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

Station:

KOAK

Date/Time:

N/A

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 Thu 49 39 SW 22 N/A N/A N/A N/A N/A
5 AM Thu 48 38 SW 22 N/A N/A N/A N/A N/A
6 AM Thu 49 39 SW 22 N/A N/A N/A N/A N/A
7 AM Thu 48 38 SW 20 N/A N/A N/A N/A N/A
8 AM Thu 49 39 SW 20 N/A N/A N/A N/A N/A
9 AM Thu 50 40 SW 20 N/A N/A N/A N/A N/A
10 AM Thu 50 40 SW 22 N/A N/A N/A N/A N/A
11 AM Thu 50 40 SW 22 N/A N/A N/A N/A N/A
12 Noon Thu 50 40 SW 22 N/A N/A N/A N/A N/A
1 PM Thu 50 40 W 23 N/A N/A N/A N/A N/A
2 PM Thu 50 40 W 23 N/A N/A N/A N/A N/A
3 PM Thu 50 40 W 23 N/A N/A N/A N/A N/A
4 PM Thu 50 40 W 17 N/A N/A N/A N/A N/A
5 PM Thu 48 38 W 17 N/A N/A N/A N/A N/A
6 PM Thu 48 38 W 17 N/A N/A N/A N/A N/A
7 PM Thu 47 37 W 15 N/A N/A N/A N/A N/A
8 PM Thu 47 37 W 15 N/A N/A N/A N/A N/A
9 PM Thu 47 37 W 15 N/A N/A N/A N/A N/A
10 PM Thu 47 37 W 7 N/A N/A N/A N/A N/A
11 PM Thu 47 37 W 7 N/A N/A N/A N/A N/A
12 Midnight Fri 47 37 W 7 N/A N/A N/A N/A N/A
1 AM Fri 46 36 W 6 N/A N/A N/A N/A N/A
2 AM Fri 46 36 W 6 N/A N/A N/A N/A N/A
3 AM Fri 45 35 W 6 N/A N/A N/A N/A N/A
4 AM Fri 45 35 N 5 N/A N/A N/A N/A N/A
5 AM Fri 44 34 N 5 N/A N/A N/A N/A N/A
6 AM Fri 44 34 N 5 N/A N/A N/A N/A N/A
7 AM Fri 44 34 N 2 N/A N/A N/A N/A N/A
8 AM Fri 49 39 N 2 N/A N/A N/A N/A N/A
9 AM Fri 51 41 N 2 N/A N/A N/A N/A N/A
10 AM Fri 53 44 NW 2 N/A N/A N/A N/A N/A
11 AM Fri 52 43 NW 2 N/A N/A N/A N/A N/A
12 Noon Fri 53 45 NW 2 N/A N/A N/A N/A N/A
1 PM Fri 53 45 NW 2 N/A N/A N/A N/A N/A
2 PM Fri 54 45 NW 2 N/A N/A N/A N/A N/A
3 PM Fri 53 43 NW 2 N/A N/A N/A N/A N/A
4 PM Fri 54 44 NE 6 N/A N/A N/A N/A N/A
5 PM Fri 52 42 NE 6 N/A N/A N/A N/A N/A
6 PM Fri 51 41 NE 6 N/A N/A N/A N/A N/A
7 PM Fri 50 40 NE 6 N/A N/A N/A N/A N/A
8 PM Fri 50 40 NE 6 N/A N/A N/A N/A N/A
9 PM Fri 51 41 NE 6 N/A N/A N/A N/A N/A
10 PM Fri 51 41 N 3 N/A N/A N/A N/A N/A
11 PM Fri 50 40 N 3 N/A N/A N/A N/A N/A
12 Midnight Sat 50 40 N 3 N/A N/A N/A N/A N/A
1 AM Sat 49 39 N 3 N/A N/A N/A N/A N/A
