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

Station:

KOAK

Date/Time:

17 JAN 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)
4 AM Wed 56 46 W 3 2792 3200 0 Blue 0
5 AM Wed 55 45 W 3 2792 3200 0 Blue 0
6 AM Wed 58 48 W 3 2792 3200 0 Blue 0
7 AM Wed 55 45 N 3 2792 3200 0 Blue 0
8 AM Wed 57 47 N 3 2792 3200 0 Blue 0
9 AM Wed 59 49 N 3 2792 3200 0 Blue 0
10 AM Wed 62 53 NW 3 3080 3200 0 Blue 1
11 AM Wed 61 52 NW 3 2792 3200 0 Blue 0
12 Noon Wed 64 55 NW 3 3453 3200 0 Blue 3
1 PM Wed 64 55 E 2 3453 3200 0 Blue 3
2 PM Wed 65 56 E 2 3531 3200 0 Blue 4
3 PM Wed 65 55 E 2 3453 3200 0 Blue 3
4 PM Wed 62 52 E 3 2792 3200 0 Blue 0
5 PM Wed 58 48 E 3 2792 3200 0 Blue 0
6 PM Wed 58 48 E 3 2792 3200 0 Blue 0
7 PM Wed 58 48 NW 1 2792 3200 0 Blue 0
8 PM Wed 57 47 NW 1 2792 3200 0 Blue 0
9 PM Wed 56 46 NW 1 2792 3200 0 Blue 0
10 PM Wed 55 45 W 2 2792 3200 0 Blue 0
11 PM Wed 56 46 W 2 2792 3200 0 Blue 0
12 Midnight Thu 55 45 W 2 2792 3200 0 Blue 0
1 AM Thu 56 46 W 3 2792 3200 0 Blue 0
2 AM Thu 56 46 W 3 2792 3200 0 Blue 0
3 AM Thu 56 46 W 3 2792 3200 0 Blue 0
4 AM Thu 56 46 W 6 2792 3200 0 Blue 0
5 AM Thu 54 44 W 6 2792 3200 0 Blue 0
6 AM Thu 55 45 W 6 2792 3200 0 Blue 0
7 AM Thu 54 44 W 7 2792 3200 0 Blue 0
8 AM Thu 55 45 W 7 2792 3200 0 Blue 0
9 AM Thu 56 46 W 7 2792 3200 0 Blue 0
10 AM Thu 58 48 W 9 2792 3200 0 Blue 0
11 AM Thu 57 47 W 9 2792 3200 0 Blue 0
12 Noon Thu 59 49 W 9 2792 3200 0 Blue 0
1 PM Thu 59 49 W 12 2792 3200 0 Blue 0
2 PM Thu 59 49 W 12 2792 3200 0 Blue 0
3 PM Thu 59 49 W 12 2792 3200 0 Blue 0
4 PM Thu 56 46 NW 14 2792 3200 0 Blue 0
5 PM Thu 50 40 NW 14 2792 3200 0 Blue 0
6 PM Thu 50 40 NW 14 2792 3200 0 Blue 0
7 PM Thu 50 40 NW 14 2792 3200 0 Blue 0
8 PM Thu 49 39 NW 14 2792 3200 0 Blue 0
9 PM Thu 48 38 NW 14 2792 3200 0 Blue 0
10 PM Thu 47 37 W 10 2792 3200 0 Blue 0
11 PM Thu 48 38 W 10 2792 3200 0 Blue 0
12 Midnight Fri 47 37 W 10 2792 3200 0 Blue 0
1 AM Fri 48 38 W 10 2792 3200 0 Blue 0
2 AM Fri 48 38 W 10 2792 3200 0 Blue 0
3 AM Fri 47 37 W 10 2792 3200 0 Blue 0
4 AM Fri 48 38 W 15 2792 3200 0 Blue 0
5 AM Fri 46 36 W 15 2792 3200 0 Blue 0
6 AM Fri 47 37 W 15 2792 3200 0 Blue 0
7 AM Fri 46 36 W 15 2792 3200 0 Blue 0
8 AM Fri 46 36 W 15 2792 3200 0 Blue 0
9 AM Fri 47 37 W 15 2792 3200 0 Blue 0
10 AM Fri 48 38 NW 15 2792 3200 0 Blue 0
11 AM Fri 48 38 NW 15 2792 3200 0 Blue 0
12 Noon Fri 49 39 NW 15 2792 3200 0 Blue 0
1 PM Fri 49 39 NW 15 2792 3200 0 Blue 0
2 PM Fri 49 39 NW 15 2792 3200 0 Blue 0
3 PM Fri 49 39 NW 15 2792 3200 0 Blue 0
4 PM Fri 47 37 N 14 2792 3200 0 Blue 0
5 PM Fri 43 33 N 14 2792 3200 0 Blue 0
6 PM Fri 43 33 N 14 2792 3200 0 Blue 0
7 PM Fri 42 32 N 14 2792 3200 0 Blue 0
8 PM Fri 42 32 N 14 2792 3200 0 Blue 0
9 PM Fri 42 32 N 14 2792 3200 0 Blue 0
10 PM Fri 41 31 NW 14 2792 3200 0 Blue 0
11 PM Fri 42 32 NW 14 2792 3200 0 Blue 0
12 Midnight Sat 40 30 NW 14 2792 3200 0 Blue 0
1 AM Sat 42 32 NW 14 2792 3200 0 Blue 0
2 AM Sat 41 31 NW 14 2792 3200 0 Blue 0
