Detailed Predictions for: Tollhouse
Launch Altitude (f): 4000
LZ Altitude (f): 1900
Sounding

Station:

KOAK

Date/Time:

19 AUG 2018

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Sun 70 65 E 2 3711 4000 0 Blue 0
6 AM Sun 70 65 E 2 3711 4000 0 Blue 0
7 AM Sun 72 67 E 2 3711 4000 0 Blue 0
8 AM Sun 77 72 SW 3 3711 4000 0 Blue 0
9 AM Sun 82 79 SW 3 3905 4000 0 Blue 0
10 AM Sun 84 83 SW 3 6439 4603 603 Blue 2
11 AM Sun 85 86 SW 8 7351 6420 2420 Blue 5
12 Noon Sun 87 89 SW 8 8814 7296 3296 Blue 8
1 PM Sun 88 91 SW 8 9735 8271 4271 Blue 10
2 PM Sun 90 92 W 10 10182 8741 4741 Blue 11
3 PM Sun 91 92 W 10 10182 8741 4741 Blue 11
4 PM Sun 92 91 W 10 9735 8271 4271 Blue 10
5 PM Sun 92 89 W 7 8814 7296 3296 Blue 8
6 PM Sun 91 87 W 7 7850 6650 2650 Blue 6
7 PM Sun 89 84 W 7 6671 5270 1270 Blue 3
8 PM Sun 84 79 N 5 3905 4000 0 Blue 0
9 PM Sun 82 77 N 5 3711 4000 0 Blue 0
10 PM Sun 79 74 N 5 3711 4000 0 Blue 0
11 PM Sun 77 72 E 6 3711 4000 0 Blue 0
12 Midnight Mon 76 71 E 6 3711 4000 0 Blue 0
1 AM Mon 75 70 E 6 3711 4000 0 Blue 0
2 AM Mon 74 69 NE 7 3711 4000 0 Blue 0
3 AM Mon 73 68 NE 7 3711 4000 0 Blue 0
4 AM Mon 72 67 NE 7 3711 4000 0 Blue 0
5 AM Mon 70 65 E 5 3711 4000 0 Blue 0
6 AM Mon 70 65 E 5 3711 4000 0 Blue 0
7 AM Mon 71 66 E 5 3711 4000 0 Blue 0
8 AM Mon 76 71 SE 3 3711 4000 0 Blue 0
9 AM Mon 82 79 SE 3 3905 4000 0 Blue 0
10 AM Mon 83 82 SE 3 5949 4000 0 Blue 1
11 AM Mon 84 85 S 7 6901 5908 1908 Blue 4
12 Noon Mon 86 88 S 7 8338 6880 2880 Blue 7
1 PM Mon 88 91 S 7 9735 8271 4271 Blue 10
2 PM Mon 89 91 SW 7 9735 8271 4271 Blue 10
3 PM Mon 90 91 SW 7 9735 8271 4271 Blue 10
4 PM Mon 91 90 SW 7 9279 7789 3789 Blue 9
5 PM Mon 91 88 S 3 8338 6880 2880 Blue 7
6 PM Mon 90 86 S 3 7351 6420 2420 Blue 5
7 PM Mon 88 83 S 3 6439 4603 603 Blue 2
8 PM Mon 82 77 E 5 3711 4000 0 Blue 0
9 PM Mon 81 76 E 5 3711 4000 0 Blue 0
10 PM Mon 77 72 E 5 3711 4000 0 Blue 0
11 PM Mon 75 70 E 6 3711 4000 0 Blue 0
12 Midnight Tue 74 69 E 6 3711 4000 0 Blue 0
1 AM Tue 73 68 E 6 3711 4000 0 Blue 0
2 AM Tue 72 67 E 5 3711 4000 0 Blue 0
3 AM Tue 71 66 E 5 3711 4000 0 Blue 0
4 AM Tue 70 65 E 5 3711 4000 0 Blue 0
5 AM Tue 68 63 SE 2 3711 4000 0 Blue 0
6 AM Tue 68 63 SE 2 3711 4000 0 Blue 0
7 AM Tue 69 64 SE 2 3711 4000 0 Blue 0
8 AM Tue 74 69 SE 2 3711 4000 0 Blue 0
9 AM Tue 80 77 SE 2 3711 4000 0 Blue 0
10 AM Tue 81 80 SE 2 4619 4000 0 Blue 0
11 AM Tue 82 82 SW 7 5949 4000 0 Blue 1
12 Noon Tue 84 85 SW 7 6901 5908 1908 Blue 4
1 PM Tue 86 88 SW 7 8338 6880 2880 Blue 7
2 PM Tue 87 88 SW 7 8338 6880 2880 Blue 7
3 PM Tue 88 88 SW 7 8338 6880 2880 Blue 7
4 PM Tue 89 88 SW 7 8338 6880 2880 Blue 7
5 PM Tue 89 86 SE 1 7351 6420 2420 Blue 5
6 PM Tue 88 84 SE 1 6671 5270 1270 Blue 3
7 PM Tue 86 81 SE 1 5299 4000 0 Blue 0
8 PM Tue 81 76 SE 1 3711 4000 0 Blue 0
9 PM Tue 79 74 SE 1 3711 4000 0 Blue 0
10 PM Tue 76 71 SE 1 3711 4000 0 Blue 0
11 PM Tue 74 69 E 3 3711 4000 0 Blue 0
12 Midnight Wed 73 68 E 3 3711 4000 0 Blue 0
1 AM Wed 72 67 E 3 3711 4000 0 Blue 0
2 AM Wed 71 66 E 3 3711 4000 0 Blue 0
3 AM Wed 70 65 E 3 3711 4000 0 Blue 0
