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

Station:

KOAK

Date/Time:

17 JAN 2018

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 Wed 42 42 SW 5 4337 6350 0 Blue 0
5 AM Wed 42 42 SW 5 4337 6350 0 Blue 0
6 AM Wed 43 43 SW 5 4337 6350 0 Blue 0
7 AM Wed 44 44 S 6 4337 6350 0 Blue 0
8 AM Wed 45 45 S 6 4337 6350 0 Blue 0
9 AM Wed 47 47 S 6 4337 6350 0 Blue 0
10 AM Wed 49 49 S 6 4337 6350 0 Blue 0
11 AM Wed 51 51 S 6 4337 6350 0 Blue 0
12 Noon Wed 52 53 S 6 4337 6350 0 Blue 0
1 PM Wed 52 53 SW 8 4337 6350 0 Blue 0
2 PM Wed 52 52 SW 8 4337 6350 0 Blue 0
3 PM Wed 51 51 SW 8 4337 6350 0 Blue 0
4 PM Wed 50 50 SW 8 4337 6350 0 Blue 0
5 PM Wed 48 48 SW 8 4337 6350 0 Blue 0
6 PM Wed 47 47 SW 8 4337 6350 0 Blue 0
7 PM Wed 46 46 SW 8 4337 6350 0 Blue 0
8 PM Wed 45 45 SW 8 4337 6350 0 Blue 0
9 PM Wed 45 45 SW 8 4337 6350 0 Blue 0
10 PM Wed 44 44 SW 13 4337 6350 0 Blue 0
11 PM Wed 44 44 SW 13 4337 6350 0 Blue 0
12 Midnight Thu 44 44 SW 13 4337 6350 0 Blue 0
1 AM Thu 44 44 SW 14 4337 6350 0 Blue 0
2 AM Thu 44 44 SW 14 4337 6350 0 Blue 0
3 AM Thu 44 44 SW 14 4337 6350 0 Blue 0
4 AM Thu 44 44 SW 17 4337 6350 0 Blue 0
5 AM Thu 44 44 SW 17 4337 6350 0 Blue 0
6 AM Thu 44 44 SW 17 4337 6350 0 Blue 0
7 AM Thu 46 46 SW 17 4337 6350 0 Blue 0
8 AM Thu 43 43 SW 17 4337 6350 0 Blue 0
9 AM Thu 44 44 SW 17 4337 6350 0 Blue 0
10 AM Thu 44 44 SW 16 4337 6350 0 Blue 0
11 AM Thu 43 43 SW 16 4337 6350 0 Blue 0
12 Noon Thu 43 43 SW 16 4337 6350 0 Blue 0
1 PM Thu 43 43 SW 18 4337 6350 0 Blue 0
2 PM Thu 42 42 SW 18 4337 6350 0 Blue 0
3 PM Thu 42 42 SW 18 4337 6350 0 Blue 0
4 PM Thu 41 41 W 18 4337 6350 0 Blue 0
5 PM Thu 40 40 W 18 4337 6350 0 Blue 0
6 PM Thu 39 39 W 18 4337 6350 0 Blue 0
7 PM Thu 39 39 W 18 4337 6350 0 Blue 0
8 PM Thu 38 38 W 18 4337 6350 0 Blue 0
9 PM Thu 37 37 W 18 4337 6350 0 Blue 0
10 PM Thu 36 36 SW 15 4337 6350 0 Blue 0
11 PM Thu 36 36 SW 15 4337 6350 0 Blue 0
12 Midnight Fri 36 36 SW 15 4337 6350 0 Blue 0
1 AM Fri 36 36 SW 15 4337 6350 0 Blue 0
2 AM Fri 35 35 SW 15 4337 6350 0 Blue 0
3 AM Fri 35 35 SW 15 4337 6350 0 Blue 0
4 AM Fri 35 35 W 10 4337 6350 0 Blue 0
5 AM Fri 34 34 W 10 4337 6350 0 Blue 0
6 AM Fri 34 34 W 10 4337 6350 0 Blue 0
7 AM Fri 34 34 W 10 4337 6350 0 Blue 0
8 AM Fri 34 34 W 10 4337 6350 0 Blue 0
9 AM Fri 35 35 W 10 4337 6350 0 Blue 0
10 AM Fri 36 36 W 7 4337 6350 0 Blue 0
11 AM Fri 36 36 W 7 4337 6350 0 Blue 0
12 Noon Fri 37 37 W 7 4337 6350 0 Blue 0
1 PM Fri 37 37 W 7 4337 6350 0 Blue 0
2 PM Fri 37 37 W 7 4337 6350 0 Blue 0
3 PM Fri 37 37 W 7 4337 6350 0 Blue 0
4 PM Fri 36 36 W 7 4337 6350 0 Blue 0
5 PM Fri 34 34 W 7 4337 6350 0 Blue 0
6 PM Fri 32 32 W 7 4337 6350 0 Blue 0
7 PM Fri 31 31 W 7 4337 6350 0 Blue 0
8 PM Fri 30 30 W 7 4337 6350 0 Blue 0
9 PM Fri 30 30 W 7 4337 6350 0 Blue 0
10 PM Fri 30 30 NW 8 4337 6350 0 Blue 0
11 PM Fri 30 30 NW 8 4337 6350 0 Blue 0
12 Midnight Sat 30 30 NW 8 4337 6350 0 Blue 0
1 AM Sat 30 30 NW 8 4337 6350 0 Blue 0
2 AM Sat 30 30 NW 8 4337 6350 0 Blue 0
