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

Station:

KOAK

Date/Time:

N/A

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)
4 AM Thu 36 36 SW 28 N/A N/A N/A N/A N/A
5 AM Thu 36 36 SW 28 N/A N/A N/A N/A N/A
6 AM Thu 36 36 SW 28 N/A N/A N/A N/A N/A
7 AM Thu 36 36 SW 28 N/A N/A N/A N/A N/A
8 AM Thu 36 36 SW 28 N/A N/A N/A N/A N/A
9 AM Thu 36 36 SW 28 N/A N/A N/A N/A N/A
10 AM Thu 36 36 SW 26 N/A N/A N/A N/A N/A
11 AM Thu 37 37 SW 26 N/A N/A N/A N/A N/A
12 Noon Thu 37 37 SW 26 N/A N/A N/A N/A N/A
1 PM Thu 37 37 W 25 N/A N/A N/A N/A N/A
2 PM Thu 37 37 W 25 N/A N/A N/A N/A N/A
3 PM Thu 37 37 W 25 N/A N/A N/A N/A N/A
4 PM Thu 36 36 W 22 N/A N/A N/A N/A N/A
5 PM Thu 35 35 W 22 N/A N/A N/A N/A N/A
6 PM Thu 35 35 W 22 N/A N/A N/A N/A N/A
7 PM Thu 34 34 W 18 N/A N/A N/A N/A N/A
8 PM Thu 33 33 W 18 N/A N/A N/A N/A N/A
9 PM Thu 33 33 W 18 N/A N/A N/A N/A N/A
10 PM Thu 33 33 W 14 N/A N/A N/A N/A N/A
11 PM Thu 34 34 W 14 N/A N/A N/A N/A N/A
12 Midnight Fri 34 34 W 14 N/A N/A N/A N/A N/A
1 AM Fri 35 35 W 8 N/A N/A N/A N/A N/A
2 AM Fri 35 35 W 8 N/A N/A N/A N/A N/A
3 AM Fri 35 35 W 8 N/A N/A N/A N/A N/A
4 AM Fri 35 35 SW 8 N/A N/A N/A N/A N/A
5 AM Fri 36 36 SW 8 N/A N/A N/A N/A N/A
6 AM Fri 36 36 SW 8 N/A N/A N/A N/A N/A
7 AM Fri 37 37 S 9 N/A N/A N/A N/A N/A
8 AM Fri 38 38 S 9 N/A N/A N/A N/A N/A
9 AM Fri 39 39 S 9 N/A N/A N/A N/A N/A
10 AM Fri 39 39 S 12 N/A N/A N/A N/A N/A
11 AM Fri 40 40 S 12 N/A N/A N/A N/A N/A
12 Noon Fri 40 40 S 12 N/A N/A N/A N/A N/A
1 PM Fri 40 40 S 14 N/A N/A N/A N/A N/A
2 PM Fri 40 40 S 14 N/A N/A N/A N/A N/A
3 PM Fri 39 39 S 14 N/A N/A N/A N/A N/A
4 PM Fri 39 39 SW 15 N/A N/A N/A N/A N/A
5 PM Fri 39 39 SW 15 N/A N/A N/A N/A N/A
6 PM Fri 39 39 SW 15 N/A N/A N/A N/A N/A
7 PM Fri 38 38 SW 15 N/A N/A N/A N/A N/A
8 PM Fri 38 38 SW 15 N/A N/A N/A N/A N/A
9 PM Fri 38 38 SW 15 N/A N/A N/A N/A N/A
10 PM Fri 38 38 SW 15 N/A N/A N/A N/A N/A
11 PM Fri 38 38 SW 15 N/A N/A N/A N/A N/A
12 Midnight Sat 39 39 SW 15 N/A N/A N/A N/A N/A
1 AM Sat 39 39 SW 15 N/A N/A N/A N/A N/A
