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

Station:

KOAK

Date/Time:

13 JUL 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 Sat 78 78 WSW 6 9 3996 6350 0 Blue 0
1 AM Sat 77 77 WSW 6 9 3996 6350 0 Blue 0
2 AM Sat 77 77 SW 6 9 3996 6350 0 Blue 0
3 AM Sat 76 76 SW 5 8 3996 6350 0 Blue 0
4 AM Sat 76 76 WSW 5 5 3996 6350 0 Blue 0
5 AM Sat 76 76 S 4 5 3996 6350 0 Blue 0
6 AM Sat 76 76 W 4 5 3996 6350 0 Blue 0
7 AM Sat 76 76 W 4 5 3996 6350 0 Blue 0
8 AM Sat 76 77 SSE 4 5 3996 6350 0 Blue 0
9 AM Sat 78 80 ESE 4 5 3996 6350 0 Blue 0
10 AM Sat 80 83 SE 4 6 3996 6350 0 Blue 0
11 AM Sat 81 85 SE 5 9 3996 6350 0 Blue 0
12 Noon Sat 84 88 SE 6 10 4961 6350 0 Blue 1
1 PM Sat 84 88 SE 8 11 4961 6350 0 Blue 1
2 PM Sat 85 88 S 9 13 4961 6350 0 Blue 1
3 PM Sat 86 88 S 9 14 4961 6350 0 Blue 1
4 PM Sat 85 87 SSW 10 14 4604 6350 0 Blue 0
5 PM Sat 84 85 WSW 10 14 3996 6350 0 Blue 0
6 PM Sat 83 83 WSW 10 14 3996 6350 0 Blue 0
7 PM Sat 81 81 W 10 14 3996 6350 0 Blue 0
8 PM Sat 77 77 W 10 13 3996 6350 0 Blue 0
9 PM Sat 75 75 W 8 10 3996 6350 0 Blue 0
10 PM Sat 76 76 W 5 9 3996 6350 0 Blue 0
11 PM Sat 76 76 WNW 5 6 3996 6350 0 Blue 0
12 Midnight Sun 76 76 W 4 5 3996 6350 0 Blue 0
1 AM Sun 75 75 W 4 5 3996 6350 0 Blue 0
2 AM Sun 74 74 W 3 5 3996 6350 0 Blue 0
3 AM Sun 73 73 W 3 5 3996 6350 0 Blue 0
4 AM Sun 72 72 W 3 4 3996 6350 0 Blue 0
5 AM Sun 72 72 N 3 4 3996 6350 0 Blue 0
6 AM Sun 73 73 N 3 4 3996 6350 0 Blue 0
7 AM Sun 72 72 N 3 4 3996 6350 0 Blue 0
8 AM Sun 71 71 WNW 3 5 3996 6350 0 Blue 0
9 AM Sun 71 71 WNW 3 5 3996 6350 0 Blue 0
10 AM Sun 72 73 WNW 3 5 3996 6350 0 Blue 0
11 AM Sun 71 73 SE 5 9 3996 6350 0 Blue 0
12 Noon Sun 72 75 SE 5 9 3996 6350 0 Blue 0
1 PM Sun 74 77 SE 5 9 3996 6350 0 Blue 0
2 PM Sun 76 80 S 6 11 3996 6350 0 Blue 0
3 PM Sun 77 81 S 6 11 3996 6350 0 Blue 0
4 PM Sun 77 80 S 6 11 3996 6350 0 Blue 0
5 PM Sun 77 80 SW 9 13 3996 6350 0 Blue 0
6 PM Sun 75 76 SW 9 13 3996 6350 0 Blue 0
7 PM Sun 74 74 SW 9 13 3996 6350 0 Blue 0
8 PM Sun 72 72 WSW 9 12 3996 6350 0 Blue 0
9 PM Sun 71 71 WSW 9 12 3996 6350 0 Blue 0
10 PM Sun 70 70 WSW 9 12 3996 6350 0 Blue 0
