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

Station:

KOAK

Date/Time UTC:

241105/1200

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 Tue 44 44 WNW 9 11 4181 6350 0 Blue 0
1 AM Tue 43 43 NW 5 6 4181 6350 0 Blue 0
2 AM Tue 44 44 NW 6 8 4181 6350 0 Blue 0
3 AM Tue 43 43 NW 5 6 4181 6350 0 Blue 0
4 AM Tue 44 44 NW 4 4 4181 6350 0 Blue 0
5 AM Tue 43 43 NW 4 4 4181 6350 0 Blue 0
6 AM Tue 43 43 NW 4 4 4181 6350 0 Blue 0
7 AM Tue 42 42 NNW 5 9 4181 6350 0 Blue 0
8 AM Tue 42 42 NNW 5 9 4181 6350 0 Blue 0
9 AM Tue 42 42 NNW 5 9 4181 6350 0 Blue 0
10 AM Tue 43 44 NNE 20 23 4181 6350 0 Blue 0
11 AM Tue 45 46 NNE 20 23 4181 6350 0 Blue 0
12 Noon Tue 46 47 NNE 20 23 4181 6350 0 Blue 0
1 PM Tue 47 48 N 9 19 4181 6350 0 Blue 0
2 PM Tue 48 49 N 9 19 4181 6350 0 Blue 0
3 PM Tue 46 46 N 9 19 4181 6350 0 Blue 0
4 PM Tue 45 45 N 10 14 4181 6350 0 Blue 0
5 PM Tue 42 42 N 10 17 4181 6350 0 Blue 0
6 PM Tue 40 40 N 13 19 4181 6350 0 Blue 0
7 PM Tue 40 40 N 13 20 4181 6350 0 Blue 0
8 PM Tue 41 41 N 17 25 4181 6350 0 Blue 0
9 PM Tue 41 41 N 18 27 4181 6350 0 Blue 0
10 PM Tue 40 40 N 20 27 4181 6350 0 Blue 0
11 PM Tue 39 39 N 21 29 4181 6350 0 Blue 0
12 Midnight Wed 38 38 N 21 29 4181 6350 0 Blue 0
1 AM Wed 38 38 N 21 29 4181 6350 0 Blue 0
2 AM Wed 37 37 N 21 29 4181 6350 0 Blue 0
3 AM Wed 37 37 N 21 29 4181 6350 0 Blue 0
4 AM Wed 37 37 N 21 29 4181 6350 0 Blue 0
5 AM Wed 36 36 N 21 29 4181 6350 0 Blue 0
6 AM Wed 35 35 N 21 29 4181 6350 0 Blue 0
7 AM Wed 35 35 NNE 20 28 4181 6350 0 Blue 0
8 AM Wed 33 33 NNE 20 28 4181 6350 0 Blue 0
9 AM Wed 34 35 NNE 20 28 4181 6350 0 Blue 0
10 AM Wed 34 36 NNE 18 27 4181 6350 0 Blue 0
11 AM Wed 35 37 NNE 18 27 4181 6350 0 Blue 0
12 Noon Wed 37 40 NNE 18 27 4181 6350 0 Blue 0
1 PM Wed 39 41 NNE 16 24 4181 6350 0 Blue 0
2 PM Wed 39 41 NNE 16 24 4181 6350 0 Blue 0
3 PM Wed 39 40 NNE 16 24 4181 6350 0 Blue 0
4 PM Wed 39 39 NNE 13 19 4181 6350 0 Blue 0
5 PM Wed 37 37 NNE 13 19 4181 6350 0 Blue 0
6 PM Wed 36 36 NNE 13 19 4181 6350 0 Blue 0
7 PM Wed 35 35 N 13 19 4181 6350 0 Blue 0
8 PM Wed 36 36 N 13 19 4181 6350 0 Blue 0
