Detailed Predictions for: Big Sur
Launch Altitude (f): 3200
LZ Altitude (f): 60
Sounding

Station:

KOAK

Date/Time:

25 AUG 2019

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)
5 AM Sun 64 54 SE 5 2789 3200 0 Blue 0
6 AM Sun 68 58 SE 5 2789 3200 0 Blue 0
7 AM Sun 64 54 SE 5 2789 3200 0 Blue 0
8 AM Sun 69 59 SE 3 2789 3200 0 Blue 0
9 AM Sun 71 62 SE 3 2789 3200 0 Blue 0
10 AM Sun 72 64 SE 3 2789 3200 0 Blue 0
11 AM Sun 74 68 S 3 2789 3200 0 Blue 0
12 Noon Sun 75 71 S 3 2789 3200 0 Blue 0
1 PM Sun 75 71 S 3 2789 3200 0 Blue 0
2 PM Sun 76 72 S 3 2789 3200 0 Blue 0
3 PM Sun 76 71 S 3 2789 3200 0 Blue 0
4 PM Sun 75 69 S 3 2789 3200 0 Blue 0
5 PM Sun 75 67 SW 2 2789 3200 0 Blue 0
6 PM Sun 75 66 SW 2 2789 3200 0 Blue 0
7 PM Sun 73 63 SW 2 2789 3200 0 Blue 0
8 PM Sun 71 61 SW 0 2789 3200 0 Blue 0
9 PM Sun 70 60 SW 0 2789 3200 0 Blue 0
10 PM Sun 69 59 SW 0 2789 3200 0 Blue 0
11 PM Sun 69 59 NW 2 2789 3200 0 Blue 0
12 Midnight Mon 71 61 NW 2 2789 3200 0 Blue 0
1 AM Mon 70 60 NW 2 2789 3200 0 Blue 0
2 AM Mon 69 59 N 2 2789 3200 0 Blue 0
3 AM Mon 69 59 N 2 2789 3200 0 Blue 0
4 AM Mon 68 58 N 2 2789 3200 0 Blue 0
5 AM Mon 68 58 N 2 2789 3200 0 Blue 0
6 AM Mon 68 58 N 2 2789 3200 0 Blue 0
7 AM Mon 69 59 N 2 2789 3200 0 Blue 0
8 AM Mon 72 62 N 1 2789 3200 0 Blue 0
9 AM Mon 74 65 N 1 2789 3200 0 Blue 0
10 AM Mon 76 68 N 1 2789 3200 0 Blue 0
11 AM Mon 76 68 SW 2 2789 3200 0 Blue 0
12 Noon Mon 76 68 SW 2 2789 3200 0 Blue 0
1 PM Mon 77 69 SW 2 2789 3200 0 Blue 0
2 PM Mon 77 69 W 3 2789 3200 0 Blue 0
3 PM Mon 77 69 W 3 2789 3200 0 Blue 0
4 PM Mon 77 68 W 3 2789 3200 0 Blue 0
5 PM Mon 76 67 W 3 2789 3200 0 Blue 0
6 PM Mon 75 65 W 3 2789 3200 0 Blue 0
7 PM Mon 74 64 W 3 2789 3200 0 Blue 0
8 PM Mon 72 62 NW 5 2789 3200 0 Blue 0
9 PM Mon 71 61 NW 5 2789 3200 0 Blue 0
10 PM Mon 70 60 NW 5 2789 3200 0 Blue 0
11 PM Mon 70 60 NW 6 2789 3200 0 Blue 0
12 Midnight Tue 70 60 NW 6 2789 3200 0 Blue 0
1 AM Tue 70 60 NW 6 2789 3200 0 Blue 0
2 AM Tue 70 60 N 5 2789 3200 0 Blue 0
3 AM Tue 69 59 N 5 2789 3200 0 Blue 0
4 AM Tue 68 58 N 5 2789 3200 0 Blue 0
5 AM Tue 67 57 N 5 2789 3200 0 Blue 0
6 AM Tue 68 58 N 5 2789 3200 0 Blue 0
7 AM Tue 70 60 N 5 2789 3200 0 Blue 0
8 AM Tue 72 62 N 1 2789 3200 0 Blue 0
9 AM Tue 74 65 N 1 2789 3200 0 Blue 0
10 AM Tue 74 67 N 1 2789 3200 0 Blue 0
11 AM Tue 75 69 S 2 2789 3200 0 Blue 0
12 Noon Tue 76 72 S 2 2789 3200 0 Blue 0
1 PM Tue 76 72 S 2 2789 3200 0 Blue 0
2 PM Tue 76 72 W 3 2789 3200 0 Blue 0
3 PM Tue 76 71 W 3 2789 3200 0 Blue 0
4 PM Tue 76 69 W 3 2789 3200 0 Blue 0
5 PM Tue 75 67 W 3 2789 3200 0 Blue 0
6 PM Tue 74 65 W 3 2789 3200 0 Blue 0
7 PM Tue 73 63 W 3 2789 3200 0 Blue 0
8 PM Tue 73 63 N 2 2789 3200 0 Blue 0
9 PM Tue 72 62 N 2 2789 3200 0 Blue 0
10 PM Tue 71 61 N 2 2789 3200 0 Blue 0
11 PM Tue 71 61 N 2 2789 3200 0 Blue 0
12 Midnight Wed 70 60 N 2 2789 3200 0 Blue 0
1 AM Wed 70 60 N 2 2789 3200 0 Blue 0
2 AM Wed 69 59 N 2 2789 3200 0 Blue 0
