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

Station:

KOAK

Date/Time:

26 NOV 2020

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 48 38 N 22 2733 3200 0 Blue 0
5 AM Thu 48 38 N 23 2733 3200 0 Blue 0
6 AM Thu 46 36 N 26 2733 3200 0 Blue 0
7 AM Thu 47 37 N 25 2733 3200 0 Blue 0
8 AM Thu 48 38 N 21 2733 3200 0 Blue 0
9 AM Thu 50 40 N 13 2733 3200 0 Blue 0
10 AM Thu 52 43 N 8 2733 3200 0 Blue 0
11 AM Thu 55 47 N 6 3969 3200 0 Blue 1
12 Noon Thu 56 48 NE 2 4355 3200 0 Blue 2
1 PM Thu 56 48 NE 7 4355 3200 0 Blue 2
2 PM Thu 55 46 NE 14 3561 3200 0 Blue 0
3 PM Thu 55 45 NE 15 2733 3200 0 Blue 0
4 PM Thu 54 44 NE 17 2733 3200 0 Blue 0
5 PM Thu 52 42 NE 21 2733 3200 0 Blue 0
6 PM Thu 50 40 NE 23 2733 3200 0 Blue 0
7 PM Thu 49 39 NE 21 2733 3200 0 Blue 0
8 PM Thu 49 39 NE 15 2733 3200 0 Blue 0
9 PM Thu 49 39 E 16 2733 3200 0 Blue 0
10 PM Thu 49 39 E 16 2733 3200 0 Blue 0
11 PM Thu 50 40 E 12 2733 3200 0 Blue 0
12 Midnight Fri 49 39 SE 7 2733 3200 0 Blue 0
1 AM Fri 48 38 SE 5 2733 3200 0 Blue 0
2 AM Fri 48 38 SE 5 2733 3200 0 Blue 0
3 AM Fri 48 38 SE 6 2733 3200 0 Blue 0
4 AM Fri 47 37 SE 5 2733 3200 0 Blue 0
5 AM Fri 48 38 SE 3 2733 3200 0 Blue 0
6 AM Fri 46 36 E 3 2733 3200 0 Blue 0
7 AM Fri 48 38 E 3 2733 3200 0 Blue 0
8 AM Fri 50 40 E 3 2733 3200 0 Blue 0
9 AM Fri 54 44 E 2 2733 3200 0 Blue 0
10 AM Fri 55 46 S 1 3561 3200 0 Blue 0
11 AM Fri 57 49 S 1 4736 3533 333 Blue 3
12 Noon Fri 58 50 S 1 4974 3954 754 Blue 4
1 PM Fri 57 49 W 2 4736 3533 333 Blue 3
2 PM Fri 57 48 W 2 4355 3200 0 Blue 2
3 PM Fri 56 46 W 2 3561 3200 0 Blue 0
4 PM Fri 55 45 N 1 2733 3200 0 Blue 0
5 PM Fri 54 44 N 1 2733 3200 0 Blue 0
6 PM Fri 52 42 N 1 2733 3200 0 Blue 0
7 PM Fri 51 41 E 3 2733 3200 0 Blue 0
8 PM Fri 51 41 E 3 2733 3200 0 Blue 0
9 PM Fri 51 41 E 3 2733 3200 0 Blue 0
10 PM Fri 51 41 E 5 2733 3200 0 Blue 0
11 PM Fri 51 41 E 5 2733 3200 0 Blue 0
12 Midnight Sat 51 41 E 5 2733 3200 0 Blue 0
1 AM Sat 51 41 E 5 2733 3200 0 Blue 0
2 AM Sat 51 41 E 5 2733 3200 0 Blue 0
3 AM Sat 50 40 E 5 2733 3200 0 Blue 0
4 AM Sat 50 40 E 6 2733 3200 0 Blue 0
5 AM Sat 49 39 E 6 2733 3200 0 Blue 0
6 AM Sat 49 39 E 6 2733 3200 0 Blue 0
7 AM Sat 50 40 E 5 2733 3200 0 Blue 0
8 AM Sat 52 42 E 5 2733 3200 0 Blue 0
9 AM Sat 54 44 E 5 2733 3200 0 Blue 0
10 AM Sat 57 48 E 2 4355 3200 0 Blue 2
11 AM Sat 58 50 E 2 4974 3954 754 Blue 4
12 Noon Sat 59 51 E 2 5462 4335 1135 Blue 5
1 PM Sat 59 51 S 1 5462 4335 1135 Blue 5
2 PM Sat 59 50 S 1 4974 3954 754 Blue 4
3 PM Sat 59 49 S 1 4736 3533 333 Blue 3
4 PM Sat 58 48 E 3 4355 3200 0 Blue 2
5 PM Sat 57 47 E 3 3969 3200 0 Blue 1
6 PM Sat 55 45 E 3 2733 3200 0 Blue 0
7 PM Sat 54 44 E 7 2733 3200 0 Blue 0
8 PM Sat 53 43 E 7 2733 3200 0 Blue 0
9 PM Sat 53 43 E 7 2733 3200 0 Blue 0
10 PM Sat 52 42 NE 5 2733 3200 0 Blue 0
11 PM Sat 52 42 NE 5 2733 3200 0 Blue 0
12 Midnight Sun 52 42 NE 5 2733 3200 0 Blue 0
1 AM Sun 51 41 NE 6 2733 3200 0 Blue 0
2 AM Sun 51 41 NE 6 2733 3200 0 Blue 0
