Detailed Predictions for: Burn Launch
Launch Lat, Long, Altitude (f): 40.194595, -120.923022, 6188
LZ Altitude (f): 3540
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 52 49 ENE 17 27 5151 6188 0 Blue 0
1 AM Tue 48 45 ENE 13 21 5151 6188 0 Blue 0
2 AM Tue 47 44 E 10 16 5151 6188 0 Blue 0
3 AM Tue 47 44 ENE 10 16 5151 6188 0 Blue 0
4 AM Tue 46 43 ENE 9 14 5151 6188 0 Blue 0
5 AM Tue 45 42 ENE 10 17 5151 6188 0 Blue 0
6 AM Tue 47 44 ENE 10 17 5151 6188 0 Blue 0
7 AM Tue 45 42 ENE 10 17 5151 6188 0 Blue 0
8 AM Tue 46 43 E 8 12 5151 6188 0 Blue 0
9 AM Tue 52 50 E 8 12 5151 6188 0 Blue 0
10 AM Tue 57 56 E 8 12 5151 6188 0 Blue 0
11 AM Tue 62 63 S 10 17 5151 6188 0 Blue 0
12 Noon Tue 67 69 S 10 17 7024 6188 0 Blue 0
1 PM Tue 70 72 S 10 17 7713 7018 830 Blue 3
2 PM Tue 73 75 SSW 13 21 8404 7700 1512 Blue 6
3 PM Tue 73 74 SSW 13 21 8034 7444 1256 Blue 5
4 PM Tue 73 72 SSW 13 21 7713 7018 830 Blue 3
5 PM Tue 72 70 SW 12 20 7237 6188 0 Blue 1
6 PM Tue 69 66 SW 12 20 5465 6188 0 Blue 0
7 PM Tue 65 62 SW 12 20 5151 6188 0 Blue 0
8 PM Tue 61 58 SW 9 13 5151 6188 0 Blue 0
9 PM Tue 58 55 SW 9 13 5151 6188 0 Blue 0
10 PM Tue 55 52 SW 9 13 5151 6188 0 Blue 0
11 PM Tue 54 51 SSW 6 10 5151 6188 0 Blue 0
12 Midnight Wed 54 51 SSW 6 10 5151 6188 0 Blue 0
1 AM Wed 53 50 SSW 6 10 5151 6188 0 Blue 0
2 AM Wed 51 48 S 4 6 5151 6188 0 Blue 0
3 AM Wed 50 47 S 4 6 5151 6188 0 Blue 0
4 AM Wed 50 47 S 4 6 5151 6188 0 Blue 0
5 AM Wed 49 46 SSE 4 6 5151 6188 0 Blue 0
6 AM Wed 50 47 SSE 4 6 5151 6188 0 Blue 0
7 AM Wed 49 46 SSE 4 6 5151 6188 0 Blue 0
8 AM Wed 50 47 S 6 11 5151 6188 0 Blue 0
9 AM Wed 55 52 S 6 11 5151 6188 0 Blue 0
10 AM Wed 59 57 S 6 11 5151 6188 0 Blue 0
11 AM Wed 63 63 SSW 12 20 5151 6188 0 Blue 0
12 Noon Wed 67 67 SSW 12 20 6050 6188 0 Blue 0
1 PM Wed 69 70 SSW 12 20 7237 6188 0 Blue 1
2 PM Wed 71 72 SW 17 27 7713 7018 830 Blue 3
3 PM Wed 70 70 SW 17 27 7237 6188 0 Blue 1
4 PM Wed 69 68 SW 17 27 6617 6188 0 Blue 0
5 PM Wed 67 65 WSW 14 24 5151 6188 0 Blue 0
6 PM Wed 65 62 WSW 14 24 5151 6188 0 Blue 0
7 PM Wed 62 59 WSW 14 24 5151 6188 0 Blue 0
8 PM Wed 59 56 W 9 14 5151 6188 0 Blue 0
