Detailed Predictions for: Big Sur
Launch Lat, Long, Altitude (f): 36.0, -121.47, 3200
LZ Altitude (f): 60
Sounding

Station:

KOAK

Date/Time:

21 SEP 2021

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Tue 74 64 ENE 13 17 2621 3200 0 Blue 0
1 AM Tue 74 64 E 13 17 2621 3200 0 Blue 0
2 AM Tue 74 64 E 13 17 2621 3200 0 Blue 0
3 AM Tue 74 64 E 13 17 2621 3200 0 Blue 0
4 AM Tue 73 63 ESE 11 13 2621 3200 0 Blue 0
5 AM Tue 72 62 ESE 9 11 2621 3200 0 Blue 0
6 AM Tue 72 62 ESE 9 11 2621 3200 0 Blue 0
7 AM Tue 71 61 ESE 9 11 2621 3200 0 Blue 0
8 AM Tue 72 62 ESE 8 9 2621 3200 0 Blue 0
9 AM Tue 75 66 E 6 8 2621 3200 0 Blue 0
10 AM Tue 77 69 E 5 6 2621 3200 0 Blue 0
11 AM Tue 77 71 ESE 4 4 2621 3200 0 Blue 0
12 Noon Tue 78 73 SSE 4 5 3776 3200 0 Blue 0
1 PM Tue 78 74 S 5 6 3852 3200 0 Blue 1
2 PM Tue 78 73 S 6 8 3776 3200 0 Blue 0
3 PM Tue 77 71 S 6 9 2621 3200 0 Blue 0
4 PM Tue 77 70 S 6 8 2621 3200 0 Blue 0
5 PM Tue 76 67 S 6 8 2621 3200 0 Blue 0
6 PM Tue 76 66 S 6 9 2621 3200 0 Blue 0
7 PM Tue 74 64 S 6 8 2621 3200 0 Blue 0
8 PM Tue 70 60 S 5 8 2621 3200 0 Blue 0
9 PM Tue 69 59 SSE 6 9 2621 3200 0 Blue 0
10 PM Tue 70 60 SE 9 11 2621 3200 0 Blue 0
11 PM Tue 69 59 SE 9 11 2621 3200 0 Blue 0
12 Midnight Wed 70 60 SE 8 9 2621 3200 0 Blue 0
1 AM Wed 69 59 SSE 6 9 2621 3200 0 Blue 0
2 AM Wed 68 58 SSE 6 9 2621 3200 0 Blue 0
3 AM Wed 66 56 SSE 6 8 2621 3200 0 Blue 0
4 AM Wed 67 57 SSE 5 8 2621 3200 0 Blue 0
5 AM Wed 66 56 SSE 5 6 2621 3200 0 Blue 0
6 AM Wed 68 58 SSE 4 6 2621 3200 0 Blue 0
7 AM Wed 66 56 SE 4 6 2621 3200 0 Blue 0
8 AM Wed 68 58 SSE 4 5 2621 3200 0 Blue 0
9 AM Wed 71 62 SSE 3 4 2621 3200 0 Blue 0
10 AM Wed 73 65 SSE 4 5 2621 3200 0 Blue 0
11 AM Wed 73 66 S 4 6 2621 3200 0 Blue 0
12 Noon Wed 73 67 S 4 6 2621 3200 0 Blue 0
1 PM Wed 74 69 S 4 6 2621 3200 0 Blue 0
2 PM Wed 74 69 WSW 4 5 2621 3200 0 Blue 0
3 PM Wed 74 68 WSW 4 5 2621 3200 0 Blue 0
4 PM Wed 74 66 WSW 4 5 2621 3200 0 Blue 0
5 PM Wed 73 64 W 4 5 2621 3200 0 Blue 0
6 PM Wed 72 62 W 4 5 2621 3200 0 Blue 0
7 PM Wed 71 61 W 4 5 2621 3200 0 Blue 0
8 PM Wed 70 60 WNW 3 4 2621 3200 0 Blue 0
