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

Station:

KVBG

Date/Time:

16 SEP 2018

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 Sun 56 56 W 9 2795 5000 0 Blue 0
6 AM Sun 57 57 W 9 2795 5000 0 Blue 0
7 AM Sun 56 56 W 9 2795 5000 0 Blue 0
8 AM Sun 63 63 W 6 2795 5000 0 Blue 0
9 AM Sun 69 70 W 6 3623 5000 0 Blue 0
10 AM Sun 76 79 W 6 6247 5381 381 Blue 7
11 AM Sun 81 86 SW 9 9864 8748 3748 Blue 14
12 Noon Sun 85 91 SW 9 10918 10215 5215 Blue 19
1 PM Sun 86 92 SW 9 11427 10426 5426 Blue 20
2 PM Sun 87 93 SW 12 11921 10637 5637 Blue 21
3 PM Sun 87 92 SW 12 11427 10426 5426 Blue 20
4 PM Sun 85 88 SW 12 10265 9623 4623 Blue 16
5 PM Sun 84 85 W 13 9665 8147 3147 Blue 13
6 PM Sun 81 81 W 13 7615 5667 667 Blue 9
7 PM Sun 74 74 W 13 5104 5000 0 Blue 3
8 PM Sun 72 72 W 12 4719 5000 0 Blue 1
9 PM Sun 70 70 W 12 3623 5000 0 Blue 0
10 PM Sun 68 68 W 12 3258 5000 0 Blue 0
11 PM Sun 66 66 W 10 2892 5000 0 Blue 0
12 Midnight Mon 65 65 W 10 2795 5000 0 Blue 0
1 AM Mon 63 63 W 10 2795 5000 0 Blue 0
2 AM Mon 62 62 W 9 2795 5000 0 Blue 0
3 AM Mon 61 61 W 9 2795 5000 0 Blue 0
4 AM Mon 59 59 W 9 2795 5000 0 Blue 0
5 AM Mon 58 58 W 10 2795 5000 0 Blue 0
6 AM Mon 57 57 W 10 2795 5000 0 Blue 0
7 AM Mon 56 56 W 10 2795 5000 0 Blue 0
8 AM Mon 63 63 W 7 2795 5000 0 Blue 0
9 AM Mon 69 70 W 7 3623 5000 0 Blue 0
10 AM Mon 76 79 W 7 6247 5381 381 Blue 7
11 AM Mon 81 86 W 10 9864 8748 3748 Blue 14
12 Noon Mon 85 91 W 10 10918 10215 5215 Blue 19
1 PM Mon 86 92 W 10 11427 10426 5426 Blue 20
2 PM Mon 87 93 W 14 11921 10637 5637 Blue 21
3 PM Mon 87 92 W 14 11427 10426 5426 Blue 20
4 PM Mon 85 88 W 14 10265 9623 4623 Blue 16
5 PM Mon 84 85 W 13 9665 8147 3147 Blue 13
6 PM Mon 81 81 W 13 7615 5667 667 Blue 9
7 PM Mon 74 74 W 13 5104 5000 0 Blue 3
8 PM Mon 72 72 W 13 4719 5000 0 Blue 1
9 PM Mon 70 70 W 13 3623 5000 0 Blue 0
10 PM Mon 68 68 W 13 3258 5000 0 Blue 0
11 PM Mon 66 66 W 10 2892 5000 0 Blue 0
12 Midnight Tue 65 65 W 10 2795 5000 0 Blue 0
1 AM Tue 63 63 W 10 2795 5000 0 Blue 0
2 AM Tue 62 62 W 10 2795 5000 0 Blue 0
3 AM Tue 61 61 W 10 2795 5000 0 Blue 0
4 AM Tue 59 59 W 10 2795 5000 0 Blue 0
5 AM Tue 58 58 W 9 2795 5000 0 Blue 0
6 AM Tue 57 57 W 9 2795 5000 0 Blue 0
7 AM Tue 56 56 W 9 2795 5000 0 Blue 0
8 AM Tue 62 62 W 9 2795 5000 0 Blue 0
9 AM Tue 69 70 W 9 3623 5000 0 Blue 0
10 AM Tue 76 79 W 9 6247 5381 381 Blue 7
11 AM Tue 80 85 W 13 9665 8147 3147 Blue 13
12 Noon Tue 84 90 W 13 10689 10016 5016 Blue 18
1 PM Tue 85 91 W 13 10918 10215 5215 Blue 19
2 PM Tue 86 92 W 13 11427 10426 5426 Blue 20
3 PM Tue 86 91 W 13 10918 10215 5215 Blue 19
4 PM Tue 84 87 W 13 10061 9326 4326 Blue 15
5 PM Tue 83 84 W 16 9444 7521 2521 Blue 12
6 PM Tue 80 80 W 16 6949 5524 524 Blue 8
7 PM Tue 73 73 W 16 4960 5000 0 Blue 2
8 PM Tue 71 71 W 16 3806 5000 0 Blue 0
9 PM Tue 69 69 W 16 3441 5000 0 Blue 0
10 PM Tue 67 67 W 16 3076 5000 0 Blue 0
11 PM Tue 65 65 W 9 2795 5000 0 Blue 0
12 Midnight Wed 64 64 W 9 2795 5000 0 Blue 0
1 AM Wed 62 62 W 9 2795 5000 0 Blue 0
2 AM Wed 61 61 W 9 2795 5000 0 Blue 0
3 AM Wed 60 60 W 9 2795 5000 0 Blue 0
