Detailed Predictions for: St John
Launch Lat, Long, Altitude (f): 39.424433, -122.689342, 6350
LZ Altitude (f): 1185
Sounding

Station:

KOAK

Date/Time:

19 JUN 2024

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Wed 54 54 W 10 11 3658 6350 0 Blue 0
1 AM Wed 53 53 W 9 11 3658 6350 0 Blue 0
2 AM Wed 53 53 E 8 11 3658 6350 0 Blue 0
3 AM Wed 53 53 NNE 8 10 3658 6350 0 Blue 0
4 AM Wed 53 53 N 6 9 3658 6350 0 Blue 0
5 AM Wed 53 53 NNE 5 8 3658 6350 0 Blue 0
6 AM Wed 53 53 N 5 6 3658 6350 0 Blue 0
7 AM Wed 54 54 N 4 6 3658 6350 0 Blue 0
8 AM Wed 54 55 ENE 4 6 3658 6350 0 Blue 0
9 AM Wed 55 58 E 4 5 3658 6350 0 Blue 0
10 AM Wed 57 62 E 5 8 4808 6350 0 Blue 0
11 AM Wed 58 64 E 5 10 6546 6350 0 Blue 2
12 Noon Wed 60 68 ESE 6 10 7663 6873 523 Blue 6
1 PM Wed 63 71 ESE 6 11 9252 7649 1299 Blue 9
2 PM Wed 64 72 ESE 8 11 9573 7920 1570 Blue 10
3 PM Wed 64 70 ESE 8 12 8649 7519 1169 Blue 8
4 PM Wed 65 70 SE 8 13 8649 7519 1169 Blue 8
5 PM Wed 64 67 SE 9 13 7532 6471 121 Blue 5
6 PM Wed 64 66 SE 9 13 7401 6350 0 Blue 4
7 PM Wed 63 63 SSE 9 13 5718 6350 0 Blue 1
8 PM Wed 58 58 WSW 9 12 3658 6350 0 Blue 0
9 PM Wed 56 56 W 8 11 3658 6350 0 Blue 0
10 PM Wed 56 56 W 8 11 3658 6350 0 Blue 0
11 PM Wed 56 56 W 8 10 3658 6350 0 Blue 0
12 Midnight Thu 57 57 W 6 9 3658 6350 0 Blue 0
1 AM Thu 56 56 WNW 6 9 3658 6350 0 Blue 0
2 AM Thu 56 56 N 6 9 3658 6350 0 Blue 0
3 AM Thu 56 56 NNW 6 9 3658 6350 0 Blue 0
4 AM Thu 56 56 NNW 6 8 3658 6350 0 Blue 0
5 AM Thu 55 55 N 5 8 3658 6350 0 Blue 0
6 AM Thu 56 56 N 5 8 3658 6350 0 Blue 0
7 AM Thu 56 56 N 5 8 3658 6350 0 Blue 0
8 AM Thu 57 57 NNW 4 6 3658 6350 0 Blue 0
9 AM Thu 59 60 NNW 4 6 3930 6350 0 Blue 0
10 AM Thu 61 64 NNW 4 6 6546 6350 0 Blue 2
11 AM Thu 63 68 E 4 8 7663 6873 523 Blue 6
12 Noon Thu 65 71 E 4 8 9252 7649 1299 Blue 9
1 PM Thu 67 74 E 4 8 10367 9160 2810 Blue 12
2 PM Thu 68 75 SSE 6 11 11515 9527 3177 Blue 13
3 PM Thu 69 75 SSE 6 11 11515 9527 3177 Blue 13
4 PM Thu 69 73 SSE 6 11 9848 8565 2215 Blue 11
5 PM Thu 69 72 S 8 13 9573 7920 1570 Blue 10
6 PM Thu 67 68 S 8 13 7663 6873 523 Blue 6
7 PM Thu 65 65 S 8 13 6894 6350 0 Blue 3
8 PM Thu 63 63 WSW 9 13 5718 6350 0 Blue 1
9 PM Thu 62 62 WSW 9 13 4808 6350 0 Blue 0
10 PM Thu 61 61 WSW 9 13 4373 6350 0 Blue 0
11 PM Thu 61 61 WNW 8 11 4373 6350 0 Blue 0
