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

Station:

KOAK

Date/Time:

27 MAY 2018

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 51 41 N 3 2749 3200 0 Blue 0
6 AM Sun 51 41 N 3 2749 3200 0 Blue 0
7 AM Sun 53 43 N 3 2749 3200 0 Blue 0
8 AM Sun 60 51 N 3 2749 3200 0 Blue 0
9 AM Sun 63 55 N 3 2749 3200 0 Blue 0
10 AM Sun 65 59 N 3 2900 3200 0 Blue 0
11 AM Sun 66 62 W 6 4356 3200 0 Blue 0
12 Noon Sun 70 67 W 6 6658 4796 1596 Blue 5
1 PM Sun 72 70 W 6 7674 6506 3306 Blue 8
2 PM Sun 71 68 W 6 7522 5186 1986 Blue 6
3 PM Sun 71 67 W 6 6658 4796 1596 Blue 5
4 PM Sun 71 65 W 6 5232 4344 1144 Blue 3
5 PM Sun 71 64 NW 6 4811 3951 751 Blue 2
6 PM Sun 69 60 NW 6 3443 3200 0 Blue 0
7 PM Sun 69 59 NW 6 2900 3200 0 Blue 0
8 PM Sun 66 56 N 6 2749 3200 0 Blue 0
9 PM Sun 65 55 N 6 2749 3200 0 Blue 0
10 PM Sun 64 54 N 6 2749 3200 0 Blue 0
11 PM Sun 65 55 N 5 2749 3200 0 Blue 0
12 Midnight Mon 64 54 N 5 2749 3200 0 Blue 0
1 AM Mon 63 53 N 5 2749 3200 0 Blue 0
2 AM Mon 63 53 N 5 2749 3200 0 Blue 0
3 AM Mon 62 52 N 5 2749 3200 0 Blue 0
4 AM Mon 61 51 N 5 2749 3200 0 Blue 0
5 AM Mon 60 50 N 3 2749 3200 0 Blue 0
6 AM Mon 60 50 N 3 2749 3200 0 Blue 0
7 AM Mon 63 53 N 3 2749 3200 0 Blue 0
8 AM Mon 70 61 S 2 3970 3200 0 Blue 0
9 AM Mon 73 65 S 2 5232 4344 1144 Blue 3
10 AM Mon 75 69 S 2 7598 5763 2563 Blue 7
11 AM Mon 77 73 W 5 7902 7662 4462 Blue 11
12 Noon Mon 80 77 W 5 8671 7965 4765 Blue 15
1 PM Mon 82 80 W 5 9645 8610 5410 Blue 18
2 PM Mon 81 78 W 7 8985 8041 4841 Blue 16
3 PM Mon 81 77 W 7 8671 7965 4765 Blue 15
4 PM Mon 82 76 W 7 8354 7889 4689 Blue 14
5 PM Mon 81 74 N 6 7978 7737 4537 Blue 12
6 PM Mon 78 69 N 6 7598 5763 2563 Blue 7
7 PM Mon 77 67 N 6 6658 4796 1596 Blue 5
8 PM Mon 74 64 N 6 4811 3951 751 Blue 2
9 PM Mon 71 61 N 6 3970 3200 0 Blue 0
10 PM Mon 71 61 N 6 3970 3200 0 Blue 0
11 PM Mon 72 62 N 6 4356 3200 0 Blue 0
12 Midnight Tue 70 60 N 6 3443 3200 0 Blue 0
1 AM Tue 69 59 N 6 2900 3200 0 Blue 0
2 AM Tue 68 58 N 6 2749 3200 0 Blue 0
3 AM Tue 67 57 N 6 2749 3200 0 Blue 0
4 AM Tue 66 56 N 6 2749 3200 0 Blue 0
5 AM Tue 64 54 NE 3 2749 3200 0 Blue 0
6 AM Tue 64 54 NE 3 2749 3200 0 Blue 0
7 AM Tue 66 56 NE 3 2749 3200 0 Blue 0
8 AM Tue 69 60 NE 3 3443 3200 0 Blue 0
9 AM Tue 71 64 NE 3 4811 3951 751 Blue 2
10 AM Tue 72 66 NE 3 5819 4571 1371 Blue 4
11 AM Tue 73 69 W 7 7598 5763 2563 Blue 7
12 Noon Tue 75 73 W 7 7902 7662 4462 Blue 11
1 PM Tue 76 74 W 7 7978 7737 4537 Blue 12
2 PM Tue 75 72 W 7 7826 7586 4386 Blue 10
3 PM Tue 75 71 W 7 7750 7510 4310 Blue 9
4 PM Tue 75 69 W 7 7598 5763 2563 Blue 7
5 PM Tue 75 68 W 6 7522 5186 1986 Blue 6
6 PM Tue 72 63 W 6 4584 3432 232 Blue 1
7 PM Tue 71 61 W 6 3970 3200 0 Blue 0
8 PM Tue 67 57 W 6 2749 3200 0 Blue 0
9 PM Tue 65 55 W 6 2749 3200 0 Blue 0
10 PM Tue 65 55 W 6 2749 3200 0 Blue 0
11 PM Tue 65 55 N 10 2749 3200 0 Blue 0
12 Midnight Wed 64 54 N 10 2749 3200 0 Blue 0
1 AM Wed 63 53 N 10 2749 3200 0 Blue 0
2 AM Wed 62 52 N 10 2749 3200 0 Blue 0
3 AM Wed 61 51 N 10 2749 3200 0 Blue 0