4 AM Wed 58 58 W 9 2795 5000 0 Blue 0
5 AM Wed 57 57 W 12 2795 5000 0 Blue 0
6 AM Wed 56 56 W 12 2795 5000 0 Blue 0
7 AM Wed 55 55 W 12 2795 5000 0 Blue 0
8 AM Wed 61 61 W 12 2795 5000 0 Blue 0
9 AM Wed 67 68 W 12 3258 5000 0 Blue 0
10 AM Wed 74 77 W 12 5536 5095 95 Blue 5
11 AM Wed 79 84 W 9 9444 7521 2521 Blue 12
12 Noon Wed 82 88 W 9 10265 9623 4623 Blue 16
1 PM Wed 83 89 W 9 10477 9820 4820 Blue 17
2 PM Wed 84 90 W 9 10689 10016 5016 Blue 18
3 PM Wed 84 89 W 9 10477 9820 4820 Blue 17
4 PM Wed 83 86 W 9 9864 8748 3748 Blue 14
5 PM Wed 81 82 W 12 8251 6174 1174 Blue 10
6 PM Wed 78 78 W 12 5679 5238 238 Blue 6
7 PM Wed 73 73 W 12 4960 5000 0 Blue 2
8 PM Wed 70 70 W 12 3623 5000 0 Blue 0
9 PM Wed 68 68 W 12 3258 5000 0 Blue 0
10 PM Wed 66 66 W 12 2892 5000 0 Blue 0
11 PM Wed 65 65 NW 5 2795 5000 0 Blue 0
12 Midnight Thu 64 64 NW 5 2795 5000 0 Blue 0
1 AM Thu 63 63 NW 5 2795 5000 0 Blue 0
2 AM Thu 61 61 NW 5 2795 5000 0 Blue 0
3 AM Thu 60 60 NW 5 2795 5000 0 Blue 0
4 AM Thu 59 59 NW 5 2795 5000 0 Blue 0
5 AM Thu 58 58 NW 9 2795 5000 0 Blue 0
6 AM Thu 57 57 NW 9 2795 5000 0 Blue 0
7 AM Thu 56 56 NW 9 2795 5000 0 Blue 0
8 AM Thu 63 63 NW 9 2795 5000 0 Blue 0
9 AM Thu 70 71 NW 9 3806 5000 0 Blue 0
10 AM Thu 78 81 NW 9 7615 5667 667 Blue 9
11 AM Thu 83 88 SE 5 10265 9623 4623 Blue 16
12 Noon Thu 86 92 SE 5 11427 10426 5426 Blue 20
1 PM Thu 88 94 SE 5 12402 10847 5847 Blue 22
2 PM Thu 89 95 SE 5 12871 11290 6290 Blue 23
3 PM Thu 89 94 SE 5 12402 10847 5847 Blue 22
4 PM Thu 87 90 SE 5 10689 10016 5016 Blue 18
5 PM Thu 86 87 SW 8 10061 9326 4326 Blue 15
6 PM Thu 82 82 SW 8 8251 6174 1174 Blue 10
7 PM Thu 76 76 SW 8 5392 5000 0 Blue 5
8 PM Thu 73 73 SW 8 4960 5000 0 Blue 2
9 PM Thu 71 71 SW 8 3806 5000 0 Blue 0
10 PM Thu 69 69 SW 8 3441 5000 0 Blue 0
11 PM Thu 68 68 NW 6 3258 5000 0 Blue 0
12 Midnight Fri 66 66 NW 6 2892 5000 0 Blue 0
1 AM Fri 65 65 NW 6 2795 5000 0 Blue 0
2 AM Fri 63 63 NW 6 2795 5000 0 Blue 0
3 AM Fri 62 62 NW 6 2795 5000 0 Blue 0
4 AM Fri 60 60 NW 6 2795 5000 0 Blue 0
5 AM Fri 59 59 W 8 2795 5000 0 Blue 0
6 AM Fri 58 58 W 8 2795 5000 0 Blue 0
7 AM Fri 57 57 W 8 2795 5000 0 Blue 0
8 AM Fri 64 64 W 8 2795 5000 0 Blue 0
9 AM Fri 70 71 W 8 3806 5000 0 Blue 0
10 AM Fri 77 80 W 8 6949 5524 524 Blue 8
11 AM Fri 82 87 S 6 10061 9326 4326 Blue 15
12 Noon Fri 86 92 S 6 11427 10426 5426 Blue 20
1 PM Fri 87 93 S 6 11921 10637 5637 Blue 21
2 PM Fri 88 94 S 6 12402 10847 5847 Blue 22
3 PM Fri 88 92 S 6 11427 10426 5426 Blue 20
4 PM Fri 86 89 S 6 10477 9820 4820 Blue 17
5 PM Fri 85 86 W 12 9864 8748 3748 Blue 14
6 PM Fri 82 82 W 12 8251 6174 1174 Blue 10
7 PM Fri 76 76 W 12 5392 5000 0 Blue 5
8 PM Fri 73 73 W 12 4960 5000 0 Blue 2
9 PM Fri 71 71 W 12 3806 5000 0 Blue 0
10 PM Fri 69 69 W 12 3441 5000 0 Blue 0
11 PM Fri 68 68 NW 7 3258 5000 0 Blue 0
12 Midnight Sat 67 67 NW 7 3076 5000 0 Blue 0
1 AM Sat 65 65 NW 7 2795 5000 0 Blue 0
2 AM Sat 64 64 NW 7 2795 5000 0 Blue 0
3 AM Sat 63 63 NW 7 2795 5000 0 Blue 0
4 AM Sat 61 61 NW 7 2795 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