9 PM Wed 68 58 WNW 3 4 2621 3200 0 Blue 0
10 PM Wed 67 57 WNW 3 4 2621 3200 0 Blue 0
11 PM Wed 66 56 WNW 3 4 2621 3200 0 Blue 0
12 Midnight Thu 66 56 WNW 3 4 2621 3200 0 Blue 0
1 AM Thu 66 56 WNW 3 4 2621 3200 0 Blue 0
2 AM Thu 66 56 NW 2 3 2621 3200 0 Blue 0
3 AM Thu 66 56 NW 2 3 2621 3200 0 Blue 0
4 AM Thu 65 55 NW 2 3 2621 3200 0 Blue 0
5 AM Thu 65 55 NNE 4 5 2621 3200 0 Blue 0
6 AM Thu 65 55 NNE 4 5 2621 3200 0 Blue 0
7 AM Thu 66 56 NNE 4 5 2621 3200 0 Blue 0
8 AM Thu 67 57 NE 4 5 2621 3200 0 Blue 0
9 AM Thu 69 60 NE 4 5 2621 3200 0 Blue 0
10 AM Thu 71 63 NE 4 5 2621 3200 0 Blue 0
11 AM Thu 73 67 NNW 2 3 2621 3200 0 Blue 0
12 Noon Thu 74 69 NNW 2 3 2621 3200 0 Blue 0
1 PM Thu 74 69 NNW 2 3 2621 3200 0 Blue 0
2 PM Thu 74 69 WNW 3 4 2621 3200 0 Blue 0
3 PM Thu 74 68 WNW 3 4 2621 3200 0 Blue 0
4 PM Thu 74 66 WNW 3 4 2621 3200 0 Blue 0
5 PM Thu 73 64 NW 2 2 2621 3200 0 Blue 0
6 PM Thu 72 62 NW 2 2 2621 3200 0 Blue 0
7 PM Thu 71 61 NW 2 2 2621 3200 0 Blue 0
8 PM Thu 70 60 NE 4 5 2621 3200 0 Blue 0
9 PM Thu 69 59 NE 4 5 2621 3200 0 Blue 0
10 PM Thu 68 58 NE 4 5 2621 3200 0 Blue 0
11 PM Thu 67 57 NE 8 10 2621 3200 0 Blue 0
12 Midnight Fri 67 57 NE 8 10 2621 3200 0 Blue 0
1 AM Fri 67 57 NE 8 10 2621 3200 0 Blue 0
2 AM Fri 67 57 E 6 9 2621 3200 0 Blue 0
3 AM Fri 66 56 E 6 9 2621 3200 0 Blue 0
4 AM Fri 66 56 E 6 9 2621 3200 0 Blue 0
5 AM Fri 65 55 E 6 8 2621 3200 0 Blue 0
6 AM Fri 66 56 E 6 8 2621 3200 0 Blue 0
7 AM Fri 67 57 E 6 8 2621 3200 0 Blue 0
8 AM Fri 68 58 ESE 2 3 2621 3200 0 Blue 0
9 AM Fri 70 61 ESE 2 3 2621 3200 0 Blue 0
10 AM Fri 71 63 ESE 2 3 2621 3200 0 Blue 0
11 AM Fri 73 67 S 2 2 2621 3200 0 Blue 0
12 Noon Fri 73 68 S 2 2 2621 3200 0 Blue 0
1 PM Fri 73 68 S 2 2 2621 3200 0 Blue 0
2 PM Fri 73 68 SW 2 3 2621 3200 0 Blue 0
3 PM Fri 73 67 SW 2 3 2621 3200 0 Blue 0
4 PM Fri 73 65 SW 2 3 2621 3200 0 Blue 0
5 PM Fri 72 63 W 1 1 2621 3200 0 Blue 0
6 PM Fri 72 62 W 1 1 2621 3200 0 Blue 0
7 PM Fri 71 61 W 1 1 2621 3200 0 Blue 0
8 PM Fri 70 60 WNW 0 0 2621 3200 0 Blue 0
9 PM Fri 68 58 WNW 0 0 2621 3200 0 Blue 0
10 PM Fri 67 57 WNW 0 0 2621 3200 0 Blue 0
11 PM Fri 67 57 NNW 0 0 2621 3200 0 Blue 0
