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

Station:

 KOAK

Date/Time:

 24 APR 2024

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 Wed 45 35 WSW 5 5 2697 3200 0 Blue 0
1 AM Wed 44 34 WSW 5 5 2697 3200 0 Blue 0
2 AM Wed 44 34 W 5 5 2697 3200 0 Blue 0
3 AM Wed 44 34 W 5 5 2697 3200 0 Blue 0
4 AM Wed 44 34 W 5 5 2697 3200 0 Blue 0
5 AM Wed 43 33 W 5 5 2697 3200 0 Blue 0
6 AM Wed 45 35 WSW 5 5 2697 3200 0 Blue 0
7 AM Wed 45 35 SW 5 6 2697 3200 0 Blue 0
8 AM Wed 45 35 SW 5 5 2697 3200 0 Blue 0
9 AM Wed 46 36 SSW 5 6 2697 3200 0 Blue 0
10 AM Wed 46 37 SW 5 6 2697 3200 0 Blue 0
11 AM Wed 46 38 SW 5 6 2697 3200 0 Blue 0
12 Noon Wed 48 40 SW 4 6 2697 3200 0 Blue 0
1 PM Wed 48 41 SW 5 6 2697 3200 0 Blue 0
2 PM Wed 48 40 SW 5 8 2697 3200 0 Blue 0
3 PM Wed 49 41 WSW 5 9 2697 3200 0 Blue 0
4 PM Wed 48 39 WSW 8 9 2697 3200 0 Blue 0
5 PM Wed 48 38 W 9 10 2697 3200 0 Blue 0
6 PM Wed 48 38 W 9 9 2697 3200 0 Blue 0
7 PM Wed 47 37 W 8 9 2697 3200 0 Blue 0
8 PM Wed 47 37 W 6 6 2697 3200 0 Blue 0
9 PM Wed 46 36 W 6 6 2697 3200 0 Blue 0
10 PM Wed 46 36 W 5 6 2697 3200 0 Blue 0
11 PM Wed 46 36 WNW 5 6 2697 3200 0 Blue 0
12 Midnight Thu 47 37 W 5 6 2697 3200 0 Blue 0
1 AM Thu 46 36 W 5 6 2697 3200 0 Blue 0
2 AM Thu 45 35 WNW 6 8 2697 3200 0 Blue 0
3 AM Thu 45 35 W 6 8 2697 3200 0 Blue 0
4 AM Thu 45 35 WNW 9 9 2697 3200 0 Blue 0
5 AM Thu 45 35 WNW 9 10 2697 3200 0 Blue 0
6 AM Thu 46 36 W 9 9 2697 3200 0 Blue 0
7 AM Thu 45 35 WNW 8 9 2697 3200 0 Blue 0
8 AM Thu 46 36 WNW 8 9 2697 3200 0 Blue 0
9 AM Thu 47 38 W 9 10 2697 3200 0 Blue 0
10 AM Thu 48 40 W 10 10 2697 3200 0 Blue 0
11 AM Thu 48 40 WNW 11 12 2697 3200 0 Blue 0
12 Noon Thu 49 42 WNW 11 12 2697 3200 0 Blue 0
1 PM Thu 50 43 WNW 11 12 2757 3200 0 Blue 0
2 PM Thu 50 45 WNW 11 17 4107 3200 0 White 1
3 PM Thu 51 45 WNW 11 17 4107 3200 0 White 1
4 PM Thu 51 44 WNW 11 17 3887 3200 0 White 0
5 PM Thu 51 42 WNW 16 20 2697 3200 0 Blue 0
6 PM Thu 51 41 WNW 16 20 2697 3200 0 Blue 0
7 PM Thu 50 40 WNW 16 20 2697 3200 0 Blue 0
8 PM Thu 50 40 WNW 14 16 2697 3200 0 Blue 0
9 PM Thu 49 39 WNW 14 16 2697 3200 0 Blue 0
10 PM Thu 48 38 WNW 14 16 2697 3200 0 Blue 0
11 PM Thu 48 38 NW 13 14 2697 3200 0 Blue 0
