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

Station:

KOAK

Date/Time:

26 MAY 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 46 36 NW 15 2635 3200 0 Blue 0
6 AM Sun 44 34 NW 15 2635 3200 0 Blue 0
7 AM Sun 44 34 NW 15 2635 3200 0 Blue 0
8 AM Sun 45 35 NW 15 2635 3200 0 Blue 0
9 AM Sun 45 36 NW 15 2635 3200 0 Blue 0
10 AM Sun 45 36 NW 15 2635 3200 0 Blue 0
11 AM Sun 46 38 W 21 2635 3200 0 Blue 0
12 Noon Sun 46 39 W 21 2635 3200 0 Blue 0
1 PM Sun 46 41 W 21 3410 3200 0 Blue 1
2 PM Sun 46 39 W 20 2635 3200 0 Blue 0
3 PM Sun 46 38 W 20 2635 3200 0 Blue 0
4 PM Sun 46 37 W 20 2635 3200 0 Blue 0
5 PM Sun 46 36 W 18 2635 3200 0 Blue 0
6 PM Sun 46 36 W 18 2635 3200 0 Blue 0
7 PM Sun 47 37 W 18 2635 3200 0 Blue 0
8 PM Sun 46 36 NW 18 2635 3200 0 Blue 0
9 PM Sun 46 36 NW 18 2635 3200 0 Blue 0
10 PM Sun 46 36 NW 18 2635 3200 0 Blue 0
11 PM Sun 46 36 NW 13 2635 3200 0 Blue 0
12 Midnight Mon 46 36 NW 13 2635 3200 0 Blue 0
1 AM Mon 46 36 NW 13 2635 3200 0 Blue 0
2 AM Mon 46 36 NW 12 2635 3200 0 Blue 0
3 AM Mon 46 36 NW 12 2635 3200 0 Blue 0
4 AM Mon 46 36 NW 12 2635 3200 0 Blue 0
5 AM Mon 46 36 W 8 2635 3200 0 Blue 0
6 AM Mon 46 36 W 8 2635 3200 0 Blue 0
7 AM Mon 47 37 W 8 2635 3200 0 Blue 0
8 AM Mon 48 38 NW 9 2635 3200 0 Blue 0
9 AM Mon 48 39 NW 9 2635 3200 0 Blue 0
10 AM Mon 49 40 NW 9 3039 3200 0 Blue 0
11 AM Mon 50 42 W 12 3777 3200 0 Blue 2
12 Noon Mon 50 42 W 12 3777 3200 0 Blue 2
1 PM Mon 52 44 W 12 4456 3403 203 White 4
2 PM Mon 51 45 W 12 4675 3765 565 White 5
3 PM Mon 51 44 W 12 4456 3403 203 White 4
4 PM Mon 52 44 W 12 4456 3403 203 White 4
5 PM Mon 52 43 W 9 4139 3200 0 Blue 3
6 PM Mon 52 42 W 9 3777 3200 0 Blue 2
7 PM Mon 52 42 W 9 3777 3200 0 Blue 2
8 PM Mon 52 42 NW 6 3777 3200 0 Blue 2
9 PM Mon 51 41 NW 6 3410 3200 0 Blue 1
10 PM Mon 50 40 NW 6 3039 3200 0 Blue 0
11 PM Mon 49 39 NW 5 2635 3200 0 Blue 0
12 Midnight Tue 50 40 NW 5 3039 3200 0 Blue 0
1 AM Tue 50 40 NW 5 3039 3200 0 Blue 0
2 AM Tue 49 39 N 6 2635 3200 0 Blue 0
3 AM Tue 48 38 N 6 2635 3200 0 Blue 0
4 AM Tue 48 38 N 6 2635 3200 0 Blue 0
5 AM Tue 48 38 N 3 2635 3200 0 Blue 0
6 AM Tue 48 38 N 3 2635 3200 0 Blue 0
7 AM Tue 50 40 N 3 3039 3200 0 Blue 0
8 AM Tue 52 43 NW 5 4139 3200 0 Blue 3
9 AM Tue 52 44 NW 5 4456 3403 203 White 4
10 AM Tue 54 47 NW 5 5112 4477 1277 White 7
11 AM Tue 54 51 W 6 5978 5331 2131 White 11
12 Noon Tue 55 53 W 6 6408 5733 2533 White 13
1 PM Tue 57 55 W 6 6836 6836 3636 White 15
2 PM Tue 57 54 W 7 6621 6621 3421 White 14
3 PM Tue 57 53 W 7 6408 5733 2533 White 13
4 PM Tue 57 51 W 7 5978 5331 2131 White 11
5 PM Tue 58 51 W 5 5978 5331 2131 White 11
6 PM Tue 58 49 W 5 5547 4927 1727 White 9
7 PM Tue 58 48 W 5 5330 4725 1525 White 8
8 PM Tue 58 48 N 7 5330 4725 1525 White 8
9 PM Tue 56 46 N 7 4894 4123 923 White 6
10 PM Tue 55 45 N 7 4675 3765 565 White 5
11 PM Tue 53 43 N 6 4139 3200 0 Blue 3
12 Midnight Wed 54 44 N 6 4456 3403 203 White 4
1 AM Wed 54 44 N 6 4456 3403 203 White 4
2 AM Wed 52 42 N 2 3777 3200 0 Blue 2
3 AM Wed 52 42 N 2 3777 3200 0 Blue 2
4 AM Wed 51 41 N 2 3410 3200 0 Blue 1
5 AM Wed 52 42 NE 2 3777 3200 0 Blue 2
