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

Station:

KOAK

Date/Time:

16 AUG 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 Thu 59 59 E 6 4308 6350 0 Blue 0
6 AM Thu 59 59 E 6 4308 6350 0 Blue 0
7 AM Thu 60 60 E 6 4308 6350 0 Blue 0
8 AM Thu 63 63 E 6 4308 6350 0 Blue 0
9 AM Thu 66 67 E 6 4308 6350 0 Blue 0
10 AM Thu 71 74 E 6 4878 6350 0 Blue 1
11 AM Thu 74 79 SE 3 7952 6350 0 Blue 6
12 Noon Thu 76 82 SE 3 9446 7892 1542 Blue 9
1 PM Thu 77 84 SE 3 10808 8900 2550 Blue 11
2 PM Thu 78 85 S 9 11798 9371 3021 Blue 12
3 PM Thu 79 85 S 9 11798 9371 3021 Blue 12
4 PM Thu 79 83 S 9 9949 8415 2065 Blue 10
5 PM Thu 78 81 S 8 8969 7016 666 Blue 8
6 PM Thu 75 76 S 8 5738 6350 0 Blue 3
7 PM Thu 70 70 S 8 4308 6350 0 Blue 0
8 PM Thu 66 66 S 7 4308 6350 0 Blue 0
9 PM Thu 64 64 S 7 4308 6350 0 Blue 0
10 PM Thu 63 63 S 7 4308 6350 0 Blue 0
11 PM Thu 63 63 W 5 4308 6350 0 Blue 0
12 Midnight Fri 63 63 W 5 4308 6350 0 Blue 0
1 AM Fri 62 62 W 5 4308 6350 0 Blue 0
2 AM Fri 62 62 N 3 4308 6350 0 Blue 0
3 AM Fri 61 61 N 3 4308 6350 0 Blue 0
4 AM Fri 60 60 N 3 4308 6350 0 Blue 0
5 AM Fri 60 60 N 3 4308 6350 0 Blue 0
6 AM Fri 60 60 N 3 4308 6350 0 Blue 0
7 AM Fri 61 61 N 3 4308 6350 0 Blue 0
8 AM Fri 63 63 N 3 4308 6350 0 Blue 0
9 AM Fri 67 69 N 3 4308 6350 0 Blue 0
10 AM Fri 72 75 N 3 5247 6350 0 Blue 2
11 AM Fri 76 81 E 5 8969 7016 666 Blue 8
12 Noon Fri 78 84 E 5 10808 8900 2550 Blue 11
1 PM Fri 79 86 E 5 12685 9832 3482 Blue 13
2 PM Fri 80 87 E 6 13495 10596 4246 Blue 14
3 PM Fri 81 87 E 6 13495 10596 4246 Blue 14
4 PM Fri 81 85 E 6 11798 9371 3021 Blue 12
5 PM Fri 80 83 SE 6 9949 8415 2065 Blue 10
6 PM Fri 76 77 SE 6 6218 6350 0 Blue 4
7 PM Fri 71 71 SE 6 4308 6350 0 Blue 0
8 PM Fri 67 67 SE 6 4308 6350 0 Blue 0
9 PM Fri 64 64 SE 6 4308 6350 0 Blue 0
10 PM Fri 64 64 SE 6 4308 6350 0 Blue 0
11 PM Fri 63 63 E 5 4308 6350 0 Blue 0
12 Midnight Sat 63 63 E 5 4308 6350 0 Blue 0
1 AM Sat 62 62 E 5 4308 6350 0 Blue 0
2 AM Sat 61 61 E 5 4308 6350 0 Blue 0
3 AM Sat 60 60 E 5 4308 6350 0 Blue 0
4 AM Sat 60 60 E 5 4308 6350 0 Blue 0
5 AM Sat 60 60 N 6 4308 6350 0 Blue 0
6 AM Sat 60 60 N 6 4308 6350 0 Blue 0
7 AM Sat 61 61 N 6 4308 6350 0 Blue 0
8 AM Sat 63 63 N 6 4308 6350 0 Blue 0
9 AM Sat 68 70 N 6 4308 6350 0 Blue 0
10 AM Sat 73 76 N 6 5738 6350 0 Blue 3
11 AM Sat 78 83 E 3 9949 8415 2065 Blue 10
12 Noon Sat 81 88 E 3 14077 11580 5230 Blue 15
1 PM Sat 82 89 E 3 14247 12461 6111 Blue 15
2 PM Sat 83 90 E 3 15273 13267 6917 Blue 16
3 PM Sat 83 89 E 3 14247 12461 6111 Blue 15
4 PM Sat 82 87 E 3 13495 10596 4246 Blue 14
5 PM Sat 80 83 SW 6 9949 8415 2065 Blue 10
6 PM Sat 76 77 SW 6 6218 6350 0 Blue 4
7 PM Sat 72 72 SW 6 4308 6350 0 Blue 0
8 PM Sat 68 68 SW 6 4308 6350 0 Blue 0
9 PM Sat 66 66 SW 6 4308 6350 0 Blue 0
10 PM Sat 65 65 SW 6 4308 6350 0 Blue 0
11 PM Sat 65 65 N 3 4308 6350 0 Blue 0
12 Midnight Sun 64 64 N 3 4308 6350 0 Blue 0
1 AM Sun 64 64 N 3 4308 6350 0 Blue 0
2 AM Sun 63 63 N 3 4308 6350 0 Blue 0
3 AM Sun 62 62 N 3 4308 6350 0 Blue 0
