Detailed Predictions for: Lake Isabella Ground Launch Center
Launch Altitude (f): 5000
LZ Altitude (f): 2591
Sounding

Station:

KVBG

Date/Time:

18 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 Sat 42 42 E 8 2628 5000 0 Blue 0
5 AM Sat 42 42 E 8 2628 5000 0 Blue 0
6 AM Sat 42 42 E 8 2628 5000 0 Blue 0
7 AM Sat 42 42 E 7 2628 5000 0 Blue 0
8 AM Sat 45 45 E 7 2628 5000 0 Blue 0
9 AM Sat 51 52 E 7 3124 5000 0 Blue 0
10 AM Sat 57 59 SE 10 3955 5000 0 Blue 7
11 AM Sat 61 63 SE 10 5151 5000 0 Blue 11
12 Noon Sat 63 65 SE 10 5657 5000 0 Blue 13
1 PM Sat 64 66 SE 10 5908 5133 133 Blue 14
2 PM Sat 64 65 SE 10 5657 5000 0 Blue 13
3 PM Sat 63 63 SE 10 5151 5000 0 Blue 11
4 PM Sat 61 61 S 7 4457 5000 0 Blue 9
5 PM Sat 58 58 S 7 3880 5000 0 Blue 6
6 PM Sat 54 54 S 7 3590 5000 0 Blue 2
7 PM Sat 51 51 S 6 2684 5000 0 Blue 0
8 PM Sat 49 49 S 6 2628 5000 0 Blue 0
9 PM Sat 48 48 S 6 2628 5000 0 Blue 0
10 PM Sat 47 47 S 6 2628 5000 0 Blue 0
11 PM Sat 47 47 S 6 2628 5000 0 Blue 0
12 Midnight Sun 46 46 S 6 2628 5000 0 Blue 0
1 AM Sun 45 45 S 5 2628 5000 0 Blue 0
2 AM Sun 45 45 S 5 2628 5000 0 Blue 0
3 AM Sun 44 44 S 5 2628 5000 0 Blue 0
4 AM Sun 43 43 SW 5 2628 5000 0 Blue 0
5 AM Sun 41 41 SW 5 2628 5000 0 Blue 0
6 AM Sun 41 41 SW 5 2628 5000 0 Blue 0
7 AM Sun 43 43 NW 3 2628 5000 0 Blue 0
8 AM Sun 47 47 NW 3 2628 5000 0 Blue 0
9 AM Sun 52 53 NW 3 3390 5000 0 Blue 1
10 AM Sun 58 59 W 5 3955 5000 0 Blue 7
11 AM Sun 61 63 W 5 5151 5000 0 Blue 11
12 Noon Sun 64 66 W 5 5908 5133 133 Blue 14
1 PM Sun 65 66 SW 7 5908 5133 133 Blue 14
2 PM Sun 65 66 SW 7 5908 5133 133 Blue 14
3 PM Sun 64 64 SW 7 5405 5000 0 Blue 12
4 PM Sun 61 61 W 8 4457 5000 0 Blue 9
5 PM Sun 58 58 W 8 3880 5000 0 Blue 6
6 PM Sun 54 54 W 8 3590 5000 0 Blue 2
7 PM Sun 52 52 W 8 3124 5000 0 Blue 0
8 PM Sun 50 50 W 8 2628 5000 0 Blue 0
9 PM Sun 49 49 W 8 2628 5000 0 Blue 0
10 PM Sun 49 49 NW 9 2628 5000 0 Blue 0
11 PM Sun 48 48 NW 9 2628 5000 0 Blue 0
12 Midnight Mon 48 48 NW 9 2628 5000 0 Blue 0
1 AM Mon 47 47 NW 9 2628 5000 0 Blue 0
2 AM Mon 46 46 NW 9 2628 5000 0 Blue 0
3 AM Mon 46 46 NW 9 2628 5000 0 Blue 0
4 AM Mon 45 45 NW 8 2628 5000 0 Blue 0
5 AM Mon 44 44 NW 8 2628 5000 0 Blue 0
6 AM Mon 44 44 NW 8 2628 5000 0 Blue 0
7 AM Mon 46 46 NW 8 2628 5000 0 Blue 0
8 AM Mon 51 51 NW 8 2684 5000 0 Blue 0
9 AM Mon 57 57 NW 8 3804 5000 0 Blue 5
10 AM Mon 63 64 W 9 5405 5000 0 Blue 12
11 AM Mon 67 68 W 9 6417 5635 635 Blue 16
12 Noon Mon 68 69 W 9 6770 5885 885 Blue 17
1 PM Mon 69 70 W 9 7120 6133 1133 Blue 18
2 PM Mon 69 69 W 9 6770 5885 885 Blue 17
3 PM Mon 68 68 W 9 6417 5635 635 Blue 16
4 PM Mon 66 66 W 10 5908 5133 133 Blue 14
5 PM Mon 63 63 W 10 5151 5000 0 Blue 11
6 PM Mon 59 59 W 10 3955 5000 0 Blue 7
7 PM Mon 56 56 W 10 3732 5000 0 Blue 4
8 PM Mon 53 53 W 10 3390 5000 0 Blue 1
9 PM Mon 52 52 W 10 3124 5000 0 Blue 0
10 PM Mon 51 51 SE 8 2684 5000 0 Blue 0
11 PM Mon 51 51 SE 8 2684 5000 0 Blue 0
12 Midnight Tue 51 51 SE 8 2684 5000 0 Blue 0
1 AM Tue 50 50 SE 8 2628 5000 0 Blue 0
2 AM Tue 49 49 SE 8 2628 5000 0 Blue 0