12 Midnight Fri 61 61 WNW 8 11 4373 6350 0 Blue 0
1 AM Fri 61 61 WNW 8 11 4373 6350 0 Blue 0
2 AM Fri 61 61 NW 9 11 4373 6350 0 Blue 0
3 AM Fri 60 60 NW 9 11 3930 6350 0 Blue 0
4 AM Fri 60 60 NW 9 11 3930 6350 0 Blue 0
5 AM Fri 60 60 NW 9 11 3930 6350 0 Blue 0
6 AM Fri 60 60 NW 9 11 3930 6350 0 Blue 0
7 AM Fri 61 61 NW 9 11 4373 6350 0 Blue 0
8 AM Fri 63 64 N 5 9 6546 6350 0 Blue 2
9 AM Fri 65 68 N 5 9 7663 6873 523 Blue 6
10 AM Fri 68 73 N 5 9 9848 8565 2215 Blue 11
11 AM Fri 70 77 ESE 5 10 13475 10281 3931 Blue 15
12 Noon Fri 72 80 ESE 5 10 15073 13233 6883 Blue 18
1 PM Fri 74 83 ESE 5 10 16767 14709 8359 Blue 21
2 PM Fri 76 84 SSE 6 11 17014 15449 9099 Blue 22
3 PM Fri 76 83 SSE 6 11 16767 14709 8359 Blue 21
4 PM Fri 77 82 SSE 6 11 16234 14409 8059 Blue 20
5 PM Fri 76 79 SSW 10 13 14561 12306 5956 Blue 17
6 PM Fri 74 76 SSW 10 13 12569 9800 3450 Blue 14
7 PM Fri 71 71 SSW 10 13 9252 7649 1299 Blue 9
8 PM Fri 69 69 W 10 14 8000 7388 1038 Blue 7
9 PM Fri 68 68 W 10 14 7663 6873 523 Blue 6
10 PM Fri 67 67 W 10 14 7532 6471 121 Blue 5
11 PM Fri 67 67 W 9 11 7532 6471 121 Blue 5
12 Midnight Sat 66 66 W 9 11 7401 6350 0 Blue 4
1 AM Sat 66 66 W 9 11 7401 6350 0 Blue 4
2 AM Sat 65 65 WNW 10 12 6894 6350 0 Blue 3
3 AM Sat 65 65 WNW 10 12 6894 6350 0 Blue 3
4 AM Sat 64 64 WNW 10 12 6546 6350 0 Blue 2
5 AM Sat 64 64 WNW 10 11 6546 6350 0 Blue 2
6 AM Sat 64 64 WNW 10 11 6546 6350 0 Blue 2
7 AM Sat 65 65 WNW 10 11 6894 6350 0 Blue 3
8 AM Sat 66 67 NNW 5 9 7532 6471 121 Blue 5
9 AM Sat 68 71 NNW 5 9 9252 7649 1299 Blue 9
10 AM Sat 70 75 NNW 5 9 11515 9527 3177 Blue 13
11 AM Sat 72 79 SSE 6 11 14561 12306 5956 Blue 17
12 Noon Sat 74 82 SSE 6 11 16234 14409 8059 Blue 20
1 PM Sat 76 85 SSE 6 11 17686 16011 9661 Blue 23
2 PM Sat 78 86 S 12 18 18169 16555 10205 Blue 24
3 PM Sat 79 86 S 12 18 18169 16555 10205 Blue 24
4 PM Sat 79 84 S 12 18 17014 15449 9099 Blue 22
5 PM Sat 78 81 SW 19 25 15667 13865 7515 Blue 19
6 PM Sat 75 77 SW 19 25 13475 10281 3931 Blue 15
7 PM Sat 73 73 SW 19 25 9848 8565 2215 Blue 11
8 PM Sat 70 70 WSW 13 19 8649 7519 1169 Blue 8
9 PM Sat 68 68 WSW 13 19 7663 6873 523 Blue 6
10 PM Sat 67 67 WSW 13 19 7532 6471 121 Blue 5
11 PM Sat 66 66 W 9 11 7401 6350 0 Blue 4
12 Midnight Sun 65 65 W 9 11 6894 6350 0 Blue 3