3 AM Sun 50 40 NE 6 2733 3200 0 Blue 0
4 AM Sun 50 40 NE 6 2733 3200 0 Blue 0
5 AM Sun 50 40 NE 6 2733 3200 0 Blue 0
6 AM Sun 50 40 NE 6 2733 3200 0 Blue 0
7 AM Sun 50 40 NE 5 2733 3200 0 Blue 0
8 AM Sun 52 42 NE 5 2733 3200 0 Blue 0
9 AM Sun 55 45 NE 5 2733 3200 0 Blue 0
10 AM Sun 57 48 NE 2 4355 3200 0 Blue 2
11 AM Sun 59 51 NE 2 5462 4335 1135 Blue 5
12 Noon Sun 60 52 NE 2 5978 4712 1512 Blue 6
1 PM Sun 60 51 NW 1 5462 4335 1135 Blue 5
2 PM Sun 60 51 NW 1 5462 4335 1135 Blue 5
3 PM Sun 59 49 NW 1 4736 3533 333 Blue 3
4 PM Sun 58 48 NW 1 4355 3200 0 Blue 2
5 PM Sun 57 47 NW 1 3969 3200 0 Blue 1
6 PM Sun 55 45 NW 1 2733 3200 0 Blue 0
7 PM Sun 54 44 NW 2 2733 3200 0 Blue 0
8 PM Sun 53 43 NW 2 2733 3200 0 Blue 0
9 PM Sun 52 42 NW 2 2733 3200 0 Blue 0
10 PM Sun 52 42 N 3 2733 3200 0 Blue 0
11 PM Sun 52 42 N 3 2733 3200 0 Blue 0
12 Midnight Mon 52 42 N 3 2733 3200 0 Blue 0
1 AM Mon 52 42 N 5 2733 3200 0 Blue 0
2 AM Mon 52 42 N 5 2733 3200 0 Blue 0
3 AM Mon 51 41 N 5 2733 3200 0 Blue 0
4 AM Mon 50 40 N 6 2733 3200 0 Blue 0
5 AM Mon 49 39 N 6 2733 3200 0 Blue 0
6 AM Mon 49 39 N 6 2733 3200 0 Blue 0
7 AM Mon 50 40 N 6 2733 3200 0 Blue 0
8 AM Mon 52 42 N 6 2733 3200 0 Blue 0
9 AM Mon 54 44 N 6 2733 3200 0 Blue 0
10 AM Mon 56 47 N 3 3969 3200 0 Blue 1
11 AM Mon 58 49 N 3 4736 3533 333 Blue 3
12 Noon Mon 59 51 N 3 5462 4335 1135 Blue 5
1 PM Mon 59 50 NW 2 4974 3954 754 Blue 4
2 PM Mon 60 51 NW 2 5462 4335 1135 Blue 5
3 PM Mon 59 49 NW 2 4736 3533 333 Blue 3
4 PM Mon 58 48 NW 2 4355 3200 0 Blue 2
5 PM Mon 57 47 NW 2 3969 3200 0 Blue 1
6 PM Mon 55 45 NW 2 2733 3200 0 Blue 0
7 PM Mon 53 43 N 5 2733 3200 0 Blue 0
8 PM Mon 52 42 N 5 2733 3200 0 Blue 0
9 PM Mon 52 42 N 5 2733 3200 0 Blue 0
10 PM Mon 52 42 N 6 2733 3200 0 Blue 0
11 PM Mon 52 42 N 6 2733 3200 0 Blue 0
12 Midnight Tue 52 42 N 6 2733 3200 0 Blue 0
1 AM Tue 52 42 N 6 2733 3200 0 Blue 0
2 AM Tue 51 41 N 6 2733 3200 0 Blue 0
3 AM Tue 50 40 N 6 2733 3200 0 Blue 0
4 AM Tue 50 40 N 6 2733 3200 0 Blue 0
5 AM Tue 49 39 N 6 2733 3200 0 Blue 0
6 AM Tue 49 39 N 6 2733 3200 0 Blue 0
7 AM Tue 50 40 N 6 2733 3200 0 Blue 0
8 AM Tue 51 41 N 6 2733 3200 0 Blue 0
9 AM Tue 53 43 N 6 2733 3200 0 Blue 0
10 AM Tue 55 46 NE 5 3561 3200 0 Blue 0
11 AM Tue 57 49 NE 5 4736 3533 333 Blue 3
12 Noon Tue 58 50 NE 5 4974 3954 754 Blue 4
1 PM Tue 59 51 N 2 5462 4335 1135 Blue 5
2 PM Tue 59 50 N 2 4974 3954 754 Blue 4
3 PM Tue 59 49 N 2 4736 3533 333 Blue 3
4 PM Tue 58 48 NW 1 4355 3200 0 Blue 2
5 PM Tue 57 47 NW 1 3969 3200 0 Blue 1
6 PM Tue 56 46 NW 1 3561 3200 0 Blue 0
7 PM Tue 54 44 N 2 2733 3200 0 Blue 0
8 PM Tue 54 44 N 2 2733 3200 0 Blue 0
9 PM Tue 54 44 N 2 2733 3200 0 Blue 0
10 PM Tue 53 43 NE 3 2733 3200 0 Blue 0
11 PM Tue 53 43 NE 3 2733 3200 0 Blue 0
12 Midnight Wed 53 43 NE 3 2733 3200 0 Blue 0
1 AM Wed 52 42 NE 6 2733 3200 0 Blue 0
2 AM Wed 52 42 NE 6 2733 3200 0 Blue 0
3 AM Wed 51 41 NE 6 2733 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 [email protected]