4 AM Sun 62 62 N 3 4308 6350 0 Blue 0
5 AM Sun 61 61 NE 5 4308 6350 0 Blue 0
6 AM Sun 61 61 NE 5 4308 6350 0 Blue 0
7 AM Sun 61 61 NE 5 4308 6350 0 Blue 0
8 AM Sun 63 63 NE 5 4308 6350 0 Blue 0
9 AM Sun 67 69 NE 5 4308 6350 0 Blue 0
10 AM Sun 71 74 NE 5 4878 6350 0 Blue 1
11 AM Sun 74 79 SE 5 7952 6350 0 Blue 6
12 Noon Sun 77 84 SE 5 10808 8900 2550 Blue 11
1 PM Sun 78 85 SE 5 11798 9371 3021 Blue 12
2 PM Sun 79 86 SE 5 12685 9832 3482 Blue 13
3 PM Sun 79 85 SE 5 11798 9371 3021 Blue 12
4 PM Sun 79 84 SE 5 10808 8900 2550 Blue 11
5 PM Sun 77 80 SW 8 8481 6350 0 Blue 7
6 PM Sun 74 75 SW 8 5247 6350 0 Blue 2
7 PM Sun 70 70 SW 8 4308 6350 0 Blue 0
8 PM Sun 66 66 SW 8 4308 6350 0 Blue 0
9 PM Sun 64 64 SW 8 4308 6350 0 Blue 0
10 PM Sun 63 63 SW 8 4308 6350 0 Blue 0
11 PM Sun 63 63 W 5 4308 6350 0 Blue 0
12 Midnight Mon 62 62 W 5 4308 6350 0 Blue 0
1 AM Mon 61 61 W 5 4308 6350 0 Blue 0
2 AM Mon 61 61 W 5 4308 6350 0 Blue 0
3 AM Mon 60 60 W 5 4308 6350 0 Blue 0
4 AM Mon 59 59 W 5 4308 6350 0 Blue 0
5 AM Mon 59 59 NE 7 4308 6350 0 Blue 0
6 AM Mon 59 59 NE 7 4308 6350 0 Blue 0
7 AM Mon 60 60 NE 7 4308 6350 0 Blue 0
8 AM Mon 62 62 NE 7 4308 6350 0 Blue 0
9 AM Mon 66 68 NE 7 4308 6350 0 Blue 0
10 AM Mon 70 73 NE 7 4308 6350 0 Blue 0
11 AM Mon 74 79 E 7 7952 6350 0 Blue 6
12 Noon Mon 77 84 E 7 10808 8900 2550 Blue 11
1 PM Mon 79 86 E 7 12685 9832 3482 Blue 13
2 PM Mon 80 87 E 7 13495 10596 4246 Blue 14
3 PM Mon 80 86 E 7 12685 9832 3482 Blue 13
4 PM Mon 80 85 E 7 11798 9371 3021 Blue 12
5 PM Mon 78 81 S 7 8969 7016 666 Blue 8
6 PM Mon 75 76 S 7 5738 6350 0 Blue 3
7 PM Mon 71 71 S 7 4308 6350 0 Blue 0
8 PM Mon 68 68 S 7 4308 6350 0 Blue 0
9 PM Mon 65 65 S 7 4308 6350 0 Blue 0
10 PM Mon 64 64 S 7 4308 6350 0 Blue 0
11 PM Mon 64 64 W 6 4308 6350 0 Blue 0
12 Midnight Tue 63 63 W 6 4308 6350 0 Blue 0
1 AM Tue 62 62 W 6 4308 6350 0 Blue 0
2 AM Tue 62 62 W 6 4308 6350 0 Blue 0
3 AM Tue 61 61 W 6 4308 6350 0 Blue 0
4 AM Tue 60 60 W 6 4308 6350 0 Blue 0
5 AM Tue 60 60 E 7 4308 6350 0 Blue 0
6 AM Tue 60 60 E 7 4308 6350 0 Blue 0
7 AM Tue 61 61 E 7 4308 6350 0 Blue 0
8 AM Tue 64 64 E 7 4308 6350 0 Blue 0
9 AM Tue 67 69 E 7 4308 6350 0 Blue 0
10 AM Tue 72 75 E 7 5247 6350 0 Blue 2
11 AM Tue 76 81 E 6 8969 7016 666 Blue 8
12 Noon Tue 78 85 E 6 11798 9371 3021 Blue 12
1 PM Tue 80 87 E 6 13495 10596 4246 Blue 14
2 PM Tue 80 87 E 6 13495 10596 4246 Blue 14
3 PM Tue 81 87 E 6 13495 10596 4246 Blue 14
4 PM Tue 81 86 E 6 12685 9832 3482 Blue 13
5 PM Tue 79 82 S 7 9446 7892 1542 Blue 9
6 PM Tue 76 77 S 7 6218 6350 0 Blue 4
7 PM Tue 72 72 S 7 4308 6350 0 Blue 0
8 PM Tue 68 68 S 7 4308 6350 0 Blue 0
9 PM Tue 66 66 S 7 4308 6350 0 Blue 0
10 PM Tue 65 65 S 7 4308 6350 0 Blue 0
11 PM Tue 64 64 W 5 4308 6350 0 Blue 0
12 Midnight Wed 64 64 W 5 4308 6350 0 Blue 0
1 AM Wed 63 63 W 5 4308 6350 0 Blue 0
2 AM Wed 63 63 W 5 4308 6350 0 Blue 0
3 AM Wed 62 62 W 5 4308 6350 0 Blue 0
4 AM Wed 61 61 W 5 4308 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