4 AM Wed 69 64 E 3 3711 4000 0 Blue 0
5 AM Wed 67 62 E 2 3711 4000 0 Blue 0
6 AM Wed 67 62 E 2 3711 4000 0 Blue 0
7 AM Wed 69 64 E 2 3711 4000 0 Blue 0
8 AM Wed 74 69 E 2 3711 4000 0 Blue 0
9 AM Wed 79 76 E 2 3711 4000 0 Blue 0
10 AM Wed 81 79 E 2 3905 4000 0 Blue 0
11 AM Wed 82 82 SW 6 5949 4000 0 Blue 1
12 Noon Wed 84 86 SW 6 7351 6420 2420 Blue 5
1 PM Wed 85 87 SW 6 7850 6650 2650 Blue 6
2 PM Wed 87 89 SW 6 8814 7296 3296 Blue 8
3 PM Wed 88 89 SW 6 8814 7296 3296 Blue 8
4 PM Wed 89 88 SW 6 8338 6880 2880 Blue 7
5 PM Wed 89 86 N 2 7351 6420 2420 Blue 5
6 PM Wed 88 84 N 2 6671 5270 1270 Blue 3
7 PM Wed 86 81 N 2 5299 4000 0 Blue 0
8 PM Wed 80 75 N 2 3711 4000 0 Blue 0
9 PM Wed 79 74 N 2 3711 4000 0 Blue 0
10 PM Wed 75 70 N 2 3711 4000 0 Blue 0
11 PM Wed 73 68 NE 3 3711 4000 0 Blue 0
12 Midnight Thu 72 67 NE 3 3711 4000 0 Blue 0
1 AM Thu 71 66 NE 3 3711 4000 0 Blue 0
2 AM Thu 70 65 NE 3 3711 4000 0 Blue 0
3 AM Thu 69 64 NE 3 3711 4000 0 Blue 0
4 AM Thu 68 63 NE 3 3711 4000 0 Blue 0
5 AM Thu 66 61 E 2 3711 4000 0 Blue 0
6 AM Thu 66 61 E 2 3711 4000 0 Blue 0
7 AM Thu 68 63 E 2 3711 4000 0 Blue 0
8 AM Thu 73 68 E 2 3711 4000 0 Blue 0
9 AM Thu 79 76 E 2 3711 4000 0 Blue 0
10 AM Thu 81 80 E 2 4619 4000 0 Blue 0
11 AM Thu 81 82 SW 6 5949 4000 0 Blue 1
12 Noon Thu 84 86 SW 6 7351 6420 2420 Blue 5
1 PM Thu 85 88 SW 6 8338 6880 2880 Blue 7
2 PM Thu 87 89 SW 6 8814 7296 3296 Blue 8
3 PM Thu 88 89 SW 6 8814 7296 3296 Blue 8
4 PM Thu 89 88 SW 6 8338 6880 2880 Blue 7
5 PM Thu 89 86 N 2 7351 6420 2420 Blue 5
6 PM Thu 88 84 N 2 6671 5270 1270 Blue 3
7 PM Thu 86 81 N 2 5299 4000 0 Blue 0
8 PM Thu 80 75 N 2 3711 4000 0 Blue 0
9 PM Thu 79 74 N 2 3711 4000 0 Blue 0
10 PM Thu 75 70 N 2 3711 4000 0 Blue 0
11 PM Thu 73 68 E 3 3711 4000 0 Blue 0
12 Midnight Fri 72 67 E 3 3711 4000 0 Blue 0
1 AM Fri 71 66 E 3 3711 4000 0 Blue 0
2 AM Fri 70 65 E 3 3711 4000 0 Blue 0
3 AM Fri 69 64 E 3 3711 4000 0 Blue 0
4 AM Fri 68 63 E 3 3711 4000 0 Blue 0
5 AM Fri 66 61 SE 1 3711 4000 0 Blue 0
6 AM Fri 66 61 SE 1 3711 4000 0 Blue 0
7 AM Fri 68 63 SE 1 3711 4000 0 Blue 0
8 AM Fri 73 68 SE 1 3711 4000 0 Blue 0
9 AM Fri 79 76 SE 1 3711 4000 0 Blue 0
10 AM Fri 81 80 SE 1 4619 4000 0 Blue 0
11 AM Fri 81 82 W 6 5949 4000 0 Blue 1
12 Noon Fri 84 86 W 6 7351 6420 2420 Blue 5
1 PM Fri 85 88 W 6 8338 6880 2880 Blue 7
2 PM Fri 87 89 W 6 8814 7296 3296 Blue 8
3 PM Fri 88 89 W 6 8814 7296 3296 Blue 8
4 PM Fri 89 88 W 6 8338 6880 2880 Blue 7
5 PM Fri 89 86 NW 5 7351 6420 2420 Blue 5
6 PM Fri 88 84 NW 5 6671 5270 1270 Blue 3
7 PM Fri 86 81 NW 5 5299 4000 0 Blue 0
8 PM Fri 80 75 NW 5 3711 4000 0 Blue 0
9 PM Fri 78 73 NW 5 3711 4000 0 Blue 0
10 PM Fri 75 70 NW 5 3711 4000 0 Blue 0
11 PM Fri 73 68 NE 3 3711 4000 0 Blue 0
12 Midnight Sat 71 66 NE 3 3711 4000 0 Blue 0
1 AM Sat 70 65 NE 3 3711 4000 0 Blue 0
2 AM Sat 69 64 NE 3 3711 4000 0 Blue 0
3 AM Sat 68 63 NE 3 3711 4000 0 Blue 0
4 AM Sat 67 62 NE 3 3711 4000 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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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