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

Station:

KVBG

Date/Time:

25 SEP 2017

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 Mon 69 69 NE 17 1429 1640 0 Blue 0
6 AM Mon 66 66 NE 17 1010 1640 0 Blue 0
7 AM Mon 66 66 NE 17 1010 1640 0 Blue 0
8 AM Mon 67 67 NE 18 1064 1640 0 Blue 0
9 AM Mon 70 71 NE 18 2097 1640 0 Blue 1
10 AM Mon 74 77 NE 18 6432 4257 2617 Blue 7
11 AM Mon 79 83 NE 17 8379 8018 6378 Blue 13
12 Noon Mon 83 88 NE 17 8941 8577 6937 Blue 18
1 PM Mon 87 93 NE 17 10252 9346 7706 Blue 23
2 PM Mon 90 95 N 5 10812 9888 8248 Blue 25
3 PM Mon 93 97 N 5 11364 10449 8809 Blue 27
4 PM Mon 94 96 N 5 11089 10170 8530 Blue 26
5 PM Mon 93 94 N 8 10533 9603 7963 Blue 24
6 PM Mon 90 90 N 8 9413 8801 7161 Blue 20
7 PM Mon 87 87 N 8 8828 8465 6825 Blue 17
8 PM Mon 84 84 NW 10 8491 8130 6490 Blue 14
9 PM Mon 83 83 NW 10 8379 8018 6378 Blue 13
10 PM Mon 83 83 NW 10 8379 8018 6378 Blue 13
11 PM Mon 84 84 N 12 8491 8130 6490 Blue 14
12 Midnight Tue 83 83 N 12 8379 8018 6378 Blue 13
1 AM Tue 82 82 N 12 8266 7646 6006 Blue 12
2 AM Tue 80 80 NE 16 8042 6321 4681 Blue 10
3 AM Tue 78 78 NE 16 7121 4874 3234 Blue 8
4 AM Tue 77 77 NE 16 6432 4257 2617 Blue 7
5 AM Tue 75 75 NE 21 4922 2790 1150 Blue 5
6 AM Tue 73 73 NE 21 3593 1640 0 Blue 3
7 AM Tue 72 72 NE 21 2822 1640 0 Blue 2
8 AM Tue 73 73 NE 22 3593 1640 0 Blue 3
9 AM Tue 76 77 NE 22 6432 4257 2617 Blue 7
10 AM Tue 80 83 NE 22 8379 8018 6378 Blue 13
11 AM Tue 85 89 NE 24 9156 8689 7049 Blue 19
12 Noon Tue 89 94 NE 24 10533 9603 7963 Blue 24
1 PM Tue 92 98 NE 24 11638 10726 9086 Blue 28
2 PM Tue 94 99 N 8 11909 11001 9361 Blue 29
3 PM Tue 94 98 N 8 11638 10726 9086 Blue 28
4 PM Tue 93 95 N 8 10812 9888 8248 Blue 25
5 PM Tue 92 93 N 6 10252 9346 7706 Blue 23
6 PM Tue 90 90 N 6 9413 8801 7161 Blue 20
7 PM Tue 89 89 N 6 9156 8689 7049 Blue 19
8 PM Tue 87 87 N 5 8828 8465 6825 Blue 17
9 PM Tue 85 85 N 5 8604 8242 6602 Blue 15
10 PM Tue 82 82 N 5 8266 7646 6006 Blue 12
11 PM Tue 80 80 NE 8 8042 6321 4681 Blue 10
12 Midnight Wed 77 77 NE 8 6432 4257 2617 Blue 7
1 AM Wed 75 75 NE 8 4922 2790 1150 Blue 5
2 AM Wed 73 73 NE 14 3593 1640 0 Blue 3
3 AM Wed 72 72 NE 14 2822 1640 0 Blue 2
4 AM Wed 73 73 NE 14 3593 1640 0 Blue 3
5 AM Wed 73 73 N 16 3593 1640 0 Blue 3
6 AM Wed 72 72 N 16 2822 1640 0 Blue 2
7 AM Wed 72 72 N 16 2822 1640 0 Blue 2
8 AM Wed 73 73 N 18 3593 1640 0 Blue 3
9 AM Wed 78 79 N 18 7775 5602 3962 Blue 9
10 AM Wed 83 86 N 18 8716 8354 6714 Blue 16
11 AM Wed 89 93 NE 16 10252 9346 7706 Blue 23
12 Noon Wed 92 97 NE 16 11364 10449 8809 Blue 27
1 PM Wed 94 100 NE 16 12179 11275 9635 Blue 30
2 PM Wed 94 99 S 10 11909 11001 9361 Blue 29
3 PM Wed 93 97 S 10 11364 10449 8809 Blue 27
4 PM Wed 91 93 S 10 10252 9346 7706 Blue 23
5 PM Wed 90 91 W 7 9681 8913 7273 Blue 21
6 PM Wed 89 89 W 7 9156 8689 7049 Blue 19
7 PM Wed 88 88 W 7 8941 8577 6937 Blue 18
8 PM Wed 86 86 W 7 8716 8354 6714 Blue 16
9 PM Wed 83 83 W 7 8379 8018 6378 Blue 13
10 PM Wed 79 79 W 7 7775 5602 3962 Blue 9
11 PM Wed 76 76 E 8 5702 3545 1905 Blue 6
12 Midnight Thu 74 74 E 8 4319 2085 445 Blue 4
1 AM Thu 72 72 E 8 2822 1640 0 Blue 2
2 AM Thu 72 72 E 8 2822 1640 0 Blue 2
3 AM Thu 72 72 E 8 2822 1640 0 Blue 2