2 AM Sat 49 39 N 3 N/A N/A N/A N/A N/A
3 AM Sat 48 38 N 3 N/A N/A N/A N/A N/A
4 AM Sat 48 38 NE 6 N/A N/A N/A N/A N/A
5 AM Sat 47 37 NE 6 N/A N/A N/A N/A N/A
6 AM Sat 47 37 NE 6 N/A N/A N/A N/A N/A
7 AM Sat 47 37 NE 6 N/A N/A N/A N/A N/A
8 AM Sat 53 43 NE 6 N/A N/A N/A N/A N/A
9 AM Sat 56 46 NE 6 N/A N/A N/A N/A N/A
10 AM Sat 58 49 W 2 N/A N/A N/A N/A N/A
11 AM Sat 57 48 W 2 N/A N/A N/A N/A N/A
12 Noon Sat 58 49 W 2 N/A N/A N/A N/A N/A
1 PM Sat 58 49 W 2 N/A N/A N/A N/A N/A
2 PM Sat 59 50 W 2 N/A N/A N/A N/A N/A
3 PM Sat 58 48 W 2 N/A N/A N/A N/A N/A
4 PM Sat 59 49 W 3 N/A N/A N/A N/A N/A
5 PM Sat 56 46 W 3 N/A N/A N/A N/A N/A
6 PM Sat 54 44 W 3 N/A N/A N/A N/A N/A
7 PM Sat 53 43 W 3 N/A N/A N/A N/A N/A
8 PM Sat 54 44 W 3 N/A N/A N/A N/A N/A
9 PM Sat 54 44 W 3 N/A N/A N/A N/A N/A
10 PM Sat 54 44 W 7 N/A N/A N/A N/A N/A
11 PM Sat 54 44 W 7 N/A N/A N/A N/A N/A
12 Midnight Sun 53 43 W 7 N/A N/A N/A N/A N/A
1 AM Sun 52 42 W 7 N/A N/A N/A N/A N/A
2 AM Sun 51 41 W 7 N/A N/A N/A N/A N/A
3 AM Sun 50 40 W 7 N/A N/A N/A N/A N/A
4 AM Sun 50 40 W 5 N/A N/A N/A N/A N/A
5 AM Sun 49 39 W 5 N/A N/A N/A N/A N/A
6 AM Sun 49 39 W 5 N/A N/A N/A N/A N/A
7 AM Sun 48 38 W 5 N/A N/A N/A N/A N/A
8 AM Sun 52 42 W 5 N/A N/A N/A N/A N/A
9 AM Sun 54 44 W 5 N/A N/A N/A N/A N/A
10 AM Sun 55 45 NW 8 N/A N/A N/A N/A N/A
11 AM Sun 54 45 NW 8 N/A N/A N/A N/A N/A
12 Noon Sun 55 46 NW 8 N/A N/A N/A N/A N/A
1 PM Sun 55 46 NW 8 N/A N/A N/A N/A N/A
2 PM Sun 55 45 NW 8 N/A N/A N/A N/A N/A
3 PM Sun 54 44 NW 8 N/A N/A N/A N/A N/A
4 PM Sun 55 45 NW 14 N/A N/A N/A N/A N/A
5 PM Sun 51 41 NW 14 N/A N/A N/A N/A N/A
6 PM Sun 49 39 NW 14 N/A N/A N/A N/A N/A
7 PM Sun 48 38 NW 14 N/A N/A N/A N/A N/A
8 PM Sun 49 39 NW 14 N/A N/A N/A N/A N/A
9 PM Sun 49 39 NW 14 N/A N/A N/A N/A N/A
10 PM Sun 49 39 N 15 N/A N/A N/A N/A N/A
11 PM Sun 48 38 N 15 N/A N/A N/A N/A N/A
12 Midnight Mon 47 37 N 15 N/A N/A N/A N/A N/A
1 AM Mon 46 36 N 15 N/A N/A N/A N/A N/A
2 AM Mon 45 35 N 15 N/A N/A N/A N/A N/A
3 AM Mon 44 34 N 15 N/A N/A N/A N/A N/A
