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

Station:

KVBG

Date/Time:

26 MAR 2019

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 Tue 47 47 NW 9 2979 5000 0 Blue 0
6 AM Tue 47 47 NW 9 2979 5000 0 Blue 0
7 AM Tue 46 46 SW 8 2979 5000 0 Blue 0
8 AM Tue 48 48 NW 7 2979 5000 0 Blue 0
9 AM Tue 54 54 W 7 3910 5000 0 Blue 2
10 AM Tue 59 60 W 8 5751 5000 0 Blue 8
11 AM Tue 63 65 W 9 8268 6850 1850 White 13
12 Noon Tue 66 68 W 12 8909 8438 3438 White 16
1 PM Tue 68 71 W 14 9543 9543 4543 White 19
2 PM Tue 70 73 W 16 9976 9809 4809 White 21
3 PM Tue 71 73 W 18 9976 9809 4809 White 21
4 PM Tue 70 71 W 18 9543 9543 4543 White 19
5 PM Tue 68 68 W 18 8909 8438 3438 White 16
6 PM Tue 65 65 W 17 8268 6850 1850 White 13
7 PM Tue 62 62 W 14 6921 5142 142 Blue 10
8 PM Tue 60 60 W 13 5751 5000 0 Blue 8
9 PM Tue 57 57 W 12 4599 5000 0 Blue 5
10 PM Tue 56 56 W 10 4164 5000 0 Blue 4
11 PM Tue 54 54 SW 10 3910 5000 0 Blue 2
12 Midnight Wed 53 53 SW 9 3676 5000 0 Blue 1
1 AM Wed 52 52 SW 9 3096 5000 0 Blue 0
2 AM Wed 50 50 W 9 2979 5000 0 Blue 0
3 AM Wed 50 50 W 10 2979 5000 0 Blue 0
4 AM Wed 49 49 W 10 2979 5000 0 Blue 0
5 AM Wed 48 48 W 10 2979 5000 0 Blue 0
6 AM Wed 49 49 W 10 2979 5000 0 Blue 0
7 AM Wed 48 48 W 10 2979 5000 0 Blue 0
8 AM Wed 50 50 W 12 2979 5000 0 Blue 0
9 AM Wed 55 55 W 14 4037 5000 0 Blue 3
10 AM Wed 58 59 W 15 5165 5000 0 Blue 7
11 AM Wed 61 62 W 16 6921 5142 142 Blue 10
12 Noon Wed 63 64 W 18 8053 6284 1284 White 12
1 PM Wed 65 67 W 21 8695 7925 2925 White 15
2 PM Wed 65 66 W 22 8482 7396 2396 White 14
3 PM Wed 65 66 W 23 8482 7396 2396 White 14
4 PM Wed 64 64 W 23 8053 6284 1284 White 12
5 PM Wed 62 62 W 22 6921 5142 142 Blue 10
6 PM Wed 60 60 W 21 5751 5000 0 Blue 8
7 PM Wed 58 58 W 20 4860 5000 0 Blue 6
8 PM Wed 56 56 W 18 4164 5000 0 Blue 4
9 PM Wed 55 55 W 18 4037 5000 0 Blue 3
10 PM Wed 53 53 W 17 3676 5000 0 Blue 1
11 PM Wed 52 52 W 17 3096 5000 0 Blue 0
12 Midnight Thu 51 51 W 16 2979 5000 0 Blue 0
1 AM Thu 49 49 W 16 2979 5000 0 Blue 0
2 AM Thu 48 48 W 15 2979 5000 0 Blue 0
3 AM Thu 47 47 W 15 2979 5000 0 Blue 0
4 AM Thu 46 46 W 15 2979 5000 0 Blue 0
5 AM Thu 46 46 W 15 2979 5000 0 Blue 0
6 AM Thu 45 45 W 15 2979 5000 0 Blue 0
7 AM Thu 45 45 W 15 2979 5000 0 Blue 0
8 AM Thu 45 45 W 15 2979 5000 0 Blue 0
9 AM Thu 48 49 W 16 2979 5000 0 Blue 0
10 AM Thu 51 53 W 17 3676 5000 0 Blue 1
11 AM Thu 55 59 W 18 5165 5000 0 Blue 7
12 Noon Thu 57 62 W 21 6921 5142 142 Blue 10
1 PM Thu 59 64 W 23 8053 6284 1284 White 12
2 PM Thu 60 64 W 25 8053 6284 1284 White 12
3 PM Thu 60 63 W 26 7475 5697 697 Blue 11
4 PM Thu 59 61 W 26 6348 5000 0 Blue 9
5 PM Thu 58 59 W 25 5165 5000 0 Blue 7
6 PM Thu 56 56 W 24 4164 5000 0 Blue 4
7 PM Thu 53 53 W 23 3676 5000 0 Blue 1
8 PM Thu 51 51 W 21 2979 5000 0 Blue 0
9 PM Thu 49 49 W 18 2979 5000 0 Blue 0
10 PM Thu 48 48 W 16 2979 5000 0 Blue 0
11 PM Thu 47 47 W 15 2979 5000 0 Blue 0
12 Midnight Fri 46 46 W 14 2979 5000 0 Blue 0
1 AM Fri 44 44 W 13 2979 5000 0 Blue 0
2 AM Fri 43 43 W 13 2979 5000 0 Blue 0
3 AM Fri 42 42 W 13 2979 5000 0 Blue 0
