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

Station:

 KOAK

Date/Time:

 3 SEP 2010

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
5 AM Fri 78 68 N 7 2605 3200 0 Blue 0
6 AM Fri 78 68 N 7 2605 3200 0 Blue 0
7 AM Fri 77 67 N 7 2605 3200 0 Blue 0
8 AM Fri 80 70 NE 3 2605 3200 0 Blue 0
9 AM Fri 81 72 NE 3 2605 3200 0 Blue 0
10 AM Fri 83 75 NE 3 2605 3200 0 Blue 0
11 AM Fri 84 78 W 3 2915 3200 0 Blue 0
12 Noon Fri 86 82 W 3 4209 3238 38 Blue 4
1 PM Fri 85 81 W 3 3890 3200 0 Blue 3
2 PM Fri 86 82 W 5 4209 3238 38 Blue 4
3 PM Fri 87 82 W 5 4209 3238 38 Blue 4
4 PM Fri 87 80 W 5 3567 3200 0 Blue 2
5 PM Fri 86 78 W 2 2915 3200 0 Blue 0
6 PM Fri 86 76 W 2 2605 3200 0 Blue 0
7 PM Fri 84 74 W 2 2605 3200 0 Blue 0
8 PM Fri 81 71 N 8 2605 3200 0 Blue 0
9 PM Fri 81 71 N 8 2605 3200 0 Blue 0
10 PM Fri 81 71 N 8 2605 3200 0 Blue 0
11 PM Fri 81 71 NW 6 2605 3200 0 Blue 0
12 Midnight Sat 80 70 NW 6 2605 3200 0 Blue 0
1 AM Sat 80 70 NW 6 2605 3200 0 Blue 0
2 AM Sat 79 69 NW 6 2605 3200 0 Blue 0
3 AM Sat 78 68 NW 6 2605 3200 0 Blue 0
4 AM Sat 77 67 NW 6 2605 3200 0 Blue 0
5 AM Sat 77 67 NW 6 2605 3200 0 Blue 0
6 AM Sat 77 67 NW 6 2605 3200 0 Blue 0
7 AM Sat 76 66 NW 6 2605 3200 0 Blue 0
8 AM Sat 79 69 W 3 2605 3200 0 Blue 0
9 AM Sat 80 70 W 3 2605 3200 0 Blue 0
10 AM Sat 82 72 W 3 2605 3200 0 Blue 0
11 AM Sat 83 77 W 6 2732 3200 0 Blue 0
12 Noon Sat 85 80 W 6 3567 3200 0 Blue 2
1 PM Sat 85 80 W 6 3567 3200 0 Blue 2
2 PM Sat 85 80 W 6 3567 3200 0 Blue 2
3 PM Sat 86 80 W 6 3567 3200 0 Blue 2
4 PM Sat 86 79 W 6 3242 3200 0 Blue 1
5 PM Sat 85 76 NW 8 2605 3200 0 Blue 0
6 PM Sat 84 74 NW 8 2605 3200 0 Blue 0
7 PM Sat 82 72 NW 8 2605 3200 0 Blue 0
8 PM Sat 77 67 NW 8 2605 3200 0 Blue 0
9 PM Sat 77 67 NW 8 2605 3200 0 Blue 0
10 PM Sat 76 66 NW 8 2605 3200 0 Blue 0
11 PM Sat 76 66 N 8 2605 3200 0 Blue 0
12 Midnight Sun 75 65 N 8 2605 3200 0 Blue 0
1 AM Sun 74 64 N 8 2605 3200 0 Blue 0
2 AM Sun 73 63 N 8 2605 3200 0 Blue 0
3 AM Sun 72 62 N 8 2605 3200 0 Blue 0
4 AM Sun 70 60 N 8 2605 3200 0 Blue 0
5 AM Sun 69 59 N 8 2605 3200 0 Blue 0
6 AM Sun 69 59 N 8 2605 3200 0 Blue 0
7 AM Sun 68 58 N 8 2605 3200 0 Blue 0
8 AM Sun 71 61 N 8 2605 3200 0 Blue 0
9 AM Sun 73 63 N 8 2605 3200 0 Blue 0
10 AM Sun 75 66 N 8 2605 3200 0 Blue 0
11 AM Sun 76 70 W 9 2605 3200 0 Blue 0
12 Noon Sun 78 73 W 9 2605 3200 0 Blue 0
1 PM Sun 77 72 W 9 2605 3200 0 Blue 0
2 PM Sun 78 73 W 9 2605 3200 0 Blue 0
3 PM Sun 79 73 W 9 2605 3200 0 Blue 0
4 PM Sun 79 72 W 9 2605 3200 0 Blue 0
5 PM Sun 78 69 NW 9 2605 3200 0 Blue 0
6 PM Sun 78 68 NW 9 2605 3200 0 Blue 0
7 PM Sun 76 66 NW 9 2605 3200 0 Blue 0
8 PM Sun 71 61 NW 9 2605 3200 0 Blue 0
9 PM Sun 71 61 NW 9 2605 3200 0 Blue 0
10 PM Sun 71 61 NW 9 2605 3200 0 Blue 0
11 PM Sun 71 61 NE 8 2605 3200 0 Blue 0
12 Midnight Mon 69 59 NE 8 2605 3200 0 Blue 0
1 AM Mon 69 59 NE 8 2605 3200 0 Blue 0
2 AM Mon 68 58 NE 8 2605 3200 0 Blue 0
3 AM Mon 67 57 NE 8 2605 3200 0 Blue 0