11 PM Sun 70 70 W 5 8 3996 6350 0 Blue 0
12 Midnight Mon 69 69 W 5 8 3996 6350 0 Blue 0
1 AM Mon 69 69 W 5 8 3996 6350 0 Blue 0
2 AM Mon 68 68 W 4 5 3996 6350 0 Blue 0
3 AM Mon 68 68 W 4 5 3996 6350 0 Blue 0
4 AM Mon 67 67 W 4 5 3996 6350 0 Blue 0
5 AM Mon 67 67 WNW 3 4 3996 6350 0 Blue 0
6 AM Mon 67 67 WNW 3 4 3996 6350 0 Blue 0
7 AM Mon 67 67 WNW 3 4 3996 6350 0 Blue 0
8 AM Mon 68 69 NNW 3 5 3996 6350 0 Blue 0
9 AM Mon 69 71 NNW 3 5 3996 6350 0 Blue 0
10 AM Mon 71 75 NNW 3 5 3996 6350 0 Blue 0
11 AM Mon 72 78 SE 5 10 3996 6350 0 Blue 0
12 Noon Mon 73 81 SE 5 10 3996 6350 0 Blue 0
1 PM Mon 75 83 SE 5 10 3996 6350 0 Blue 0
2 PM Mon 76 84 SSE 10 16 3996 6350 0 Blue 0
3 PM Mon 76 83 SSE 10 16 3996 6350 0 Blue 0
4 PM Mon 76 81 SSE 10 16 3996 6350 0 Blue 0
5 PM Mon 76 79 S 11 17 3996 6350 0 Blue 0
6 PM Mon 75 77 S 11 17 3996 6350 0 Blue 0
7 PM Mon 73 73 S 11 17 3996 6350 0 Blue 0
8 PM Mon 71 71 SW 10 13 3996 6350 0 Blue 0
9 PM Mon 70 70 SW 10 13 3996 6350 0 Blue 0
10 PM Mon 69 69 SW 10 13 3996 6350 0 Blue 0
11 PM Mon 68 68 W 5 6 3996 6350 0 Blue 0
12 Midnight Tue 68 68 W 5 6 3996 6350 0 Blue 0
1 AM Tue 67 67 W 5 6 3996 6350 0 Blue 0
2 AM Tue 67 67 W 4 5 3996 6350 0 Blue 0
3 AM Tue 67 67 W 4 5 3996 6350 0 Blue 0
4 AM Tue 66 66 W 4 5 3996 6350 0 Blue 0
5 AM Tue 66 66 NW 3 4 3996 6350 0 Blue 0
6 AM Tue 65 65 NW 3 4 3996 6350 0 Blue 0
7 AM Tue 65 65 NW 3 4 3996 6350 0 Blue 0
8 AM Tue 66 67 NE 4 6 3996 6350 0 Blue 0
9 AM Tue 66 68 NE 4 6 3996 6350 0 Blue 0
10 AM Tue 68 72 NE 4 6 3996 6350 0 Blue 0
11 AM Tue 69 75 ESE 6 10 3996 6350 0 Blue 0
12 Noon Tue 70 78 ESE 6 10 3996 6350 0 Blue 0
1 PM Tue 72 80 ESE 6 10 3996 6350 0 Blue 0
2 PM Tue 73 81 SE 10 16 3996 6350 0 Blue 0
3 PM Tue 73 80 SE 10 16 3996 6350 0 Blue 0
4 PM Tue 74 79 SE 10 16 3996 6350 0 Blue 0
5 PM Tue 73 76 S 13 18 3996 6350 0 Blue 0
6 PM Tue 71 73 S 13 18 3996 6350 0 Blue 0
7 PM Tue 69 69 S 13 18 3996 6350 0 Blue 0
8 PM Tue 67 67 WSW 10 14 3996 6350 0 Blue 0
9 PM Tue 66 66 WSW 10 14 3996 6350 0 Blue 0
10 PM Tue 65 65 WSW 10 14 3996 6350 0 Blue 0
11 PM Tue 64 64 W 5 8 3996 6350 0 Blue 0