2 AM Sat 39 39 SW 15 N/A N/A N/A N/A N/A
3 AM Sat 39 39 SW 15 N/A N/A N/A N/A N/A
4 AM Sat 39 39 W 13 N/A N/A N/A N/A N/A
5 AM Sat 39 39 W 13 N/A N/A N/A N/A N/A
6 AM Sat 39 39 W 13 N/A N/A N/A N/A N/A
7 AM Sat 40 40 W 13 N/A N/A N/A N/A N/A
8 AM Sat 41 41 W 13 N/A N/A N/A N/A N/A
9 AM Sat 41 41 W 13 N/A N/A N/A N/A N/A
10 AM Sat 42 42 W 14 N/A N/A N/A N/A N/A
11 AM Sat 43 43 W 14 N/A N/A N/A N/A N/A
12 Noon Sat 43 43 W 14 N/A N/A N/A N/A N/A
1 PM Sat 44 44 W 14 N/A N/A N/A N/A N/A
2 PM Sat 45 45 W 14 N/A N/A N/A N/A N/A
3 PM Sat 45 45 W 14 N/A N/A N/A N/A N/A
4 PM Sat 45 45 W 14 N/A N/A N/A N/A N/A
5 PM Sat 43 43 W 14 N/A N/A N/A N/A N/A
6 PM Sat 41 41 W 14 N/A N/A N/A N/A N/A
7 PM Sat 40 40 W 14 N/A N/A N/A N/A N/A
8 PM Sat 40 40 W 14 N/A N/A N/A N/A N/A
9 PM Sat 40 40 W 14 N/A N/A N/A N/A N/A
10 PM Sat 40 40 W 18 N/A N/A N/A N/A N/A
11 PM Sat 40 40 W 18 N/A N/A N/A N/A N/A
12 Midnight Sun 40 40 W 18 N/A N/A N/A N/A N/A
1 AM Sun 40 40 W 18 N/A N/A N/A N/A N/A
2 AM Sun 40 40 W 18 N/A N/A N/A N/A N/A
3 AM Sun 40 40 W 18 N/A N/A N/A N/A N/A
4 AM Sun 40 40 W 22 N/A N/A N/A N/A N/A
5 AM Sun 40 40 W 22 N/A N/A N/A N/A N/A
6 AM Sun 40 40 W 22 N/A N/A N/A N/A N/A
7 AM Sun 40 40 W 22 N/A N/A N/A N/A N/A
8 AM Sun 41 41 W 22 N/A N/A N/A N/A N/A
9 AM Sun 41 41 W 22 N/A N/A N/A N/A N/A
10 AM Sun 41 41 W 24 N/A N/A N/A N/A N/A
11 AM Sun 41 41 W 24 N/A N/A N/A N/A N/A
12 Noon Sun 41 41 W 24 N/A N/A N/A N/A N/A
1 PM Sun 41 41 W 24 N/A N/A N/A N/A N/A
2 PM Sun 40 40 W 24 N/A N/A N/A N/A N/A
3 PM Sun 39 39 W 24 N/A N/A N/A N/A N/A
4 PM Sun 38 38 W 25 N/A N/A N/A N/A N/A
5 PM Sun 37 37 W 25 N/A N/A N/A N/A N/A
6 PM Sun 36 36 W 25 N/A N/A N/A N/A N/A
7 PM Sun 34 34 W 25 N/A N/A N/A N/A N/A
8 PM Sun 33 33 W 25 N/A N/A N/A N/A N/A
9 PM Sun 32 32 W 25 N/A N/A N/A N/A N/A
10 PM Sun 32 32 NW 18 N/A N/A N/A N/A N/A
11 PM Sun 32 32 NW 18 N/A N/A N/A N/A N/A
12 Midnight Mon 33 33 NW 18 N/A N/A N/A N/A N/A
1 AM Mon 33 33 NW 18 N/A N/A N/A N/A N/A
2 AM Mon 34 34 NW 18 N/A N/A N/A N/A N/A
