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

Station:

KOAK

Date/Time:

22 SEP 2017

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 Fri 47 37 W 6 2470 3200 0 Blue 0
6 AM Fri 47 37 W 6 2470 3200 0 Blue 0
7 AM Fri 47 37 W 6 2470 3200 0 Blue 0
8 AM Fri 47 37 W 6 2470 3200 0 Blue 0
9 AM Fri 48 39 W 6 2470 3200 0 Blue 0
10 AM Fri 49 41 W 6 2470 3200 0 Blue 0
11 AM Fri 50 43 W 9 2470 3200 0 Blue 0
12 Noon Fri 52 46 W 9 2470 3200 0 Blue 0
1 PM Fri 54 48 W 9 2470 3200 0 Blue 0
2 PM Fri 55 49 W 10 2818 3200 0 Blue 0
3 PM Fri 57 50 W 10 3246 3200 0 Blue 0
4 PM Fri 58 50 W 10 3246 3200 0 Blue 0
5 PM Fri 58 49 W 9 2818 3200 0 Blue 0
6 PM Fri 58 48 W 9 2470 3200 0 Blue 0
7 PM Fri 52 42 W 9 2470 3200 0 Blue 0
8 PM Fri 52 42 N 13 2470 3200 0 Blue 0
9 PM Fri 52 42 N 13 2470 3200 0 Blue 0
10 PM Fri 53 43 N 13 2470 3200 0 Blue 0
11 PM Fri 54 44 N 15 2470 3200 0 Blue 0
12 Midnight Sat 54 44 N 15 2470 3200 0 Blue 0
1 AM Sat 55 45 N 15 2470 3200 0 Blue 0
2 AM Sat 55 45 N 13 2470 3200 0 Blue 0
3 AM Sat 56 46 N 13 2470 3200 0 Blue 0
4 AM Sat 56 46 N 13 2470 3200 0 Blue 0
5 AM Sat 55 45 N 12 2470 3200 0 Blue 0
6 AM Sat 55 45 N 12 2470 3200 0 Blue 0
7 AM Sat 55 45 N 12 2470 3200 0 Blue 0
8 AM Sat 55 45 N 9 2470 3200 0 Blue 0
9 AM Sat 57 48 N 9 2470 3200 0 Blue 0
10 AM Sat 58 50 N 9 3246 3200 0 Blue 0
11 AM Sat 60 54 W 7 4406 3489 289 Blue 4
12 Noon Sat 62 57 W 7 5604 4387 1187 Blue 7
1 PM Sat 64 60 W 7 7424 5553 2353 Blue 10
2 PM Sat 65 60 W 8 7424 5553 2353 Blue 10
3 PM Sat 66 60 W 8 7424 5553 2353 Blue 10
4 PM Sat 67 60 W 8 7424 5553 2353 Blue 10
5 PM Sat 67 58 N 15 6084 4980 1780 Blue 8
6 PM Sat 66 56 N 15 5349 4020 820 Blue 6
7 PM Sat 64 54 N 15 4406 3489 289 Blue 4
8 PM Sat 62 52 N 15 3730 3200 0 Blue 2
9 PM Sat 61 51 N 15 3494 3200 0 Blue 1
10 PM Sat 62 52 N 15 3730 3200 0 Blue 2
11 PM Sat 62 52 N 15 3730 3200 0 Blue 2
12 Midnight Sun 63 53 N 15 4035 3240 40 Blue 3
1 AM Sun 63 53 N 15 4035 3240 40 Blue 3
2 AM Sun 62 52 N 15 3730 3200 0 Blue 2
3 AM Sun 61 51 N 15 3494 3200 0 Blue 1
4 AM Sun 59 49 N 15 2818 3200 0 Blue 0
5 AM Sun 57 47 N 5 2470 3200 0 Blue 0
6 AM Sun 56 46 N 5 2470 3200 0 Blue 0
7 AM Sun 56 46 N 5 2470 3200 0 Blue 0
8 AM Sun 57 47 N 5 2470 3200 0 Blue 0
9 AM Sun 58 49 N 5 2818 3200 0 Blue 0
10 AM Sun 60 52 N 5 3730 3200 0 Blue 2
11 AM Sun 63 57 W 6 5604 4387 1187 Blue 7
12 Noon Sun 65 60 W 6 7424 5553 2353 Blue 10
1 PM Sun 67 63 W 6 9613 7308 4108 White 13
2 PM Sun 69 64 W 6 9832 8040 4840 White 14
3 PM Sun 71 65 W 6 10043 8387 5187 White 15
4 PM Sun 72 65 W 6 10043 8387 5187 White 15
5 PM Sun 72 63 N 14 9613 7308 4108 White 13
6 PM Sun 72 62 N 14 8450 6523 3323 Blue 12
7 PM Sun 71 61 N 14 8117 6035 2835 Blue 11
8 PM Sun 71 61 N 14 8117 6035 2835 Blue 11
9 PM Sun 71 61 N 14 8117 6035 2835 Blue 11
10 PM Sun 72 62 N 14 8450 6523 3323 Blue 12
11 PM Sun 72 62 N 14 8450 6523 3323 Blue 12
12 Midnight Mon 72 62 N 14 8450 6523 3323 Blue 12
1 AM Mon 72 62 N 14 8450 6523 3323 Blue 12
2 AM Mon 72 62 N 14 8450 6523 3323 Blue 12
3 AM Mon 73 63 N 14 9613 7308 4108 White 13
4 AM Mon 73 63 N 14 9613 7308 4108 White 13
5 AM Mon 71 61 N 5 8117 6035 2835 Blue 11
