Detailed Predictions for: St John
Launch Altitude (f): 6350
LZ Altitude (f): 1185
Sounding

Station:

KOAK

Date/Time:

25 AUG 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 Sun 62 62 W 6 4278 6350 0 Blue 0
6 AM Sun 67 67 W 6 4278 6350 0 Blue 0
7 AM Sun 62 62 W 6 4278 6350 0 Blue 0
8 AM Sun 67 67 S 3 4278 6350 0 Blue 0
9 AM Sun 71 72 S 3 4278 6350 0 Blue 0
10 AM Sun 71 74 S 3 5056 6350 0 Blue 1
11 AM Sun 71 76 SE 5 6010 6350 0 Blue 3
12 Noon Sun 74 80 SE 5 7320 6442 92 Blue 7
1 PM Sun 75 82 SE 5 7541 7079 729 Blue 9
2 PM Sun 77 84 S 6 8690 7420 1070 Blue 11
3 PM Sun 78 84 S 6 8690 7420 1070 Blue 11
4 PM Sun 79 83 S 6 8483 7310 960 Blue 10
5 PM Sun 78 80 SW 8 7320 6442 92 Blue 7
6 PM Sun 76 77 SW 8 6471 6350 0 Blue 4
7 PM Sun 74 74 SW 8 5056 6350 0 Blue 1
8 PM Sun 70 70 W 9 4278 6350 0 Blue 0
9 PM Sun 69 69 W 9 4278 6350 0 Blue 0
10 PM Sun 68 68 W 9 4278 6350 0 Blue 0
11 PM Sun 67 67 W 5 4278 6350 0 Blue 0
12 Midnight Mon 68 68 W 5 4278 6350 0 Blue 0
1 AM Mon 66 66 W 5 4278 6350 0 Blue 0
2 AM Mon 66 66 N 5 4278 6350 0 Blue 0
3 AM Mon 64 64 N 5 4278 6350 0 Blue 0
4 AM Mon 63 63 N 5 4278 6350 0 Blue 0
5 AM Mon 63 63 N 5 4278 6350 0 Blue 0
6 AM Mon 64 64 N 5 4278 6350 0 Blue 0
7 AM Mon 64 64 N 5 4278 6350 0 Blue 0
8 AM Mon 68 68 W 5 4278 6350 0 Blue 0
9 AM Mon 71 72 W 5 4278 6350 0 Blue 0
10 AM Mon 72 75 W 5 5538 6350 0 Blue 2
11 AM Mon 73 78 S 5 6830 6350 0 Blue 5
12 Noon Mon 75 81 S 5 7430 6810 460 Blue 8
1 PM Mon 77 84 S 5 8690 7420 1070 Blue 11
2 PM Mon 79 86 S 7 9139 8286 1936 Blue 13
3 PM Mon 81 87 S 7 9398 8662 2312 Blue 14
4 PM Mon 81 85 S 7 8896 7530 1180 Blue 12
5 PM Mon 80 82 SW 9 7541 7079 729 Blue 9
6 PM Mon 78 79 SW 9 7102 6350 0 Blue 6
7 PM Mon 76 76 SW 9 6010 6350 0 Blue 3
8 PM Mon 73 73 SW 9 4386 6350 0 Blue 0
9 PM Mon 71 71 SW 9 4278 6350 0 Blue 0
10 PM Mon 70 70 SW 9 4278 6350 0 Blue 0
11 PM Mon 69 69 N 6 4278 6350 0 Blue 0
12 Midnight Tue 68 68 N 6 4278 6350 0 Blue 0
1 AM Tue 68 68 N 6 4278 6350 0 Blue 0
2 AM Tue 67 67 N 6 4278 6350 0 Blue 0
3 AM Tue 66 66 N 6 4278 6350 0 Blue 0
4 AM Tue 65 65 N 6 4278 6350 0 Blue 0
5 AM Tue 65 65 N 3 4278 6350 0 Blue 0
6 AM Tue 66 66 N 3 4278 6350 0 Blue 0
7 AM Tue 68 68 N 3 4278 6350 0 Blue 0
8 AM Tue 70 70 N 3 4278 6350 0 Blue 0
9 AM Tue 72 73 N 3 4386 6350 0 Blue 0
10 AM Tue 73 76 N 3 6010 6350 0 Blue 3
11 AM Tue 75 80 W 8 7320 6442 92 Blue 7
12 Noon Tue 77 83 W 8 8483 7310 960 Blue 10
1 PM Tue 79 86 W 8 9139 8286 1936 Blue 13
2 PM Tue 80 87 W 8 9398 8662 2312 Blue 14
3 PM Tue 81 87 W 8 9398 8662 2312 Blue 14
4 PM Tue 81 85 W 8 8896 7530 1180 Blue 12
5 PM Tue 80 82 SW 9 7541 7079 729 Blue 9
6 PM Tue 78 79 SW 9 7102 6350 0 Blue 6
7 PM Tue 75 75 SW 9 5538 6350 0 Blue 2
8 PM Tue 73 73 SW 9 4386 6350 0 Blue 0
9 PM Tue 72 72 SW 9 4278 6350 0 Blue 0
10 PM Tue 71 71 SW 9 4278 6350 0 Blue 0
11 PM Tue 70 70 W 10 4278 6350 0 Blue 0
12 Midnight Wed 69 69 W 10 4278 6350 0 Blue 0
1 AM Wed 68 68 W 10 4278 6350 0 Blue 0
2 AM Wed 67 67 W 10 4278 6350 0 Blue 0