12 Midnight Fri 47 37 NW 13 14 2697 3200 0 Blue 0
1 AM Fri 47 37 NW 13 14 2697 3200 0 Blue 0
2 AM Fri 47 37 NW 11 12 2697 3200 0 Blue 0
3 AM Fri 47 37 NW 11 12 2697 3200 0 Blue 0
4 AM Fri 46 36 NW 11 12 2697 3200 0 Blue 0
5 AM Fri 46 36 NNW 13 13 2697 3200 0 Blue 0
6 AM Fri 47 37 NNW 13 13 2697 3200 0 Blue 0
7 AM Fri 48 38 NNW 13 13 2697 3200 0 Blue 0
8 AM Fri 48 38 NW 12 13 2697 3200 0 Blue 0
9 AM Fri 49 40 NW 12 13 2697 3200 0 Blue 0
10 AM Fri 50 42 NW 12 13 2697 3200 0 Blue 0
11 AM Fri 51 43 NW 13 17 2757 3200 0 Blue 0
12 Noon Fri 52 45 NW 13 17 4107 3200 0 White 1
1 PM Fri 52 45 NW 13 17 4107 3200 0 White 1
2 PM Fri 52 47 WNW 18 24 4550 3953 753 White 3
3 PM Fri 52 46 WNW 18 24 4329 3200 0 White 2
4 PM Fri 52 45 WNW 18 24 4107 3200 0 White 1
5 PM Fri 52 44 NW 26 39 3887 3200 0 White 0
6 PM Fri 51 41 NW 26 39 2697 3200 0 Blue 0
7 PM Fri 50 40 NW 26 39 2697 3200 0 Blue 0
8 PM Fri 49 39 NW 24 36 2697 3200 0 Blue 0
9 PM Fri 49 39 NW 24 36 2697 3200 0 Blue 0
10 PM Fri 48 38 NW 24 36 2697 3200 0 Blue 0
11 PM Fri 47 37 NNW 19 29 2697 3200 0 Blue 0
12 Midnight Sat 47 37 NNW 19 29 2697 3200 0 Blue 0
1 AM Sat 46 36 NNW 19 29 2697 3200 0 Blue 0
2 AM Sat 46 36 NNW 18 24 2697 3200 0 Blue 0
3 AM Sat 45 35 NNW 18 24 2697 3200 0 Blue 0
4 AM Sat 45 35 NNW 18 24 2697 3200 0 Blue 0
5 AM Sat 44 34 NNW 20 21 2697 3200 0 Blue 0
6 AM Sat 45 35 NNW 20 21 2697 3200 0 Blue 0
7 AM Sat 46 36 NNW 20 21 2697 3200 0 Blue 0
8 AM Sat 47 38 NNW 13 14 2697 3200 0 Blue 0
9 AM Sat 48 40 NNW 13 14 2697 3200 0 Blue 0
10 AM Sat 50 44 NNW 13 14 3887 3200 0 White 0
11 AM Sat 51 47 NW 14 17 4550 3953 753 White 3
12 Noon Sat 52 49 NW 14 17 4991 4991 1791 White 5
1 PM Sat 53 51 NW 14 17 5246 5209 2009 Blue 7
2 PM Sat 53 50 WNW 18 21 5207 5181 1981 White 6
3 PM Sat 54 50 WNW 18 21 5207 5181 1981 White 6
4 PM Sat 54 48 WNW 18 21 4772 4534 1334 White 4
5 PM Sat 54 46 NW 18 23 4329 3200 0 White 2
6 PM Sat 53 44 NW 18 23 3887 3200 0 White 0
7 PM Sat 52 42 NW 18 23 2697 3200 0 Blue 0
8 PM Sat 51 41 NW 19 20 2697 3200 0 Blue 0
9 PM Sat 50 40 NW 19 20 2697 3200 0 Blue 0
10 PM Sat 49 39 NW 19 20 2697 3200 0 Blue 0
11 PM Sat 48 38 NNW 14 17 2697 3200 0 Blue 0
