Detailed Predictions for: Lake Isabella Ground Launch Center
Launch Lat, Long, Altitude (f): 35.654428, -118.297628, 5000
LZ Altitude (f): 2591
Sounding

Station:

KVBG

Date/Time:

20 JAN 2021

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)
12 Midnight Mon 41 41 W 15 2533 5000 0 Blue 0
1 AM Mon 41 41 W 14 2533 5000 0 Blue 0
2 AM Mon 39 39 W 14 2533 5000 0 Blue 0
3 AM Mon 38 38 WSW 14 2533 5000 0 Blue 0
4 AM Mon 38 38 WSW 21 2533 5000 0 Blue 0
5 AM Mon 36 36 WSW 28 2533 5000 0 Blue 0
6 AM Mon 30 30 WSW 20 2533 5000 0 Blue 0
7 AM Mon 29 29 WSW 23 2533 5000 0 Blue 0
8 AM Mon 29 29 WSW 25 2533 5000 0 Blue 0
9 AM Mon 31 31 W 24 2533 5000 0 Blue 0
10 AM Mon 33 33 W 24 2533 5000 0 Blue 0
11 AM Mon 34 34 WSW 25 2533 5000 0 Blue 0
12 Noon Mon 36 36 WSW 25 2533 5000 0 Blue 0
1 PM Mon 36 36 W 24 2533 5000 0 Blue 0
2 PM Mon 37 37 WSW 25 2533 5000 0 Blue 0
3 PM Mon 37 37 W 24 2533 5000 0 Blue 0
4 PM Mon 36 36 WSW 26 2533 5000 0 Blue 0
5 PM Mon 34 34 WSW 24 2533 5000 0 Blue 0
6 PM Mon 34 34 WSW 24 2533 5000 0 Blue 0
7 PM Mon 33 33 WSW 22 2533 5000 0 Blue 0
8 PM Mon 32 32 WSW 20 2533 5000 0 Blue 0
9 PM Mon 31 31 WSW 18 2533 5000 0 Blue 0
10 PM Mon 31 31 WSW 20 2533 5000 0 Blue 0
11 PM Mon 31 31 WSW 20 2533 5000 0 Blue 0
12 Midnight Tue 30 30 WSW 20 2533 5000 0 Blue 0
1 AM Tue 30 30 WSW 21 2533 5000 0 Blue 0
2 AM Tue 30 30 WSW 21 2533 5000 0 Blue 0
3 AM Tue 29 29 SW 22 2533 5000 0 Blue 0
4 AM Tue 29 29 SW 22 2533 5000 0 Blue 0
5 AM Tue 29 29 SW 23 2533 5000 0 Blue 0
6 AM Tue 28 28 SW 24 2533 5000 0 Blue 0
7 AM Tue 28 28 SW 23 2533 5000 0 Blue 0
8 AM Tue 28 28 WSW 21 2533 5000 0 Blue 0
9 AM Tue 30 31 WSW 18 2533 5000 0 Blue 0
10 AM Tue 34 35 WSW 20 2533 5000 0 Blue 0
11 AM Tue 36 38 WSW 18 2533 5000 0 Blue 0
12 Noon Tue 38 40 WSW 17 2533 5000 0 Blue 0
1 PM Tue 39 41 WSW 22 2533 5000 0 Blue 0
2 PM Tue 40 41 WSW 21 2533 5000 0 Blue 0
3 PM Tue 40 41 WSW 25 2533 5000 0 Blue 0
4 PM Tue 38 38 WSW 22 2533 5000 0 Blue 0
5 PM Tue 37 37 WSW 21 2533 5000 0 Blue 0
6 PM Tue 36 36 WSW 13 2533 5000 0 Blue 0
7 PM Tue 35 35 NW 6 2533 5000 0 Blue 0
8 PM Tue 34 34 N 6 2533 5000 0 Blue 0
9 PM Tue 33 33 NNE 2 2533 5000 0 Blue 0
10 PM Tue 32 32 W 9 2533 5000 0 Blue 0
11 PM Tue 32 32 W 9 2533 5000 0 Blue 0
12 Midnight Wed 32 32 W 9 2533 5000 0 Blue 0
1 AM Wed 32 32 SW 9 2533 5000 0 Blue 0
2 AM Wed 31 31 SW 9 2533 5000 0 Blue 0
3 AM Wed 31 31 SW 9 2533 5000 0 Blue 0
4 AM Wed 30 30 SSE 8 2533 5000 0 Blue 0
5 AM Wed 30 30 SSE 8 2533 5000 0 Blue 0
6 AM Wed 29 29 SSE 8 2533 5000 0 Blue 0
7 AM Wed 29 29 SSE 10 2533 5000 0 Blue 0
8 AM Wed 29 29 SSE 10 2533 5000 0 Blue 0
9 AM Wed 32 32 SSE 10 2533 5000 0 Blue 0
10 AM Wed 36 36 SE 10 2533 5000 0 Blue 0
11 AM Wed 39 39 SE 10 2533 5000 0 Blue 0
12 Noon Wed 42 42 SE 10 2533 5000 0 Blue 0
1 PM Wed 44 44 SE 14 2533 5000 0 Blue 0
2 PM Wed 45 45 SE 14 2533 5000 0 Blue 0
3 PM Wed 45 45 SE 14 2533 5000 0 Blue 0
4 PM Wed 44 44 SE 16 2533 5000 0 Blue 0
