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

Station:

KVBG

Date/Time:

1 DEC 2020

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 Tue 43 43 N 15 1286 1640 0 Blue 0
5 AM Tue 42 42 N 15 1286 1640 0 Blue 0
6 AM Tue 43 43 N 15 1286 1640 0 Blue 0
7 AM Tue 42 42 N 16 1286 1640 0 Blue 0
8 AM Tue 49 49 N 16 1286 1640 0 Blue 0
9 AM Tue 60 61 N 16 1322 1640 0 Blue 0
10 AM Tue 67 69 NE 20 2733 1838 198 Blue 2
11 AM Tue 74 76 NE 20 4473 3261 1621 Blue 9
12 Noon Tue 77 79 NE 20 5449 4435 2795 Blue 12
1 PM Tue 78 80 N 14 5815 4828 3188 Blue 13
2 PM Tue 78 79 N 14 5449 4435 2795 Blue 12
3 PM Tue 77 77 N 14 4870 3631 1991 Blue 10
4 PM Tue 74 74 N 14 3659 2995 1355 Blue 7
5 PM Tue 68 68 N 14 2426 1735 95 Blue 1
6 PM Tue 64 64 N 14 1632 1640 0 Blue 0
7 PM Tue 61 61 NE 17 1322 1640 0 Blue 0
8 PM Tue 58 58 NE 17 1286 1640 0 Blue 0
9 PM Tue 57 57 NE 17 1286 1640 0 Blue 0
10 PM Tue 55 55 NE 22 1286 1640 0 Blue 0
11 PM Tue 55 55 NE 22 1286 1640 0 Blue 0
12 Midnight Wed 55 55 NE 22 1286 1640 0 Blue 0
1 AM Wed 54 54 NE 22 1286 1640 0 Blue 0
2 AM Wed 53 53 NE 22 1286 1640 0 Blue 0
3 AM Wed 52 52 NE 22 1286 1640 0 Blue 0
4 AM Wed 51 51 NE 23 1286 1640 0 Blue 0
5 AM Wed 50 50 NE 23 1286 1640 0 Blue 0
6 AM Wed 51 51 NE 23 1286 1640 0 Blue 0
7 AM Wed 50 50 NE 25 1286 1640 0 Blue 0
8 AM Wed 55 55 NE 25 1286 1640 0 Blue 0
9 AM Wed 61 62 NE 25 1425 1640 0 Blue 0
10 AM Wed 66 67 NE 25 2066 1640 0 Blue 0
11 AM Wed 71 72 NE 25 3135 2728 1088 Blue 5
12 Noon Wed 72 74 NE 25 3659 2995 1355 Blue 7
1 PM Wed 73 74 N 20 3659 2995 1355 Blue 7
2 PM Wed 73 74 N 20 3659 2995 1355 Blue 7
3 PM Wed 72 72 N 20 3135 2728 1088 Blue 5
4 PM Wed 69 69 N 20 2733 1838 198 Blue 2
5 PM Wed 64 64 N 20 1632 1640 0 Blue 0
6 PM Wed 60 60 N 20 1286 1640 0 Blue 0
7 PM Wed 57 57 N 20 1286 1640 0 Blue 0
8 PM Wed 55 55 N 20 1286 1640 0 Blue 0
9 PM Wed 53 53 N 20 1286 1640 0 Blue 0
10 PM Wed 52 52 NE 22 1286 1640 0 Blue 0
11 PM Wed 52 52 NE 22 1286 1640 0 Blue 0
12 Midnight Thu 51 51 NE 22 1286 1640 0 Blue 0
1 AM Thu 51 51 NE 24 1286 1640 0 Blue 0
2 AM Thu 50 50 NE 24 1286 1640 0 Blue 0
3 AM Thu 49 49 NE 24 1286 1640 0 Blue 0
4 AM Thu 48 48 NE 24 1286 1640 0 Blue 0
5 AM Thu 47 47 NE 24 1286 1640 0 Blue 0
6 AM Thu 48 48 NE 24 1286 1640 0 Blue 0
7 AM Thu 47 47 N 29 1286 1640 0 Blue 0
8 AM Thu 52 52 N 29 1286 1640 0 Blue 0
9 AM Thu 58 58 N 29 1286 1640 0 Blue 0
10 AM Thu 62 63 N 30 1528 1640 0 Blue 0
11 AM Thu 67 69 N 30 2733 1838 198 Blue 2
12 Noon Thu 68 70 N 30 2867 2060 420 Blue 3
1 PM Thu 69 71 N 29 3001 2415 775 Blue 4
2 PM Thu 69 70 N 29 2867 2060 420 Blue 3
3 PM Thu 68 68 N 29 2426 1735 95 Blue 1
4 PM Thu 65 65 N 28 1735 1640 0 Blue 0
5 PM Thu 60 60 N 28 1286 1640 0 Blue 0
6 PM Thu 56 56 N 28 1286 1640 0 Blue 0
7 PM Thu 53 53 N 24 1286 1640 0 Blue 0
8 PM Thu 51 51 N 24 1286 1640 0 Blue 0
9 PM Thu 49 49 N 24 1286 1640 0 Blue 0
10 PM Thu 48 48 NE 25 1286 1640 0 Blue 0
11 PM Thu 48 48 NE 25 1286 1640 0 Blue 0
12 Midnight Fri 47 47 NE 25 1286 1640 0 Blue 0
1 AM Fri 47 47 NE 28 1286 1640 0 Blue 0
2 AM Fri 46 46 NE 28 1286 1640 0 Blue 0