4 AM Mon 65 55 NE 8 2605 3200 0 Blue 0
5 AM Mon 65 55 NE 5 2605 3200 0 Blue 0
6 AM Mon 65 55 NE 5 2605 3200 0 Blue 0
7 AM Mon 64 54 NE 5 2605 3200 0 Blue 0
8 AM Mon 67 57 NE 5 2605 3200 0 Blue 0
9 AM Mon 70 60 NE 5 2605 3200 0 Blue 0
10 AM Mon 72 62 NE 5 2605 3200 0 Blue 0
11 AM Mon 73 68 S 3 2605 3200 0 Blue 0
12 Noon Mon 76 72 S 3 2605 3200 0 Blue 0
1 PM Mon 75 72 S 3 2605 3200 0 Blue 0
2 PM Mon 77 73 S 3 2605 3200 0 Blue 0
3 PM Mon 77 72 S 3 2605 3200 0 Blue 0
4 PM Mon 78 72 S 3 2605 3200 0 Blue 0
5 PM Mon 77 69 W 10 2605 3200 0 Blue 0
6 PM Mon 76 66 W 10 2605 3200 0 Blue 0
7 PM Mon 74 64 W 10 2605 3200 0 Blue 0
8 PM Mon 69 59 W 10 2605 3200 0 Blue 0
9 PM Mon 68 58 W 10 2605 3200 0 Blue 0
10 PM Mon 68 58 W 10 2605 3200 0 Blue 0
11 PM Mon 68 58 NW 8 2605 3200 0 Blue 0
12 Midnight Tue 66 56 NW 8 2605 3200 0 Blue 0
1 AM Tue 66 56 NW 8 2605 3200 0 Blue 0
2 AM Tue 65 55 NW 8 2605 3200 0 Blue 0
3 AM Tue 64 54 NW 8 2605 3200 0 Blue 0
4 AM Tue 62 52 NW 8 2605 3200 0 Blue 0
5 AM Tue 61 51 W 6 2605 3200 0 Blue 0
6 AM Tue 61 51 W 6 2605 3200 0 Blue 0
7 AM Tue 60 50 W 6 2605 3200 0 Blue 0
8 AM Tue 62 52 W 6 2605 3200 0 Blue 0
9 AM Tue 64 54 W 6 2605 3200 0 Blue 0
10 AM Tue 66 57 W 6 2605 3200 0 Blue 0
11 AM Tue 67 61 W 7 2605 3200 0 Blue 0
12 Noon Tue 68 63 W 7 2605 3200 0 Blue 0
1 PM Tue 68 63 W 7 2605 3200 0 Blue 0
2 PM Tue 69 64 W 7 2605 3200 0 Blue 0
3 PM Tue 70 64 W 7 2605 3200 0 Blue 0
4 PM Tue 70 63 W 7 2605 3200 0 Blue 0
5 PM Tue 69 60 NW 13 2605 3200 0 Blue 0
6 PM Tue 68 58 NW 13 2605 3200 0 Blue 0
7 PM Tue 67 57 NW 13 2605 3200 0 Blue 0
8 PM Tue 63 53 NW 13 2605 3200 0 Blue 0
9 PM Tue 63 53 NW 13 2605 3200 0 Blue 0
10 PM Tue 62 52 NW 13 2605 3200 0 Blue 0
11 PM Tue 63 53 NW 15 2605 3200 0 Blue 0
12 Midnight Wed 61 51 NW 15 2605 3200 0 Blue 0
1 AM Wed 61 51 NW 15 2605 3200 0 Blue 0
2 AM Wed 60 50 NW 15 2605 3200 0 Blue 0
3 AM Wed 60 50 NW 15 2605 3200 0 Blue 0
4 AM Wed 58 48 NW 15 2605 3200 0 Blue 0
5 AM Wed 58 48 NW 15 2605 3200 0 Blue 0
6 AM Wed 58 48 NW 15 2605 3200 0 Blue 0
7 AM Wed 57 47 NW 15 2605 3200 0 Blue 0
8 AM Wed 59 49 NW 15 2605 3200 0 Blue 0
9 AM Wed 61 51 NW 15 2605 3200 0 Blue 0
10 AM Wed 63 54 NW 15 2605 3200 0 Blue 0
11 AM Wed 63 56 NW 12 2605 3200 0 Blue 0
12 Noon Wed 65 59 NW 12 2605 3200 0 Blue 0
1 PM Wed 65 60 NW 12 2605 3200 0 Blue 0
2 PM Wed 65 60 NW 12 2605 3200 0 Blue 0
3 PM Wed 66 60 NW 12 2605 3200 0 Blue 0
4 PM Wed 66 59 NW 12 2605 3200 0 Blue 0
5 PM Wed 66 57 NW 16 2605 3200 0 Blue 0
6 PM Wed 65 55 NW 16 2605 3200 0 Blue 0
7 PM Wed 64 54 NW 16 2605 3200 0 Blue 0
8 PM Wed 61 51 NW 16 2605 3200 0 Blue 0
9 PM Wed 61 51 NW 16 2605 3200 0 Blue 0
10 PM Wed 60 50 NW 16 2605 3200 0 Blue 0
11 PM Wed 61 51 N 13 2605 3200 0 Blue 0
12 Midnight Thu 60 50 N 13 2605 3200 0 Blue 0
1 AM Thu 59 49 N 13 2605 3200 0 Blue 0
2 AM Thu 59 49 N 13 2605 3200 0 Blue 0
3 AM Thu 58 48 N 13 2605 3200 0 Blue 0
4 AM Thu 57 47 N 13 2605 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