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

Station:

KOAK

Date/Time:

25 AUG 2019

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 73 68 NE 2 3573 4000 0 Blue 0
6 AM Sun 72 67 E 2 3573 4000 0 Blue 0
7 AM Sun 71 66 NE 2 3573 4000 0 Blue 0
8 AM Sun 72 67 SE 2 3573 4000 0 Blue 0
9 AM Sun 77 74 SW 2 3884 4000 0 Blue 0
10 AM Sun 81 80 SW 5 6487 5068 1068 Blue 5
11 AM Sun 82 82 SW 6 7107 5999 1999 Blue 7
12 Noon Sun 84 86 SW 6 8480 7309 3309 Blue 11
1 PM Sun 85 87 SW 8 8686 7419 3419 Blue 12
2 PM Sun 86 88 W 8 8891 7528 3528 Blue 13
3 PM Sun 87 87 W 9 8686 7419 3419 Blue 12
4 PM Sun 88 87 W 9 8686 7419 3419 Blue 12
5 PM Sun 88 85 W 9 7541 7080 3080 Blue 10
6 PM Sun 88 84 W 9 7431 6813 2813 Blue 9
7 PM Sun 87 82 W 7 7107 5999 1999 Blue 7
8 PM Sun 84 79 NW 6 6030 4396 396 Blue 4
9 PM Sun 79 74 N 5 3884 4000 0 Blue 0
10 PM Sun 78 73 N 6 3590 4000 0 Blue 0
11 PM Sun 77 72 N 5 3573 4000 0 Blue 0
12 Midnight Mon 77 72 NE 3 3573 4000 0 Blue 0
1 AM Mon 76 71 NE 2 3573 4000 0 Blue 0
2 AM Mon 76 71 NE 3 3573 4000 0 Blue 0
3 AM Mon 75 70 NE 2 3573 4000 0 Blue 0
4 AM Mon 74 69 NE 2 3573 4000 0 Blue 0
5 AM Mon 74 69 NE 2 3573 4000 0 Blue 0
6 AM Mon 74 69 NE 2 3573 4000 0 Blue 0
7 AM Mon 72 67 NE 2 3573 4000 0 Blue 0
8 AM Mon 73 68 E 2 3573 4000 0 Blue 0
9 AM Mon 78 75 SW 2 4177 4000 0 Blue 0
10 AM Mon 81 80 SW 5 6487 5068 1068 Blue 5
11 AM Mon 83 83 SW 6 7321 6451 2451 Blue 8
12 Noon Mon 85 86 SW 6 8480 7309 3309 Blue 11
1 PM Mon 86 87 SW 6 8686 7419 3419 Blue 12
2 PM Mon 87 87 W 8 8686 7419 3419 Blue 12
3 PM Mon 88 87 W 8 8686 7419 3419 Blue 12
4 PM Mon 89 87 W 8 8686 7419 3419 Blue 12
5 PM Mon 89 84 W 9 7431 6813 2813 Blue 9
6 PM Mon 88 83 W 9 7321 6451 2451 Blue 8
7 PM Mon 86 81 W 9 6837 5539 1539 Blue 6
8 PM Mon 84 79 NW 6 6030 4396 396 Blue 4
9 PM Mon 82 77 NW 6 5086 4000 0 Blue 2
10 PM Mon 81 76 NW 6 4399 4000 0 Blue 1
11 PM Mon 79 74 NE 3 3884 4000 0 Blue 0
12 Midnight Tue 78 73 NE 3 3590 4000 0 Blue 0
1 AM Tue 77 72 NE 3 3573 4000 0 Blue 0
2 AM Tue 76 71 NE 2 3573 4000 0 Blue 0
3 AM Tue 76 71 NE 2 3573 4000 0 Blue 0
4 AM Tue 75 70 NE 2 3573 4000 0 Blue 0
5 AM Tue 75 70 NE 2 3573 4000 0 Blue 0
6 AM Tue 74 69 NE 2 3573 4000 0 Blue 0
7 AM Tue 73 68 NE 2 3573 4000 0 Blue 0
8 AM Tue 74 69 NE 2 3573 4000 0 Blue 0
9 AM Tue 77 74 NE 2 3884 4000 0 Blue 0
10 AM Tue 81 80 NE 2 6487 5068 1068 Blue 5
11 AM Tue 85 84 SW 5 7431 6813 2813 Blue 9
12 Noon Tue 87 87 SW 5 8686 7419 3419 Blue 12
1 PM Tue 88 88 SW 5 8891 7528 3528 Blue 13
2 PM Tue 89 89 SW 8 9130 8232 4232 Blue 14
3 PM Tue 90 89 SW 8 9130 8232 4232 Blue 14
4 PM Tue 91 89 SW 8 9130 8232 4232 Blue 14
5 PM Tue 91 88 W 7 8891 7528 3528 Blue 13
6 PM Tue 90 85 W 7 7541 7080 3080 Blue 10
7 PM Tue 87 82 W 7 7107 5999 1999 Blue 7
8 PM Tue 85 80 W 5 6487 5068 1068 Blue 5
9 PM Tue 83 78 W 5 5563 4174 174 Blue 3
10 PM Tue 81 76 W 5 4399 4000 0 Blue 1
11 PM Tue 79 74 NE 3 3884 4000 0 Blue 0
12 Midnight Wed 78 73 NE 3 3590 4000 0 Blue 0
1 AM Wed 77 72 NE 3 3573 4000 0 Blue 0
2 AM Wed 77 72 NE 2 3573 4000 0 Blue 0
