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

Station:

KVBG

Date/Time:

17 JAN 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)
4 AM Wed 42 42 N 6 2720 5000 0 Blue 0
5 AM Wed 41 41 N 6 2720 5000 0 Blue 0
6 AM Wed 41 41 N 6 2720 5000 0 Blue 0
7 AM Wed 42 42 NE 6 2720 5000 0 Blue 0
8 AM Wed 46 46 NE 6 2720 5000 0 Blue 0
9 AM Wed 52 52 NE 6 2720 5000 0 Blue 0
10 AM Wed 57 58 E 7 2720 5000 0 Blue 0
11 AM Wed 61 62 E 7 2965 5000 0 Blue 0
12 Noon Wed 63 64 E 7 3643 5000 0 Blue 1
1 PM Wed 65 66 S 3 4124 5000 0 Blue 3
2 PM Wed 66 67 S 3 4500 5000 0 Blue 4
3 PM Wed 66 66 S 3 4124 5000 0 Blue 3
4 PM Wed 65 65 S 3 3884 5000 0 Blue 2
5 PM Wed 61 61 S 3 2720 5000 0 Blue 0
6 PM Wed 57 57 S 3 2720 5000 0 Blue 0
7 PM Wed 54 54 E 7 2720 5000 0 Blue 0
8 PM Wed 51 51 E 7 2720 5000 0 Blue 0
9 PM Wed 51 51 E 7 2720 5000 0 Blue 0
10 PM Wed 50 50 N 6 2720 5000 0 Blue 0
11 PM Wed 50 50 N 6 2720 5000 0 Blue 0
12 Midnight Thu 49 49 N 6 2720 5000 0 Blue 0
1 AM Thu 49 49 N 6 2720 5000 0 Blue 0
2 AM Thu 48 48 N 6 2720 5000 0 Blue 0
3 AM Thu 47 47 N 6 2720 5000 0 Blue 0
4 AM Thu 46 46 N 6 2720 5000 0 Blue 0
5 AM Thu 44 44 N 6 2720 5000 0 Blue 0
6 AM Thu 43 43 N 6 2720 5000 0 Blue 0
7 AM Thu 44 44 NW 5 2720 5000 0 Blue 0
8 AM Thu 48 48 NW 5 2720 5000 0 Blue 0
9 AM Thu 53 53 NW 5 2720 5000 0 Blue 0
10 AM Thu 58 59 SW 12 2720 5000 0 Blue 0
11 AM Thu 63 64 SW 12 3643 5000 0 Blue 1
12 Noon Thu 66 67 SW 12 4500 5000 0 Blue 4
1 PM Thu 68 69 W 14 5296 5000 0 Blue 6
2 PM Thu 68 69 W 14 5296 5000 0 Blue 6
3 PM Thu 67 67 W 14 4500 5000 0 Blue 4
4 PM Thu 65 65 W 12 3884 5000 0 Blue 2
5 PM Thu 62 62 W 12 2965 5000 0 Blue 0
6 PM Thu 58 58 W 12 2720 5000 0 Blue 0
7 PM Thu 55 55 W 12 2720 5000 0 Blue 0
8 PM Thu 53 53 W 12 2720 5000 0 Blue 0
9 PM Thu 52 52 W 12 2720 5000 0 Blue 0
10 PM Thu 51 51 W 13 2720 5000 0 Blue 0
11 PM Thu 50 50 W 13 2720 5000 0 Blue 0
12 Midnight Fri 49 49 W 13 2720 5000 0 Blue 0
1 AM Fri 48 48 W 13 2720 5000 0 Blue 0
2 AM Fri 48 48 W 13 2720 5000 0 Blue 0
3 AM Fri 47 47 W 13 2720 5000 0 Blue 0
4 AM Fri 47 47 W 14 2720 5000 0 Blue 0
5 AM Fri 45 45 W 14 2720 5000 0 Blue 0
6 AM Fri 44 44 W 14 2720 5000 0 Blue 0
7 AM Fri 49 49 W 14 2720 5000 0 Blue 0
8 AM Fri 42 42 W 14 2720 5000 0 Blue 0
9 AM Fri 44 44 W 14 2720 5000 0 Blue 0
10 AM Fri 49 49 W 20 2720 5000 0 Blue 0
11 AM Fri 53 53 W 20 2720 5000 0 Blue 0
12 Noon Fri 53 53 W 20 2720 5000 0 Blue 0
1 PM Fri 53 53 W 20 2720 5000 0 Blue 0
2 PM Fri 52 52 W 20 2720 5000 0 Blue 0
3 PM Fri 51 51 W 20 2720 5000 0 Blue 0
4 PM Fri 49 49 W 20 2720 5000 0 Blue 0
5 PM Fri 47 47 W 20 2720 5000 0 Blue 0
6 PM Fri 45 45 W 20 2720 5000 0 Blue 0
7 PM Fri 43 43 W 20 2720 5000 0 Blue 0
8 PM Fri 42 42 W 20 2720 5000 0 Blue 0
9 PM Fri 41 41 W 20 2720 5000 0 Blue 0
10 PM Fri 40 40 W 13 2720 5000 0 Blue 0
11 PM Fri 39 39 W 13 2720 5000 0 Blue 0
12 Midnight Sat 37 37 W 13 2720 5000 0 Blue 0
1 AM Sat 36 36 W 13 2720 5000 0 Blue 0
2 AM Sat 35 35 W 13 2720 5000 0 Blue 0
