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

Station:

KOAK

Date/Time:

17 SEP 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 Tue 43 43 S 5 4334 6350 0 Blue 0
6 AM Tue 43 43 S 5 4334 6350 0 Blue 0
7 AM Tue 45 45 S 5 4334 6350 0 Blue 0
8 AM Tue 49 49 S 3 4334 6350 0 Blue 0
9 AM Tue 52 53 S 3 4754 6350 0 Blue 0
10 AM Tue 54 56 S 3 5843 6350 0 Blue 2
11 AM Tue 55 59 S 7 6731 6350 0 Blue 5
12 Noon Tue 57 62 S 7 7402 6698 348 Blue 8
1 PM Tue 60 65 S 7 8025 7391 1041 Blue 11
2 PM Tue 61 66 S 9 8234 7584 1234 Blue 12
3 PM Tue 61 65 S 9 8025 7391 1041 Blue 11
4 PM Tue 61 64 S 9 7815 7275 925 Blue 10
5 PM Tue 58 59 SW 12 6731 6350 0 Blue 5
6 PM Tue 57 57 SW 12 6025 6350 0 Blue 3
7 PM Tue 54 54 SW 12 4942 6350 0 Blue 0
8 PM Tue 52 52 NW 13 4566 6350 0 Blue 0
9 PM Tue 52 52 NW 13 4566 6350 0 Blue 0
10 PM Tue 52 52 NW 13 4566 6350 0 Blue 0
11 PM Tue 51 51 W 15 4378 6350 0 Blue 0
12 Midnight Wed 52 52 W 15 4566 6350 0 Blue 0
1 AM Wed 51 51 W 15 4378 6350 0 Blue 0
2 AM Wed 51 51 W 18 4378 6350 0 Blue 0
3 AM Wed 51 51 W 18 4378 6350 0 Blue 0
4 AM Wed 51 51 W 18 4378 6350 0 Blue 0
5 AM Wed 51 51 W 14 4378 6350 0 Blue 0
6 AM Wed 51 51 W 14 4378 6350 0 Blue 0
7 AM Wed 48 48 W 14 4334 6350 0 Blue 0
8 AM Wed 49 49 SW 10 4334 6350 0 Blue 0
9 AM Wed 52 52 SW 10 4566 6350 0 Blue 0
10 AM Wed 51 52 SW 10 4566 6350 0 Blue 0
11 AM Wed 51 53 S 12 4754 6350 0 Blue 0
12 Noon Wed 53 56 S 12 5843 6350 0 Blue 2
1 PM Wed 55 58 S 12 6283 6350 0 Blue 4
2 PM Wed 55 58 S 13 6283 6350 0 Blue 4
3 PM Wed 54 57 S 13 6025 6350 0 Blue 3
4 PM Wed 53 55 S 13 5637 6350 0 Blue 1
5 PM Wed 52 53 N 13 4754 6350 0 Blue 0
6 PM Wed 51 51 N 13 4378 6350 0 Blue 0
7 PM Wed 50 50 N 13 4334 6350 0 Blue 0
8 PM Wed 49 49 N 13 4334 6350 0 Blue 0
9 PM Wed 49 49 N 13 4334 6350 0 Blue 0
10 PM Wed 48 48 N 13 4334 6350 0 Blue 0
11 PM Wed 48 48 N 9 4334 6350 0 Blue 0
12 Midnight Thu 48 48 N 9 4334 6350 0 Blue 0
1 AM Thu 48 48 N 9 4334 6350 0 Blue 0
2 AM Thu 48 48 N 9 4334 6350 0 Blue 0
3 AM Thu 47 47 N 9 4334 6350 0 Blue 0
4 AM Thu 47 47 N 9 4334 6350 0 Blue 0
5 AM Thu 46 46 N 7 4334 6350 0 Blue 0
6 AM Thu 46 46 N 7 4334 6350 0 Blue 0
7 AM Thu 47 47 N 7 4334 6350 0 Blue 0
8 AM Thu 49 49 N 7 4334 6350 0 Blue 0
9 AM Thu 51 52 N 7 4566 6350 0 Blue 0
10 AM Thu 52 54 N 7 4942 6350 0 Blue 0
11 AM Thu 54 57 N 9 6025 6350 0 Blue 3
12 Noon Thu 57 61 N 9 7286 6350 0 Blue 7
1 PM Thu 58 63 N 9 7605 7132 782 Blue 9
2 PM Thu 60 65 N 9 8025 7391 1041 Blue 11
3 PM Thu 61 65 N 9 8025 7391 1041 Blue 11
4 PM Thu 62 65 N 9 8025 7391 1041 Blue 11
5 PM Thu 62 63 N 6 7605 7132 782 Blue 9
6 PM Thu 60 60 N 6 7169 6350 0 Blue 6
7 PM Thu 58 58 N 6 6283 6350 0 Blue 4
8 PM Thu 56 56 N 6 5843 6350 0 Blue 2
9 PM Thu 54 54 N 6 4942 6350 0 Blue 0
10 PM Thu 54 54 N 6 4942 6350 0 Blue 0
11 PM Thu 54 54 NW 12 4942 6350 0 Blue 0
12 Midnight Fri 54 54 NW 12 4942 6350 0 Blue 0
1 AM Fri 54 54 NW 12 4942 6350 0 Blue 0
2 AM Fri 54 54 NW 12 4942 6350 0 Blue 0
3 AM Fri 53 53 NW 12 4754 6350 0 Blue 0
4 AM Fri 52 52 NW 12 4566 6350 0 Blue 0
