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

Station:

KVBG

Date/Time:

17 NOV 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)
4 AM Fri 58 58 NW 6 1714 1640 0 Blue 0
5 AM Fri 57 57 NW 6 1308 1640 0 Blue 0
6 AM Fri 55 55 NW 6 477 1640 0 Blue 0
7 AM Fri 54 54 W 3 427 1640 0 Blue 0
8 AM Fri 54 54 W 3 427 1640 0 Blue 0
9 AM Fri 56 56 W 3 896 1640 0 Blue 0
10 AM Fri 60 61 W 6 2719 1712 72 White 1
11 AM Fri 64 66 W 6 3817 3688 2048 White 6
12 Noon Fri 68 70 W 6 4690 4690 3050 White 10
1 PM Fri 71 72 W 5 5119 5119 3479 White 12
2 PM Fri 72 73 W 5 5332 5332 3692 White 13
3 PM Fri 71 71 W 5 4906 4906 3266 White 11
4 PM Fri 70 70 W 9 4690 4690 3050 White 10
5 PM Fri 68 68 W 9 4254 4254 2614 White 8
6 PM Fri 66 66 W 9 3817 3688 2048 White 6
7 PM Fri 65 65 W 9 3598 3295 1655 White 5
8 PM Fri 65 65 W 9 3598 3295 1655 White 5
9 PM Fri 65 65 W 9 3598 3295 1655 White 5
10 PM Fri 65 65 NE 16 3598 3295 1655 White 5
11 PM Fri 63 63 NE 16 3159 2497 857 White 3
12 Midnight Sat 59 59 NE 16 2115 1640 0 Blue 0
1 AM Sat 57 57 NE 16 1308 1640 0 Blue 0
2 AM Sat 55 55 NE 16 477 1640 0 Blue 0
3 AM Sat 54 54 NE 16 427 1640 0 Blue 0
4 AM Sat 53 53 NE 16 427 1640 0 Blue 0
5 AM Sat 52 52 NE 16 427 1640 0 Blue 0
6 AM Sat 50 50 NE 16 427 1640 0 Blue 0
7 AM Sat 50 50 NE 16 427 1640 0 Blue 0
8 AM Sat 52 52 NE 16 427 1640 0 Blue 0
9 AM Sat 55 56 NE 16 896 1640 0 Blue 0
10 AM Sat 60 62 N 15 2939 2107 467 White 2
11 AM Sat 65 67 N 15 4035 4035 2395 White 7
12 Noon Sat 69 72 N 15 5119 5119 3479 White 12
1 PM Sat 73 75 N 15 5756 5756 4116 White 15
2 PM Sat 76 77 N 15 6180 6180 4540 White 17
3 PM Sat 77 77 N 15 6180 6180 4540 White 17
4 PM Sat 77 77 N 9 6180 6180 4540 White 17
5 PM Sat 76 76 N 9 5969 5969 4329 White 16
6 PM Sat 73 73 N 9 5332 5332 3692 White 13
7 PM Sat 70 70 N 9 4690 4690 3050 White 10
8 PM Sat 67 67 N 9 4035 4035 2395 White 7
9 PM Sat 64 64 N 9 3379 2897 1257 White 4
10 PM Sat 61 61 NE 9 2719 1712 72 White 1
11 PM Sat 59 59 NE 9 2115 1640 0 Blue 0
12 Midnight Sun 58 58 NE 9 1714 1640 0 Blue 0
1 AM Sun 57 57 NE 9 1308 1640 0 Blue 0
2 AM Sun 55 55 NE 9 477 1640 0 Blue 0
3 AM Sun 54 54 NE 9 427 1640 0 Blue 0
4 AM Sun 52 52 N 12 427 1640 0 Blue 0
5 AM Sun 50 50 N 12 427 1640 0 Blue 0
6 AM Sun 49 49 N 12 427 1640 0 Blue 0
7 AM Sun 50 50 N 12 427 1640 0 Blue 0
8 AM Sun 53 53 N 12 427 1640 0 Blue 0
9 AM Sun 59 60 N 12 2498 1640 0 White 0
10 AM Sun 65 67 W 8 4035 4035 2395 White 7
11 AM Sun 70 72 W 8 5119 5119 3479 White 12
12 Noon Sun 75 77 W 8 6180 6180 4540 White 17
1 PM Sun 78 80 W 8 6812 6812 5172 White 20
2 PM Sun 78 79 W 8 6602 6602 4962 White 19
3 PM Sun 77 77 W 8 6180 6180 4540 White 17
4 PM Sun 75 75 W 10 5756 5756 4116 White 15
5 PM Sun 74 74 W 10 5545 5545 3905 White 14
6 PM Sun 72 72 W 10 5119 5119 3479 White 12
7 PM Sun 70 70 W 10 4690 4690 3050 White 10
8 PM Sun 68 68 W 10 4254 4254 2614 White 8
9 PM Sun 65 65 W 10 3598 3295 1655 White 5
10 PM Sun 63 63 N 5 3159 2497 857 White 3
11 PM Sun 62 62 N 5 2939 2107 467 White 2
12 Midnight Mon 61 61 N 5 2719 1712 72 White 1
1 AM Mon 61 61 N 5 2719 1712 72 White 1
2 AM Mon 59 59 N 5 2115 1640 0 Blue 0
3 AM Mon 58 58 N 5 1714 1640 0 Blue 0