9 PM Wed 38 38 N 13 19 4181 6350 0 Blue 0
10 PM Wed 39 39 N 12 17 4181 6350 0 Blue 0
11 PM Wed 39 39 N 12 17 4181 6350 0 Blue 0
12 Midnight Thu 39 39 N 12 17 4181 6350 0 Blue 0
1 AM Thu 38 38 NNW 10 14 4181 6350 0 Blue 0
2 AM Thu 38 38 NNW 10 14 4181 6350 0 Blue 0
3 AM Thu 38 38 NNW 10 14 4181 6350 0 Blue 0
4 AM Thu 38 38 NW 8 11 4181 6350 0 Blue 0
5 AM Thu 37 37 NW 8 11 4181 6350 0 Blue 0
6 AM Thu 37 37 NW 8 11 4181 6350 0 Blue 0
7 AM Thu 37 37 NW 6 9 4181 6350 0 Blue 0
8 AM Thu 37 37 NW 6 9 4181 6350 0 Blue 0
9 AM Thu 38 39 NW 6 9 4181 6350 0 Blue 0
10 AM Thu 39 41 NNE 5 8 4181 6350 0 Blue 0
11 AM Thu 42 44 NNE 5 8 4181 6350 0 Blue 0
12 Noon Thu 44 47 NNE 5 8 4181 6350 0 Blue 0
1 PM Thu 46 48 E 3 6 4181 6350 0 Blue 0
2 PM Thu 46 48 E 3 6 4181 6350 0 Blue 0
3 PM Thu 46 47 E 3 6 4181 6350 0 Blue 0
4 PM Thu 44 44 SE 2 4 4181 6350 0 Blue 0
5 PM Thu 42 42 SE 2 4 4181 6350 0 Blue 0
6 PM Thu 39 39 SE 2 4 4181 6350 0 Blue 0
7 PM Thu 38 38 W 3 5 4181 6350 0 Blue 0
8 PM Thu 38 38 W 3 5 4181 6350 0 Blue 0
9 PM Thu 39 39 W 3 5 4181 6350 0 Blue 0
10 PM Thu 40 40 W 3 5 4181 6350 0 Blue 0
11 PM Thu 41 41 W 3 5 4181 6350 0 Blue 0
12 Midnight Fri 41 41 W 3 5 4181 6350 0 Blue 0
1 AM Fri 40 40 WNW 3 4 4181 6350 0 Blue 0
2 AM Fri 40 40 WNW 3 4 4181 6350 0 Blue 0
3 AM Fri 40 40 WNW 3 4 4181 6350 0 Blue 0
4 AM Fri 40 40 WNW 3 4 4181 6350 0 Blue 0
5 AM Fri 39 39 WNW 3 4 4181 6350 0 Blue 0
6 AM Fri 39 39 WNW 3 4 4181 6350 0 Blue 0
7 AM Fri 39 39 WNW 3 4 4181 6350 0 Blue 0
8 AM Fri 39 39 WNW 3 4 4181 6350 0 Blue 0
9 AM Fri 40 41 WNW 3 4 4181 6350 0 Blue 0
10 AM Fri 41 43 ESE 2 4 4181 6350 0 Blue 0
11 AM Fri 43 45 ESE 2 4 4181 6350 0 Blue 0
12 Noon Fri 45 48 ESE 2 4 4181 6350 0 Blue 0
1 PM Fri 46 48 SE 2 5 4181 6350 0 Blue 0
2 PM Fri 46 47 SE 2 5 4181 6350 0 Blue 0
3 PM Fri 45 46 SE 2 5 4181 6350 0 Blue 0
4 PM Fri 43 43 SSE 2 4 4181 6350 0 Blue 0
5 PM Fri 42 42 SSE 2 4 4181 6350 0 Blue 0
6 PM Fri 40 40 SSE 2 4 4181 6350 0 Blue 0
7 PM Fri 39 39 W 2 4 4181 6350 0 Blue 0
8 PM Fri 40 40 W 2 4 4181 6350 0 Blue 0
9 PM Fri 41 41 W 2 4 4181 6350 0 Blue 0