3 AM Fri 45 45 NE 28 1286 1640 0 Blue 0
4 AM Fri 44 44 N 29 1286 1640 0 Blue 0
5 AM Fri 43 43 N 29 1286 1640 0 Blue 0
6 AM Fri 44 44 N 29 1286 1640 0 Blue 0
7 AM Fri 43 43 N 29 1286 1640 0 Blue 0
8 AM Fri 49 49 N 29 1286 1640 0 Blue 0
9 AM Fri 56 57 N 29 1286 1640 0 Blue 0
10 AM Fri 62 64 N 25 1632 1640 0 Blue 0
11 AM Fri 67 69 N 25 2733 1838 198 Blue 2
12 Noon Fri 69 71 N 25 3001 2415 775 Blue 4
1 PM Fri 70 72 N 20 3135 2728 1088 Blue 5
2 PM Fri 70 71 N 20 3001 2415 775 Blue 4
3 PM Fri 69 69 N 20 2733 1838 198 Blue 2
4 PM Fri 66 66 N 17 1839 1640 0 Blue 0
5 PM Fri 61 61 N 17 1322 1640 0 Blue 0
6 PM Fri 57 57 N 17 1286 1640 0 Blue 0
7 PM Fri 54 54 N 14 1286 1640 0 Blue 0
8 PM Fri 52 52 N 14 1286 1640 0 Blue 0
9 PM Fri 50 50 N 14 1286 1640 0 Blue 0
10 PM Fri 49 49 NE 20 1286 1640 0 Blue 0
11 PM Fri 49 49 NE 20 1286 1640 0 Blue 0
12 Midnight Sat 48 48 NE 20 1286 1640 0 Blue 0
1 AM Sat 48 48 NE 20 1286 1640 0 Blue 0
2 AM Sat 47 47 NE 20 1286 1640 0 Blue 0
3 AM Sat 46 46 NE 20 1286 1640 0 Blue 0
4 AM Sat 45 45 NE 16 1286 1640 0 Blue 0
5 AM Sat 44 44 NE 16 1286 1640 0 Blue 0
6 AM Sat 45 45 NE 16 1286 1640 0 Blue 0
7 AM Sat 44 44 NE 21 1286 1640 0 Blue 0
8 AM Sat 50 50 NE 21 1286 1640 0 Blue 0
9 AM Sat 58 59 NE 21 1286 1640 0 Blue 0
10 AM Sat 64 66 NE 20 1839 1640 0 Blue 0
11 AM Sat 69 71 NE 20 3001 2415 775 Blue 4
12 Noon Sat 71 73 NE 20 3269 2861 1221 Blue 6
1 PM Sat 72 74 N 15 3659 2995 1355 Blue 7
2 PM Sat 72 73 N 15 3269 2861 1221 Blue 6
3 PM Sat 71 71 N 15 3001 2415 775 Blue 4
4 PM Sat 68 68 N 15 2426 1735 95 Blue 1
5 PM Sat 62 62 N 15 1425 1640 0 Blue 0
6 PM Sat 58 58 N 15 1286 1640 0 Blue 0
7 PM Sat 56 56 N 9 1286 1640 0 Blue 0
8 PM Sat 53 53 N 9 1286 1640 0 Blue 0
9 PM Sat 52 52 N 9 1286 1640 0 Blue 0
10 PM Sat 50 50 N 10 1286 1640 0 Blue 0
11 PM Sat 50 50 N 10 1286 1640 0 Blue 0
12 Midnight Sun 49 49 N 10 1286 1640 0 Blue 0
1 AM Sun 49 49 N 10 1286 1640 0 Blue 0
2 AM Sun 48 48 N 10 1286 1640 0 Blue 0
3 AM Sun 47 47 N 10 1286 1640 0 Blue 0
4 AM Sun 46 46 NE 10 1286 1640 0 Blue 0
5 AM Sun 45 45 NE 10 1286 1640 0 Blue 0
6 AM Sun 46 46 NE 10 1286 1640 0 Blue 0
7 AM Sun 45 45 NE 12 1286 1640 0 Blue 0
8 AM Sun 51 51 NE 12 1286 1640 0 Blue 0
9 AM Sun 59 60 NE 12 1286 1640 0 Blue 0
10 AM Sun 65 67 NE 12 2066 1640 0 Blue 0
11 AM Sun 70 72 NE 12 3135 2728 1088 Blue 5
12 Noon Sun 72 74 NE 12 3659 2995 1355 Blue 7
1 PM Sun 73 75 W 12 4069 3128 1488 Blue 8
2 PM Sun 73 74 W 12 3659 2995 1355 Blue 7
3 PM Sun 72 72 W 12 3135 2728 1088 Blue 5
4 PM Sun 69 69 NW 10 2733 1838 198 Blue 2
5 PM Sun 63 63 NW 10 1528 1640 0 Blue 0
6 PM Sun 59 59 NW 10 1286 1640 0 Blue 0
7 PM Sun 56 56 N 7 1286 1640 0 Blue 0
8 PM Sun 53 53 N 7 1286 1640 0 Blue 0
9 PM Sun 52 52 N 7 1286 1640 0 Blue 0
10 PM Sun 50 50 N 7 1286 1640 0 Blue 0
11 PM Sun 50 50 N 7 1286 1640 0 Blue 0
12 Midnight Mon 50 50 N 7 1286 1640 0 Blue 0
1 AM Mon 49 49 NE 8 1286 1640 0 Blue 0
2 AM Mon 48 48 NE 8 1286 1640 0 Blue 0
3 AM Mon 47 47 NE 8 1286 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 [email protected]