3 AM Wed 67 57 N 2 2789 3200 0 Blue 0
4 AM Wed 66 56 N 2 2789 3200 0 Blue 0
5 AM Wed 66 56 NE 2 2789 3200 0 Blue 0
6 AM Wed 67 57 NE 2 2789 3200 0 Blue 0
7 AM Wed 69 59 NE 2 2789 3200 0 Blue 0
8 AM Wed 71 61 W 7 2789 3200 0 Blue 0
9 AM Wed 72 63 W 7 2789 3200 0 Blue 0
10 AM Wed 73 66 W 7 2789 3200 0 Blue 0
11 AM Wed 73 68 W 7 2789 3200 0 Blue 0
12 Noon Wed 73 70 W 7 2789 3200 0 Blue 0
1 PM Wed 73 71 W 7 2789 3200 0 Blue 0
2 PM Wed 73 70 W 8 2789 3200 0 Blue 0
3 PM Wed 73 69 W 8 2789 3200 0 Blue 0
4 PM Wed 73 67 W 8 2789 3200 0 Blue 0
5 PM Wed 73 65 W 8 2789 3200 0 Blue 0
6 PM Wed 72 63 W 8 2789 3200 0 Blue 0
7 PM Wed 71 61 W 8 2789 3200 0 Blue 0
8 PM Wed 71 61 W 6 2789 3200 0 Blue 0
9 PM Wed 70 60 W 6 2789 3200 0 Blue 0
10 PM Wed 69 59 W 6 2789 3200 0 Blue 0
11 PM Wed 69 59 NW 6 2789 3200 0 Blue 0
12 Midnight Thu 68 58 NW 6 2789 3200 0 Blue 0
1 AM Thu 68 58 NW 6 2789 3200 0 Blue 0
2 AM Thu 67 57 NW 6 2789 3200 0 Blue 0
3 AM Thu 66 56 NW 6 2789 3200 0 Blue 0
4 AM Thu 66 56 NW 6 2789 3200 0 Blue 0
5 AM Thu 66 56 NW 7 2789 3200 0 Blue 0
6 AM Thu 66 56 NW 7 2789 3200 0 Blue 0
7 AM Thu 68 58 NW 7 2789 3200 0 Blue 0
8 AM Thu 70 60 NW 7 2789 3200 0 Blue 0
9 AM Thu 71 62 NW 7 2789 3200 0 Blue 0
10 AM Thu 72 65 NW 7 2789 3200 0 Blue 0
11 AM Thu 72 67 NW 8 2789 3200 0 Blue 0
12 Noon Thu 73 70 NW 8 2789 3200 0 Blue 0
1 PM Thu 74 72 NW 8 2789 3200 0 Blue 0
2 PM Thu 74 71 W 12 2789 3200 0 Blue 0
3 PM Thu 74 70 W 12 2789 3200 0 Blue 0
4 PM Thu 74 68 W 12 2789 3200 0 Blue 0
5 PM Thu 74 66 W 10 2789 3200 0 Blue 0
6 PM Thu 73 64 W 10 2789 3200 0 Blue 0
7 PM Thu 73 63 W 10 2789 3200 0 Blue 0
8 PM Thu 72 62 NW 7 2789 3200 0 Blue 0
9 PM Thu 71 61 NW 7 2789 3200 0 Blue 0
10 PM Thu 70 60 NW 7 2789 3200 0 Blue 0
11 PM Thu 70 60 NW 6 2789 3200 0 Blue 0
12 Midnight Fri 69 59 NW 6 2789 3200 0 Blue 0
1 AM Fri 68 58 NW 6 2789 3200 0 Blue 0
2 AM Fri 68 58 N 6 2789 3200 0 Blue 0
3 AM Fri 67 57 N 6 2789 3200 0 Blue 0
4 AM Fri 66 56 N 6 2789 3200 0 Blue 0
5 AM Fri 66 56 N 7 2789 3200 0 Blue 0
6 AM Fri 66 56 N 7 2789 3200 0 Blue 0
7 AM Fri 68 58 N 7 2789 3200 0 Blue 0
8 AM Fri 70 60 N 7 2789 3200 0 Blue 0
9 AM Fri 71 62 N 7 2789 3200 0 Blue 0
10 AM Fri 72 65 N 7 2789 3200 0 Blue 0
11 AM Fri 72 67 NW 8 2789 3200 0 Blue 0
12 Noon Fri 73 70 NW 8 2789 3200 0 Blue 0
1 PM Fri 74 72 NW 8 2789 3200 0 Blue 0
2 PM Fri 74 71 NW 10 2789 3200 0 Blue 0
3 PM Fri 75 71 NW 10 2789 3200 0 Blue 0
4 PM Fri 75 69 NW 10 2789 3200 0 Blue 0
5 PM Fri 74 66 NW 9 2789 3200 0 Blue 0
6 PM Fri 74 65 NW 9 2789 3200 0 Blue 0
7 PM Fri 73 63 NW 9 2789 3200 0 Blue 0
8 PM Fri 72 62 NW 6 2789 3200 0 Blue 0
9 PM Fri 71 61 NW 6 2789 3200 0 Blue 0
10 PM Fri 70 60 NW 6 2789 3200 0 Blue 0
11 PM Fri 69 59 N 7 2789 3200 0 Blue 0
12 Midnight Sat 69 59 N 7 2789 3200 0 Blue 0
1 AM Sat 68 58 N 7 2789 3200 0 Blue 0
2 AM Sat 67 57 N 7 2789 3200 0 Blue 0
3 AM Sat 66 56 N 7 2789 3200 0 Blue 0
4 AM Sat 65 55 N 7 2789 3200 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