Detailed Predictions for: Timberline
Launch Lat, Long, Altitude (f): 39.509442, -122.937570, 5810
LZ Altitude (f): 1840
Sounding

Station:

KOAK

Date/Time:

12 MAY 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 Wed 60 60 N 3 4 4488 5810 0 Blue 0
1 AM Wed 60 60 N 3 4 4488 5810 0 Blue 0
2 AM Wed 60 60 N 5 6 4488 5810 0 Blue 0
3 AM Wed 60 60 N 5 6 4488 5810 0 Blue 0
4 AM Wed 60 60 N 5 6 4488 5810 0 Blue 0
5 AM Wed 60 60 NE 8 10 4488 5810 0 Blue 0
6 AM Wed 62 62 NE 8 10 4488 5810 0 Blue 0
7 AM Wed 64 64 NE 8 10 4488 5810 0 Blue 0
8 AM Wed 66 67 S 2 2 5825 5810 0 Blue 2
9 AM Wed 68 70 S 2 2 8263 5815 5 Blue 5
10 AM Wed 70 74 S 2 2 9552 8590 2780 Blue 9
11 AM Wed 72 77 SSW 6 9 12093 9429 3619 Blue 12
12 Noon Wed 73 79 SSW 6 9 13574 11083 5273 Blue 14
1 PM Wed 74 81 SSW 6 9 14882 12663 6853 Blue 16
2 PM Wed 75 81 SSW 9 11 14882 12663 6853 Blue 16
3 PM Wed 75 80 SSW 9 11 14248 11904 6094 Blue 15
4 PM Wed 75 79 SSW 9 11 13574 11083 5273 Blue 14
5 PM Wed 74 76 SW 8 10 11263 9291 3481 Blue 11
6 PM Wed 73 74 SW 8 10 9552 8590 2780 Blue 9
7 PM Wed 71 71 SW 8 10 8658 6101 291 Blue 6
8 PM Wed 69 69 WNW 4 5 7212 5810 0 Blue 4
9 PM Wed 67 67 WNW 4 5 5825 5810 0 Blue 2
10 PM Wed 65 65 WNW 4 5 4742 5810 0 Blue 0
11 PM Wed 63 63 WNW 4 5 4488 5810 0 Blue 0
12 Midnight Thu 61 61 WNW 4 5 4488 5810 0 Blue 0
1 AM Thu 60 60 WNW 4 5 4488 5810 0 Blue 0
2 AM Thu 59 59 NW 5 6 4488 5810 0 Blue 0
3 AM Thu 59 59 NW 5 6 4488 5810 0 Blue 0
4 AM Thu 59 59 NW 5 6 4488 5810 0 Blue 0
5 AM Thu 60 60 N 5 6 4488 5810 0 Blue 0
6 AM Thu 62 62 N 5 6 4488 5810 0 Blue 0
7 AM Thu 64 64 N 5 6 4488 5810 0 Blue 0
8 AM Thu 67 68 ENE 2 3 6114 5810 0 Blue 3
9 AM Thu 69 71 ENE 2 3 8658 6101 291 Blue 6
10 AM Thu 71 75 ENE 2 3 10350 9127 3317 Blue 10
11 AM Thu 73 79 SSW 6 9 13574 11083 5273 Blue 14
12 Noon Thu 75 82 SSW 6 9 15234 13373 7563 Blue 17
1 PM Thu 76 84 SSW 6 9 15926 14678 8868 Blue 19
2 PM Thu 76 83 SW 6 9 15582 14042 8232 Blue 18
3 PM Thu 76 82 SW 6 9 15234 13373 7563 Blue 17
4 PM Thu 75 79 SW 6 9 13574 11083 5273 Blue 14
5 PM Thu 74 76 W 8 10 11263 9291 3481 Blue 11
6 PM Thu 72 73 W 8 10 9307 8226 2416 Blue 8
7 PM Thu 70 70 W 8 10 8263 5815 5 Blue 5