4 AM Wed 60 50 N 10 2749 3200 0 Blue 0
5 AM Wed 58 48 NW 14 2749 3200 0 Blue 0
6 AM Wed 58 48 NW 14 2749 3200 0 Blue 0
7 AM Wed 59 49 NW 14 2749 3200 0 Blue 0
8 AM Wed 60 51 NW 14 2749 3200 0 Blue 0
9 AM Wed 60 52 NW 14 2749 3200 0 Blue 0
10 AM Wed 61 55 NW 14 2749 3200 0 Blue 0
11 AM Wed 61 56 NW 13 2749 3200 0 Blue 0
12 Noon Wed 62 59 NW 13 2900 3200 0 Blue 0
1 PM Wed 62 59 NW 13 2900 3200 0 Blue 0
2 PM Wed 61 58 NW 13 2749 3200 0 Blue 0
3 PM Wed 61 56 NW 13 2749 3200 0 Blue 0
4 PM Wed 61 55 NW 13 2749 3200 0 Blue 0
5 PM Wed 61 53 NW 20 2749 3200 0 Blue 0
6 PM Wed 58 49 NW 20 2749 3200 0 Blue 0
7 PM Wed 58 48 NW 20 2749 3200 0 Blue 0
8 PM Wed 54 44 NW 20 2749 3200 0 Blue 0
9 PM Wed 52 42 NW 20 2749 3200 0 Blue 0
10 PM Wed 52 42 NW 20 2749 3200 0 Blue 0
11 PM Wed 52 42 NW 15 2749 3200 0 Blue 0
12 Midnight Thu 51 41 NW 15 2749 3200 0 Blue 0
1 AM Thu 51 41 NW 15 2749 3200 0 Blue 0
2 AM Thu 50 40 NW 15 2749 3200 0 Blue 0
3 AM Thu 49 39 NW 15 2749 3200 0 Blue 0
4 AM Thu 48 38 NW 15 2749 3200 0 Blue 0
5 AM Thu 46 36 NW 16 2749 3200 0 Blue 0
6 AM Thu 46 36 NW 16 2749 3200 0 Blue 0
7 AM Thu 48 38 NW 16 2749 3200 0 Blue 0
8 AM Thu 50 41 NW 16 2749 3200 0 Blue 0
9 AM Thu 51 43 NW 16 2749 3200 0 Blue 0
10 AM Thu 52 46 NW 16 2749 3200 0 Blue 0
11 AM Thu 53 49 NW 15 2749 3200 0 Blue 0
12 Noon Thu 54 51 NW 15 2749 3200 0 Blue 0
1 PM Thu 55 53 NW 15 2749 3200 0 Blue 0
2 PM Thu 55 52 NW 15 2749 3200 0 Blue 0
3 PM Thu 55 51 NW 15 2749 3200 0 Blue 0
4 PM Thu 55 49 NW 15 2749 3200 0 Blue 0
5 PM Thu 54 46 NW 17 2749 3200 0 Blue 0
6 PM Thu 53 44 NW 17 2749 3200 0 Blue 0
7 PM Thu 53 43 NW 17 2749 3200 0 Blue 0
8 PM Thu 52 42 NW 17 2749 3200 0 Blue 0
9 PM Thu 51 41 NW 17 2749 3200 0 Blue 0
10 PM Thu 50 40 NW 17 2749 3200 0 Blue 0
11 PM Thu 51 41 NW 18 2749 3200 0 Blue 0
12 Midnight Fri 50 40 NW 18 2749 3200 0 Blue 0
1 AM Fri 50 40 NW 18 2749 3200 0 Blue 0
2 AM Fri 50 40 NW 18 2749 3200 0 Blue 0
3 AM Fri 49 39 NW 18 2749 3200 0 Blue 0
4 AM Fri 49 39 NW 18 2749 3200 0 Blue 0
5 AM Fri 48 38 NW 16 2749 3200 0 Blue 0
6 AM Fri 48 38 NW 16 2749 3200 0 Blue 0
7 AM Fri 50 40 NW 16 2749 3200 0 Blue 0
8 AM Fri 54 45 NW 16 2749 3200 0 Blue 0
9 AM Fri 57 49 NW 16 2749 3200 0 Blue 0
10 AM Fri 58 52 NW 16 2749 3200 0 Blue 0
11 AM Fri 59 55 N 9 2749 3200 0 Blue 0
12 Noon Fri 61 58 N 9 2749 3200 0 Blue 0
1 PM Fri 63 61 N 9 3970 3200 0 Blue 0
2 PM Fri 62 59 N 9 2900 3200 0 Blue 0
3 PM Fri 62 58 N 9 2749 3200 0 Blue 0
4 PM Fri 62 56 N 9 2749 3200 0 Blue 0
5 PM Fri 62 54 N 16 2749 3200 0 Blue 0
6 PM Fri 60 51 N 16 2749 3200 0 Blue 0
7 PM Fri 60 50 N 16 2749 3200 0 Blue 0
8 PM Fri 58 48 N 16 2749 3200 0 Blue 0
9 PM Fri 57 47 N 16 2749 3200 0 Blue 0
10 PM Fri 57 47 N 16 2749 3200 0 Blue 0
11 PM Fri 57 47 N 10 2749 3200 0 Blue 0
12 Midnight Sat 56 46 N 10 2749 3200 0 Blue 0
1 AM Sat 56 46 N 10 2749 3200 0 Blue 0
2 AM Sat 55 45 N 10 2749 3200 0 Blue 0
3 AM Sat 55 45 N 10 2749 3200 0 Blue 0
4 AM Sat 54 44 N 10 2749 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