1 AM Sun 64 64 W 9 11 6546 6350 0 Blue 2
2 AM Sun 64 64 WNW 8 10 6546 6350 0 Blue 2
3 AM Sun 63 63 WNW 8 10 5718 6350 0 Blue 1
4 AM Sun 63 63 WNW 8 10 5718 6350 0 Blue 1
5 AM Sun 63 63 NW 6 8 5718 6350 0 Blue 1
6 AM Sun 63 63 NW 6 8 5718 6350 0 Blue 1
7 AM Sun 63 63 NW 6 8 5718 6350 0 Blue 1
8 AM Sun 64 65 N 5 8 6894 6350 0 Blue 3
9 AM Sun 66 69 N 5 8 8000 7388 1038 Blue 7
10 AM Sun 68 73 N 5 8 9848 8565 2215 Blue 11
11 AM Sun 70 77 SE 8 12 13475 10281 3931 Blue 15
12 Noon Sun 72 80 SE 8 12 15073 13233 6883 Blue 18
1 PM Sun 74 83 SE 8 12 16767 14709 8359 Blue 21
2 PM Sun 75 83 S 12 19 16767 14709 8359 Blue 21
3 PM Sun 76 83 S 12 19 16767 14709 8359 Blue 21
4 PM Sun 76 81 S 12 19 15667 13865 7515 Blue 19
5 PM Sun 75 78 SSW 17 21 14044 11253 4903 Blue 16
6 PM Sun 73 75 SSW 17 21 11515 9527 3177 Blue 13
7 PM Sun 70 70 SSW 17 21 8649 7519 1169 Blue 8
8 PM Sun 68 68 WSW 13 18 7663 6873 523 Blue 6
9 PM Sun 67 67 WSW 13 18 7532 6471 121 Blue 5
10 PM Sun 66 66 WSW 13 18 7401 6350 0 Blue 4
11 PM Sun 65 65 W 8 10 6894 6350 0 Blue 3
12 Midnight Mon 64 64 W 8 10 6546 6350 0 Blue 2
1 AM Mon 63 63 W 8 10 5718 6350 0 Blue 1
2 AM Mon 62 62 WNW 5 9 4808 6350 0 Blue 0
3 AM Mon 61 61 WNW 5 9 4373 6350 0 Blue 0
4 AM Mon 60 60 WNW 5 9 3930 6350 0 Blue 0
5 AM Mon 60 60 NW 5 8 3930 6350 0 Blue 0
6 AM Mon 60 60 NW 5 8 3930 6350 0 Blue 0
7 AM Mon 61 61 NW 5 8 4373 6350 0 Blue 0
8 AM Mon 62 63 NNE 5 9 5718 6350 0 Blue 1
9 AM Mon 64 67 NNE 5 9 7532 6471 121 Blue 5
10 AM Mon 65 70 NNE 5 9 8649 7519 1169 Blue 8
11 AM Mon 67 74 ESE 8 11 10367 9160 2810 Blue 12
12 Noon Mon 69 77 ESE 8 11 13475 10281 3931 Blue 15
1 PM Mon 71 80 ESE 8 11 15073 13233 6883 Blue 18
2 PM Mon 73 81 SSE 10 16 15667 13865 7515 Blue 19
3 PM Mon 73 80 SSE 10 16 15073 13233 6883 Blue 18
4 PM Mon 73 78 SSE 10 16 14044 11253 4903 Blue 16
5 PM Mon 73 76 SSW 13 19 12569 9800 3450 Blue 14
6 PM Mon 71 73 SSW 13 19 9848 8565 2215 Blue 11
7 PM Mon 68 68 SSW 13 19 7663 6873 523 Blue 6
8 PM Mon 66 66 WSW 12 17 7401 6350 0 Blue 4
9 PM Mon 65 65 WSW 12 17 6894 6350 0 Blue 3
10 PM Mon 64 64 WSW 12 17 6546 6350 0 Blue 2

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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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 [email protected]