12 Midnight Sat 66 56 NNW 0 0 2621 3200 0 Blue 0
1 AM Sat 66 56 NNW 0 0 2621 3200 0 Blue 0
2 AM Sat 66 56 N 1 1 2621 3200 0 Blue 0
3 AM Sat 66 56 N 1 1 2621 3200 0 Blue 0
4 AM Sat 65 55 N 1 1 2621 3200 0 Blue 0
5 AM Sat 65 55 NNW 1 1 2621 3200 0 Blue 0
6 AM Sat 65 55 NNW 1 1 2621 3200 0 Blue 0
7 AM Sat 66 56 NNW 1 1 2621 3200 0 Blue 0
8 AM Sat 67 57 N 2 2 2621 3200 0 Blue 0
9 AM Sat 68 59 N 2 2 2621 3200 0 Blue 0
10 AM Sat 69 61 N 2 2 2621 3200 0 Blue 0
11 AM Sat 70 64 SW 2 2 2621 3200 0 Blue 0
12 Noon Sat 71 66 SW 2 2 2621 3200 0 Blue 0
1 PM Sat 71 66 SW 2 2 2621 3200 0 Blue 0
2 PM Sat 71 66 WSW 3 4 2621 3200 0 Blue 0
3 PM Sat 71 65 WSW 3 4 2621 3200 0 Blue 0
4 PM Sat 70 62 WSW 3 4 2621 3200 0 Blue 0
5 PM Sat 70 61 W 2 2 2621 3200 0 Blue 0
6 PM Sat 69 59 W 2 2 2621 3200 0 Blue 0
7 PM Sat 68 58 W 2 2 2621 3200 0 Blue 0
8 PM Sat 67 57 WNW 1 1 2621 3200 0 Blue 0
9 PM Sat 66 56 WNW 1 1 2621 3200 0 Blue 0
10 PM Sat 66 56 WNW 1 1 2621 3200 0 Blue 0
11 PM Sat 65 55 NW 1 1 2621 3200 0 Blue 0
12 Midnight Sun 65 55 NW 1 1 2621 3200 0 Blue 0
1 AM Sun 65 55 NW 1 1 2621 3200 0 Blue 0
2 AM Sun 65 55 NNW 2 2 2621 3200 0 Blue 0
3 AM Sun 64 54 NNW 2 2 2621 3200 0 Blue 0
4 AM Sun 63 53 NNW 2 2 2621 3200 0 Blue 0
5 AM Sun 63 53 NW 2 2 2621 3200 0 Blue 0
6 AM Sun 63 53 NW 2 2 2621 3200 0 Blue 0
7 AM Sun 64 54 NW 2 2 2621 3200 0 Blue 0
8 AM Sun 65 55 NW 3 4 2621 3200 0 Blue 0
9 AM Sun 66 57 NW 3 4 2621 3200 0 Blue 0
10 AM Sun 67 59 NW 3 4 2621 3200 0 Blue 0
11 AM Sun 68 61 W 2 2 2621 3200 0 Blue 0
12 Noon Sun 68 62 W 2 2 2621 3200 0 Blue 0
1 PM Sun 68 62 W 2 2 2621 3200 0 Blue 0
2 PM Sun 68 62 W 3 4 2621 3200 0 Blue 0
3 PM Sun 68 62 W 3 4 2621 3200 0 Blue 0
4 PM Sun 67 59 W 3 4 2621 3200 0 Blue 0
5 PM Sun 67 58 W 3 4 2621 3200 0 Blue 0
6 PM Sun 66 56 W 3 4 2621 3200 0 Blue 0
7 PM Sun 65 55 W 3 4 2621 3200 0 Blue 0
8 PM Sun 64 54 WNW 1 1 2621 3200 0 Blue 0
9 PM Sun 64 54 WNW 1 1 2621 3200 0 Blue 0
10 PM Sun 63 53 WNW 1 1 2621 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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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]