6 AM Mon 65 55 N 5 5022 3723 523 Blue 5
7 AM Mon 60 50 N 5 3246 3200 0 Blue 0
8 AM Mon 58 48 N 5 2470 3200 0 Blue 0
9 AM Mon 61 52 N 5 3730 3200 0 Blue 2
10 AM Mon 66 58 N 5 6084 4980 1780 Blue 8
11 AM Mon 71 65 NE 3 10043 8387 5187 White 15
12 Noon Mon 74 69 NE 3 10866 10866 7666 White 19
1 PM Mon 75 71 NE 3 11274 11274 8074 White 21
2 PM Mon 75 70 NE 3 11070 11070 7870 White 20
3 PM Mon 74 68 NE 3 10661 10661 7461 White 18
4 PM Mon 74 67 NE 3 10456 10456 7256 White 17
5 PM Mon 73 64 NW 8 9832 8040 4840 White 14
6 PM Mon 71 61 NW 8 8117 6035 2835 Blue 11
7 PM Mon 70 60 NW 8 7424 5553 2353 Blue 10
8 PM Mon 68 58 NW 8 6084 4980 1780 Blue 8
9 PM Mon 67 57 NW 8 5604 4387 1187 Blue 7
10 PM Mon 65 55 NW 8 5022 3723 523 Blue 5
11 PM Mon 65 55 N 7 5022 3723 523 Blue 5
12 Midnight Tue 64 54 N 7 4406 3489 289 Blue 4
1 AM Tue 64 54 N 7 4406 3489 289 Blue 4
2 AM Tue 64 54 N 7 4406 3489 289 Blue 4
3 AM Tue 64 54 N 7 4406 3489 289 Blue 4
4 AM Tue 63 53 N 7 4035 3240 40 Blue 3
5 AM Tue 63 53 N 5 4035 3240 40 Blue 3
6 AM Tue 62 52 N 5 3730 3200 0 Blue 2
7 AM Tue 62 52 N 5 3730 3200 0 Blue 2
8 AM Tue 64 54 N 5 4406 3489 289 Blue 4
9 AM Tue 67 58 N 5 6084 4980 1780 Blue 8
10 AM Tue 72 65 N 5 10043 8387 5187 White 15
11 AM Tue 76 70 E 3 11070 11070 7870 White 20
12 Noon Tue 78 73 E 3 11679 11679 8479 White 23
1 PM Tue 79 75 E 3 12081 12081 8881 White 25
2 PM Tue 79 74 E 3 11881 11881 8681 White 24
3 PM Tue 78 72 E 3 11477 11477 8277 White 22
4 PM Tue 77 70 E 3 11070 11070 7870 White 20
5 PM Tue 76 67 NW 5 10456 10456 7256 White 17
6 PM Tue 74 64 NW 5 9832 8040 4840 White 14
7 PM Tue 72 62 NW 5 8450 6523 3323 Blue 12
8 PM Tue 71 61 NW 5 8117 6035 2835 Blue 11
9 PM Tue 69 59 NW 5 6626 5334 2134 Blue 9
10 PM Tue 67 57 NW 5 5604 4387 1187 Blue 7
11 PM Tue 66 56 NE 5 5349 4020 820 Blue 6
12 Midnight Wed 66 56 NE 5 5349 4020 820 Blue 6
1 AM Wed 66 56 NE 5 5349 4020 820 Blue 6
2 AM Wed 65 55 NE 5 5022 3723 523 Blue 5
3 AM Wed 64 54 NE 5 4406 3489 289 Blue 4
4 AM Wed 64 54 NE 5 4406 3489 289 Blue 4
5 AM Wed 63 53 E 5 4035 3240 40 Blue 3
6 AM Wed 63 53 E 5 4035 3240 40 Blue 3
7 AM Wed 64 54 E 5 4406 3489 289 Blue 4
8 AM Wed 66 56 E 5 5349 4020 820 Blue 6
9 AM Wed 69 60 E 5 7424 5553 2353 Blue 10
10 AM Wed 74 66 E 5 10249 9360 6160 White 16
11 AM Wed 77 70 E 3 11070 11070 7870 White 20
12 Noon Wed 79 73 E 3 11679 11679 8479 White 23
1 PM Wed 80 75 E 3 12081 12081 8881 White 25
2 PM Wed 80 75 E 3 12081 12081 8881 White 25
3 PM Wed 80 74 E 3 11881 11881 8681 White 24
4 PM Wed 79 71 E 3 11274 11274 8074 White 21
5 PM Wed 78 69 W 5 10866 10866 7666 White 19
6 PM Wed 76 66 W 5 10249 9360 6160 White 16
7 PM Wed 74 64 W 5 9832 8040 4840 White 14
8 PM Wed 72 62 W 5 8450 6523 3323 Blue 12
9 PM Wed 70 60 W 5 7424 5553 2353 Blue 10
10 PM Wed 69 59 W 5 6626 5334 2134 Blue 9
11 PM Wed 68 58 N 3 6084 4980 1780 Blue 8
12 Midnight Thu 68 58 N 3 6084 4980 1780 Blue 8
1 AM Thu 67 57 N 3 5604 4387 1187 Blue 7
2 AM Thu 67 57 N 3 5604 4387 1187 Blue 7
3 AM Thu 66 56 N 3 5349 4020 820 Blue 6
4 AM Thu 66 56 N 3 5349 4020 820 Blue 6

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