5 AM Fri 51 51 NW 9 4378 6350 0 Blue 0
6 AM Fri 51 51 NW 9 4378 6350 0 Blue 0
7 AM Fri 53 53 NW 9 4754 6350 0 Blue 0
8 AM Fri 54 54 NW 9 4942 6350 0 Blue 0
9 AM Fri 56 57 NW 9 6025 6350 0 Blue 3
10 AM Fri 58 60 NW 9 7169 6350 0 Blue 6
11 AM Fri 60 64 N 10 7815 7275 925 Blue 10
12 Noon Fri 61 66 N 10 8234 7584 1234 Blue 12
1 PM Fri 63 68 N 10 8810 8000 1650 Blue 14
2 PM Fri 64 69 N 10 9118 8208 1858 Blue 15
3 PM Fri 65 69 N 10 9118 8208 1858 Blue 15
4 PM Fri 65 68 N 10 8810 8000 1650 Blue 14
5 PM Fri 64 65 E 7 8025 7391 1041 Blue 11
6 PM Fri 62 62 E 7 7402 6698 348 Blue 8
7 PM Fri 60 60 E 7 7169 6350 0 Blue 6
8 PM Fri 58 58 E 7 6283 6350 0 Blue 4
9 PM Fri 57 57 E 7 6025 6350 0 Blue 3
10 PM Fri 58 58 E 7 6283 6350 0 Blue 4
11 PM Fri 58 58 NW 8 6283 6350 0 Blue 4
12 Midnight Sat 57 57 NW 8 6025 6350 0 Blue 3
1 AM Sat 56 56 NW 8 5843 6350 0 Blue 2
2 AM Sat 55 55 NW 8 5637 6350 0 Blue 1
3 AM Sat 54 54 NW 8 4942 6350 0 Blue 0
4 AM Sat 54 54 NW 8 4942 6350 0 Blue 0
5 AM Sat 54 54 N 10 4942 6350 0 Blue 0
6 AM Sat 55 55 N 10 5637 6350 0 Blue 1
7 AM Sat 56 56 N 10 5843 6350 0 Blue 2
8 AM Sat 57 57 N 10 6025 6350 0 Blue 3
9 AM Sat 59 60 N 10 7169 6350 0 Blue 6
10 AM Sat 61 63 N 10 7605 7132 782 Blue 9
11 AM Sat 63 67 NW 7 8500 7792 1442 Blue 13
12 Noon Sat 65 70 NW 7 9424 8459 2109 Blue 16
1 PM Sat 66 72 NW 7 10235 9071 2721 Blue 18
2 PM Sat 67 72 NW 7 10235 9071 2721 Blue 18
3 PM Sat 68 72 NW 7 10235 9071 2721 Blue 18
4 PM Sat 68 71 NW 7 9726 8766 2416 Blue 17
5 PM Sat 67 68 W 6 8810 8000 1650 Blue 14
6 PM Sat 65 65 W 6 8025 7391 1041 Blue 11
7 PM Sat 63 63 W 6 7605 7132 782 Blue 9
8 PM Sat 61 61 W 6 7286 6350 0 Blue 7
9 PM Sat 60 60 W 6 7169 6350 0 Blue 6
10 PM Sat 59 59 W 6 6731 6350 0 Blue 5
11 PM Sat 59 59 N 6 6731 6350 0 Blue 5
12 Midnight Sun 58 58 N 6 6283 6350 0 Blue 4
1 AM Sun 58 58 N 6 6283 6350 0 Blue 4
2 AM Sun 57 57 N 6 6025 6350 0 Blue 3
3 AM Sun 56 56 N 6 5843 6350 0 Blue 2
4 AM Sun 55 55 N 6 5637 6350 0 Blue 1
5 AM Sun 55 55 NW 6 5637 6350 0 Blue 1
6 AM Sun 55 55 NW 6 5637 6350 0 Blue 1
7 AM Sun 57 57 NW 6 6025 6350 0 Blue 3
8 AM Sun 58 58 NW 6 6283 6350 0 Blue 4
9 AM Sun 60 61 NW 6 7286 6350 0 Blue 7
10 AM Sun 62 64 NW 6 7815 7275 925 Blue 10
11 AM Sun 64 67 W 9 8500 7792 1442 Blue 13
12 Noon Sun 65 69 W 9 9118 8208 1858 Blue 15
1 PM Sun 66 70 W 9 9424 8459 2109 Blue 16
2 PM Sun 67 71 W 9 9726 8766 2416 Blue 17
3 PM Sun 67 70 W 9 9424 8459 2109 Blue 16
4 PM Sun 66 68 W 9 8810 8000 1650 Blue 14
5 PM Sun 65 66 W 12 8234 7584 1234 Blue 12
6 PM Sun 63 63 W 12 7605 7132 782 Blue 9
7 PM Sun 62 62 W 12 7402 6698 348 Blue 8
8 PM Sun 61 61 W 12 7286 6350 0 Blue 7
9 PM Sun 60 60 W 12 7169 6350 0 Blue 6
10 PM Sun 59 59 W 12 6731 6350 0 Blue 5
11 PM Sun 58 58 NW 10 6283 6350 0 Blue 4
12 Midnight Mon 58 58 NW 10 6283 6350 0 Blue 4
1 AM Mon 57 57 NW 10 6025 6350 0 Blue 3
2 AM Mon 56 56 NW 10 5843 6350 0 Blue 2
3 AM Mon 55 55 NW 10 5637 6350 0 Blue 1
4 AM Mon 54 54 NW 10 4942 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