9 PM Wed 56 53 W 9 14 5151 6188 0 Blue 0
10 PM Wed 53 50 W 9 14 5151 6188 0 Blue 0
11 PM Wed 51 48 N 5 9 5151 6188 0 Blue 0
12 Midnight Thu 50 47 N 5 9 5151 6188 0 Blue 0
1 AM Thu 49 46 N 5 9 5151 6188 0 Blue 0
2 AM Thu 49 46 NNE 6 11 5151 6188 0 Blue 0
3 AM Thu 49 46 NNE 6 11 5151 6188 0 Blue 0
4 AM Thu 48 45 NNE 6 11 5151 6188 0 Blue 0
5 AM Thu 47 44 NE 8 13 5151 6188 0 Blue 0
6 AM Thu 46 43 NE 8 13 5151 6188 0 Blue 0
7 AM Thu 46 43 NE 8 13 5151 6188 0 Blue 0
8 AM Thu 47 44 NE 8 12 5151 6188 0 Blue 0
9 AM Thu 50 48 NE 8 12 5151 6188 0 Blue 0
10 AM Thu 55 54 NE 8 12 5151 6188 0 Blue 0
11 AM Thu 60 61 ENE 9 13 5151 6188 0 Blue 0
12 Noon Thu 64 66 ENE 9 13 5465 6188 0 Blue 0
1 PM Thu 67 69 ENE 9 13 7024 6188 0 Blue 0
2 PM Thu 69 70 ENE 10 16 7237 6188 0 Blue 1
3 PM Thu 70 70 ENE 10 16 7237 6188 0 Blue 1
4 PM Thu 70 69 ENE 10 16 7024 6188 0 Blue 0
5 PM Thu 69 67 ENE 9 14 6050 6188 0 Blue 0
6 PM Thu 67 64 ENE 9 14 5151 6188 0 Blue 0
7 PM Thu 65 62 ENE 9 14 5151 6188 0 Blue 0
8 PM Thu 62 59 ENE 9 14 5151 6188 0 Blue 0
9 PM Thu 59 56 ENE 9 14 5151 6188 0 Blue 0
10 PM Thu 57 54 ENE 9 14 5151 6188 0 Blue 0
11 PM Thu 54 51 ENE 11 18 5151 6188 0 Blue 0
12 Midnight Fri 53 50 ENE 11 18 5151 6188 0 Blue 0
1 AM Fri 52 49 ENE 11 18 5151 6188 0 Blue 0
2 AM Fri 51 48 ENE 8 13 5151 6188 0 Blue 0
3 AM Fri 51 48 ENE 8 13 5151 6188 0 Blue 0
4 AM Fri 50 47 ENE 8 13 5151 6188 0 Blue 0
5 AM Fri 50 47 NE 9 14 5151 6188 0 Blue 0
6 AM Fri 48 45 NE 9 14 5151 6188 0 Blue 0
7 AM Fri 48 45 NE 9 14 5151 6188 0 Blue 0
8 AM Fri 50 47 ENE 6 11 5151 6188 0 Blue 0
9 AM Fri 54 52 ENE 6 11 5151 6188 0 Blue 0
10 AM Fri 60 59 ENE 6 11 5151 6188 0 Blue 0
11 AM Fri 66 67 ESE 5 10 6050 6188 0 Blue 0
12 Noon Fri 70 72 ESE 5 10 7713 7018 830 Blue 3
1 PM Fri 73 75 ESE 5 10 8404 7700 1512 Blue 6
2 PM Fri 75 77 SSW 8 12 9315 8027 1839 Blue 8
3 PM Fri 76 77 SSW 8 12 9315 8027 1839 Blue 8
4 PM Fri 76 75 SSW 8 12 8404 7700 1512 Blue 6
5 PM Fri 75 73 SW 9 13 7927 7230 1042 Blue 4
6 PM Fri 72 69 SW 9 13 7024 6188 0 Blue 0
7 PM Fri 69 66 SW 9 13 5465 6188 0 Blue 0
8 PM Fri 65 62 WSW 8 12 5151 6188 0 Blue 0
9 PM Fri 61 58 WSW 8 12 5151 6188 0 Blue 0