8 PM Thu 68 68 W 5 6 6114 5810 0 Blue 3
9 PM Thu 66 66 W 5 6 5535 5810 0 Blue 1
10 PM Thu 64 64 W 5 6 4488 5810 0 Blue 0
11 PM Thu 62 62 NNW 6 9 4488 5810 0 Blue 0
12 Midnight Fri 60 60 NNW 6 9 4488 5810 0 Blue 0
1 AM Fri 59 59 NNW 6 9 4488 5810 0 Blue 0
2 AM Fri 58 58 NNW 4 5 4488 5810 0 Blue 0
3 AM Fri 58 58 NNW 4 5 4488 5810 0 Blue 0
4 AM Fri 58 58 NNW 4 5 4488 5810 0 Blue 0
5 AM Fri 59 59 NNW 5 6 4488 5810 0 Blue 0
6 AM Fri 60 60 NNW 5 6 4488 5810 0 Blue 0
7 AM Fri 62 62 NNW 5 6 4488 5810 0 Blue 0
8 AM Fri 64 65 NNW 5 6 4742 5810 0 Blue 0
9 AM Fri 66 68 NNW 5 6 6114 5810 0 Blue 3
10 AM Fri 68 72 NNW 5 6 9203 7117 1307 Blue 7
11 AM Fri 69 73 W 3 4 9307 8226 2416 Blue 8
12 Noon Fri 71 76 W 3 4 11263 9291 3481 Blue 11
1 PM Fri 71 77 W 3 4 12093 9429 3619 Blue 12
2 PM Fri 71 76 W 3 4 11263 9291 3481 Blue 11
3 PM Fri 71 75 W 3 4 10350 9127 3317 Blue 10
4 PM Fri 70 73 W 3 4 9307 8226 2416 Blue 8
5 PM Fri 68 70 W 6 9 8263 5815 5 Blue 5
6 PM Fri 67 68 W 6 9 6114 5810 0 Blue 3
7 PM Fri 65 65 W 6 9 4742 5810 0 Blue 0
8 PM Fri 63 63 W 6 9 4488 5810 0 Blue 0
9 PM Fri 61 61 W 6 9 4488 5810 0 Blue 0
10 PM Fri 59 59 W 6 9 4488 5810 0 Blue 0
11 PM Fri 57 57 NNE 6 9 4488 5810 0 Blue 0
12 Midnight Sat 56 56 NNE 6 9 4488 5810 0 Blue 0
1 AM Sat 55 55 NNE 6 9 4488 5810 0 Blue 0
2 AM Sat 54 54 NNE 6 9 4488 5810 0 Blue 0
3 AM Sat 54 54 NNE 6 9 4488 5810 0 Blue 0
4 AM Sat 54 54 NNE 6 9 4488 5810 0 Blue 0
5 AM Sat 55 55 NNE 5 6 4488 5810 0 Blue 0
6 AM Sat 56 56 NNE 5 6 4488 5810 0 Blue 0
7 AM Sat 58 58 NNE 5 6 4488 5810 0 Blue 0
8 AM Sat 60 61 NNE 5 6 4488 5810 0 Blue 0
9 AM Sat 62 64 NNE 5 6 4488 5810 0 Blue 0
10 AM Sat 64 68 NNE 5 6 6114 5810 0 Blue 3
11 AM Sat 66 72 N 4 5 9203 7117 1307 Blue 7
12 Noon Sat 68 75 N 4 5 10350 9127 3317 Blue 10
1 PM Sat 69 76 N 4 5 11263 9291 3481 Blue 11
2 PM Sat 70 77 N 4 5 12093 9429 3619 Blue 12
3 PM Sat 71 77 N 4 5 12093 9429 3619 Blue 12
4 PM Sat 71 75 N 4 5 10350 9127 3317 Blue 10
5 PM Sat 70 71 WNW 3 4 8658 6101 291 Blue 6
6 PM Sat 69 69 WNW 3 4 7212 5810 0 Blue 4
7 PM Sat 67 67 WNW 3 4 5825 5810 0 Blue 2
8 PM Sat 65 65 WNW 3 4 4742 5810 0 Blue 0
9 PM Sat 62 62 WNW 3 4 4488 5810 0 Blue 0
