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

Station:

KOAK

Date/Time:

18 SEP 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 Wed 59 49 W 1 2572 3200 0 Blue 0
6 AM Wed 62 52 W 1 2572 3200 0 Blue 0
7 AM Wed 58 48 W 1 2572 3200 0 Blue 0
8 AM Wed 63 53 W 2 2825 3200 0 Blue 0
9 AM Wed 65 56 W 2 3699 3200 0 Blue 1
10 AM Wed 65 58 W 2 3998 3513 313 Blue 3
11 AM Wed 66 60 W 6 4258 3864 664 Blue 5
12 Noon Wed 68 63 W 6 5058 4252 1052 Blue 8
1 PM Wed 67 63 W 6 5058 4252 1052 Blue 8
2 PM Wed 67 62 W 9 4995 4122 922 Blue 7
3 PM Wed 67 61 W 9 4933 3993 793 Blue 6
4 PM Wed 66 59 W 9 4128 3693 493 Blue 4
5 PM Wed 66 57 W 9 3868 3210 10 Blue 2
6 PM Wed 66 56 W 9 3699 3200 0 Blue 1
7 PM Wed 65 55 W 9 3517 3200 0 Blue 0
8 PM Wed 64 54 W 7 3215 3200 0 Blue 0
9 PM Wed 62 52 W 7 2572 3200 0 Blue 0
10 PM Wed 61 51 W 7 2572 3200 0 Blue 0
11 PM Wed 60 50 NW 3 2572 3200 0 Blue 0
12 Midnight Thu 61 51 NW 3 2572 3200 0 Blue 0
1 AM Thu 60 50 NW 3 2572 3200 0 Blue 0
2 AM Thu 59 49 NW 5 2572 3200 0 Blue 0
3 AM Thu 57 47 NW 5 2572 3200 0 Blue 0
4 AM Thu 57 47 NW 5 2572 3200 0 Blue 0
5 AM Thu 56 46 NW 3 2572 3200 0 Blue 0
6 AM Thu 57 47 NW 3 2572 3200 0 Blue 0
7 AM Thu 56 46 NW 3 2572 3200 0 Blue 0
8 AM Thu 60 50 NW 2 2572 3200 0 Blue 0
9 AM Thu 61 52 NW 2 2572 3200 0 Blue 0
10 AM Thu 61 53 NW 2 2825 3200 0 Blue 0
11 AM Thu 62 56 W 6 3699 3200 0 Blue 1
12 Noon Thu 64 59 W 6 4128 3693 493 Blue 4
1 PM Thu 64 59 W 6 4128 3693 493 Blue 4
2 PM Thu 64 58 W 8 3998 3513 313 Blue 3
3 PM Thu 64 57 W 8 3868 3210 10 Blue 2
4 PM Thu 64 56 W 8 3699 3200 0 Blue 1
5 PM Thu 65 56 NW 2 3699 3200 0 Blue 1
6 PM Thu 65 55 NW 2 3517 3200 0 Blue 0
7 PM Thu 65 55 NW 2 3517 3200 0 Blue 0
8 PM Thu 64 54 N 6 3215 3200 0 Blue 0
9 PM Thu 64 54 N 6 3215 3200 0 Blue 0
10 PM Thu 64 54 N 6 3215 3200 0 Blue 0
11 PM Thu 63 53 N 9 2825 3200 0 Blue 0
12 Midnight Fri 63 53 N 9 2825 3200 0 Blue 0
1 AM Fri 62 52 N 9 2572 3200 0 Blue 0
2 AM Fri 62 52 N 6 2572 3200 0 Blue 0
3 AM Fri 60 50 N 6 2572 3200 0 Blue 0
4 AM Fri 60 50 N 6 2572 3200 0 Blue 0
5 AM Fri 60 50 N 5 2572 3200 0 Blue 0
6 AM Fri 61 51 N 5 2572 3200 0 Blue 0
7 AM Fri 62 52 N 5 2572 3200 0 Blue 0
8 AM Fri 64 54 N 3 3215 3200 0 Blue 0
9 AM Fri 66 57 N 3 3868 3210 10 Blue 2
10 AM Fri 67 60 N 3 4258 3864 664 Blue 5
11 AM Fri 68 62 NW 2 4995 4122 922 Blue 7
12 Noon Fri 69 65 NW 2 5183 4991 1791 Blue 10
1 PM Fri 69 65 NW 2 5183 4991 1791 Blue 10
2 PM Fri 70 65 W 5 5183 4991 1791 Blue 10
3 PM Fri 70 64 W 5 5121 4928 1728 Blue 9
4 PM Fri 70 63 W 5 5058 4252 1052 Blue 8
5 PM Fri 70 61 N 2 4933 3993 793 Blue 6
6 PM Fri 69 59 N 2 4128 3693 493 Blue 4
7 PM Fri 69 59 N 2 4128 3693 493 Blue 4
8 PM Fri 68 58 N 8 3998 3513 313 Blue 3
9 PM Fri 66 56 N 8 3699 3200 0 Blue 1
10 PM Fri 66 56 N 8 3699 3200 0 Blue 1
11 PM Fri 65 55 N 7 3517 3200 0 Blue 0
12 Midnight Sat 65 55 N 7 3517 3200 0 Blue 0
1 AM Sat 65 55 N 7 3517 3200 0 Blue 0
2 AM Sat 64 54 N 5 3215 3200 0 Blue 0
3 AM Sat 64 54 N 5 3215 3200 0 Blue 0
4 AM Sat 63 53 N 5 2825 3200 0 Blue 0
