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:

 260912/1200

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 Sat 60 60 W 8 9 4331 6350 0 Blue 0
1 AM Sat 59 59 W 6 9 4331 6350 0 Blue 0
2 AM Sat 59 59 W 6 9 4331 6350 0 Blue 0
3 AM Sat 58 58 W 6 8 4331 6350 0 Blue 0
4 AM Sat 58 58 W 6 8 4331 6350 0 Blue 0
5 AM Sat 58 58 W 6 6 4331 6350 0 Blue 0
6 AM Sat 57 57 W 5 6 4331 6350 0 Blue 0
7 AM Sat 57 57 W 4 5 4331 6350 0 Blue 0
8 AM Sat 56 56 W 4 5 4331 6350 0 Blue 0
9 AM Sat 58 59 WSW 4 6 4331 6350 0 Blue 0
10 AM Sat 59 61 WSW 5 9 4331 6350 0 Blue 0
11 AM Sat 59 62 SW 6 11 4331 6350 0 Blue 0
12 Noon Sat 60 65 SW 9 14 4331 6350 0 Blue 0
1 PM Sat 61 65 WSW 10 17 4331 6350 0 Blue 0
2 PM Sat 61 66 WSW 12 19 4331 6350 0 Blue 0
3 PM Sat 62 66 WSW 14 21 4331 6350 0 Blue 0
4 PM Sat 58 60 W 16 23 4331 6350 0 Blue 0
5 PM Sat 56 57 W 16 23 4331 6350 0 Blue 0
6 PM Sat 54 54 W 19 26 4331 6350 0 Blue 0
7 PM Sat 49 49 W 19 26 4331 6350 0 Blue 0
8 PM Sat 46 46 W 17 23 4331 6350 0 Blue 0
9 PM Sat 46 46 W 19 25 4331 6350 0 Blue 0
10 PM Sat 45 45 W 18 25 4331 6350 0 Blue 0
11 PM Sat 45 45 WNW 16 23 4331 6350 0 Blue 0
12 Midnight Sun 44 44 W 16 20 4331 6350 0 Blue 0
1 AM Sun 43 43 W 13 18 4331 6350 0 Blue 0
2 AM Sun 43 43 WNW 11 14 4331 6350 0 Blue 0
3 AM Sun 42 42 W 10 12 4331 6350 0 Blue 0
4 AM Sun 41 41 WNW 8 10 4331 6350 0 Blue 0
5 AM Sun 41 41 WNW 6 9 4331 6350 0 Blue 0
6 AM Sun 41 41 WNW 6 9 4331 6350 0 Blue 0
7 AM Sun 40 40 WNW 6 9 4331 6350 0 Blue 0
8 AM Sun 42 42 NNW 4 8 4331 6350 0 Blue 0
9 AM Sun 42 43 NNW 4 8 4331 6350 0 Blue 0
10 AM Sun 46 49 NNW 4 8 4331 6350 0 Blue 0
11 AM Sun 48 52 ENE 5 9 4331 6350 0 Blue 0
12 Noon Sun 51 56 ENE 5 9 4331 6350 0 Blue 0
1 PM Sun 52 58 ENE 5 9 4331 6350 0 Blue 0
2 PM Sun 53 58 E 4 9 4331 6350 0 Blue 0
3 PM Sun 55 59 E 4 9 4331 6350 0 Blue 0
4 PM Sun 53 56 E 4 9 4331 6350 0 Blue 0
5 PM Sun 53 54 E 3 6 4331 6350 0 Blue 0
6 PM Sun 52 52 E 3 6 4331 6350 0 Blue 0
7 PM Sun 49 49 E 3 6 4331 6350 0 Blue 0
8 PM Sun 47 47 WNW 2 4 4331 6350 0 Blue 0
9 PM Sun 47 47 WNW 2 4 4331 6350 0 Blue 0
