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

Station:

KOAK

Date/Time:

26 APR 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 Thu 57 52 SE 3 3166 4000 0 Blue 0
6 AM Thu 57 52 SE 3 3166 4000 0 Blue 0
7 AM Thu 57 52 SE 3 3166 4000 0 Blue 0
8 AM Thu 62 58 SE 2 3166 4000 0 Blue 0
9 AM Thu 68 65 SE 2 5345 4561 561 Blue 2
10 AM Thu 70 69 SE 2 6775 5541 1541 Blue 6
11 AM Thu 72 71 SW 5 7643 5951 1951 Blue 8
12 Noon Thu 73 73 SW 5 8986 7181 3181 Blue 10
1 PM Thu 74 74 SW 5 9431 7509 3509 Blue 11
2 PM Thu 75 75 SW 6 9830 8460 4460 Blue 12
3 PM Thu 75 74 SW 6 9431 7509 3509 Blue 11
4 PM Thu 76 74 SW 6 9431 7509 3509 Blue 11
5 PM Thu 77 73 SW 6 8986 7181 3181 Blue 10
6 PM Thu 77 72 SW 6 8531 6750 2750 Blue 9
7 PM Thu 73 68 SW 6 5965 5335 1335 Blue 5
8 PM Thu 68 63 S 3 4930 4000 0 Blue 0
9 PM Thu 66 61 S 3 4134 4000 0 Blue 0
10 PM Thu 64 59 S 3 3236 4000 0 Blue 0
11 PM Thu 63 58 SE 6 3166 4000 0 Blue 0
12 Midnight Fri 61 56 SE 6 3166 4000 0 Blue 0
1 AM Fri 58 53 SE 6 3166 4000 0 Blue 0
2 AM Fri 57 52 SE 7 3166 4000 0 Blue 0
3 AM Fri 56 51 SE 7 3166 4000 0 Blue 0
4 AM Fri 55 50 SE 7 3166 4000 0 Blue 0
5 AM Fri 54 49 S 7 3166 4000 0 Blue 0
6 AM Fri 53 48 S 7 3166 4000 0 Blue 0
7 AM Fri 53 48 S 7 3166 4000 0 Blue 0
8 AM Fri 57 53 S 6 3166 4000 0 Blue 0
9 AM Fri 61 58 S 6 3166 4000 0 Blue 0
10 AM Fri 63 61 S 6 4134 4000 0 Blue 0
11 AM Fri 64 64 S 5 5137 4130 130 Blue 1
12 Noon Fri 65 66 S 5 5552 4923 923 Blue 3
1 PM Fri 66 68 S 5 5965 5335 1335 Blue 5
2 PM Fri 67 68 SW 7 5965 5335 1335 Blue 5
3 PM Fri 67 67 SW 7 5759 5129 1129 Blue 4
4 PM Fri 67 65 SW 7 5345 4561 561 Blue 2
5 PM Fri 68 65 W 10 5345 4561 561 Blue 2
6 PM Fri 68 63 W 10 4930 4000 0 Blue 0
7 PM Fri 64 59 W 10 3236 4000 0 Blue 0
8 PM Fri 60 55 W 10 3166 4000 0 Blue 0
9 PM Fri 58 53 W 10 3166 4000 0 Blue 0
10 PM Fri 57 52 W 10 3166 4000 0 Blue 0
11 PM Fri 55 50 E 7 3166 4000 0 Blue 0
12 Midnight Sat 54 49 E 7 3166 4000 0 Blue 0
1 AM Sat 52 47 E 7 3166 4000 0 Blue 0
2 AM Sat 51 46 E 7 3166 4000 0 Blue 0
3 AM Sat 50 45 E 7 3166 4000 0 Blue 0
4 AM Sat 49 44 E 7 3166 4000 0 Blue 0
5 AM Sat 47 42 SW 7 3166 4000 0 Blue 0
6 AM Sat 47 42 SW 7 3166 4000 0 Blue 0
7 AM Sat 47 42 SW 7 3166 4000 0 Blue 0
8 AM Sat 51 46 SW 7 3166 4000 0 Blue 0
9 AM Sat 55 51 SW 7 3166 4000 0 Blue 0
10 AM Sat 57 55 SW 7 3166 4000 0 Blue 0
11 AM Sat 58 57 W 9 3166 4000 0 Blue 0
12 Noon Sat 59 58 W 9 3166 4000 0 Blue 0
1 PM Sat 60 59 W 9 3236 4000 0 Blue 0
2 PM Sat 61 60 W 9 3689 4000 0 Blue 0
3 PM Sat 61 59 W 9 3236 4000 0 Blue 0
4 PM Sat 61 58 W 9 3166 4000 0 Blue 0
5 PM Sat 62 58 W 14 3166 4000 0 Blue 0
6 PM Sat 62 57 W 14 3166 4000 0 Blue 0
7 PM Sat 59 54 W 14 3166 4000 0 Blue 0
8 PM Sat 56 51 W 14 3166 4000 0 Blue 0
9 PM Sat 55 50 W 14 3166 4000 0 Blue 0
10 PM Sat 54 49 W 14 3166 4000 0 Blue 0
11 PM Sat 52 47 E 6 3166 4000 0 Blue 0
12 Midnight Sun 51 46 E 6 3166 4000 0 Blue 0
1 AM Sun 50 45 E 6 3166 4000 0 Blue 0
2 AM Sun 49 44 E 6 3166 4000 0 Blue 0