5 PM Wed 43 43 SE 16 2533 5000 0 Blue 0
6 PM Wed 42 42 SE 16 2533 5000 0 Blue 0
7 PM Wed 42 42 SE 13 2533 5000 0 Blue 0
8 PM Wed 40 40 SE 13 2533 5000 0 Blue 0
9 PM Wed 40 40 SE 13 2533 5000 0 Blue 0
10 PM Wed 39 39 ESE 12 2533 5000 0 Blue 0
11 PM Wed 39 39 ESE 12 2533 5000 0 Blue 0
12 Midnight Thu 39 39 ESE 12 2533 5000 0 Blue 0
1 AM Thu 39 39 E 10 2533 5000 0 Blue 0
2 AM Thu 39 39 E 10 2533 5000 0 Blue 0
3 AM Thu 38 38 E 10 2533 5000 0 Blue 0
4 AM Thu 38 38 E 9 2533 5000 0 Blue 0
5 AM Thu 38 38 E 9 2533 5000 0 Blue 0
6 AM Thu 37 37 E 9 2533 5000 0 Blue 0
7 AM Thu 37 37 E 9 2533 5000 0 Blue 0
8 AM Thu 37 37 E 9 2533 5000 0 Blue 0
9 AM Thu 39 39 E 9 2533 5000 0 Blue 0
10 AM Thu 42 42 E 8 2533 5000 0 Blue 0
11 AM Thu 44 44 E 8 2533 5000 0 Blue 0
12 Noon Thu 45 45 E 8 2533 5000 0 Blue 0
1 PM Thu 46 46 E 10 2533 5000 0 Blue 0
2 PM Thu 47 47 E 10 2533 5000 0 Blue 0
3 PM Thu 47 47 E 10 2533 5000 0 Blue 0
4 PM Thu 45 45 E 13 2533 5000 0 Blue 0
5 PM Thu 44 44 E 13 2533 5000 0 Blue 0
6 PM Thu 43 43 E 13 2533 5000 0 Blue 0
7 PM Thu 42 42 E 10 2533 5000 0 Blue 0
8 PM Thu 41 41 E 10 2533 5000 0 Blue 0
9 PM Thu 40 40 E 10 2533 5000 0 Blue 0
10 PM Thu 39 39 ESE 9 2533 5000 0 Blue 0
11 PM Thu 39 39 ESE 9 2533 5000 0 Blue 0
12 Midnight Fri 39 39 ESE 9 2533 5000 0 Blue 0
1 AM Fri 39 39 SE 8 2533 5000 0 Blue 0
2 AM Fri 38 38 SE 8 2533 5000 0 Blue 0
3 AM Fri 38 38 SE 8 2533 5000 0 Blue 0
4 AM Fri 37 37 SSW 6 2533 5000 0 Blue 0
5 AM Fri 37 37 SSW 6 2533 5000 0 Blue 0
6 AM Fri 36 36 SSW 6 2533 5000 0 Blue 0
7 AM Fri 36 36 SW 7 2533 5000 0 Blue 0
8 AM Fri 36 36 SW 7 2533 5000 0 Blue 0
9 AM Fri 38 38 SW 7 2533 5000 0 Blue 0
10 AM Fri 40 40 WSW 7 2533 5000 0 Blue 0
11 AM Fri 41 41 WSW 7 2533 5000 0 Blue 0
12 Noon Fri 43 43 WSW 7 2533 5000 0 Blue 0
1 PM Fri 43 43 W 10 2533 5000 0 Blue 0
2 PM Fri 44 44 W 10 2533 5000 0 Blue 0
3 PM Fri 44 44 W 10 2533 5000 0 Blue 0
4 PM Fri 42 42 W 14 2533 5000 0 Blue 0
5 PM Fri 41 41 W 14 2533 5000 0 Blue 0
6 PM Fri 40 40 W 14 2533 5000 0 Blue 0
7 PM Fri 40 40 W 10 2533 5000 0 Blue 0
8 PM Fri 38 38 W 10 2533 5000 0 Blue 0
9 PM Fri 38 38 W 10 2533 5000 0 Blue 0
10 PM Fri 37 37 W 10 2533 5000 0 Blue 0
11 PM Fri 37 37 W 10 2533 5000 0 Blue 0
12 Midnight Sat 36 36 W 10 2533 5000 0 Blue 0
1 AM Sat 36 36 W 10 2533 5000 0 Blue 0
2 AM Sat 36 36 W 10 2533 5000 0 Blue 0
3 AM Sat 36 36 W 10 2533 5000 0 Blue 0
4 AM Sat 35 35 W 9 2533 5000 0 Blue 0
5 AM Sat 35 35 W 9 2533 5000 0 Blue 0
6 AM Sat 34 34 W 9 2533 5000 0 Blue 0
7 AM Sat 34 34 W 9 2533 5000 0 Blue 0
8 AM Sat 34 34 W 9 2533 5000 0 Blue 0
9 AM Sat 37 37 W 9 2533 5000 0 Blue 0
10 AM Sat 40 41 W 9 2533 5000 0 Blue 0
11 AM Sat 43 44 W 9 2533 5000 0 Blue 0
12 Noon Sat 45 46 W 9 2533 5000 0 Blue 0
1 PM Sat 47 48 W 10 2533 5000 0 Blue 0
2 PM Sat 48 49 W 10 2533 5000 0 Blue 0
3 PM Sat 48 48 W 10 2533 5000 0 Blue 0
4 PM Sat 46 46 W 12 2533 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