4 AM Fri 41 41 W 13 2979 5000 0 Blue 0
5 AM Fri 41 41 W 13 2979 5000 0 Blue 0
6 AM Fri 41 41 NW 13 2979 5000 0 Blue 0
7 AM Fri 41 41 NW 12 2979 5000 0 Blue 0
8 AM Fri 43 43 NW 12 2979 5000 0 Blue 0
9 AM Fri 47 48 NW 12 2979 5000 0 Blue 0
10 AM Fri 52 55 W 12 4037 5000 0 Blue 3
11 AM Fri 57 62 W 12 6921 5142 142 Blue 10
12 Noon Fri 60 66 W 14 8482 7396 2396 White 14
1 PM Fri 63 69 W 15 9123 8937 3937 White 17
2 PM Fri 64 69 W 17 9123 8937 3937 White 17
3 PM Fri 64 68 W 18 8909 8438 3438 White 16
4 PM Fri 64 67 W 20 8695 7925 2925 White 15
5 PM Fri 63 64 W 17 8053 6284 1284 White 12
6 PM Fri 61 61 W 17 6348 5000 0 Blue 9
7 PM Fri 58 58 W 17 4860 5000 0 Blue 6
8 PM Fri 55 55 W 17 4037 5000 0 Blue 3
9 PM Fri 53 53 W 17 3676 5000 0 Blue 1
10 PM Fri 52 52 W 17 3096 5000 0 Blue 0
11 PM Fri 50 50 NW 12 2979 5000 0 Blue 0
12 Midnight Sat 48 48 NW 12 2979 5000 0 Blue 0
1 AM Sat 46 46 NW 12 2979 5000 0 Blue 0
2 AM Sat 45 45 NW 12 2979 5000 0 Blue 0
3 AM Sat 44 44 NW 12 2979 5000 0 Blue 0
4 AM Sat 43 43 NW 12 2979 5000 0 Blue 0
5 AM Sat 43 43 N 10 2979 5000 0 Blue 0
6 AM Sat 43 43 N 10 2979 5000 0 Blue 0
7 AM Sat 44 44 N 10 2979 5000 0 Blue 0
8 AM Sat 46 46 N 10 2979 5000 0 Blue 0
9 AM Sat 50 51 N 10 2979 5000 0 Blue 0
10 AM Sat 56 59 N 10 5165 5000 0 Blue 7
11 AM Sat 61 66 N 14 8482 7396 2396 White 14
12 Noon Sat 64 70 N 14 9335 9335 4335 White 18
1 PM Sat 67 73 N 14 9976 9809 4809 White 21
2 PM Sat 68 74 N 14 10196 9934 4934 White 22
3 PM Sat 68 72 N 14 9753 9726 4726 White 20
4 PM Sat 68 71 N 14 9543 9543 4543 White 19
5 PM Sat 67 68 W 14 8909 8438 3438 White 16
6 PM Sat 65 65 W 14 8268 6850 1850 White 13
7 PM Sat 62 62 W 14 6921 5142 142 Blue 10
8 PM Sat 59 59 W 14 5165 5000 0 Blue 7
9 PM Sat 57 57 W 14 4599 5000 0 Blue 5
10 PM Sat 55 55 W 14 4037 5000 0 Blue 3
11 PM Sat 53 53 N 10 3676 5000 0 Blue 1
12 Midnight Sun 51 51 N 10 2979 5000 0 Blue 0
1 AM Sun 50 50 N 10 2979 5000 0 Blue 0
2 AM Sun 49 49 N 10 2979 5000 0 Blue 0
3 AM Sun 48 48 N 10 2979 5000 0 Blue 0
4 AM Sun 46 46 N 10 2979 5000 0 Blue 0
5 AM Sun 46 46 N 9 2979 5000 0 Blue 0
6 AM Sun 46 46 N 9 2979 5000 0 Blue 0
7 AM Sun 47 47 N 9 2979 5000 0 Blue 0
8 AM Sun 49 49 N 9 2979 5000 0 Blue 0
9 AM Sun 53 54 N 9 3910 5000 0 Blue 2
10 AM Sun 59 62 N 9 6921 5142 142 Blue 10
11 AM Sun 64 69 NW 8 9123 8937 3937 White 17
12 Noon Sun 68 74 NW 8 10196 9934 4934 White 22
1 PM Sun 71 77 NW 8 10818 10674 5674 White 25
2 PM Sun 72 78 NW 8 11025 11025 6025 White 26
3 PM Sun 72 76 NW 8 10612 10470 5470 White 24
4 PM Sun 72 75 NW 8 10404 10221 5221 White 23
5 PM Sun 70 71 W 14 9543 9543 4543 White 19
6 PM Sun 68 68 W 14 8909 8438 3438 White 16
7 PM Sun 65 65 W 14 8268 6850 1850 White 13
8 PM Sun 62 62 W 14 6921 5142 142 Blue 10
9 PM Sun 59 59 W 14 5165 5000 0 Blue 7
10 PM Sun 57 57 W 14 4599 5000 0 Blue 5
11 PM Sun 55 55 W 9 4037 5000 0 Blue 3
12 Midnight Mon 53 53 W 9 3676 5000 0 Blue 1
1 AM Mon 52 52 W 9 3096 5000 0 Blue 0
2 AM Mon 51 51 W 9 2979 5000 0 Blue 0
3 AM Mon 50 50 W 9 2979 5000 0 Blue 0
4 AM Mon 49 49 W 9 2979 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