Detailed Predictions for: Burn Launch
Launch Altitude (f): 6188
LZ Altitude (f): 3540
Sounding

Station:

KOAK

Date/Time:

23 SEP 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)
5 AM Sat 35 32 E 10 5807 6188 0 Blue 0
6 AM Sat 35 32 E 10 5807 6188 0 Blue 0
7 AM Sat 35 32 E 10 5807 6188 0 Blue 0
8 AM Sat 37 34 E 10 5807 6188 0 Blue 0
9 AM Sat 40 38 E 10 5807 6188 0 Blue 0
10 AM Sat 44 43 E 10 7868 6188 0 Blue 2
11 AM Sat 48 48 E 10 10594 9062 2874 Blue 7
12 Noon Sat 52 53 E 10 12262 11460 5272 Blue 12
1 PM Sat 54 55 E 10 12531 12101 5913 Blue 14
2 PM Sat 56 57 NE 8 12800 12369 6181 Blue 16
3 PM Sat 58 58 NE 8 12946 12502 6314 Blue 17
4 PM Sat 58 57 NE 8 12800 12369 6181 Blue 16
5 PM Sat 57 55 NE 8 12531 12101 5913 Blue 14
6 PM Sat 55 52 NE 8 12128 10908 4720 Blue 11
7 PM Sat 53 50 NE 8 11561 10165 3977 Blue 9
8 PM Sat 50 47 NE 7 10216 8556 2368 Blue 6
9 PM Sat 48 45 NE 7 9109 7101 913 Blue 4
10 PM Sat 46 43 NE 7 7868 6188 0 Blue 2
11 PM Sat 45 42 NE 7 7115 6188 0 Blue 1
12 Midnight Sun 44 41 NE 7 6668 6188 0 Blue 0
1 AM Sun 44 41 NE 7 6668 6188 0 Blue 0
2 AM Sun 43 40 NE 7 6043 6188 0 Blue 0
3 AM Sun 41 38 NE 7 5807 6188 0 Blue 0
4 AM Sun 39 36 NE 7 5807 6188 0 Blue 0
5 AM Sun 38 35 NE 8 5807 6188 0 Blue 0
6 AM Sun 37 34 NE 8 5807 6188 0 Blue 0
7 AM Sun 38 35 NE 8 5807 6188 0 Blue 0
8 AM Sun 40 37 NE 8 5807 6188 0 Blue 0
9 AM Sun 44 42 NE 8 7115 6188 0 Blue 1
10 AM Sun 49 48 NE 8 10594 9062 2874 Blue 7
11 AM Sun 54 54 NE 9 12397 11946 5758 Blue 13
12 Noon Sun 57 58 NE 9 12946 12502 6314 Blue 17
1 PM Sun 60 62 NE 9 13923 13064 6876 Blue 21
2 PM Sun 61 62 NE 8 13923 13064 6876 Blue 21
3 PM Sun 62 62 NE 8 13923 13064 6876 Blue 21
4 PM Sun 63 62 NE 8 13923 13064 6876 Blue 21
5 PM Sun 62 60 N 8 13253 12770 6582 Blue 19
6 PM Sun 60 57 N 8 12800 12369 6181 Blue 16
7 PM Sun 57 54 N 8 12397 11946 5758 Blue 13
8 PM Sun 54 51 N 8 11993 10539 4351 Blue 10
9 PM Sun 52 49 N 8 10967 9752 3564 Blue 8
10 PM Sun 50 47 N 8 10216 8556 2368 Blue 6
11 PM Sun 49 46 NE 7 9813 7825 1637 Blue 5
12 Midnight Mon 49 46 NE 7 9813 7825 1637 Blue 5
1 AM Mon 48 45 NE 7 9109 7101 913 Blue 4
2 AM Mon 47 44 NE 7 8614 6661 473 Blue 3
3 AM Mon 46 43 NE 7 7868 6188 0 Blue 2
4 AM Mon 44 41 NE 7 6668 6188 0 Blue 0
5 AM Mon 43 40 NE 7 6043 6188 0 Blue 0
6 AM Mon 44 41 NE 7 6668 6188 0 Blue 0
7 AM Mon 44 41 NE 7 6668 6188 0 Blue 0
8 AM Mon 45 42 NE 7 7115 6188 0 Blue 1
9 AM Mon 41 39 NE 7 5807 6188 0 Blue 0
10 AM Mon 38 37 NE 7 5807 6188 0 Blue 0
11 AM Mon 36 36 NE 10 5807 6188 0 Blue 0
12 Noon Mon 35 36 NE 10 5807 6188 0 Blue 0
1 PM Mon 35 36 NE 10 5807 6188 0 Blue 0
2 PM Mon 34 35 NE 10 5807 6188 0 Blue 0
3 PM Mon 33 33 NE 10 5807 6188 0 Blue 0
4 PM Mon 33 32 NE 10 5807 6188 0 Blue 0
5 PM Mon 35 33 NE 9 5807 6188 0 Blue 0
6 PM Mon 41 38 NE 9 5807 6188 0 Blue 0
7 PM Mon 56 53 NE 9 12262 11460 5272 Blue 12
8 PM Mon 67 64 NE 9 14741 13397 7209 Blue 23
9 PM Mon 68 65 NE 9 15139 13814 7626 Blue 24
10 PM Mon 62 59 NE 9 13100 12636 6448 Blue 18
11 PM Mon 54 51 NE 8 11993 10539 4351 Blue 10
12 Midnight Tue 52 49 NE 8 10967 9752 3564 Blue 8
1 AM Tue 54 51 NE 8 11993 10539 4351 Blue 10
2 AM Tue 54 51 NE 8 11993 10539 4351 Blue 10
3 AM Tue 51 48 NE 8 10594 9062 2874 Blue 7
4 AM Tue 46 43 NE 8 7868 6188 0 Blue 2