3 AM Sat 30 30 NW 8 4337 6350 0 Blue 0
4 AM Sat 30 30 NW 8 4337 6350 0 Blue 0
5 AM Sat 30 30 NW 8 4337 6350 0 Blue 0
6 AM Sat 30 30 NW 8 4337 6350 0 Blue 0
7 AM Sat 30 30 NW 8 4337 6350 0 Blue 0
8 AM Sat 32 32 NW 8 4337 6350 0 Blue 0
9 AM Sat 34 34 NW 8 4337 6350 0 Blue 0
10 AM Sat 36 36 NW 8 4337 6350 0 Blue 0
11 AM Sat 38 38 NW 8 4337 6350 0 Blue 0
12 Noon Sat 40 40 NW 8 4337 6350 0 Blue 0
1 PM Sat 41 41 NW 8 4337 6350 0 Blue 0
2 PM Sat 41 41 NW 8 4337 6350 0 Blue 0
3 PM Sat 39 39 NW 8 4337 6350 0 Blue 0
4 PM Sat 38 38 NW 6 4337 6350 0 Blue 0
5 PM Sat 36 36 NW 6 4337 6350 0 Blue 0
6 PM Sat 34 34 NW 6 4337 6350 0 Blue 0
7 PM Sat 33 33 NW 6 4337 6350 0 Blue 0
8 PM Sat 33 33 NW 6 4337 6350 0 Blue 0
9 PM Sat 33 33 NW 6 4337 6350 0 Blue 0
10 PM Sat 33 33 W 10 4337 6350 0 Blue 0
11 PM Sat 33 33 W 10 4337 6350 0 Blue 0
12 Midnight Sun 33 33 W 10 4337 6350 0 Blue 0
1 AM Sun 33 33 W 10 4337 6350 0 Blue 0
2 AM Sun 34 34 W 10 4337 6350 0 Blue 0
3 AM Sun 34 34 W 10 4337 6350 0 Blue 0
4 AM Sun 34 34 SW 8 4337 6350 0 Blue 0
5 AM Sun 34 34 SW 8 4337 6350 0 Blue 0
6 AM Sun 35 35 SW 8 4337 6350 0 Blue 0
7 AM Sun 35 35 SW 8 4337 6350 0 Blue 0
8 AM Sun 36 36 SW 8 4337 6350 0 Blue 0
9 AM Sun 37 37 SW 8 4337 6350 0 Blue 0
10 AM Sun 38 38 S 14 4337 6350 0 Blue 0
11 AM Sun 39 39 S 14 4337 6350 0 Blue 0
12 Noon Sun 40 40 S 14 4337 6350 0 Blue 0
1 PM Sun 40 40 S 14 4337 6350 0 Blue 0
2 PM Sun 40 40 S 14 4337 6350 0 Blue 0
3 PM Sun 39 39 S 14 4337 6350 0 Blue 0
4 PM Sun 39 39 S 15 4337 6350 0 Blue 0
5 PM Sun 38 38 S 15 4337 6350 0 Blue 0
6 PM Sun 38 38 S 15 4337 6350 0 Blue 0
7 PM Sun 37 37 S 15 4337 6350 0 Blue 0
8 PM Sun 37 37 S 15 4337 6350 0 Blue 0
9 PM Sun 37 37 S 15 4337 6350 0 Blue 0
10 PM Sun 36 36 S 12 4337 6350 0 Blue 0
11 PM Sun 36 36 S 12 4337 6350 0 Blue 0
12 Midnight Mon 36 36 S 12 4337 6350 0 Blue 0
1 AM Mon 36 36 S 12 4337 6350 0 Blue 0
2 AM Mon 36 36 S 12 4337 6350 0 Blue 0
3 AM Mon 36 36 S 12 4337 6350 0 Blue 0
4 AM Mon 36 36 SW 6 4337 6350 0 Blue 0
5 AM Mon 36 36 SW 6 4337 6350 0 Blue 0
6 AM Mon 36 36 SW 6 4337 6350 0 Blue 0
7 AM Mon 36 36 SW 6 4337 6350 0 Blue 0
8 AM Mon 36 36 SW 6 4337 6350 0 Blue 0
9 AM Mon 37 37 SW 6 4337 6350 0 Blue 0
10 AM Mon 38 38 N 6 4337 6350 0 Blue 0
11 AM Mon 39 39 N 6 4337 6350 0 Blue 0
12 Noon Mon 40 40 N 6 4337 6350 0 Blue 0
1 PM Mon 41 41 N 6 4337 6350 0 Blue 0
2 PM Mon 41 41 N 6 4337 6350 0 Blue 0
3 PM Mon 40 40 N 6 4337 6350 0 Blue 0
4 PM Mon 39 39 N 7 4337 6350 0 Blue 0
5 PM Mon 38 38 N 7 4337 6350 0 Blue 0
6 PM Mon 36 36 N 7 4337 6350 0 Blue 0
7 PM Mon 35 35 N 7 4337 6350 0 Blue 0
8 PM Mon 35 35 N 7 4337 6350 0 Blue 0
9 PM Mon 35 35 N 7 4337 6350 0 Blue 0
10 PM Mon 35 35 N 7 4337 6350 0 Blue 0
11 PM Mon 36 36 N 7 4337 6350 0 Blue 0
12 Midnight Tue 36 36 N 7 4337 6350 0 Blue 0
1 AM Tue 35 35 N 7 4337 6350 0 Blue 0
2 AM Tue 35 35 N 7 4337 6350 0 Blue 0
3 AM Tue 35 35 N 7 4337 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 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