4 AM Mon 56 56 N 5 896 1640 0 Blue 0
5 AM Mon 54 54 N 5 427 1640 0 Blue 0
6 AM Mon 54 54 N 5 427 1640 0 Blue 0
7 AM Mon 56 56 N 5 896 1640 0 Blue 0
8 AM Mon 60 60 N 5 2498 1640 0 White 0
9 AM Mon 66 67 N 5 4035 4035 2395 White 7
10 AM Mon 72 73 SW 12 5332 5332 3692 White 13
11 AM Mon 75 77 SW 12 6180 6180 4540 White 17
12 Noon Mon 77 79 SW 12 6602 6602 4962 White 19
1 PM Mon 77 79 SW 12 6602 6602 4962 White 19
2 PM Mon 75 76 SW 12 5969 5969 4329 White 16
3 PM Mon 72 72 SW 12 5119 5119 3479 White 12
4 PM Mon 70 70 SW 12 4690 4690 3050 White 10
5 PM Mon 69 69 SW 12 4471 4471 2831 White 9
6 PM Mon 70 70 SW 12 4690 4690 3050 White 10
7 PM Mon 70 70 SW 12 4690 4690 3050 White 10
8 PM Mon 71 71 SW 12 4906 4906 3266 White 11
9 PM Mon 71 71 SW 12 4906 4906 3266 White 11
10 PM Mon 70 70 N 3 4690 4690 3050 White 10
11 PM Mon 67 67 N 3 4035 4035 2395 White 7
12 Midnight Tue 64 64 N 3 3379 2897 1257 White 4
1 AM Tue 59 59 N 3 2115 1640 0 Blue 0
2 AM Tue 56 56 N 3 896 1640 0 Blue 0
3 AM Tue 53 53 N 3 427 1640 0 Blue 0
4 AM Tue 53 53 N 6 427 1640 0 Blue 0
5 AM Tue 54 54 N 6 427 1640 0 Blue 0
6 AM Tue 56 56 N 6 896 1640 0 Blue 0
7 AM Tue 59 59 N 6 2115 1640 0 Blue 0
8 AM Tue 62 62 N 6 2939 2107 467 White 2
9 AM Tue 66 67 N 6 4035 4035 2395 White 7
10 AM Tue 69 70 W 10 4690 4690 3050 White 10
11 AM Tue 72 74 W 10 5545 5545 3905 White 14
12 Noon Tue 75 77 W 10 6180 6180 4540 White 17
1 PM Tue 77 79 W 10 6602 6602 4962 White 19
2 PM Tue 79 80 W 10 6812 6812 5172 White 20
3 PM Tue 80 80 W 10 6812 6812 5172 White 20
4 PM Tue 80 80 NW 10 6812 6812 5172 White 20
5 PM Tue 79 79 NW 10 6602 6602 4962 White 19
6 PM Tue 77 77 NW 10 6180 6180 4540 White 17
7 PM Tue 74 74 NW 10 5545 5545 3905 White 14
8 PM Tue 71 71 NW 10 4906 4906 3266 White 11
9 PM Tue 67 67 NW 10 4035 4035 2395 White 7
10 PM Tue 64 64 N 7 3379 2897 1257 White 4
11 PM Tue 61 61 N 7 2719 1712 72 White 1
12 Midnight Wed 58 58 N 7 1714 1640 0 Blue 0
1 AM Wed 57 57 N 7 1308 1640 0 Blue 0
2 AM Wed 56 56 N 7 896 1640 0 Blue 0
3 AM Wed 56 56 N 7 896 1640 0 Blue 0
4 AM Wed 57 57 N 9 1308 1640 0 Blue 0
5 AM Wed 59 59 N 9 2115 1640 0 Blue 0
6 AM Wed 62 62 N 9 2939 2107 467 White 2
7 AM Wed 65 65 N 9 3598 3295 1655 White 5
8 AM Wed 68 68 N 9 4254 4254 2614 White 8
9 AM Wed 72 73 N 9 5332 5332 3692 White 13
10 AM Wed 75 77 NW 14 6180 6180 4540 White 17
11 AM Wed 78 80 NW 14 6812 6812 5172 White 20
12 Noon Wed 81 83 NW 14 7441 7441 5801 White 23
1 PM Wed 84 86 NW 14 8065 8065 6425 White 26
2 PM Wed 86 87 NW 14 8273 8273 6633 White 26
3 PM Wed 87 87 NW 14 8273 8273 6633 White 26
4 PM Wed 87 87 NW 14 8273 8273 6633 White 26
5 PM Wed 86 86 NW 14 8065 8065 6425 White 26
6 PM Wed 84 84 NW 14 7650 7650 6010 White 24
7 PM Wed 82 82 NW 14 7232 7232 5592 White 22
8 PM Wed 79 79 NW 14 6602 6602 4962 White 19
9 PM Wed 75 75 NW 14 5756 5756 4116 White 15
10 PM Wed 71 71 N 9 4906 4906 3266 White 11
11 PM Wed 68 68 N 9 4254 4254 2614 White 8
12 Midnight Thu 64 64 N 9 3379 2897 1257 White 4
1 AM Thu 62 62 N 9 2939 2107 467 White 2
2 AM Thu 60 60 N 9 2498 1640 0 White 0
3 AM Thu 59 59 N 9 2115 1640 0 Blue 0

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