10 PM Fri 42 42 W 3 4 4181 6350 0 Blue 0
11 PM Fri 42 42 W 3 4 4181 6350 0 Blue 0
12 Midnight Sat 42 42 W 3 4 4181 6350 0 Blue 0
1 AM Sat 42 42 W 3 4 4181 6350 0 Blue 0
2 AM Sat 42 42 W 3 4 4181 6350 0 Blue 0
3 AM Sat 41 41 W 3 4 4181 6350 0 Blue 0
4 AM Sat 41 41 WSW 3 4 4181 6350 0 Blue 0
5 AM Sat 40 40 WSW 3 4 4181 6350 0 Blue 0
6 AM Sat 40 40 WSW 3 4 4181 6350 0 Blue 0
7 AM Sat 40 40 SW 3 4 4181 6350 0 Blue 0
8 AM Sat 40 40 SW 3 4 4181 6350 0 Blue 0
9 AM Sat 40 40 SW 3 4 4181 6350 0 Blue 0
10 AM Sat 40 41 S 3 6 4181 6350 0 Blue 0
11 AM Sat 42 43 S 3 6 4181 6350 0 Blue 0
12 Noon Sat 43 44 S 3 6 4181 6350 0 Blue 0
1 PM Sat 44 45 S 3 8 4181 6350 0 Blue 0
2 PM Sat 43 44 S 3 8 4181 6350 0 Blue 0
3 PM Sat 41 41 S 3 8 4181 6350 0 Blue 0
4 PM Sat 40 40 S 2 6 4181 6350 0 Blue 0
5 PM Sat 39 39 S 2 6 4181 6350 0 Blue 0
6 PM Sat 39 39 S 2 6 4181 6350 0 Blue 0
7 PM Sat 39 39 W 4 6 4181 6350 0 Blue 0
8 PM Sat 40 40 W 4 6 4181 6350 0 Blue 0
9 PM Sat 41 41 W 4 6 4181 6350 0 Blue 0
10 PM Sat 41 41 NW 5 8 4181 6350 0 Blue 0
11 PM Sat 42 42 NW 5 8 4181 6350 0 Blue 0
12 Midnight Sun 41 41 NW 5 8 4181 6350 0 Blue 0
1 AM Sun 41 41 NNW 5 8 4181 6350 0 Blue 0
2 AM Sun 41 41 NNW 5 8 4181 6350 0 Blue 0
3 AM Sun 41 41 NNW 5 8 4181 6350 0 Blue 0
4 AM Sun 41 41 NW 5 6 4181 6350 0 Blue 0
5 AM Sun 42 42 NW 5 6 4181 6350 0 Blue 0
6 AM Sun 42 42 NW 5 6 4181 6350 0 Blue 0
7 AM Sun 42 42 NW 4 5 4181 6350 0 Blue 0
8 AM Sun 41 41 NW 4 5 4181 6350 0 Blue 0
9 AM Sun 41 41 NW 4 5 4181 6350 0 Blue 0
10 AM Sun 41 42 NW 4 6 4181 6350 0 Blue 0
11 AM Sun 42 43 NW 4 6 4181 6350 0 Blue 0
12 Noon Sun 43 44 NW 4 6 4181 6350 0 Blue 0
1 PM Sun 44 45 W 3 8 4181 6350 0 Blue 0
2 PM Sun 43 43 W 3 8 4181 6350 0 Blue 0
3 PM Sun 43 43 W 3 8 4181 6350 0 Blue 0
4 PM Sun 42 42 WSW 4 8 4181 6350 0 Blue 0
5 PM Sun 41 41 WSW 4 8 4181 6350 0 Blue 0
6 PM Sun 41 41 WSW 4 8 4181 6350 0 Blue 0
7 PM Sun 41 41 W 5 10 4181 6350 0 Blue 0
8 PM Sun 41 41 W 5 10 4181 6350 0 Blue 0
9 PM Sun 43 43 W 5 10 4181 6350 0 Blue 0
10 PM Sun 43 43 W 9 14 4181 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]