3 AM Wed 76 71 NE 2 3573 4000 0 Blue 0
4 AM Wed 76 71 NE 2 3573 4000 0 Blue 0
5 AM Wed 75 70 NE 2 3573 4000 0 Blue 0
6 AM Wed 74 69 NE 2 3573 4000 0 Blue 0
7 AM Wed 73 68 NE 2 3573 4000 0 Blue 0
8 AM Wed 74 69 E 2 3573 4000 0 Blue 0
9 AM Wed 77 74 E 2 3884 4000 0 Blue 0
10 AM Wed 80 79 E 2 6030 4396 396 Blue 4
11 AM Wed 83 83 SW 6 7321 6451 2451 Blue 8
12 Noon Wed 85 86 SW 6 8480 7309 3309 Blue 11
1 PM Wed 85 86 SW 6 8480 7309 3309 Blue 11
2 PM Wed 86 87 SW 8 8686 7419 3419 Blue 12
3 PM Wed 87 87 SW 8 8686 7419 3419 Blue 12
4 PM Wed 88 86 SW 8 8480 7309 3309 Blue 11
5 PM Wed 88 85 W 8 7541 7080 3080 Blue 10
6 PM Wed 87 83 W 8 7321 6451 2451 Blue 8
7 PM Wed 85 80 W 8 6487 5068 1068 Blue 5
8 PM Wed 83 78 W 5 5563 4174 174 Blue 3
9 PM Wed 81 76 W 5 4399 4000 0 Blue 1
10 PM Wed 79 74 W 5 3884 4000 0 Blue 0
11 PM Wed 77 72 NW 3 3573 4000 0 Blue 0
12 Midnight Thu 76 71 NW 3 3573 4000 0 Blue 0
1 AM Thu 75 70 NW 3 3573 4000 0 Blue 0
2 AM Thu 74 69 NE 2 3573 4000 0 Blue 0
3 AM Thu 73 68 NE 2 3573 4000 0 Blue 0
4 AM Thu 73 68 NE 2 3573 4000 0 Blue 0
5 AM Thu 72 67 NE 2 3573 4000 0 Blue 0
6 AM Thu 71 66 NE 2 3573 4000 0 Blue 0
7 AM Thu 70 65 NE 2 3573 4000 0 Blue 0
8 AM Thu 71 66 SE 2 3573 4000 0 Blue 0
9 AM Thu 74 71 SE 2 3573 4000 0 Blue 0
10 AM Thu 77 76 SE 2 4399 4000 0 Blue 1
11 AM Thu 80 80 SW 6 6487 5068 1068 Blue 5
12 Noon Thu 82 84 SW 6 7431 6813 2813 Blue 9
1 PM Thu 82 84 SW 6 7431 6813 2813 Blue 9
2 PM Thu 83 85 SW 8 7541 7080 3080 Blue 10
3 PM Thu 84 84 SW 8 7431 6813 2813 Blue 9
4 PM Thu 85 84 SW 8 7431 6813 2813 Blue 9
5 PM Thu 85 82 W 9 7107 5999 1999 Blue 7
6 PM Thu 84 80 W 9 6487 5068 1068 Blue 5
7 PM Thu 82 77 W 9 5086 4000 0 Blue 2
8 PM Thu 80 75 W 6 4177 4000 0 Blue 0
9 PM Thu 78 73 W 6 3590 4000 0 Blue 0
10 PM Thu 76 71 W 6 3573 4000 0 Blue 0
11 PM Thu 75 70 N 3 3573 4000 0 Blue 0
12 Midnight Fri 74 69 N 3 3573 4000 0 Blue 0
1 AM Fri 74 69 N 3 3573 4000 0 Blue 0
2 AM Fri 73 68 N 2 3573 4000 0 Blue 0
3 AM Fri 72 67 N 2 3573 4000 0 Blue 0
4 AM Fri 72 67 N 2 3573 4000 0 Blue 0
5 AM Fri 71 66 N 2 3573 4000 0 Blue 0
6 AM Fri 70 65 N 2 3573 4000 0 Blue 0
7 AM Fri 69 64 N 2 3573 4000 0 Blue 0
8 AM Fri 69 64 S 2 3573 4000 0 Blue 0
9 AM Fri 72 69 S 2 3573 4000 0 Blue 0
10 AM Fri 76 75 S 2 4177 4000 0 Blue 0
11 AM Fri 80 80 SW 6 6487 5068 1068 Blue 5
12 Noon Fri 82 84 SW 6 7431 6813 2813 Blue 9
1 PM Fri 82 84 SW 6 7431 6813 2813 Blue 9
2 PM Fri 83 85 W 8 7541 7080 3080 Blue 10
3 PM Fri 84 84 W 8 7431 6813 2813 Blue 9
4 PM Fri 86 85 W 8 7541 7080 3080 Blue 10
5 PM Fri 86 83 W 9 7321 6451 2451 Blue 8
6 PM Fri 85 81 W 9 6837 5539 1539 Blue 6
7 PM Fri 82 77 W 9 5086 4000 0 Blue 2
8 PM Fri 80 75 W 6 4177 4000 0 Blue 0
9 PM Fri 78 73 W 6 3590 4000 0 Blue 0
10 PM Fri 76 71 W 6 3573 4000 0 Blue 0
11 PM Fri 74 69 N 3 3573 4000 0 Blue 0
12 Midnight Sat 73 68 N 3 3573 4000 0 Blue 0
1 AM Sat 72 67 N 3 3573 4000 0 Blue 0
2 AM Sat 72 67 N 2 3573 4000 0 Blue 0
3 AM Sat 72 67 N 2 3573 4000 0 Blue 0
4 AM Sat 71 66 N 2 3573 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