10 PM Sun 48 48 WNW 2 4 4331 6350 0 Blue 0
11 PM Sun 49 49 WNW 5 9 4331 6350 0 Blue 0
12 Midnight Mon 49 49 WNW 5 9 4331 6350 0 Blue 0
1 AM Mon 49 49 WNW 5 9 4331 6350 0 Blue 0
2 AM Mon 49 49 WNW 10 13 4331 6350 0 Blue 0
3 AM Mon 49 49 WNW 10 13 4331 6350 0 Blue 0
4 AM Mon 48 48 WNW 10 13 4331 6350 0 Blue 0
5 AM Mon 48 48 WNW 9 11 4331 6350 0 Blue 0
6 AM Mon 48 48 WNW 9 11 4331 6350 0 Blue 0
7 AM Mon 48 48 WNW 9 11 4331 6350 0 Blue 0
8 AM Mon 49 49 W 8 11 4331 6350 0 Blue 0
9 AM Mon 52 53 W 8 11 4331 6350 0 Blue 0
10 AM Mon 54 56 W 8 11 4331 6350 0 Blue 0
11 AM Mon 57 61 W 5 9 4331 6350 0 Blue 0
12 Noon Mon 59 64 W 5 9 4331 6350 0 Blue 0
1 PM Mon 61 67 W 5 9 4331 6350 0 Blue 0
2 PM Mon 62 68 S 4 8 4331 6350 0 Blue 0
3 PM Mon 62 67 S 4 8 4331 6350 0 Blue 0
4 PM Mon 62 65 S 4 8 4331 6350 0 Blue 0
5 PM Mon 61 63 S 2 5 4331 6350 0 Blue 0
6 PM Mon 59 59 S 2 5 4331 6350 0 Blue 0
7 PM Mon 56 56 S 2 5 4331 6350 0 Blue 0
8 PM Mon 54 54 WSW 1 2 4331 6350 0 Blue 0
9 PM Mon 54 54 WSW 1 2 4331 6350 0 Blue 0
10 PM Mon 54 54 WSW 1 2 4331 6350 0 Blue 0
11 PM Mon 55 55 W 3 5 4331 6350 0 Blue 0
12 Midnight Tue 55 55 W 3 5 4331 6350 0 Blue 0
1 AM Tue 55 55 W 3 5 4331 6350 0 Blue 0
2 AM Tue 54 54 W 4 6 4331 6350 0 Blue 0
3 AM Tue 54 54 W 4 6 4331 6350 0 Blue 0
4 AM Tue 53 53 W 4 6 4331 6350 0 Blue 0
5 AM Tue 53 53 WNW 3 4 4331 6350 0 Blue 0
6 AM Tue 52 52 WNW 3 4 4331 6350 0 Blue 0
7 AM Tue 52 52 WNW 3 4 4331 6350 0 Blue 0
8 AM Tue 53 53 WNW 3 4 4331 6350 0 Blue 0
9 AM Tue 54 55 WNW 3 4 4331 6350 0 Blue 0
10 AM Tue 56 58 WNW 3 4 4331 6350 0 Blue 0
11 AM Tue 58 62 ESE 4 6 4331 6350 0 Blue 0
12 Noon Tue 60 65 ESE 4 6 4331 6350 0 Blue 0
1 PM Tue 62 68 ESE 4 6 4331 6350 0 Blue 0
2 PM Tue 63 69 SSE 5 9 4331 6350 0 Blue 0
3 PM Tue 63 68 SSE 5 9 4331 6350 0 Blue 0
4 PM Tue 63 66 SSE 5 9 4331 6350 0 Blue 0
5 PM Tue 61 62 S 4 8 4331 6350 0 Blue 0
6 PM Tue 58 58 S 4 8 4331 6350 0 Blue 0
7 PM Tue 56 56 S 4 8 4331 6350 0 Blue 0
8 PM Tue 54 54 WSW 1 2 4331 6350 0 Blue 0
9 PM Tue 54 54 WSW 1 2 4331 6350 0 Blue 0
10 PM Tue 55 55 WSW 1 2 4331 6350 0 Blue 0