3 AM Sat 41 31 NW 14 2792 3200 0 Blue 0
4 AM Sat 42 32 NW 15 2792 3200 0 Blue 0
5 AM Sat 40 30 NW 15 2792 3200 0 Blue 0
6 AM Sat 41 31 NW 15 2792 3200 0 Blue 0
7 AM Sat 40 30 NW 15 2792 3200 0 Blue 0
8 AM Sat 41 31 NW 15 2792 3200 0 Blue 0
9 AM Sat 43 33 NW 15 2792 3200 0 Blue 0
10 AM Sat 46 37 NW 13 2792 3200 0 Blue 0
11 AM Sat 45 36 NW 13 2792 3200 0 Blue 0
12 Noon Sat 47 39 NW 13 2792 3200 0 Blue 0
1 PM Sat 47 39 NW 13 2792 3200 0 Blue 0
2 PM Sat 48 39 NW 13 2792 3200 0 Blue 0
3 PM Sat 48 38 NW 13 2792 3200 0 Blue 0
4 PM Sat 46 36 NW 13 2792 3200 0 Blue 0
5 PM Sat 44 34 NW 13 2792 3200 0 Blue 0
6 PM Sat 44 34 NW 13 2792 3200 0 Blue 0
7 PM Sat 44 34 NW 13 2792 3200 0 Blue 0
8 PM Sat 44 34 NW 13 2792 3200 0 Blue 0
9 PM Sat 43 33 NW 13 2792 3200 0 Blue 0
10 PM Sat 42 32 NW 10 2792 3200 0 Blue 0
11 PM Sat 43 33 NW 10 2792 3200 0 Blue 0
12 Midnight Sun 42 32 NW 10 2792 3200 0 Blue 0
1 AM Sun 43 33 NW 10 2792 3200 0 Blue 0
2 AM Sun 43 33 NW 10 2792 3200 0 Blue 0
3 AM Sun 43 33 NW 10 2792 3200 0 Blue 0
4 AM Sun 43 33 NW 6 2792 3200 0 Blue 0
5 AM Sun 42 32 NW 6 2792 3200 0 Blue 0
6 AM Sun 42 32 NW 6 2792 3200 0 Blue 0
7 AM Sun 42 32 NW 6 2792 3200 0 Blue 0
8 AM Sun 44 34 NW 6 2792 3200 0 Blue 0
9 AM Sun 46 36 NW 6 2792 3200 0 Blue 0
10 AM Sun 50 40 N 5 2792 3200 0 Blue 0
11 AM Sun 48 39 N 5 2792 3200 0 Blue 0
12 Noon Sun 52 43 N 5 2792 3200 0 Blue 0
1 PM Sun 52 43 N 5 2792 3200 0 Blue 0
2 PM Sun 52 42 N 5 2792 3200 0 Blue 0
3 PM Sun 52 42 N 5 2792 3200 0 Blue 0
4 PM Sun 51 41 NW 7 2792 3200 0 Blue 0
5 PM Sun 49 39 NW 7 2792 3200 0 Blue 0
6 PM Sun 49 39 NW 7 2792 3200 0 Blue 0
7 PM Sun 49 39 NW 7 2792 3200 0 Blue 0
8 PM Sun 48 38 NW 7 2792 3200 0 Blue 0
9 PM Sun 48 38 NW 7 2792 3200 0 Blue 0
10 PM Sun 48 38 W 5 2792 3200 0 Blue 0
11 PM Sun 48 38 W 5 2792 3200 0 Blue 0
12 Midnight Mon 48 38 W 5 2792 3200 0 Blue 0
1 AM Mon 48 38 W 5 2792 3200 0 Blue 0
2 AM Mon 48 38 W 5 2792 3200 0 Blue 0
3 AM Mon 48 38 W 5 2792 3200 0 Blue 0
4 AM Mon 48 38 SW 6 2792 3200 0 Blue 0
5 AM Mon 47 37 SW 6 2792 3200 0 Blue 0
6 AM Mon 48 38 SW 6 2792 3200 0 Blue 0
7 AM Mon 47 37 SW 6 2792 3200 0 Blue 0
8 AM Mon 49 39 SW 6 2792 3200 0 Blue 0
9 AM Mon 50 40 SW 6 2792 3200 0 Blue 0
10 AM Mon 53 43 W 7 2792 3200 0 Blue 0
11 AM Mon 52 42 W 7 2792 3200 0 Blue 0
12 Noon Mon 55 45 W 7 2792 3200 0 Blue 0
1 PM Mon 55 45 W 7 2792 3200 0 Blue 0
2 PM Mon 55 45 W 7 2792 3200 0 Blue 0
3 PM Mon 55 45 W 7 2792 3200 0 Blue 0
4 PM Mon 54 44 NW 8 2792 3200 0 Blue 0
5 PM Mon 52 42 NW 8 2792 3200 0 Blue 0
6 PM Mon 51 41 NW 8 2792 3200 0 Blue 0
7 PM Mon 51 41 NW 8 2792 3200 0 Blue 0
8 PM Mon 51 41 NW 8 2792 3200 0 Blue 0
9 PM Mon 50 40 NW 8 2792 3200 0 Blue 0
10 PM Mon 50 40 N 6 2792 3200 0 Blue 0
11 PM Mon 50 40 N 6 2792 3200 0 Blue 0
12 Midnight Tue 50 40 N 6 2792 3200 0 Blue 0
1 AM Tue 51 41 N 6 2792 3200 0 Blue 0
2 AM Tue 50 40 N 6 2792 3200 0 Blue 0
3 AM Tue 50 40 N 6 2792 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