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

Station:

 KVBG

Date/Time:

 4 FEB 2012

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
4 AM Sat 43 43 N 22 771 1640 0 Blue 0
5 AM Sat 42 42 N 22 771 1640 0 Blue 0
6 AM Sat 43 43 N 22 771 1640 0 Blue 0
7 AM Sat 45 45 N 22 771 1640 0 Blue 0
8 AM Sat 50 50 N 22 771 1640 0 Blue 0
9 AM Sat 56 57 N 22 1259 1640 0 Blue 0
10 AM Sat 62 64 N 22 5529 2870 1230 Blue 4
11 AM Sat 66 68 N 22 7572 5984 4344 Blue 8
12 Noon Sat 69 72 N 22 8152 7785 6145 Blue 12
1 PM Sat 70 72 E 10 8152 7785 6145 Blue 12
2 PM Sat 70 72 E 10 8152 7785 6145 Blue 12
3 PM Sat 70 71 E 10 8038 7475 5835 Blue 11
4 PM Sat 68 68 E 6 7572 5984 4344 Blue 8
5 PM Sat 65 65 E 6 6062 3954 2314 Blue 5
6 PM Sat 61 61 E 6 2924 1640 0 Blue 1
7 PM Sat 58 58 NE 16 1495 1640 0 Blue 0
8 PM Sat 56 56 NE 16 1021 1640 0 Blue 0
9 PM Sat 55 55 NE 16 783 1640 0 Blue 0
10 PM Sat 55 55 NE 23 783 1640 0 Blue 0
11 PM Sat 54 54 NE 23 771 1640 0 Blue 0
12 Midnight Sun 54 54 NE 23 771 1640 0 Blue 0
1 AM Sun 53 53 NE 23 771 1640 0 Blue 0
2 AM Sun 53 53 NE 23 771 1640 0 Blue 0
3 AM Sun 53 53 NE 23 771 1640 0 Blue 0
4 AM Sun 52 52 NE 22 771 1640 0 Blue 0
5 AM Sun 52 52 NE 22 771 1640 0 Blue 0
6 AM Sun 52 52 NE 22 771 1640 0 Blue 0
7 AM Sun 53 53 NE 22 771 1640 0 Blue 0
8 AM Sun 56 56 NE 22 1021 1640 0 Blue 0
9 AM Sun 60 60 NE 22 2083 1640 0 Blue 0
10 AM Sun 64 65 E 17 6062 3954 2314 Blue 5
11 AM Sun 67 69 E 17 7809 6495 4855 Blue 9
12 Noon Sun 69 71 E 17 8038 7475 5835 Blue 11
1 PM Sun 71 73 NE 12 8267 7899 6259 Blue 13
2 PM Sun 72 73 NE 12 8267 7899 6259 Blue 13
3 PM Sun 71 72 NE 12 8152 7785 6145 Blue 12
4 PM Sun 70 70 E 3 7923 6991 5351 Blue 10
5 PM Sun 67 67 E 3 7082 5459 3819 Blue 7
6 PM Sun 63 63 E 3 4978 2070 430 Blue 3
7 PM Sun 60 60 E 3 2083 1640 0 Blue 0
8 PM Sun 58 58 E 3 1495 1640 0 Blue 0
9 PM Sun 57 57 E 3 1259 1640 0 Blue 0
10 PM Sun 56 56 NE 8 1021 1640 0 Blue 0
11 PM Sun 55 55 NE 8 783 1640 0 Blue 0
12 Midnight Mon 55 55 NE 8 783 1640 0 Blue 0
1 AM Mon 54 54 NE 8 771 1640 0 Blue 0
2 AM Mon 53 53 NE 8 771 1640 0 Blue 0
3 AM Mon 53 53 NE 8 771 1640 0 Blue 0
4 AM Mon 53 53 NE 13 771 1640 0 Blue 0
5 AM Mon 52 52 NE 13 771 1640 0 Blue 0
6 AM Mon 52 52 NE 13 771 1640 0 Blue 0
7 AM Mon 53 53 NE 13 771 1640 0 Blue 0
8 AM Mon 56 56 NE 13 1021 1640 0 Blue 0
9 AM Mon 60 60 NE 13 2083 1640 0 Blue 0
10 AM Mon 63 64 NE 6 5529 2870 1230 Blue 4
11 AM Mon 66 68 NE 6 7572 5984 4344 Blue 8
12 Noon Mon 69 71 NE 6 8038 7475 5835 Blue 11
1 PM Mon 70 72 NE 6 8152 7785 6145 Blue 12
2 PM Mon 70 71 NE 6 8038 7475 5835 Blue 11
3 PM Mon 70 70 NE 6 7923 6991 5351 Blue 10
4 PM Mon 68 68 E 3 7572 5984 4344 Blue 8
5 PM Mon 65 65 E 3 6062 3954 2314 Blue 5
6 PM Mon 62 62 E 3 4037 1729 89 Blue 2
7 PM Mon 59 59 E 3 1730 1640 0 Blue 0
8 PM Mon 57 57 E 3 1259 1640 0 Blue 0
9 PM Mon 56 56 E 3 1021 1640 0 Blue 0
10 PM Mon 55 55 NE 5 783 1640 0 Blue 0
11 PM Mon 54 54 NE 5 771 1640 0 Blue 0
12 Midnight Tue 54 54 NE 5 771 1640 0 Blue 0