3 AM Wed 66 66 W 10 4278 6350 0 Blue 0
4 AM Wed 65 65 W 10 4278 6350 0 Blue 0
5 AM Wed 65 65 W 7 4278 6350 0 Blue 0
6 AM Wed 66 66 W 7 4278 6350 0 Blue 0
7 AM Wed 68 68 W 7 4278 6350 0 Blue 0
8 AM Wed 69 69 W 7 4278 6350 0 Blue 0
9 AM Wed 70 71 W 7 4278 6350 0 Blue 0
10 AM Wed 71 73 W 7 4386 6350 0 Blue 0
11 AM Wed 72 76 S 9 6010 6350 0 Blue 3
12 Noon Wed 74 79 S 9 7102 6350 0 Blue 6
1 PM Wed 76 81 S 9 7430 6810 460 Blue 8
2 PM Wed 77 82 S 9 7541 7079 729 Blue 9
3 PM Wed 78 83 S 9 8483 7310 960 Blue 10
4 PM Wed 78 81 S 9 7430 6810 460 Blue 8
5 PM Wed 76 78 SW 14 6830 6350 0 Blue 5
6 PM Wed 74 75 SW 14 5538 6350 0 Blue 2
7 PM Wed 71 71 SW 14 4278 6350 0 Blue 0
8 PM Wed 69 69 SW 14 4278 6350 0 Blue 0
9 PM Wed 68 68 SW 14 4278 6350 0 Blue 0
10 PM Wed 67 67 SW 14 4278 6350 0 Blue 0
11 PM Wed 67 67 W 8 4278 6350 0 Blue 0
12 Midnight Thu 66 66 W 8 4278 6350 0 Blue 0
1 AM Thu 65 65 W 8 4278 6350 0 Blue 0
2 AM Thu 64 64 W 8 4278 6350 0 Blue 0
3 AM Thu 63 63 W 8 4278 6350 0 Blue 0
4 AM Thu 62 62 W 8 4278 6350 0 Blue 0
5 AM Thu 62 62 SW 6 4278 6350 0 Blue 0
6 AM Thu 63 63 SW 6 4278 6350 0 Blue 0
7 AM Thu 64 64 SW 6 4278 6350 0 Blue 0
8 AM Thu 66 66 SW 6 4278 6350 0 Blue 0
9 AM Thu 67 68 SW 6 4278 6350 0 Blue 0
10 AM Thu 68 71 SW 6 4278 6350 0 Blue 0
11 AM Thu 69 74 S 9 5056 6350 0 Blue 1
12 Noon Thu 70 76 S 9 6010 6350 0 Blue 3
1 PM Thu 72 79 S 9 7102 6350 0 Blue 6
2 PM Thu 74 81 S 9 7430 6810 460 Blue 8
3 PM Thu 75 81 S 9 7430 6810 460 Blue 8
4 PM Thu 75 79 S 9 7102 6350 0 Blue 6
5 PM Thu 74 76 SW 12 6010 6350 0 Blue 3
6 PM Thu 72 73 SW 12 4386 6350 0 Blue 0
7 PM Thu 70 70 SW 12 4278 6350 0 Blue 0
8 PM Thu 68 68 SW 12 4278 6350 0 Blue 0
9 PM Thu 66 66 SW 12 4278 6350 0 Blue 0
10 PM Thu 66 66 SW 12 4278 6350 0 Blue 0
11 PM Thu 65 65 W 7 4278 6350 0 Blue 0
12 Midnight Fri 65 65 W 7 4278 6350 0 Blue 0
1 AM Fri 64 64 W 7 4278 6350 0 Blue 0
2 AM Fri 63 63 W 7 4278 6350 0 Blue 0
3 AM Fri 62 62 W 7 4278 6350 0 Blue 0
4 AM Fri 61 61 W 7 4278 6350 0 Blue 0
5 AM Fri 61 61 S 6 4278 6350 0 Blue 0
6 AM Fri 62 62 S 6 4278 6350 0 Blue 0
7 AM Fri 64 64 S 6 4278 6350 0 Blue 0
8 AM Fri 66 66 S 6 4278 6350 0 Blue 0
9 AM Fri 67 68 S 6 4278 6350 0 Blue 0
10 AM Fri 67 70 S 6 4278 6350 0 Blue 0
11 AM Fri 68 73 S 9 4386 6350 0 Blue 0
12 Noon Fri 70 76 S 9 6010 6350 0 Blue 3
1 PM Fri 72 79 S 9 7102 6350 0 Blue 6
2 PM Fri 74 81 S 9 7430 6810 460 Blue 8
3 PM Fri 75 81 S 9 7430 6810 460 Blue 8
4 PM Fri 76 80 S 9 7320 6442 92 Blue 7
5 PM Fri 75 77 SW 9 6471 6350 0 Blue 4
6 PM Fri 73 74 SW 9 5056 6350 0 Blue 1
7 PM Fri 70 70 SW 9 4278 6350 0 Blue 0
8 PM Fri 68 68 SW 9 4278 6350 0 Blue 0
9 PM Fri 66 66 SW 9 4278 6350 0 Blue 0
10 PM Fri 65 65 SW 9 4278 6350 0 Blue 0
11 PM Fri 64 64 W 7 4278 6350 0 Blue 0
12 Midnight Sat 64 64 W 7 4278 6350 0 Blue 0
1 AM Sat 64 64 W 7 4278 6350 0 Blue 0
2 AM Sat 63 63 W 7 4278 6350 0 Blue 0
3 AM Sat 62 62 W 7 4278 6350 0 Blue 0
4 AM Sat 61 61 W 7 4278 6350 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