3 AM Sun 48 43 E 6 3166 4000 0 Blue 0
4 AM Sun 48 43 E 6 3166 4000 0 Blue 0
5 AM Sun 46 41 S 5 3166 4000 0 Blue 0
6 AM Sun 46 41 S 5 3166 4000 0 Blue 0
7 AM Sun 46 41 S 5 3166 4000 0 Blue 0
8 AM Sun 50 45 S 5 3166 4000 0 Blue 0
9 AM Sun 54 51 S 5 3166 4000 0 Blue 0
10 AM Sun 56 54 S 5 3166 4000 0 Blue 0
11 AM Sun 58 57 W 7 3166 4000 0 Blue 0
12 Noon Sun 59 59 W 7 3236 4000 0 Blue 0
1 PM Sun 60 60 W 7 3689 4000 0 Blue 0
2 PM Sun 61 61 W 7 4134 4000 0 Blue 0
3 PM Sun 60 59 W 7 3236 4000 0 Blue 0
4 PM Sun 61 58 W 7 3166 4000 0 Blue 0
5 PM Sun 62 58 W 8 3166 4000 0 Blue 0
6 PM Sun 62 57 W 8 3166 4000 0 Blue 0
7 PM Sun 59 54 W 8 3166 4000 0 Blue 0
8 PM Sun 56 51 W 8 3166 4000 0 Blue 0
9 PM Sun 55 50 W 8 3166 4000 0 Blue 0
10 PM Sun 54 49 W 8 3166 4000 0 Blue 0
11 PM Sun 52 47 W 7 3166 4000 0 Blue 0
12 Midnight Mon 51 46 W 7 3166 4000 0 Blue 0
1 AM Mon 50 45 W 7 3166 4000 0 Blue 0
2 AM Mon 49 44 W 7 3166 4000 0 Blue 0
3 AM Mon 48 43 W 7 3166 4000 0 Blue 0
4 AM Mon 48 43 W 7 3166 4000 0 Blue 0
5 AM Mon 46 41 SE 8 3166 4000 0 Blue 0
6 AM Mon 46 41 SE 8 3166 4000 0 Blue 0
7 AM Mon 46 41 SE 8 3166 4000 0 Blue 0
8 AM Mon 50 45 SE 8 3166 4000 0 Blue 0
9 AM Mon 54 50 SE 8 3166 4000 0 Blue 0
10 AM Mon 56 54 SE 8 3166 4000 0 Blue 0
11 AM Mon 57 56 W 7 3166 4000 0 Blue 0
12 Noon Mon 58 57 W 7 3166 4000 0 Blue 0
1 PM Mon 59 59 W 7 3236 4000 0 Blue 0
2 PM Mon 60 59 W 7 3236 4000 0 Blue 0
3 PM Mon 60 58 W 7 3166 4000 0 Blue 0
4 PM Mon 60 57 W 7 3166 4000 0 Blue 0
5 PM Mon 61 57 W 7 3166 4000 0 Blue 0
6 PM Mon 61 56 W 7 3166 4000 0 Blue 0
7 PM Mon 59 54 W 7 3166 4000 0 Blue 0
8 PM Mon 57 52 W 7 3166 4000 0 Blue 0
9 PM Mon 56 51 W 7 3166 4000 0 Blue 0
10 PM Mon 55 50 W 7 3166 4000 0 Blue 0
11 PM Mon 54 49 S 6 3166 4000 0 Blue 0
12 Midnight Tue 53 48 S 6 3166 4000 0 Blue 0
1 AM Tue 52 47 S 6 3166 4000 0 Blue 0
2 AM Tue 51 46 S 6 3166 4000 0 Blue 0
3 AM Tue 51 46 S 6 3166 4000 0 Blue 0
4 AM Tue 50 45 S 6 3166 4000 0 Blue 0
5 AM Tue 49 44 S 5 3166 4000 0 Blue 0
6 AM Tue 49 44 S 5 3166 4000 0 Blue 0
7 AM Tue 49 44 S 5 3166 4000 0 Blue 0
8 AM Tue 53 48 S 5 3166 4000 0 Blue 0
9 AM Tue 57 53 S 5 3166 4000 0 Blue 0
10 AM Tue 59 56 S 5 3166 4000 0 Blue 0
11 AM Tue 61 59 W 7 3236 4000 0 Blue 0
12 Noon Tue 62 61 W 7 4134 4000 0 Blue 0
1 PM Tue 63 62 W 7 4571 4000 0 Blue 0
2 PM Tue 64 63 W 7 4930 4000 0 Blue 0
3 PM Tue 63 61 W 7 4134 4000 0 Blue 0
4 PM Tue 64 61 W 7 4134 4000 0 Blue 0
5 PM Tue 65 61 W 7 4134 4000 0 Blue 0
6 PM Tue 65 60 W 7 3689 4000 0 Blue 0
7 PM Tue 62 57 W 7 3166 4000 0 Blue 0
8 PM Tue 60 55 W 7 3166 4000 0 Blue 0
9 PM Tue 58 53 W 7 3166 4000 0 Blue 0
10 PM Tue 57 52 W 7 3166 4000 0 Blue 0
11 PM Tue 56 51 NE 6 3166 4000 0 Blue 0
12 Midnight Wed 55 50 NE 6 3166 4000 0 Blue 0
1 AM Wed 53 48 NE 6 3166 4000 0 Blue 0
2 AM Wed 53 48 NE 6 3166 4000 0 Blue 0
3 AM Wed 52 47 NE 6 3166 4000 0 Blue 0
4 AM Wed 51 46 NE 6 3166 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