10 PM Fri 58 55 WSW 8 12 5151 6188 0 Blue 0
11 PM Fri 55 52 N 5 10 5151 6188 0 Blue 0
12 Midnight Sat 54 51 N 5 10 5151 6188 0 Blue 0
1 AM Sat 53 50 N 5 10 5151 6188 0 Blue 0
2 AM Sat 52 49 NNE 4 6 5151 6188 0 Blue 0
3 AM Sat 52 49 NNE 4 6 5151 6188 0 Blue 0
4 AM Sat 51 48 NNE 4 6 5151 6188 0 Blue 0
5 AM Sat 50 47 NE 5 9 5151 6188 0 Blue 0
6 AM Sat 49 46 NE 5 9 5151 6188 0 Blue 0
7 AM Sat 49 46 NE 5 9 5151 6188 0 Blue 0
8 AM Sat 50 47 E 4 8 5151 6188 0 Blue 0
9 AM Sat 54 52 E 4 8 5151 6188 0 Blue 0
10 AM Sat 60 59 E 4 8 5151 6188 0 Blue 0
11 AM Sat 65 66 SSW 6 11 5465 6188 0 Blue 0
12 Noon Sat 69 71 SSW 6 11 7454 6609 421 Blue 2
1 PM Sat 71 73 SSW 6 11 7927 7230 1042 Blue 4
2 PM Sat 73 75 SW 10 16 8404 7700 1512 Blue 6
3 PM Sat 74 75 SW 10 16 8404 7700 1512 Blue 6
4 PM Sat 74 73 SW 10 16 7927 7230 1042 Blue 4
5 PM Sat 73 71 WSW 10 17 7454 6609 421 Blue 2
6 PM Sat 70 67 WSW 10 17 6050 6188 0 Blue 0
7 PM Sat 67 64 WSW 10 17 5151 6188 0 Blue 0
8 PM Sat 63 60 WSW 8 12 5151 6188 0 Blue 0
9 PM Sat 60 57 WSW 8 12 5151 6188 0 Blue 0
10 PM Sat 57 54 WSW 8 12 5151 6188 0 Blue 0
11 PM Sat 55 52 W 5 10 5151 6188 0 Blue 0
12 Midnight Sun 54 51 W 5 10 5151 6188 0 Blue 0
1 AM Sun 53 50 W 5 10 5151 6188 0 Blue 0
2 AM Sun 52 49 SE 4 8 5151 6188 0 Blue 0
3 AM Sun 51 48 SE 4 8 5151 6188 0 Blue 0
4 AM Sun 51 48 SE 4 8 5151 6188 0 Blue 0
5 AM Sun 50 47 E 4 8 5151 6188 0 Blue 0
6 AM Sun 49 46 E 4 8 5151 6188 0 Blue 0
7 AM Sun 49 46 E 4 8 5151 6188 0 Blue 0
8 AM Sun 50 47 SSE 3 6 5151 6188 0 Blue 0
9 AM Sun 54 52 SSE 3 6 5151 6188 0 Blue 0
10 AM Sun 58 57 SSE 3 6 5151 6188 0 Blue 0
11 AM Sun 63 63 SSW 6 11 5151 6188 0 Blue 0
12 Noon Sun 66 67 SSW 6 11 6050 6188 0 Blue 0
1 PM Sun 69 71 SSW 6 11 7454 6609 421 Blue 2
2 PM Sun 70 70 SW 10 16 7237 6188 0 Blue 1
3 PM Sun 71 71 SW 10 16 7454 6609 421 Blue 2
4 PM Sun 70 69 SW 10 16 7024 6188 0 Blue 0
5 PM Sun 69 67 SW 9 14 6050 6188 0 Blue 0
6 PM Sun 67 64 SW 9 14 5151 6188 0 Blue 0
7 PM Sun 63 60 SW 9 14 5151 6188 0 Blue 0
8 PM Sun 60 57 WSW 6 10 5151 6188 0 Blue 0
9 PM Sun 57 54 WSW 6 10 5151 6188 0 Blue 0
10 PM Sun 55 52 WSW 6 10 5151 6188 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]