4 AM Mon 44 34 N 14 N/A N/A N/A N/A N/A
5 AM Mon 42 32 N 14 N/A N/A N/A N/A N/A
6 AM Mon 42 32 N 14 N/A N/A N/A N/A N/A
7 AM Mon 42 32 N 14 N/A N/A N/A N/A N/A
8 AM Mon 46 36 N 14 N/A N/A N/A N/A N/A
9 AM Mon 48 38 N 14 N/A N/A N/A N/A N/A
10 AM Mon 49 40 N 14 N/A N/A N/A N/A N/A
11 AM Mon 48 40 N 14 N/A N/A N/A N/A N/A
12 Noon Mon 49 41 N 14 N/A N/A N/A N/A N/A
1 PM Mon 49 41 N 14 N/A N/A N/A N/A N/A
2 PM Mon 50 41 N 14 N/A N/A N/A N/A N/A
3 PM Mon 49 40 N 14 N/A N/A N/A N/A N/A
4 PM Mon 50 40 N 14 N/A N/A N/A N/A N/A
5 PM Mon 47 37 N 14 N/A N/A N/A N/A N/A
6 PM Mon 46 36 N 14 N/A N/A N/A N/A N/A
7 PM Mon 46 36 N 14 N/A N/A N/A N/A N/A
8 PM Mon 46 36 N 14 N/A N/A N/A N/A N/A
9 PM Mon 46 36 N 14 N/A N/A N/A N/A N/A
10 PM Mon 46 36 N 14 N/A N/A N/A N/A N/A
11 PM Mon 46 36 N 14 N/A N/A N/A N/A N/A
12 Midnight Tue 45 35 N 14 N/A N/A N/A N/A N/A
1 AM Tue 44 34 N 14 N/A N/A N/A N/A N/A
2 AM Tue 44 34 N 14 N/A N/A N/A N/A N/A
3 AM Tue 43 33 N 14 N/A N/A N/A N/A N/A
4 AM Tue 43 33 N 13 N/A N/A N/A N/A N/A
5 AM Tue 42 32 N 13 N/A N/A N/A N/A N/A
6 AM Tue 42 32 N 13 N/A N/A N/A N/A N/A
7 AM Tue 42 32 N 13 N/A N/A N/A N/A N/A
8 AM Tue 47 37 N 13 N/A N/A N/A N/A N/A
9 AM Tue 50 40 N 13 N/A N/A N/A N/A N/A
10 AM Tue 52 43 N 10 N/A N/A N/A N/A N/A
11 AM Tue 51 43 N 10 N/A N/A N/A N/A N/A
12 Noon Tue 52 44 N 10 N/A N/A N/A N/A N/A
1 PM Tue 52 44 N 10 N/A N/A N/A N/A N/A
2 PM Tue 53 44 N 10 N/A N/A N/A N/A N/A
3 PM Tue 52 43 N 10 N/A N/A N/A N/A N/A
4 PM Tue 53 43 N 7 N/A N/A N/A N/A N/A
5 PM Tue 50 40 N 7 N/A N/A N/A N/A N/A
6 PM Tue 49 39 N 7 N/A N/A N/A N/A N/A
7 PM Tue 48 38 N 7 N/A N/A N/A N/A N/A
8 PM Tue 48 38 N 7 N/A N/A N/A N/A N/A
9 PM Tue 49 39 N 7 N/A N/A N/A N/A N/A
10 PM Tue 49 39 NE 7 N/A N/A N/A N/A N/A
11 PM Tue 48 38 NE 7 N/A N/A N/A N/A N/A
12 Midnight Wed 48 38 NE 7 N/A N/A N/A N/A N/A
1 AM Wed 47 37 NE 7 N/A N/A N/A N/A N/A
2 AM Wed 46 36 NE 7 N/A N/A N/A N/A N/A
3 AM Wed 46 36 NE 7 N/A N/A N/A N/A N/A

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