6 AM Wed 50 40 NE 2 3039 3200 0 Blue 0
7 AM Wed 52 42 NE 2 3777 3200 0 Blue 2
8 AM Wed 54 45 N 7 4675 3765 565 White 5
9 AM Wed 55 47 N 7 5112 4477 1277 White 7
10 AM Wed 56 49 N 7 5547 4927 1727 White 9
11 AM Wed 57 53 NW 7 6408 5733 2533 White 13
12 Noon Wed 58 55 NW 7 6836 6836 3636 White 15
1 PM Wed 60 57 NW 7 7262 7262 4062 White 17
2 PM Wed 59 57 NW 8 7262 7262 4062 White 17
3 PM Wed 59 56 NW 8 7049 7049 3849 White 16
4 PM Wed 60 55 NW 8 6836 6836 3636 White 15
5 PM Wed 60 53 NW 9 6408 5733 2533 White 13
6 PM Wed 60 51 NW 9 5978 5331 2131 White 11
7 PM Wed 61 51 NW 9 5978 5331 2131 White 11
8 PM Wed 60 50 NW 8 5753 5130 1930 Blue 10
9 PM Wed 57 47 NW 8 5112 4477 1277 White 7
10 PM Wed 57 47 NW 8 5112 4477 1277 White 7
11 PM Wed 55 45 NW 9 4675 3765 565 White 5
12 Midnight Thu 56 46 NW 9 4894 4123 923 White 6
1 AM Thu 56 46 NW 9 4894 4123 923 White 6
2 AM Thu 54 44 NW 9 4456 3403 203 White 4
3 AM Thu 53 43 NW 9 4139 3200 0 Blue 3
4 AM Thu 52 42 NW 9 3777 3200 0 Blue 2
5 AM Thu 53 43 NW 9 4139 3200 0 Blue 3
6 AM Thu 51 41 NW 9 3410 3200 0 Blue 1
7 AM Thu 53 43 NW 9 4139 3200 0 Blue 3
8 AM Thu 54 45 NW 7 4675 3765 565 White 5
9 AM Thu 55 47 NW 7 5112 4477 1277 White 7
10 AM Thu 56 50 NW 7 5753 5130 1930 Blue 10
11 AM Thu 56 52 NW 8 6194 5533 2333 White 12
12 Noon Thu 57 55 NW 8 6836 6836 3636 White 15
1 PM Thu 58 56 NW 8 7049 7049 3849 White 16
2 PM Thu 58 56 NW 10 7049 7049 3849 White 16
3 PM Thu 58 54 NW 10 6621 6621 3421 White 14
4 PM Thu 59 54 NW 10 6621 6621 3421 White 14
5 PM Thu 59 52 NW 10 6194 5533 2333 White 12
6 PM Thu 59 50 NW 10 5753 5130 1930 Blue 10
7 PM Thu 59 49 NW 10 5547 4927 1727 White 9
8 PM Thu 58 48 NW 10 5330 4725 1525 White 8
9 PM Thu 56 46 NW 10 4894 4123 923 White 6
10 PM Thu 56 46 NW 10 4894 4123 923 White 6
11 PM Thu 54 44 NW 10 4456 3403 203 White 4
12 Midnight Fri 55 45 NW 10 4675 3765 565 White 5
1 AM Fri 55 45 NW 10 4675 3765 565 White 5
2 AM Fri 53 43 N 10 4139 3200 0 Blue 3
3 AM Fri 52 42 N 10 3777 3200 0 Blue 2
4 AM Fri 52 42 N 10 3777 3200 0 Blue 2
5 AM Fri 52 42 N 9 3777 3200 0 Blue 2
6 AM Fri 51 41 N 9 3410 3200 0 Blue 1
7 AM Fri 53 43 N 9 4139 3200 0 Blue 3
8 AM Fri 54 44 N 8 4456 3403 203 White 4
9 AM Fri 55 47 N 8 5112 4477 1277 White 7
10 AM Fri 56 49 N 8 5547 4927 1727 White 9
11 AM Fri 57 51 NW 8 5978 5331 2131 White 11
12 Noon Fri 58 53 NW 8 6408 5733 2533 White 13
1 PM Fri 59 54 NW 8 6621 6621 3421 White 14
2 PM Fri 59 54 NW 9 6621 6621 3421 White 14
3 PM Fri 59 53 NW 9 6408 5733 2533 White 13
4 PM Fri 59 52 NW 9 6194 5533 2333 White 12
5 PM Fri 59 51 NW 9 5978 5331 2131 White 11
6 PM Fri 60 51 NW 9 5978 5331 2131 White 11
7 PM Fri 60 50 NW 9 5753 5130 1930 Blue 10
8 PM Fri 59 49 NW 9 5547 4927 1727 White 9
9 PM Fri 57 47 NW 9 5112 4477 1277 White 7
10 PM Fri 56 46 NW 9 4894 4123 923 White 6
11 PM Fri 55 45 NW 10 4675 3765 565 White 5
12 Midnight Sat 56 46 NW 10 4894 4123 923 White 6
1 AM Sat 56 46 NW 10 4894 4123 923 White 6
2 AM Sat 54 44 NW 9 4456 3403 203 White 4
3 AM Sat 53 43 NW 9 4139 3200 0 Blue 3
4 AM Sat 52 42 NW 9 3777 3200 0 Blue 2

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