5 AM Sat 63 53 N 3 2825 3200 0 Blue 0
6 AM Sat 64 54 N 3 3215 3200 0 Blue 0
7 AM Sat 65 55 N 3 3517 3200 0 Blue 0
8 AM Sat 67 57 NE 3 3868 3210 10 Blue 2
9 AM Sat 68 59 NE 3 4128 3693 493 Blue 4
10 AM Sat 70 63 NE 3 5058 4252 1052 Blue 8
11 AM Sat 71 65 NW 2 5183 4991 1791 Blue 10
12 Noon Sat 72 68 NW 2 5566 5178 1978 Blue 13
1 PM Sat 73 69 NW 2 5859 5241 2041 Blue 14
2 PM Sat 73 69 NW 3 5859 5241 2041 Blue 14
3 PM Sat 74 69 NW 3 5859 5241 2041 Blue 14
4 PM Sat 74 67 NW 3 5389 5116 1916 Blue 12
5 PM Sat 73 64 NW 5 5121 4928 1728 Blue 9
6 PM Sat 72 62 NW 5 4995 4122 922 Blue 7
7 PM Sat 70 60 NW 5 4258 3864 664 Blue 5
8 PM Sat 69 59 NW 2 4128 3693 493 Blue 4
9 PM Sat 68 58 NW 2 3998 3513 313 Blue 3
10 PM Sat 68 58 NW 2 3998 3513 313 Blue 3
11 PM Sat 68 58 N 2 3998 3513 313 Blue 3
12 Midnight Sun 67 57 N 2 3868 3210 10 Blue 2
1 AM Sun 67 57 N 2 3868 3210 10 Blue 2
2 AM Sun 66 56 N 3 3699 3200 0 Blue 1
3 AM Sun 65 55 N 3 3517 3200 0 Blue 0
4 AM Sun 64 54 N 3 3215 3200 0 Blue 0
5 AM Sun 64 54 N 3 3215 3200 0 Blue 0
6 AM Sun 65 55 N 3 3517 3200 0 Blue 0
7 AM Sun 67 57 N 3 3868 3210 10 Blue 2
8 AM Sun 68 58 N 3 3998 3513 313 Blue 3
9 AM Sun 70 61 N 3 4933 3993 793 Blue 6
10 AM Sun 71 64 N 3 5121 4928 1728 Blue 9
11 AM Sun 72 65 NW 5 5183 4991 1791 Blue 10
12 Noon Sun 73 67 NW 5 5389 5116 1916 Blue 12
1 PM Sun 73 68 NW 5 5566 5178 1978 Blue 13
2 PM Sun 73 68 NW 9 5566 5178 1978 Blue 13
3 PM Sun 73 67 NW 9 5389 5116 1916 Blue 12
4 PM Sun 73 65 NW 9 5183 4991 1791 Blue 10
5 PM Sun 72 63 NW 9 5058 4252 1052 Blue 8
6 PM Sun 71 61 NW 9 4933 3993 793 Blue 6
7 PM Sun 70 60 NW 9 4258 3864 664 Blue 5
8 PM Sun 69 59 NW 6 4128 3693 493 Blue 4
9 PM Sun 68 58 NW 6 3998 3513 313 Blue 3
10 PM Sun 67 57 NW 6 3868 3210 10 Blue 2
11 PM Sun 66 56 N 7 3699 3200 0 Blue 1
12 Midnight Mon 66 56 N 7 3699 3200 0 Blue 1
1 AM Mon 65 55 N 7 3517 3200 0 Blue 0
2 AM Mon 64 54 N 8 3215 3200 0 Blue 0
3 AM Mon 63 53 N 8 2825 3200 0 Blue 0
4 AM Mon 62 52 N 8 2572 3200 0 Blue 0
5 AM Mon 62 52 N 7 2572 3200 0 Blue 0
6 AM Mon 62 52 N 7 2572 3200 0 Blue 0
7 AM Mon 64 54 N 7 3215 3200 0 Blue 0
8 AM Mon 65 55 N 7 3517 3200 0 Blue 0
9 AM Mon 66 57 N 7 3868 3210 10 Blue 2
10 AM Mon 67 59 N 7 4128 3693 493 Blue 4
11 AM Mon 68 61 W 9 4933 3993 793 Blue 6
12 Noon Mon 69 63 W 9 5058 4252 1052 Blue 8
1 PM Mon 70 64 W 9 5121 4928 1728 Blue 9
2 PM Mon 71 65 NW 9 5183 4991 1791 Blue 10
3 PM Mon 71 64 NW 9 5121 4928 1728 Blue 9
4 PM Mon 71 63 NW 9 5058 4252 1052 Blue 8
5 PM Mon 71 62 NW 8 4995 4122 922 Blue 7
6 PM Mon 70 60 NW 8 4258 3864 664 Blue 5
7 PM Mon 69 59 NW 8 4128 3693 493 Blue 4
8 PM Mon 68 58 NW 5 3998 3513 313 Blue 3
9 PM Mon 67 57 NW 5 3868 3210 10 Blue 2
10 PM Mon 66 56 NW 5 3699 3200 0 Blue 1
11 PM Mon 66 56 N 5 3699 3200 0 Blue 1
12 Midnight Tue 66 56 N 5 3699 3200 0 Blue 1
1 AM Tue 65 55 N 5 3517 3200 0 Blue 0
2 AM Tue 65 55 N 5 3517 3200 0 Blue 0
3 AM Tue 64 54 N 5 3215 3200 0 Blue 0
4 AM Tue 64 54 N 5 3215 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