5 AM Tue 42 39 NE 8 5807 6188 0 Blue 0
6 AM Tue 41 38 NE 8 5807 6188 0 Blue 0
7 AM Tue 42 39 NE 8 5807 6188 0 Blue 0
8 AM Tue 45 42 NE 8 7115 6188 0 Blue 1
9 AM Tue 49 47 NE 8 10216 8556 2368 Blue 6
10 AM Tue 54 53 NE 8 12262 11460 5272 Blue 12
11 AM Tue 59 59 NE 8 13100 12636 6448 Blue 18
12 Noon Tue 63 65 NE 8 15139 13814 7626 Blue 24
1 PM Tue 67 69 NE 8 16072 15406 9218 White 28
2 PM Tue 69 71 NE 8 16479 16444 10256 White 30
3 PM Tue 70 71 NE 8 16479 16444 10256 White 30
4 PM Tue 69 68 NE 8 15869 15018 8830 White 27
5 PM Tue 67 65 NE 9 15139 13814 7626 Blue 24
6 PM Tue 64 61 NE 9 13503 12911 6723 Blue 20
7 PM Tue 61 58 NE 9 12946 12502 6314 Blue 17
8 PM Tue 59 56 NE 9 12666 12235 6047 Blue 15
9 PM Tue 56 53 NE 9 12262 11460 5272 Blue 12
10 PM Tue 55 52 NE 9 12128 10908 4720 Blue 11
11 PM Tue 53 50 E 8 11561 10165 3977 Blue 9
12 Midnight Wed 51 48 E 8 10594 9062 2874 Blue 7
1 AM Wed 50 47 E 8 10216 8556 2368 Blue 6
2 AM Wed 49 46 E 8 9813 7825 1637 Blue 5
3 AM Wed 48 45 E 8 9109 7101 913 Blue 4
4 AM Wed 48 45 E 8 9109 7101 913 Blue 4
5 AM Wed 48 45 E 8 9109 7101 913 Blue 4
6 AM Wed 47 44 E 8 8614 6661 473 Blue 3
7 AM Wed 47 44 E 8 8614 6661 473 Blue 3
8 AM Wed 49 46 E 8 9813 7825 1637 Blue 5
9 AM Wed 53 51 E 8 11993 10539 4351 Blue 10
10 AM Wed 59 58 E 8 12946 12502 6314 Blue 17
11 AM Wed 64 64 E 8 14741 13397 7209 Blue 23
12 Noon Wed 68 69 E 8 16072 15406 9218 White 28
1 PM Wed 71 73 E 8 16884 16884 10696 White 32
2 PM Wed 72 73 E 8 16884 16884 10696 White 32
3 PM Wed 73 74 E 8 17086 17086 10898 White 33
4 PM Wed 73 72 E 8 16681 16681 10493 White 31
5 PM Wed 71 69 E 8 16072 15406 9218 White 28
6 PM Wed 68 65 E 8 15139 13814 7626 Blue 24
7 PM Wed 64 61 E 8 13503 12911 6723 Blue 20
8 PM Wed 61 58 E 8 12946 12502 6314 Blue 17
9 PM Wed 59 56 E 8 12666 12235 6047 Blue 15
10 PM Wed 58 55 E 8 12531 12101 5913 Blue 14
11 PM Wed 57 54 E 6 12397 11946 5758 Blue 13
12 Midnight Thu 55 52 E 6 12128 10908 4720 Blue 11
1 AM Thu 53 50 E 6 11561 10165 3977 Blue 9
2 AM Thu 51 48 E 6 10594 9062 2874 Blue 7
3 AM Thu 50 47 E 6 10216 8556 2368 Blue 6
4 AM Thu 50 47 E 6 10216 8556 2368 Blue 6
5 AM Thu 49 46 E 5 9813 7825 1637 Blue 5
6 AM Thu 49 46 E 5 9813 7825 1637 Blue 5
7 AM Thu 49 46 E 5 9813 7825 1637 Blue 5
8 AM Thu 51 48 E 5 10594 9062 2874 Blue 7
9 AM Thu 55 53 E 5 12262 11460 5272 Blue 12
10 AM Thu 60 59 E 5 13100 12636 6448 Blue 18
11 AM Thu 65 65 E 5 15139 13814 7626 Blue 24
12 Noon Thu 69 70 E 5 16276 15882 9694 White 29
1 PM Thu 72 74 E 5 17086 17086 10898 White 33
2 PM Thu 74 75 E 5 17287 17287 11099 White 34
3 PM Thu 75 75 E 5 17287 17287 11099 White 34
4 PM Thu 74 73 E 5 16884 16884 10696 White 32
5 PM Thu 72 70 SW 3 16276 15882 9694 White 29
6 PM Thu 68 65 SW 3 15139 13814 7626 Blue 24
7 PM Thu 64 61 SW 3 13503 12911 6723 Blue 20
8 PM Thu 60 57 SW 3 12800 12369 6181 Blue 16
9 PM Thu 58 55 SW 3 12531 12101 5913 Blue 14
10 PM Thu 57 54 SW 3 12397 11946 5758 Blue 13
11 PM Thu 56 53 E 3 12262 11460 5272 Blue 12
12 Midnight Fri 54 51 E 3 11993 10539 4351 Blue 10
1 AM Fri 52 49 E 3 10967 9752 3564 Blue 8
2 AM Fri 51 48 E 3 10594 9062 2874 Blue 7
3 AM Fri 50 47 E 3 10216 8556 2368 Blue 6
4 AM Fri 50 47 E 3 10216 8556 2368 Blue 6

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