3 AM Mon 34 34 NW 18 N/A N/A N/A N/A N/A
4 AM Mon 33 33 N 12 N/A N/A N/A N/A N/A
5 AM Mon 33 33 N 12 N/A N/A N/A N/A N/A
6 AM Mon 33 33 N 12 N/A N/A N/A N/A N/A
7 AM Mon 33 33 N 12 N/A N/A N/A N/A N/A
8 AM Mon 34 34 N 12 N/A N/A N/A N/A N/A
9 AM Mon 36 36 N 12 N/A N/A N/A N/A N/A
10 AM Mon 37 37 N 13 N/A N/A N/A N/A N/A
11 AM Mon 39 40 N 13 N/A N/A N/A N/A N/A
12 Noon Mon 40 41 N 13 N/A N/A N/A N/A N/A
1 PM Mon 41 42 N 13 N/A N/A N/A N/A N/A
2 PM Mon 41 42 N 13 N/A N/A N/A N/A N/A
3 PM Mon 41 41 N 13 N/A N/A N/A N/A N/A
4 PM Mon 40 40 N 13 N/A N/A N/A N/A N/A
5 PM Mon 38 38 N 13 N/A N/A N/A N/A N/A
6 PM Mon 37 37 N 13 N/A N/A N/A N/A N/A
7 PM Mon 35 35 N 13 N/A N/A N/A N/A N/A
8 PM Mon 35 35 N 13 N/A N/A N/A N/A N/A
9 PM Mon 35 35 N 13 N/A N/A N/A N/A N/A
10 PM Mon 34 34 N 15 N/A N/A N/A N/A N/A
11 PM Mon 34 34 N 15 N/A N/A N/A N/A N/A
12 Midnight Tue 34 34 N 15 N/A N/A N/A N/A N/A
1 AM Tue 34 34 N 15 N/A N/A N/A N/A N/A
2 AM Tue 34 34 N 15 N/A N/A N/A N/A N/A
3 AM Tue 34 34 N 15 N/A N/A N/A N/A N/A
4 AM Tue 34 34 N 15 N/A N/A N/A N/A N/A
5 AM Tue 33 33 N 15 N/A N/A N/A N/A N/A
6 AM Tue 33 33 N 15 N/A N/A N/A N/A N/A
7 AM Tue 33 33 N 15 N/A N/A N/A N/A N/A
8 AM Tue 35 35 N 15 N/A N/A N/A N/A N/A
9 AM Tue 37 37 N 15 N/A N/A N/A N/A N/A
10 AM Tue 40 40 N 16 N/A N/A N/A N/A N/A
11 AM Tue 42 43 N 16 N/A N/A N/A N/A N/A
12 Noon Tue 43 44 N 16 N/A N/A N/A N/A N/A
1 PM Tue 44 45 N 16 N/A N/A N/A N/A N/A
2 PM Tue 45 46 N 16 N/A N/A N/A N/A N/A
3 PM Tue 46 46 N 16 N/A N/A N/A N/A N/A
4 PM Tue 45 45 N 14 N/A N/A N/A N/A N/A
5 PM Tue 43 43 N 14 N/A N/A N/A N/A N/A
6 PM Tue 40 40 N 14 N/A N/A N/A N/A N/A
7 PM Tue 37 37 N 14 N/A N/A N/A N/A N/A
8 PM Tue 36 36 N 14 N/A N/A N/A N/A N/A
9 PM Tue 36 36 N 14 N/A N/A N/A N/A N/A
10 PM Tue 37 37 N 9 N/A N/A N/A N/A N/A
11 PM Tue 37 37 N 9 N/A N/A N/A N/A N/A
12 Midnight Wed 37 37 N 9 N/A N/A N/A N/A N/A
1 AM Wed 37 37 N 9 N/A N/A N/A N/A N/A
2 AM Wed 36 36 N 9 N/A N/A N/A N/A N/A
3 AM Wed 36 36 N 9 N/A N/A N/A N/A N/A

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