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

Station:

 KOAK

Date/Time:

 11 MAR 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)
7 AM Thu 33 23 N 5 2690 3200 0 Blue 0
8 AM Thu 38 28 N 5 2690 3200 0 Blue 0
9 AM Thu 46 38 N 5 2690 3200 0 Blue 0
10 AM Thu 49 42 W 2 2922 3200 0 Blue 0
11 AM Thu 50 44 W 2 3807 3200 0 Blue 0
12 Noon Thu 50 44 W 2 3807 3200 0 Blue 0
1 PM Thu 52 46 W 5 4274 3361 161 Blue 2
2 PM Thu 54 47 W 5 4507 3793 593 Blue 3
3 PM Thu 56 48 W 5 4719 4031 831 Blue 4
4 PM Thu 52 43 W 6 3369 3200 0 Blue 0
5 PM Thu 51 41 W 6 2690 3200 0 Blue 0
6 PM Thu 48 38 W 6 2690 3200 0 Blue 0
7 PM Thu 47 37 NW 4 2690 3200 0 Blue 0
8 PM Thu 47 37 NW 4 2690 3200 0 Blue 0
9 PM Thu 45 35 NW 4 2690 3200 0 Blue 0
10 PM Thu 45 35 NW 3 2690 3200 0 Blue 0
11 PM Thu 47 37 NW 3 2690 3200 0 Blue 0
12 Midnight Fri 44 34 NW 3 2690 3200 0 Blue 0
1 AM Fri 43 33 NW 2 2690 3200 0 Blue 0
2 AM Fri 45 35 NW 2 2690 3200 0 Blue 0
3 AM Fri 43 33 NW 2 2690 3200 0 Blue 0
4 AM Fri 43 33 E 3 2690 3200 0 Blue 0
5 AM Fri 45 35 E 3 2690 3200 0 Blue 0
6 AM Fri 44 34 E 3 2690 3200 0 Blue 0
7 AM Fri 44 34 SW 3 2690 3200 0 Blue 0
8 AM Fri 46 36 SW 3 2690 3200 0 Blue 0
9 AM Fri 50 40 SW 3 2690 3200 0 Blue 0
10 AM Fri 51 41 W 8 2690 3200 0 Blue 0
11 AM Fri 52 43 W 8 3369 3200 0 Blue 0
12 Noon Fri 52 43 W 8 3369 3200 0 Blue 0
1 PM Fri 53 44 SW 9 3807 3200 0 Blue 0
2 PM Fri 54 45 SW 9 4041 3200 0 Blue 1
3 PM Fri 55 45 SW 9 4041 3200 0 Blue 1
4 PM Fri 51 41 SW 11 2690 3200 0 Blue 0
5 PM Fri 49 39 SW 11 2690 3200 0 Blue 0
6 PM Fri 47 37 SW 11 2690 3200 0 Blue 0
7 PM Fri 46 36 SW 11 2690 3200 0 Blue 0
8 PM Fri 45 35 SW 11 2690 3200 0 Blue 0
9 PM Fri 44 34 SW 11 2690 3200 0 Blue 0
10 PM Fri 44 34 W 10 2690 3200 0 Blue 0
11 PM Fri 45 35 W 10 2690 3200 0 Blue 0
12 Midnight Sat 42 32 W 10 2690 3200 0 Blue 0
1 AM Sat 41 31 W 10 2690 3200 0 Blue 0
2 AM Sat 43 33 W 10 2690 3200 0 Blue 0
3 AM Sat 41 31 W 10 2690 3200 0 Blue 0
4 AM Sat 41 31 NW 9 2690 3200 0 Blue 0
5 AM Sat 43 33 NW 9 2690 3200 0 Blue 0
6 AM Sat 41 31 NW 9 2690 3200 0 Blue 0
7 AM Sat 41 31 NW 9 2690 3200 0 Blue 0
8 AM Sat 43 33 NW 9 2690 3200 0 Blue 0
9 AM Sat 46 37 NW 9 2690 3200 0 Blue 0
10 AM Sat 47 39 NW 10 2690 3200 0 Blue 0
11 AM Sat 47 39 NW 10 2690 3200 0 Blue 0
12 Noon Sat 47 40 NW 10 2690 3200 0 Blue 0
1 PM Sat 48 40 NW 10 2690 3200 0 Blue 0
2 PM Sat 49 41 NW 10 2690 3200 0 Blue 0
3 PM Sat 49 40 NW 10 2690 3200 0 Blue 0
4 PM Sat 46 37 N 16 2690 3200 0 Blue 0
5 PM Sat 45 35 N 16 2690 3200 0 Blue 0
6 PM Sat 43 33 N 16 2690 3200 0 Blue 0
7 PM Sat 43 33 N 16 2690 3200 0 Blue 0
8 PM Sat 42 32 N 16 2690 3200 0 Blue 0
9 PM Sat 41 31 N 16 2690 3200 0 Blue 0
10 PM Sat 41 31 N 14 2690 3200 0 Blue 0
11 PM Sat 42 32 N 14 2690 3200 0 Blue 0
12 Midnight Sun 40 30 N 14 2690 3200 0 Blue 0
1 AM Sun 40 30 N 14 2690 3200 0 Blue 0
2 AM Sun 41 31 N 14 2690 3200 0 Blue 0
3 AM Sun 40 30 N 14 2690 3200 0 Blue 0
4 AM Sun 39 29 N 7 2690 3200 0 Blue 0
5 AM Sun 43 33 N 7 2690 3200 0 Blue 0
