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

Station:

 KOAK

Date/Time:

 11 DEC 2023

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 Mon 49 39 N 1 3 1929 3200 0 Blue 0
1 AM Mon 49 39 N 1 3 1929 3200 0 Blue 0
2 AM Mon 49 39 N 1 3 1929 3200 0 Blue 0
3 AM Mon 48 38 NNW 2 4 1929 3200 0 Blue 0
4 AM Mon 47 37 N 2 4 1929 3200 0 Blue 0
5 AM Mon 47 37 N 2 4 1929 3200 0 Blue 0
6 AM Mon 46 36 NNW 2 5 1929 3200 0 Blue 0
7 AM Mon 45 35 N 2 4 1929 3200 0 Blue 0
8 AM Mon 46 36 N 2 4 1929 3200 0 Blue 0
9 AM Mon 50 40 N 2 4 1929 3200 0 Blue 0
10 AM Mon 54 45 NNE 2 3 1929 3200 0 Blue 0
11 AM Mon 57 48 NNE 3 3 1929 3200 0 Blue 0
12 Noon Mon 60 52 NNE 3 4 2239 3200 0 Blue 0
1 PM Mon 63 55 NNE 4 4 2950 3200 0 Blue 3
2 PM Mon 64 55 N 5 6 2950 3200 0 Blue 3
3 PM Mon 64 54 N 4 5 2871 3200 0 Blue 2
4 PM Mon 62 52 N 5 6 2239 3200 0 Blue 0
5 PM Mon 57 47 NNE 3 5 1929 3200 0 Blue 0
6 PM Mon 54 44 NNW 3 6 1929 3200 0 Blue 0
7 PM Mon 52 42 NNW 4 8 1929 3200 0 Blue 0
8 PM Mon 50 40 NNW 4 8 1929 3200 0 Blue 0
9 PM Mon 49 39 NNW 4 8 1929 3200 0 Blue 0
10 PM Mon 48 38 N 3 6 1929 3200 0 Blue 0
11 PM Mon 47 37 N 2 6 1929 3200 0 Blue 0
12 Midnight Tue 46 36 NNW 2 4 1929 3200 0 Blue 0
1 AM Tue 45 35 NNW 3 7 1929 3200 0 Blue 0
2 AM Tue 45 35 N 2 6 1929 3200 0 Blue 0
3 AM Tue 44 34 N 2 5 1929 3200 0 Blue 0
4 AM Tue 44 34 N 3 6 1929 3200 0 Blue 0
5 AM Tue 44 34 NNW 2 5 1929 3200 0 Blue 0
6 AM Tue 43 33 NNW 2 5 1929 3200 0 Blue 0
7 AM Tue 43 33 N 2 5 1929 3200 0 Blue 0
8 AM Tue 44 34 N 2 4 1929 3200 0 Blue 0
9 AM Tue 48 38 NNW 1 3 1929 3200 0 Blue 0
10 AM Tue 52 43 NNE 2 3 1929 3200 0 Blue 0
11 AM Tue 55 47 NE 2 3 1929 3200 0 Blue 0
12 Noon Tue 59 51 NE 2 2 2055 3200 0 Blue 0
1 PM Tue 61 53 NNE 2 3 2696 3200 0 Blue 1
2 PM Tue 62 53 NNE 3 4 2696 3200 0 Blue 1
3 PM Tue 63 53 NNE 3 4 2696 3200 0 Blue 1
4 PM Tue 61 51 N 4 4 2055 3200 0 Blue 0
5 PM Tue 57 47 N 2 3 1929 3200 0 Blue 0
6 PM Tue 53 43 NNW 1 3 1929 3200 0 Blue 0
7 PM Tue 51 41 NNW 2 4 1929 3200 0 Blue 0
8 PM Tue 50 40 NNW 2 5 1929 3200 0 Blue 0
9 PM Tue 48 38 N 2 4 1929 3200 0 Blue 0
10 PM Tue 47 37 N 1 2 1929 3200 0 Blue 0
11 PM Tue 46 36 NNE 0 1 1929 3200 0 Blue 0
12 Midnight Wed 45 35 NE 1 2 1929 3200 0 Blue 0
1 AM Wed 44 34 NNE 0 1 1929 3200 0 Blue 0
2 AM Wed 44 34 N 0 0 1929 3200 0 Blue 0
3 AM Wed 43 33 NNE 0 0 1929 3200 0 Blue 0
4 AM Wed 43 33 N 1 2 1929 3200 0 Blue 0
5 AM Wed 43 33 NE 0 1 1929 3200 0 Blue 0
6 AM Wed 42 32 N 0 1 1929 3200 0 Blue 0
7 AM Wed 42 32 NE 0 1 1929 3200 0 Blue 0
8 AM Wed 43 33 E 0 1 1929 3200 0 Blue 0
9 AM Wed 48 38 ENE 0 0 1929 3200 0 Blue 0
10 AM Wed 52 43 ENE 1 2 1929 3200 0 Blue 0
11 AM Wed 55 47 E 2 2 1929 3200 0 Blue 0
12 Noon Wed 58 50 E 2 3 1939 3200 0 Blue 0
1 PM Wed 61 53 ESE 2 3 2696 3200 0 Blue 1
2 PM Wed 62 53 ESE 2 3 2696 3200 0 Blue 1
3 PM Wed 63 53 ESE 2 2 2696 3200 0 Blue 1
4 PM Wed 61 51 E 1 1 2055 3200 0 Blue 0
5 PM Wed 56 46 E 2 3 1929 3200 0 Blue 0
6 PM Wed 53 43 ENE 1 2 1929 3200 0 Blue 0
7 PM Wed 51 41 NW 1 2 1929 3200 0 Blue 0
8 PM Wed 50 40 WNW 1 2 1929 3200 0 Blue 0
9 PM Wed 49 39 NW 1 3 1929 3200 0 Blue 0
10 PM Wed 48 38 NNW 0 0 1929 3200 0 Blue 0
11 PM Wed 48 38 ESE 0 0 1929 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]