3 AM Tue 48 48 SE 8 2628 5000 0 Blue 0
4 AM Tue 48 48 S 7 2628 5000 0 Blue 0
5 AM Tue 49 49 S 7 2628 5000 0 Blue 0
6 AM Tue 52 52 S 7 3124 5000 0 Blue 0
7 AM Tue 55 55 S 7 3661 5000 0 Blue 3
8 AM Tue 59 59 S 7 3955 5000 0 Blue 7
9 AM Tue 63 64 S 7 5405 5000 0 Blue 12
10 AM Tue 66 67 SW 5 6158 5385 385 Blue 15
11 AM Tue 69 71 SW 5 7465 6380 1380 Blue 19
12 Noon Tue 70 72 SW 5 7806 6728 1728 Blue 20
1 PM Tue 72 73 SW 5 8144 7073 2073 Blue 21
2 PM Tue 72 73 SW 5 8144 7073 2073 Blue 21
3 PM Tue 72 72 SW 5 7806 6728 1728 Blue 20
4 PM Tue 70 70 NW 8 7120 6133 1133 Blue 18
5 PM Tue 68 68 NW 8 6417 5635 635 Blue 16
6 PM Tue 66 66 NW 8 5908 5133 133 Blue 14
7 PM Tue 63 63 NW 8 5151 5000 0 Blue 11
8 PM Tue 60 60 NW 8 4105 5000 0 Blue 8
9 PM Tue 57 57 NW 8 3804 5000 0 Blue 5
10 PM Tue 54 54 S 7 3590 5000 0 Blue 2
11 PM Tue 52 52 S 7 3124 5000 0 Blue 0
12 Midnight Wed 50 50 S 7 2628 5000 0 Blue 0
1 AM Wed 48 48 S 7 2628 5000 0 Blue 0
2 AM Wed 48 48 S 7 2628 5000 0 Blue 0
3 AM Wed 48 48 S 7 2628 5000 0 Blue 0
4 AM Wed 50 50 SE 6 2628 5000 0 Blue 0
5 AM Wed 53 53 SE 6 3390 5000 0 Blue 1
6 AM Wed 56 56 SE 6 3732 5000 0 Blue 4
7 AM Wed 60 60 SE 6 4105 5000 0 Blue 8
8 AM Wed 64 64 SE 6 5405 5000 0 Blue 12
9 AM Wed 68 69 SE 6 6770 5885 885 Blue 17
10 AM Wed 71 73 S 3 8144 7073 2073 Blue 21
11 AM Wed 74 76 S 3 8979 8088 3088 Blue 24
12 Noon Wed 76 78 S 3 9448 8699 3699 Blue 26
1 PM Wed 77 79 S 3 9681 8933 3933 Blue 27
2 PM Wed 77 78 S 3 9448 8699 3699 Blue 26
3 PM Wed 76 76 S 3 8979 8088 3088 Blue 24
4 PM Wed 75 75 W 6 8744 7753 2753 Blue 23
5 PM Wed 73 73 W 6 8144 7073 2073 Blue 21
6 PM Wed 70 70 W 6 7120 6133 1133 Blue 18
7 PM Wed 67 67 W 6 6158 5385 385 Blue 15
8 PM Wed 63 63 W 6 5151 5000 0 Blue 11
9 PM Wed 60 60 W 6 4105 5000 0 Blue 8
10 PM Wed 56 56 S 7 3732 5000 0 Blue 4
11 PM Wed 53 53 S 7 3390 5000 0 Blue 1
12 Midnight Thu 51 51 S 7 2684 5000 0 Blue 0
1 AM Thu 49 49 S 7 2628 5000 0 Blue 0
2 AM Thu 48 48 S 7 2628 5000 0 Blue 0
3 AM Thu 48 48 S 7 2628 5000 0 Blue 0
4 AM Thu 49 49 SE 7 2628 5000 0 Blue 0
5 AM Thu 52 52 SE 7 3124 5000 0 Blue 0
6 AM Thu 56 56 SE 7 3732 5000 0 Blue 4
7 AM Thu 60 60 SE 7 4105 5000 0 Blue 8
8 AM Thu 64 64 SE 7 5405 5000 0 Blue 12
9 AM Thu 68 69 SE 7 6770 5885 885 Blue 17
10 AM Thu 72 74 W 6 8479 7415 2415 Blue 22
11 AM Thu 75 77 W 6 9214 8419 3419 Blue 25
12 Noon Thu 76 78 W 6 9448 8699 3699 Blue 26
1 PM Thu 77 79 W 6 9681 8933 3933 Blue 27
2 PM Thu 77 78 W 6 9448 8699 3699 Blue 26
3 PM Thu 76 76 W 6 8979 8088 3088 Blue 24
4 PM Thu 74 74 W 9 8479 7415 2415 Blue 22
5 PM Thu 72 72 W 9 7806 6728 1728 Blue 20
6 PM Thu 69 69 W 9 6770 5885 885 Blue 17
7 PM Thu 65 65 W 9 5657 5000 0 Blue 13
8 PM Thu 62 62 W 9 4806 5000 0 Blue 10
9 PM Thu 59 59 W 9 3955 5000 0 Blue 7
10 PM Thu 56 56 NW 9 3732 5000 0 Blue 4
11 PM Thu 53 53 NW 9 3390 5000 0 Blue 1
12 Midnight Fri 51 51 NW 9 2684 5000 0 Blue 0
1 AM Fri 50 50 NW 9 2628 5000 0 Blue 0
2 AM Fri 49 49 NW 9 2628 5000 0 Blue 0
3 AM Fri 49 49 NW 9 2628 5000 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