12 Midnight Sun 48 38 NNW 14 17 2697 3200 0 Blue 0
1 AM Sun 48 38 NNW 14 17 2697 3200 0 Blue 0
2 AM Sun 48 38 NNW 12 14 2697 3200 0 Blue 0
3 AM Sun 47 37 NNW 12 14 2697 3200 0 Blue 0
4 AM Sun 47 37 NNW 12 14 2697 3200 0 Blue 0
5 AM Sun 47 37 N 11 13 2697 3200 0 Blue 0
6 AM Sun 48 38 N 11 13 2697 3200 0 Blue 0
7 AM Sun 49 39 N 11 13 2697 3200 0 Blue 0
8 AM Sun 50 41 NNW 11 12 2697 3200 0 Blue 0
9 AM Sun 51 43 NNW 11 12 2757 3200 0 Blue 0
10 AM Sun 53 47 NNW 11 12 4550 3953 753 White 3
11 AM Sun 54 50 NW 13 16 5207 5181 1981 White 6
12 Noon Sun 55 52 NW 13 16 5276 5220 2020 Blue 8
1 PM Sun 55 53 NW 13 16 5307 5230 2030 Blue 9
2 PM Sun 56 53 NW 17 20 5307 5230 2030 Blue 9
3 PM Sun 56 52 NW 17 20 5276 5220 2020 Blue 8
4 PM Sun 57 51 NW 17 20 5246 5209 2009 Blue 7
5 PM Sun 57 49 NW 18 20 4991 4991 1791 White 5
6 PM Sun 56 47 NW 18 20 4550 3953 753 White 3
7 PM Sun 55 45 NW 18 20 4107 3200 0 White 1
8 PM Sun 54 44 NNW 17 18 3887 3200 0 White 0
9 PM Sun 53 43 NNW 17 18 2757 3200 0 Blue 0
10 PM Sun 52 42 NNW 17 18 2697 3200 0 Blue 0
11 PM Sun 51 41 NNW 13 14 2697 3200 0 Blue 0
12 Midnight Mon 50 40 NNW 13 14 2697 3200 0 Blue 0
1 AM Mon 50 40 NNW 13 14 2697 3200 0 Blue 0
2 AM Mon 49 39 N 12 14 2697 3200 0 Blue 0
3 AM Mon 49 39 N 12 14 2697 3200 0 Blue 0
4 AM Mon 48 38 N 12 14 2697 3200 0 Blue 0
5 AM Mon 48 38 N 12 13 2697 3200 0 Blue 0
6 AM Mon 48 38 N 12 13 2697 3200 0 Blue 0
7 AM Mon 49 39 N 12 13 2697 3200 0 Blue 0
8 AM Mon 50 41 NNW 12 14 2697 3200 0 Blue 0
9 AM Mon 52 44 NNW 12 14 3887 3200 0 White 0
10 AM Mon 54 48 NNW 12 14 4772 4534 1334 White 4
11 AM Mon 56 52 NW 14 17 5276 5220 2020 Blue 8
12 Noon Mon 57 54 NW 14 17 5336 5243 2043 Blue 10
1 PM Mon 58 56 NW 14 17 5369 5304 2104 Blue 12
2 PM Mon 58 55 NW 17 20 5352 5274 2074 Blue 11
3 PM Mon 58 54 NW 17 20 5336 5243 2043 Blue 10
4 PM Mon 57 51 NW 17 20 5246 5209 2009 Blue 7
5 PM Mon 57 49 NW 20 23 4991 4991 1791 White 5
6 PM Mon 56 47 NW 20 23 4550 3953 753 White 3
7 PM Mon 54 44 NW 20 23 3887 3200 0 White 0
8 PM Mon 53 43 NNW 18 21 2757 3200 0 Blue 0
9 PM Mon 52 42 NNW 18 21 2697 3200 0 Blue 0
10 PM Mon 51 41 NNW 18 21 2697 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]