11 PM Tue 56 56 W 2 5 4331 6350 0 Blue 0
12 Midnight Wed 55 55 W 2 5 4331 6350 0 Blue 0
1 AM Wed 54 54 W 2 5 4331 6350 0 Blue 0
2 AM Wed 53 53 W 3 5 4331 6350 0 Blue 0
3 AM Wed 53 53 W 3 5 4331 6350 0 Blue 0
4 AM Wed 54 54 W 3 5 4331 6350 0 Blue 0
5 AM Wed 54 54 WNW 3 5 4331 6350 0 Blue 0
6 AM Wed 53 53 WNW 3 5 4331 6350 0 Blue 0
7 AM Wed 53 53 WNW 3 5 4331 6350 0 Blue 0
8 AM Wed 53 53 WNW 3 6 4331 6350 0 Blue 0
9 AM Wed 55 56 WNW 3 6 4331 6350 0 Blue 0
10 AM Wed 57 59 WNW 3 6 4331 6350 0 Blue 0
11 AM Wed 59 63 ESE 5 9 4331 6350 0 Blue 0
12 Noon Wed 61 66 ESE 5 9 4331 6350 0 Blue 0
1 PM Wed 62 68 ESE 5 9 4331 6350 0 Blue 0
2 PM Wed 62 68 SE 4 8 4331 6350 0 Blue 0
3 PM Wed 62 67 SE 4 8 4331 6350 0 Blue 0
4 PM Wed 61 64 SE 4 8 4331 6350 0 Blue 0
5 PM Wed 60 62 SSE 3 5 4331 6350 0 Blue 0
6 PM Wed 58 58 SSE 3 5 4331 6350 0 Blue 0
7 PM Wed 56 56 SSE 3 5 4331 6350 0 Blue 0
8 PM Wed 54 54 W 1 2 4331 6350 0 Blue 0
9 PM Wed 54 54 W 1 2 4331 6350 0 Blue 0
10 PM Wed 55 55 W 1 2 4331 6350 0 Blue 0
11 PM Wed 56 56 W 2 4 4331 6350 0 Blue 0
12 Midnight Thu 55 55 W 2 4 4331 6350 0 Blue 0
1 AM Thu 54 54 W 2 4 4331 6350 0 Blue 0
2 AM Thu 53 53 W 2 5 4331 6350 0 Blue 0
3 AM Thu 53 53 W 2 5 4331 6350 0 Blue 0
4 AM Thu 54 54 W 2 5 4331 6350 0 Blue 0
5 AM Thu 54 54 NW 2 5 4331 6350 0 Blue 0
6 AM Thu 54 54 NW 2 5 4331 6350 0 Blue 0
7 AM Thu 54 54 NW 2 5 4331 6350 0 Blue 0
8 AM Thu 54 54 N 3 5 4331 6350 0 Blue 0
9 AM Thu 55 56 N 3 5 4331 6350 0 Blue 0
10 AM Thu 57 59 N 3 5 4331 6350 0 Blue 0
11 AM Thu 59 63 E 5 9 4331 6350 0 Blue 0
12 Noon Thu 60 65 E 5 9 4331 6350 0 Blue 0
1 PM Thu 61 67 E 5 9 4331 6350 0 Blue 0
2 PM Thu 62 67 SE 5 9 4331 6350 0 Blue 0
3 PM Thu 62 66 SE 5 9 4331 6350 0 Blue 0
4 PM Thu 62 65 SE 5 9 4331 6350 0 Blue 0
5 PM Thu 61 62 SSE 4 6 4331 6350 0 Blue 0
6 PM Thu 59 59 SSE 4 6 4331 6350 0 Blue 0
7 PM Thu 57 57 SSE 4 6 4331 6350 0 Blue 0
8 PM Thu 55 55 WSW 2 4 4331 6350 0 Blue 0
9 PM Thu 55 55 WSW 2 4 4331 6350 0 Blue 0
10 PM Thu 56 56 WSW 2 4 4331 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]