1 AM Tue 53 53 NE 5 771 1640 0 Blue 0
2 AM Tue 53 53 NE 5 771 1640 0 Blue 0
3 AM Tue 52 52 NE 5 771 1640 0 Blue 0
4 AM Tue 51 51 NE 5 771 1640 0 Blue 0
5 AM Tue 51 51 NE 5 771 1640 0 Blue 0
6 AM Tue 50 50 NE 5 771 1640 0 Blue 0
7 AM Tue 50 50 NE 5 771 1640 0 Blue 0
8 AM Tue 52 52 NE 5 771 1640 0 Blue 0
9 AM Tue 53 53 NE 5 771 1640 0 Blue 0
10 AM Tue 55 55 S 8 783 1640 0 Blue 0
11 AM Tue 57 57 S 8 1259 1640 0 Blue 0
12 Noon Tue 59 59 S 8 1730 1640 0 Blue 0
1 PM Tue 59 59 S 8 1730 1640 0 Blue 0
2 PM Tue 59 59 S 8 1730 1640 0 Blue 0
3 PM Tue 57 57 S 8 1259 1640 0 Blue 0
4 PM Tue 56 56 S 6 1021 1640 0 Blue 0
5 PM Tue 54 54 S 6 771 1640 0 Blue 0
6 PM Tue 52 52 S 6 771 1640 0 Blue 0
7 PM Tue 51 51 S 6 771 1640 0 Blue 0
8 PM Tue 50 50 S 6 771 1640 0 Blue 0
9 PM Tue 49 49 S 6 771 1640 0 Blue 0
10 PM Tue 48 48 NW 7 771 1640 0 Blue 0
11 PM Tue 47 47 NW 7 771 1640 0 Blue 0
12 Midnight Wed 47 47 NW 7 771 1640 0 Blue 0
1 AM Wed 47 47 NW 7 771 1640 0 Blue 0
2 AM Wed 47 47 NW 7 771 1640 0 Blue 0
3 AM Wed 46 46 NW 7 771 1640 0 Blue 0
4 AM Wed 46 46 NE 15 771 1640 0 Blue 0
5 AM Wed 46 46 NE 15 771 1640 0 Blue 0
6 AM Wed 46 46 NE 15 771 1640 0 Blue 0
7 AM Wed 47 47 NE 15 771 1640 0 Blue 0
8 AM Wed 49 49 NE 15 771 1640 0 Blue 0
9 AM Wed 52 52 NE 15 771 1640 0 Blue 0
10 AM Wed 55 56 N 13 1021 1640 0 Blue 0
11 AM Wed 58 60 N 13 2083 1640 0 Blue 0
12 Noon Wed 60 62 N 13 4037 1729 89 Blue 2
1 PM Wed 61 63 N 13 4978 2070 430 Blue 3
2 PM Wed 61 62 N 13 4037 1729 89 Blue 2
3 PM Wed 61 62 N 13 4037 1729 89 Blue 2
4 PM Wed 60 60 N 10 2083 1640 0 Blue 0
5 PM Wed 58 58 N 10 1495 1640 0 Blue 0
6 PM Wed 56 56 N 10 1021 1640 0 Blue 0
7 PM Wed 54 54 N 10 771 1640 0 Blue 0
8 PM Wed 53 53 N 10 771 1640 0 Blue 0
9 PM Wed 52 52 N 10 771 1640 0 Blue 0
10 PM Wed 51 51 N 13 771 1640 0 Blue 0
11 PM Wed 51 51 N 13 771 1640 0 Blue 0
12 Midnight Thu 51 51 N 13 771 1640 0 Blue 0
1 AM Thu 50 50 N 13 771 1640 0 Blue 0
2 AM Thu 50 50 N 13 771 1640 0 Blue 0
3 AM Thu 50 50 N 13 771 1640 0 Blue 0
4 AM Thu 50 50 N 18 771 1640 0 Blue 0
5 AM Thu 49 49 N 18 771 1640 0 Blue 0
6 AM Thu 50 50 N 18 771 1640 0 Blue 0
7 AM Thu 51 51 N 18 771 1640 0 Blue 0
8 AM Thu 53 53 N 18 771 1640 0 Blue 0
9 AM Thu 57 58 N 18 1495 1640 0 Blue 0
10 AM Thu 60 62 NW 7 4037 1729 89 Blue 2
11 AM Thu 63 66 NW 7 6580 4912 3272 Blue 6
12 Noon Thu 65 68 NW 7 7572 5984 4344 Blue 8
1 PM Thu 66 69 NW 7 7809 6495 4855 Blue 9
2 PM Thu 66 68 NW 7 7572 5984 4344 Blue 8
3 PM Thu 66 67 NW 7 7082 5459 3819 Blue 7
4 PM Thu 65 65 NW 7 6062 3954 2314 Blue 5
5 PM Thu 63 63 NW 7 4978 2070 430 Blue 3
6 PM Thu 59 59 NW 7 1730 1640 0 Blue 0
7 PM Thu 56 56 NW 7 1021 1640 0 Blue 0
8 PM Thu 55 55 NW 7 783 1640 0 Blue 0
9 PM Thu 54 54 NW 7 771 1640 0 Blue 0
10 PM Thu 53 53 N 14 771 1640 0 Blue 0
11 PM Thu 52 52 N 14 771 1640 0 Blue 0
12 Midnight Fri 52 52 N 14 771 1640 0 Blue 0
1 AM Fri 51 51 N 14 771 1640 0 Blue 0
2 AM Fri 50 50 N 14 771 1640 0 Blue 0
3 AM Fri 49 49 N 14 771 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