12 Midnight Wed 63 63 W 5 8 3996 6350 0 Blue 0
1 AM Wed 63 63 W 5 8 3996 6350 0 Blue 0
2 AM Wed 62 62 WNW 3 5 3996 6350 0 Blue 0
3 AM Wed 61 61 WNW 3 5 3996 6350 0 Blue 0
4 AM Wed 60 60 WNW 3 5 3996 6350 0 Blue 0
5 AM Wed 60 60 NNW 4 5 3996 6350 0 Blue 0
6 AM Wed 59 59 NNW 4 5 3996 6350 0 Blue 0
7 AM Wed 59 59 NNW 4 5 3996 6350 0 Blue 0
8 AM Wed 60 61 NNE 4 5 3996 6350 0 Blue 0
9 AM Wed 61 63 NNE 4 5 3996 6350 0 Blue 0
10 AM Wed 63 67 NNE 4 5 3996 6350 0 Blue 0
11 AM Wed 65 71 E 5 9 3996 6350 0 Blue 0
12 Noon Wed 67 75 E 5 9 3996 6350 0 Blue 0
1 PM Wed 69 77 E 5 9 3996 6350 0 Blue 0
2 PM Wed 71 79 SSE 9 13 3996 6350 0 Blue 0
3 PM Wed 72 79 SSE 9 13 3996 6350 0 Blue 0
4 PM Wed 72 77 SSE 9 13 3996 6350 0 Blue 0
5 PM Wed 71 74 S 10 16 3996 6350 0 Blue 0
6 PM Wed 70 72 S 10 16 3996 6350 0 Blue 0
7 PM Wed 68 68 S 10 16 3996 6350 0 Blue 0
8 PM Wed 66 66 W 10 13 3996 6350 0 Blue 0
9 PM Wed 65 65 W 10 13 3996 6350 0 Blue 0
10 PM Wed 64 64 W 10 13 3996 6350 0 Blue 0
11 PM Wed 63 63 WNW 5 8 3996 6350 0 Blue 0
12 Midnight Thu 62 62 WNW 5 8 3996 6350 0 Blue 0
1 AM Thu 62 62 WNW 5 8 3996 6350 0 Blue 0
2 AM Thu 61 61 NW 5 6 3996 6350 0 Blue 0
3 AM Thu 61 61 NW 5 6 3996 6350 0 Blue 0
4 AM Thu 60 60 NW 5 6 3996 6350 0 Blue 0
5 AM Thu 60 60 NNW 5 6 3996 6350 0 Blue 0
6 AM Thu 60 60 NNW 5 6 3996 6350 0 Blue 0
7 AM Thu 60 60 NNW 5 6 3996 6350 0 Blue 0
8 AM Thu 61 62 N 4 5 3996 6350 0 Blue 0
9 AM Thu 63 65 N 4 5 3996 6350 0 Blue 0
10 AM Thu 65 69 N 4 5 3996 6350 0 Blue 0
11 AM Thu 67 73 E 5 8 3996 6350 0 Blue 0
12 Noon Thu 69 77 E 5 8 3996 6350 0 Blue 0
1 PM Thu 71 79 E 5 8 3996 6350 0 Blue 0
2 PM Thu 72 80 S 6 12 3996 6350 0 Blue 0
3 PM Thu 73 80 S 6 12 3996 6350 0 Blue 0
4 PM Thu 73 78 S 6 12 3996 6350 0 Blue 0
5 PM Thu 73 76 SW 10 13 3996 6350 0 Blue 0
6 PM Thu 71 73 SW 10 13 3996 6350 0 Blue 0
7 PM Thu 69 69 SW 10 13 3996 6350 0 Blue 0
8 PM Thu 67 67 W 10 14 3996 6350 0 Blue 0
9 PM Thu 66 66 W 10 14 3996 6350 0 Blue 0
10 PM Thu 65 65 W 10 14 3996 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 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]