3 AM Sat 34 34 W 13 2720 5000 0 Blue 0
4 AM Sat 32 32 NW 20 2720 5000 0 Blue 0
5 AM Sat 31 31 NW 20 2720 5000 0 Blue 0
6 AM Sat 30 30 NW 20 2720 5000 0 Blue 0
7 AM Sat 31 31 NW 20 2720 5000 0 Blue 0
8 AM Sat 34 34 NW 20 2720 5000 0 Blue 0
9 AM Sat 38 38 NW 20 2720 5000 0 Blue 0
10 AM Sat 42 43 W 13 2720 5000 0 Blue 0
11 AM Sat 45 47 W 13 2720 5000 0 Blue 0
12 Noon Sat 47 49 W 13 2720 5000 0 Blue 0
1 PM Sat 48 50 W 13 2720 5000 0 Blue 0
2 PM Sat 48 49 W 13 2720 5000 0 Blue 0
3 PM Sat 47 47 W 13 2720 5000 0 Blue 0
4 PM Sat 46 46 W 16 2720 5000 0 Blue 0
5 PM Sat 43 43 W 16 2720 5000 0 Blue 0
6 PM Sat 40 40 W 16 2720 5000 0 Blue 0
7 PM Sat 38 38 W 16 2720 5000 0 Blue 0
8 PM Sat 37 37 W 16 2720 5000 0 Blue 0
9 PM Sat 36 36 W 16 2720 5000 0 Blue 0
10 PM Sat 36 36 NW 6 2720 5000 0 Blue 0
11 PM Sat 35 35 NW 6 2720 5000 0 Blue 0
12 Midnight Sun 35 35 NW 6 2720 5000 0 Blue 0
1 AM Sun 34 34 NW 6 2720 5000 0 Blue 0
2 AM Sun 33 33 NW 6 2720 5000 0 Blue 0
3 AM Sun 31 31 NW 6 2720 5000 0 Blue 0
4 AM Sun 30 30 NW 9 2720 5000 0 Blue 0
5 AM Sun 28 28 NW 9 2720 5000 0 Blue 0
6 AM Sun 28 28 NW 9 2720 5000 0 Blue 0
7 AM Sun 29 29 NW 9 2720 5000 0 Blue 0
8 AM Sun 33 33 NW 9 2720 5000 0 Blue 0
9 AM Sun 38 38 NW 9 2720 5000 0 Blue 0
10 AM Sun 43 44 W 6 2720 5000 0 Blue 0
11 AM Sun 47 48 W 6 2720 5000 0 Blue 0
12 Noon Sun 50 52 W 6 2720 5000 0 Blue 0
1 PM Sun 52 53 W 6 2720 5000 0 Blue 0
2 PM Sun 53 54 W 6 2720 5000 0 Blue 0
3 PM Sun 53 53 W 6 2720 5000 0 Blue 0
4 PM Sun 51 51 W 8 2720 5000 0 Blue 0
5 PM Sun 48 48 W 8 2720 5000 0 Blue 0
6 PM Sun 44 44 W 8 2720 5000 0 Blue 0
7 PM Sun 41 41 W 8 2720 5000 0 Blue 0
8 PM Sun 40 40 W 8 2720 5000 0 Blue 0
9 PM Sun 40 40 W 8 2720 5000 0 Blue 0
10 PM Sun 40 40 W 9 2720 5000 0 Blue 0
11 PM Sun 39 39 W 9 2720 5000 0 Blue 0
12 Midnight Mon 38 38 W 9 2720 5000 0 Blue 0
1 AM Mon 37 37 W 9 2720 5000 0 Blue 0
2 AM Mon 36 36 W 9 2720 5000 0 Blue 0
3 AM Mon 36 36 W 9 2720 5000 0 Blue 0
4 AM Mon 35 35 W 9 2720 5000 0 Blue 0
5 AM Mon 34 34 W 9 2720 5000 0 Blue 0
6 AM Mon 34 34 W 9 2720 5000 0 Blue 0
7 AM Mon 35 35 W 9 2720 5000 0 Blue 0
8 AM Mon 39 39 W 9 2720 5000 0 Blue 0
9 AM Mon 44 44 W 9 2720 5000 0 Blue 0
10 AM Mon 49 49 W 10 2720 5000 0 Blue 0
11 AM Mon 53 54 W 10 2720 5000 0 Blue 0
12 Noon Mon 55 56 W 10 2720 5000 0 Blue 0
1 PM Mon 57 58 W 10 2720 5000 0 Blue 0
2 PM Mon 58 59 W 10 2720 5000 0 Blue 0
3 PM Mon 58 58 W 10 2720 5000 0 Blue 0
4 PM Mon 57 57 W 12 2720 5000 0 Blue 0
5 PM Mon 53 53 W 12 2720 5000 0 Blue 0
6 PM Mon 50 50 W 12 2720 5000 0 Blue 0
7 PM Mon 46 46 W 12 2720 5000 0 Blue 0
8 PM Mon 44 44 W 12 2720 5000 0 Blue 0
9 PM Mon 43 43 W 12 2720 5000 0 Blue 0
10 PM Mon 43 43 NW 9 2720 5000 0 Blue 0
11 PM Mon 42 42 NW 9 2720 5000 0 Blue 0
12 Midnight Tue 40 40 NW 9 2720 5000 0 Blue 0
1 AM Tue 39 39 NW 9 2720 5000 0 Blue 0
2 AM Tue 39 39 NW 9 2720 5000 0 Blue 0
3 AM Tue 38 38 NW 9 2720 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