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

Station:

KOAK

Date/Time:

22 JUL 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)
5 AM Sun 65 65 W 2 4131 6350 0 Blue 0
6 AM Sun 66 66 W 2 4131 6350 0 Blue 0
7 AM Sun 67 67 W 2 4131 6350 0 Blue 0
8 AM Sun 69 69 E 5 4131 6350 0 Blue 0
9 AM Sun 72 74 E 5 5461 6350 0 Blue 2
10 AM Sun 74 77 E 5 6449 6350 0 Blue 5
11 AM Sun 77 81 SE 6 8993 7263 913 Blue 9
12 Noon Sun 78 84 SE 6 9714 8895 2545 Blue 12
1 PM Sun 79 85 SE 6 10571 9262 2912 Blue 13
2 PM Sun 79 85 SE 10 10571 9262 2912 Blue 13
3 PM Sun 79 84 SE 10 9714 8895 2545 Blue 12
4 PM Sun 78 82 SE 10 9303 7640 1290 Blue 10
5 PM Sun 77 79 S 8 7712 6350 0 Blue 7
6 PM Sun 74 75 S 8 5887 6350 0 Blue 3
7 PM Sun 71 71 S 8 4168 6350 0 Blue 0
8 PM Sun 69 69 NW 7 4131 6350 0 Blue 0
9 PM Sun 67 67 NW 7 4131 6350 0 Blue 0
10 PM Sun 66 66 NW 7 4131 6350 0 Blue 0
11 PM Sun 65 65 W 5 4131 6350 0 Blue 0
12 Midnight Mon 64 64 W 5 4131 6350 0 Blue 0
1 AM Mon 64 64 W 5 4131 6350 0 Blue 0
2 AM Mon 63 63 E 3 4131 6350 0 Blue 0
3 AM Mon 63 63 E 3 4131 6350 0 Blue 0
4 AM Mon 63 63 E 3 4131 6350 0 Blue 0
5 AM Mon 63 63 E 2 4131 6350 0 Blue 0
6 AM Mon 64 64 E 2 4131 6350 0 Blue 0
7 AM Mon 66 66 E 2 4131 6350 0 Blue 0
8 AM Mon 69 70 E 3 4131 6350 0 Blue 0
9 AM Mon 72 74 E 3 5461 6350 0 Blue 2
10 AM Mon 77 81 E 3 8993 7263 913 Blue 9
11 AM Mon 80 86 E 5 10847 9509 3159 Blue 14
12 Noon Mon 82 89 E 5 12324 10791 4441 White 17
1 PM Mon 83 91 E 5 12746 11826 5476 White 19
2 PM Mon 83 91 SE 6 12746 11826 5476 White 19
3 PM Mon 84 91 SE 6 12746 11826 5476 White 19
4 PM Mon 84 89 SE 6 12324 10791 4441 White 17
5 PM Mon 83 86 SW 7 10847 9509 3159 Blue 14
6 PM Mon 80 81 SW 7 8993 7263 913 Blue 9
7 PM Mon 76 76 SW 7 6169 6350 0 Blue 4
8 PM Mon 72 72 SW 7 4547 6350 0 Blue 0
9 PM Mon 70 70 SW 7 4131 6350 0 Blue 0
10 PM Mon 70 70 SW 7 4131 6350 0 Blue 0
11 PM Mon 69 69 E 3 4131 6350 0 Blue 0
12 Midnight Tue 69 69 E 3 4131 6350 0 Blue 0
1 AM Tue 68 68 E 3 4131 6350 0 Blue 0
2 AM Tue 68 68 E 3 4131 6350 0 Blue 0
3 AM Tue 67 67 E 3 4131 6350 0 Blue 0
4 AM Tue 66 66 E 3 4131 6350 0 Blue 0
5 AM Tue 66 66 E 5 4131 6350 0 Blue 0
6 AM Tue 67 67 E 5 4131 6350 0 Blue 0
7 AM Tue 69 69 E 5 4131 6350 0 Blue 0
8 AM Tue 71 71 E 5 4168 6350 0 Blue 0
9 AM Tue 75 77 E 5 6449 6350 0 Blue 5
10 AM Tue 79 82 E 5 9303 7640 1290 Blue 10
11 AM Tue 82 87 E 5 11900 9685 3335 White 15
12 Noon Tue 84 91 E 5 12746 11826 5476 White 19
1 PM Tue 85 92 E 5 12957 12957 6607 White 20
2 PM Tue 85 92 E 5 12957 12957 6607 White 20
3 PM Tue 86 92 E 5 12957 12957 6607 White 20
4 PM Tue 86 91 E 5 12746 11826 5476 White 19
5 PM Tue 85 88 SW 8 12113 10517 4167 White 16
6 PM Tue 81 82 SW 8 9303 7640 1290 Blue 10
7 PM Tue 77 77 SW 8 6449 6350 0 Blue 5
8 PM Tue 73 73 SW 8 4931 6350 0 Blue 1
9 PM Tue 71 71 SW 8 4168 6350 0 Blue 0
10 PM Tue 69 69 SW 8 4131 6350 0 Blue 0
11 PM Tue 68 68 N 6 4131 6350 0 Blue 0
12 Midnight Wed 68 68 N 6 4131 6350 0 Blue 0
1 AM Wed 68 68 N 6 4131 6350 0 Blue 0
2 AM Wed 68 68 N 6 4131 6350 0 Blue 0
3 AM Wed 67 67 N 6 4131 6350 0 Blue 0