10 PM Sat 60 60 WNW 3 4 4488 5810 0 Blue 0
11 PM Sat 58 58 N 5 6 4488 5810 0 Blue 0
12 Midnight Sun 57 57 N 5 6 4488 5810 0 Blue 0
1 AM Sun 56 56 N 5 6 4488 5810 0 Blue 0
2 AM Sun 56 56 N 5 6 4488 5810 0 Blue 0
3 AM Sun 57 57 N 5 6 4488 5810 0 Blue 0
4 AM Sun 58 58 N 5 6 4488 5810 0 Blue 0
5 AM Sun 59 59 NE 4 5 4488 5810 0 Blue 0
6 AM Sun 61 61 NE 4 5 4488 5810 0 Blue 0
7 AM Sun 64 64 NE 4 5 4488 5810 0 Blue 0
8 AM Sun 67 67 NE 4 5 5825 5810 0 Blue 2
9 AM Sun 69 70 NE 4 5 8263 5815 5 Blue 5
10 AM Sun 71 72 NE 4 5 9203 7117 1307 Blue 7
11 AM Sun 73 77 SW 1 1 12093 9429 3619 Blue 12
12 Noon Sun 74 78 SW 1 1 12858 10201 4391 Blue 13
1 PM Sun 74 79 SW 1 1 13574 11083 5273 Blue 14
2 PM Sun 74 78 SW 1 1 12858 10201 4391 Blue 13
3 PM Sun 73 77 SW 1 1 12093 9429 3619 Blue 12
4 PM Sun 71 74 SW 1 1 9552 8590 2780 Blue 9
5 PM Sun 70 71 WSW 6 9 8658 6101 291 Blue 6
6 PM Sun 68 68 WSW 6 9 6114 5810 0 Blue 3
7 PM Sun 66 66 WSW 6 9 5535 5810 0 Blue 1
8 PM Sun 65 65 WSW 6 9 4742 5810 0 Blue 0
9 PM Sun 63 63 WSW 6 9 4488 5810 0 Blue 0
10 PM Sun 61 61 WSW 6 9 4488 5810 0 Blue 0
11 PM Sun 59 59 WNW 4 5 4488 5810 0 Blue 0
12 Midnight Mon 58 58 WNW 4 5 4488 5810 0 Blue 0
1 AM Mon 57 57 WNW 4 5 4488 5810 0 Blue 0
2 AM Mon 56 56 WNW 4 5 4488 5810 0 Blue 0
3 AM Mon 56 56 WNW 4 5 4488 5810 0 Blue 0
4 AM Mon 56 56 WNW 4 5 4488 5810 0 Blue 0
5 AM Mon 57 57 NW 3 4 4488 5810 0 Blue 0
6 AM Mon 58 58 NW 3 4 4488 5810 0 Blue 0
7 AM Mon 59 59 NW 3 4 4488 5810 0 Blue 0
8 AM Mon 61 61 NW 3 4 4488 5810 0 Blue 0
9 AM Mon 63 64 NW 3 4 4488 5810 0 Blue 0
10 AM Mon 65 67 NW 3 4 5825 5810 0 Blue 2
11 AM Mon 67 72 WSW 3 4 9203 7117 1307 Blue 7
12 Noon Mon 68 74 WSW 3 4 9552 8590 2780 Blue 9
1 PM Mon 70 77 WSW 3 4 12093 9429 3619 Blue 12
2 PM Mon 70 76 WSW 3 4 11263 9291 3481 Blue 11
3 PM Mon 70 75 WSW 3 4 10350 9127 3317 Blue 10
4 PM Mon 69 73 WSW 3 4 9307 8226 2416 Blue 8
5 PM Mon 68 70 W 8 10 8263 5815 5 Blue 5
6 PM Mon 66 67 W 8 10 5825 5810 0 Blue 2
7 PM Mon 64 64 W 8 10 4488 5810 0 Blue 0
8 PM Mon 61 61 W 8 10 4488 5810 0 Blue 0
9 PM Mon 58 58 W 8 10 4488 5810 0 Blue 0
10 PM Mon 56 56 W 8 10 4488 5810 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 ac_soaring@yahoo.com