4 AM Thu 73 73 E 8 3593 1640 0 Blue 3
5 AM Thu 74 74 NE 8 4319 2085 445 Blue 4
6 AM Thu 77 77 NE 8 6432 4257 2617 Blue 7
7 AM Thu 79 79 NE 8 7775 5602 3962 Blue 9
8 AM Thu 82 82 NE 8 8266 7646 6006 Blue 12
9 AM Thu 85 86 NE 8 8716 8354 6714 Blue 16
10 AM Thu 88 91 NE 8 9681 8913 7273 Blue 21
11 AM Thu 90 94 S 12 10533 9603 7963 Blue 24
12 Noon Thu 92 97 S 12 11364 10449 8809 Blue 27
1 PM Thu 93 99 S 12 11909 11001 9361 Blue 29
2 PM Thu 93 98 S 12 11638 10726 9086 Blue 28
3 PM Thu 93 97 S 12 11364 10449 8809 Blue 27
4 PM Thu 92 94 S 12 10533 9603 7963 Blue 24
5 PM Thu 91 92 S 13 9967 9092 7452 Blue 22
6 PM Thu 90 90 S 13 9413 8801 7161 Blue 20
7 PM Thu 88 88 S 13 8941 8577 6937 Blue 18
8 PM Thu 86 86 S 13 8716 8354 6714 Blue 16
9 PM Thu 84 84 S 13 8491 8130 6490 Blue 14
10 PM Thu 82 82 S 13 8266 7646 6006 Blue 12
11 PM Thu 80 80 NW 6 8042 6321 4681 Blue 10
12 Midnight Fri 77 77 NW 6 6432 4257 2617 Blue 7
1 AM Fri 75 75 NW 6 4922 2790 1150 Blue 5
2 AM Fri 73 73 NW 6 3593 1640 0 Blue 3
3 AM Fri 71 71 NW 6 2097 1640 0 Blue 1
4 AM Fri 71 71 NW 6 2097 1640 0 Blue 1
5 AM Fri 72 72 N 7 2822 1640 0 Blue 2
6 AM Fri 74 74 N 7 4319 2085 445 Blue 4
7 AM Fri 77 77 N 7 6432 4257 2617 Blue 7
8 AM Fri 81 81 N 7 8154 7000 5360 Blue 11
9 AM Fri 86 87 N 7 8828 8465 6825 Blue 17
10 AM Fri 90 93 N 7 10252 9346 7706 Blue 23
11 AM Fri 93 97 S 13 11364 10449 8809 Blue 27
12 Noon Fri 95 100 S 13 12179 11275 9635 Blue 30
1 PM Fri 97 103 S 13 12978 12083 10443 Blue 33
2 PM Fri 98 103 S 13 12978 12083 10443 Blue 33
3 PM Fri 98 102 S 13 12713 11815 10175 Blue 32
4 PM Fri 97 99 S 13 11909 11001 9361 Blue 29
5 PM Fri 96 97 S 14 11364 10449 8809 Blue 27
6 PM Fri 95 95 S 14 10812 9888 8248 Blue 25
7 PM Fri 93 93 S 14 10252 9346 7706 Blue 23
8 PM Fri 91 91 S 14 9681 8913 7273 Blue 21
9 PM Fri 88 88 S 14 8941 8577 6937 Blue 18
10 PM Fri 86 86 S 14 8716 8354 6714 Blue 16
11 PM Fri 83 83 N 6 8379 8018 6378 Blue 13
12 Midnight Sat 80 80 N 6 8042 6321 4681 Blue 10
1 AM Sat 77 77 N 6 6432 4257 2617 Blue 7
2 AM Sat 74 74 N 6 4319 2085 445 Blue 4
3 AM Sat 73 73 N 6 3593 1640 0 Blue 3
4 AM Sat 72 72 N 6 2822 1640 0 Blue 2
5 AM Sat 73 73 N 10 3593 1640 0 Blue 3
6 AM Sat 75 75 N 10 4922 2790 1150 Blue 5
7 AM Sat 78 78 N 10 7121 4874 3234 Blue 8
8 AM Sat 83 83 N 10 8379 8018 6378 Blue 13
9 AM Sat 87 88 N 10 8941 8577 6937 Blue 18
10 AM Sat 92 95 N 10 10812 9888 8248 Blue 25
11 AM Sat 95 99 S 14 11909 11001 9361 Blue 29
12 Noon Sat 98 103 S 14 12978 12083 10443 Blue 33
1 PM Sat 99 105 S 14 14563 12614 10974 Blue 35
2 PM Sat 99 104 S 14 13691 12349 10709 Blue 34
3 PM Sat 99 103 S 14 12978 12083 10443 Blue 33
4 PM Sat 98 100 S 14 12179 11275 9635 Blue 30
5 PM Sat 96 97 S 15 11364 10449 8809 Blue 27
6 PM Sat 94 94 S 15 10533 9603 7963 Blue 24
7 PM Sat 92 92 S 15 9967 9092 7452 Blue 22
8 PM Sat 90 90 S 15 9413 8801 7161 Blue 20
9 PM Sat 87 87 S 15 8828 8465 6825 Blue 17
10 PM Sat 85 85 S 15 8604 8242 6602 Blue 15
11 PM Sat 82 82 NE 2 8266 7646 6006 Blue 12
12 Midnight Sun 79 79 NE 2 7775 5602 3962 Blue 9
1 AM Sun 76 76 NE 2 5702 3545 1905 Blue 6
2 AM Sun 74 74 NE 2 4319 2085 445 Blue 4
3 AM Sun 72 72 NE 2 2822 1640 0 Blue 2
4 AM Sun 72 72 NE 2 2822 1640 0 Blue 2

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