4 AM Wed 66 66 N 6 4131 6350 0 Blue 0
5 AM Wed 66 66 N 5 4131 6350 0 Blue 0
6 AM Wed 66 66 N 5 4131 6350 0 Blue 0
7 AM Wed 68 68 N 5 4131 6350 0 Blue 0
8 AM Wed 71 72 N 5 4547 6350 0 Blue 0
9 AM Wed 75 77 N 5 6449 6350 0 Blue 5
10 AM Wed 79 83 N 5 9538 8249 1899 Blue 11
11 AM Wed 83 89 SW 5 12324 10791 4441 White 17
12 Noon Wed 85 92 SW 5 12957 12957 6607 White 20
1 PM Wed 85 93 SW 5 13166 13166 6816 White 21
2 PM Wed 86 93 SW 5 13166 13166 6816 White 21
3 PM Wed 86 92 SW 5 12957 12957 6607 White 20
4 PM Wed 86 91 SW 5 12746 11826 5476 White 19
5 PM Wed 84 87 SW 10 11900 9685 3335 White 15
6 PM Wed 81 82 SW 10 9303 7640 1290 Blue 10
7 PM Wed 77 77 SW 10 6449 6350 0 Blue 5
8 PM Wed 73 73 SW 10 4931 6350 0 Blue 1
9 PM Wed 71 71 SW 10 4168 6350 0 Blue 0
10 PM Wed 70 70 SW 10 4131 6350 0 Blue 0
11 PM Wed 69 69 W 7 4131 6350 0 Blue 0
12 Midnight Thu 68 68 W 7 4131 6350 0 Blue 0
1 AM Thu 67 67 W 7 4131 6350 0 Blue 0
2 AM Thu 67 67 W 7 4131 6350 0 Blue 0
3 AM Thu 66 66 W 7 4131 6350 0 Blue 0
4 AM Thu 65 65 W 7 4131 6350 0 Blue 0
5 AM Thu 65 65 N 8 4131 6350 0 Blue 0
6 AM Thu 66 66 N 8 4131 6350 0 Blue 0
7 AM Thu 67 67 N 8 4131 6350 0 Blue 0
8 AM Thu 70 71 N 8 4168 6350 0 Blue 0
9 AM Thu 74 76 N 8 6169 6350 0 Blue 4
10 AM Thu 78 82 N 8 9303 7640 1290 Blue 10
11 AM Thu 82 87 N 6 11900 9685 3335 White 15
12 Noon Thu 84 91 N 6 12746 11826 5476 White 19
1 PM Thu 84 91 N 6 12746 11826 5476 White 19
2 PM Thu 85 92 N 6 12957 12957 6607 White 20
3 PM Thu 85 91 N 6 12746 11826 5476 White 19
4 PM Thu 85 90 N 6 12535 11114 4764 White 18
5 PM Thu 83 86 W 9 10847 9509 3159 Blue 14
6 PM Thu 80 81 W 9 8993 7263 913 Blue 9
7 PM Thu 76 76 W 9 6169 6350 0 Blue 4
8 PM Thu 72 72 W 9 4547 6350 0 Blue 0
9 PM Thu 69 69 W 9 4131 6350 0 Blue 0
10 PM Thu 68 68 W 9 4131 6350 0 Blue 0
11 PM Thu 67 67 NW 6 4131 6350 0 Blue 0
12 Midnight Fri 66 66 NW 6 4131 6350 0 Blue 0
1 AM Fri 65 65 NW 6 4131 6350 0 Blue 0
2 AM Fri 65 65 NW 6 4131 6350 0 Blue 0
3 AM Fri 64 64 NW 6 4131 6350 0 Blue 0
4 AM Fri 63 63 NW 6 4131 6350 0 Blue 0
5 AM Fri 63 63 N 7 4131 6350 0 Blue 0
6 AM Fri 64 64 N 7 4131 6350 0 Blue 0
7 AM Fri 65 65 N 7 4131 6350 0 Blue 0
8 AM Fri 68 69 N 7 4131 6350 0 Blue 0
9 AM Fri 73 75 N 7 5887 6350 0 Blue 3
10 AM Fri 77 81 N 7 8993 7263 913 Blue 9
11 AM Fri 81 86 N 5 10847 9509 3159 Blue 14
12 Noon Fri 83 90 N 5 12535 11114 4764 White 18
1 PM Fri 84 91 N 5 12746 11826 5476 White 19
2 PM Fri 85 92 N 5 12957 12957 6607 White 20
3 PM Fri 85 91 N 5 12746 11826 5476 White 19
4 PM Fri 85 90 N 5 12535 11114 4764 White 18
5 PM Fri 83 86 SW 9 10847 9509 3159 Blue 14
6 PM Fri 80 81 SW 9 8993 7263 913 Blue 9
7 PM Fri 76 76 SW 9 6169 6350 0 Blue 4
8 PM Fri 72 72 SW 9 4547 6350 0 Blue 0
9 PM Fri 69 69 SW 9 4131 6350 0 Blue 0
10 PM Fri 68 68 SW 9 4131 6350 0 Blue 0
11 PM Fri 67 67 W 5 4131 6350 0 Blue 0
12 Midnight Sat 66 66 W 5 4131 6350 0 Blue 0
1 AM Sat 65 65 W 5 4131 6350 0 Blue 0
2 AM Sat 65 65 W 5 4131 6350 0 Blue 0
3 AM Sat 64 64 W 5 4131 6350 0 Blue 0
4 AM Sat 63 63 W 5 4131 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