 78 S 12 3908 3636 1996 Blue 15
8 PM Fri 73 73 S 12 3465 3195 1555 Blue 10
9 PM Fri 70 70 S 12 3200 2930 1290 Blue 7
10 PM Fri 67 67 S 12 2935 2666 1026 Blue 4
11 PM Fri 66 66 SE 6 2846 2578 938 Blue 3
12 Midnight Sat 65 65 SE 6 2758 2433 793 Blue 2
1 AM Sat 63 63 SE 6 2581 2051 411 Blue 0
2 AM Sat 61 61 SE 6 2247 1667 27 Blue 0
3 AM Sat 62 62 SE 6 2439 1859 219 Blue 0
4 AM Sat 61 61 SE 6 2247 1667 27 Blue 0
5 AM Sat 60 60 E 6 2054 1640 0 Blue 0
6 AM Sat 59 59 E 6 1861 1640 0 Blue 0
7 AM Sat 59 59 E 6 1861 1640 0 Blue 0
8 AM Sat 65 65 E 6 2758 2433 793 Blue 2
9 AM Sat 71 73 E 6 3465 3195 1555 Blue 10
10 AM Sat 77 81 E 6 4174 3901 2261 Blue 18
11 AM Sat 83 89 SW 12 4884 4609 2969 Blue 26
12 Noon Sat 87 94 SW 12 6564 5467 3827 Blue 31
1 PM Sat 89 97 SW 12 7582 6508 4868 Blue 34
2 PM Sat 90 97 SW 12 7582 6508 4868 Blue 34
3 PM Sat 90 96 SW 12 7246 6165 4525 Blue 33
4 PM Sat 91 95 SW 12 6907 5818 4178 Blue 32
5 PM Sat 89 91 SW 12 5512 4786 3146 Blue 28
6 PM Sat 87 88 SW 12 4796 4520 2880 Blue 25
7 PM Sat 83 83 SW 12 4351 4078 2438 Blue 20
8 PM Sat 77 77 SW 12 3819 3548 1908 Blue 14
9 PM Sat 73 73 SW 12 3465 3195 1555 Blue 10
10 PM Sat 71 71 SW 12 3288 3019 1379 Blue 8
11 PM Sat 69 69 SW 2 3111 2842 1202 Blue 6
12 Midnight Sun 68 68 SW 2 3023 2754 1114 Blue 5
1 AM Sun 67 67 SW 2 2935 2666 1026 Blue 4
2 AM Sun 65 65 SW 2 2758 2433 793 Blue 2
3 AM Sun 65 65 SW 2 2758 2433 793 Blue 2
4 AM Sun 64 64 SW 2 2670 2242 602 Blue 1
5 AM Sun 63 63 NW 2 2581 2051 411 Blue 0
6 AM Sun 62 62 NW 2 2439 1859 219 Blue 0
7 AM Sun 62 62 NW 2 2439 1859 219 Blue 0
8 AM Sun 68 68 NW 2 3023 2754 1114 Blue 5
9 AM Sun 73 75 NW 2 3642 3371 1731 Blue 12
10 AM Sun 79 83 NW 2 4351 4078 2438 Blue 20
11 AM Sun 84 90 SW 13 5154 4698 3058 Blue 27
12 Noon Sun 88 95 SW 13 6907 5818 4178 Blue 32
1 PM Sun 90 98 SW 13 7915 6848 5208 Blue 35
2 PM Sun 91 98 SW 13 7915 6848 5208 Blue 35
3 PM Sun 92 98 SW 13 7915 6848 5208 Blue 35
4 PM Sun 92 96 SW 13 7246 6165 4525 Blue 33
5 PM Sun 90 92 SW 13 5867 4875 3235 Blue 29
6 PM Sun 88 89 SW 13 4884 4609 2969 Blue 26
7 PM Sun 83 83 SW 13 4351 4078 2438 Blue 20
8 PM Sun 78 78 SW 13 3908 3636 1996 Blue 15
9 PM Sun 74 74 SW 13 3554 3283 1643 Blue 11
10 PM Sun 71 71 SW 13 3288 3019 1379 Blue 8
11 PM Sun 69 69 N 0 3111 2842 1202 Blue 6
12 Midnight Mon 68 68 N 0 3023 2754 1114 Blue 5
1 AM Mon 67 67 N 0 2935 2666 1026 Blue 4
2 AM Mon 65 65 N 0 2758 2433 793 Blue 2
3 AM Mon 65 65 N 0 2758 2433 793 Blue 2
4 AM Mon 64 64 N 0 2670 2242 602 Blue 1

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