6 AM Sun 40 30 N 7 2690 3200 0 Blue 0
7 AM Sun 40 30 N 7 2690 3200 0 Blue 0
8 AM Sun 44 34 N 7 2690 3200 0 Blue 0
9 AM Sun 51 43 N 7 3369 3200 0 Blue 0
10 AM Sun 53 46 N 5 4274 3361 161 Blue 2
11 AM Sun 54 48 N 5 4719 4031 831 Blue 4
12 Noon Sun 54 48 N 5 4719 4031 831 Blue 4
1 PM Sun 56 50 N 5 4998 4493 1293 Blue 6
2 PM Sun 57 50 N 5 4998 4493 1293 Blue 6
3 PM Sun 59 51 N 5 5111 4710 1510 Blue 7
4 PM Sun 55 46 NW 6 4274 3361 161 Blue 2
5 PM Sun 54 44 NW 6 3807 3200 0 Blue 0
6 PM Sun 52 42 NW 6 2922 3200 0 Blue 0
7 PM Sun 51 41 NW 6 2690 3200 0 Blue 0
8 PM Sun 51 41 NW 6 2690 3200 0 Blue 0
9 PM Sun 50 40 NW 6 2690 3200 0 Blue 0
10 PM Sun 50 40 E 3 2690 3200 0 Blue 0
11 PM Sun 51 41 E 3 2690 3200 0 Blue 0
12 Midnight Mon 48 38 E 3 2690 3200 0 Blue 0
1 AM Mon 48 38 E 3 2690 3200 0 Blue 0
2 AM Mon 49 39 E 3 2690 3200 0 Blue 0
3 AM Mon 48 38 E 3 2690 3200 0 Blue 0
4 AM Mon 47 37 E 2 2690 3200 0 Blue 0
5 AM Mon 51 41 E 2 2690 3200 0 Blue 0
6 AM Mon 48 38 E 2 2690 3200 0 Blue 0
7 AM Mon 48 38 E 2 2690 3200 0 Blue 0
8 AM Mon 52 42 E 2 2922 3200 0 Blue 0
9 AM Mon 58 50 E 2 4998 4493 1293 Blue 6
10 AM Mon 60 53 SE 2 5583 4990 1790 Blue 9
11 AM Mon 60 54 SE 2 5855 5102 1902 Blue 10
12 Noon Mon 60 54 SE 2 5855 5102 1902 Blue 10
1 PM Mon 62 56 SE 2 6140 5557 2357 Blue 12
2 PM Mon 63 56 SE 2 6140 5557 2357 Blue 12
3 PM Mon 64 56 SE 2 6140 5557 2357 Blue 12
4 PM Mon 60 51 S 4 5111 4710 1510 Blue 7
5 PM Mon 58 48 S 4 4719 4031 831 Blue 4
6 PM Mon 55 45 S 4 4041 3200 0 Blue 1
7 PM Mon 54 44 S 4 3807 3200 0 Blue 0
8 PM Mon 54 44 S 4 3807 3200 0 Blue 0
9 PM Mon 52 42 S 4 2922 3200 0 Blue 0
10 PM Mon 52 42 S 3 2922 3200 0 Blue 0
11 PM Mon 54 44 S 3 3807 3200 0 Blue 0
12 Midnight Tue 50 40 S 3 2690 3200 0 Blue 0
1 AM Tue 49 39 S 3 2690 3200 0 Blue 0
2 AM Tue 51 41 S 3 2690 3200 0 Blue 0
3 AM Tue 49 39 S 3 2690 3200 0 Blue 0
4 AM Tue 49 39 S 3 2690 3200 0 Blue 0
5 AM Tue 52 42 S 3 2922 3200 0 Blue 0
6 AM Tue 50 40 S 3 2690 3200 0 Blue 0
7 AM Tue 50 40 S 3 2690 3200 0 Blue 0
8 AM Tue 53 43 S 3 3369 3200 0 Blue 0
9 AM Tue 58 49 S 3 4868 4263 1063 Blue 5
10 AM Tue 60 52 W 3 5308 4857 1657 Blue 8
11 AM Tue 60 53 W 3 5583 4990 1790 Blue 9
12 Noon Tue 61 55 W 3 6018 5286 2086 Blue 11
1 PM Tue 62 55 W 3 6018 5286 2086 Blue 11
2 PM Tue 63 56 W 3 6140 5557 2357 Blue 12
3 PM Tue 64 56 W 3 6140 5557 2357 Blue 12
4 PM Tue 59 49 N 6 4868 4263 1063 Blue 5
5 PM Tue 57 47 N 6 4507 3793 593 Blue 3
6 PM Tue 54 44 N 6 3807 3200 0 Blue 0
7 PM Tue 53 43 N 6 3369 3200 0 Blue 0
8 PM Tue 52 42 N 6 2922 3200 0 Blue 0
9 PM Tue 50 40 N 6 2690 3200 0 Blue 0
10 PM Tue 50 40 N 5 2690 3200 0 Blue 0
11 PM Tue 52 42 N 5 2922 3200 0 Blue 0
12 Midnight Wed 48 38 N 5 2690 3200 0 Blue 0
1 AM Wed 47 37 N 5 2690 3200 0 Blue 0
2 AM Wed 50 40 N 5 2690 3200 0 Blue 0
3 AM Wed 48 38 N 5 2690 3200 0 Blue 0
4 AM Wed 47 37 NE 4 2690 3200 0 Blue 0
5 AM Wed 49 39 NE 4 2690 3200 0 Blue 0
6 AM Wed 48 38 NE 4 2690 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