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

Station:

KOAK

Date/Time:

23 FEB 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)
4 AM Fri 28 23 N 6 2736 4000 0 Blue 0
5 AM Fri 27 22 N 6 2736 4000 0 Blue 0
6 AM Fri 26 21 N 6 2736 4000 0 Blue 0
7 AM Fri 27 22 N 6 2736 4000 0 Blue 0
8 AM Fri 29 24 N 6 2736 4000 0 Blue 0
9 AM Fri 33 29 N 6 3965 4000 0 Blue 0
10 AM Fri 36 32 NW 5 7195 4000 0 Blue 3
11 AM Fri 38 35 NW 5 8010 7165 3165 White 6
12 Noon Fri 40 37 NW 5 8435 7877 3877 White 8
1 PM Fri 40 37 NW 8 8435 7877 3877 White 8
2 PM Fri 41 37 NW 8 8435 7877 3877 White 8
3 PM Fri 41 37 NW 8 8435 7877 3877 White 8
4 PM Fri 40 35 NW 9 8010 7165 3165 White 6
5 PM Fri 39 34 NW 9 7798 6101 2101 White 5
6 PM Fri 36 31 NW 9 6269 4000 0 Blue 2
7 PM Fri 34 29 N 8 3965 4000 0 Blue 0
8 PM Fri 33 28 N 8 2736 4000 0 Blue 0
9 PM Fri 32 27 N 8 2736 4000 0 Blue 0
10 PM Fri 31 26 NE 8 2736 4000 0 Blue 0
11 PM Fri 31 26 NE 8 2736 4000 0 Blue 0
12 Midnight Sat 31 26 NE 8 2736 4000 0 Blue 0
1 AM Sat 31 26 NE 6 2736 4000 0 Blue 0
2 AM Sat 31 26 NE 6 2736 4000 0 Blue 0
3 AM Sat 31 26 NE 6 2736 4000 0 Blue 0
4 AM Sat 30 25 NE 6 2736 4000 0 Blue 0
5 AM Sat 29 24 NE 6 2736 4000 0 Blue 0
6 AM Sat 29 24 NE 6 2736 4000 0 Blue 0
7 AM Sat 31 26 NE 5 2736 4000 0 Blue 0
8 AM Sat 34 29 NE 5 3965 4000 0 Blue 0
9 AM Sat 39 35 NE 5 8010 7165 3165 White 6
10 AM Sat 42 39 SW 5 8855 8271 4271 White 10
11 AM Sat 45 43 SW 5 9707 9707 5707 White 14
12 Noon Sat 46 44 SW 5 9917 9917 5917 White 15
1 PM Sat 47 45 NW 6 10123 10123 6123 White 16
2 PM Sat 47 44 NW 6 9917 9917 5917 White 15
3 PM Sat 47 43 NW 6 9707 9707 5707 White 14
4 PM Sat 46 41 N 10 9280 8722 4722 White 12
5 PM Sat 43 38 N 10 8645 8153 4153 White 9
6 PM Sat 41 36 N 10 8222 7424 3424 White 7
7 PM Sat 38 33 N 10 7456 4611 611 Blue 4
8 PM Sat 37 32 N 10 7195 4000 0 Blue 3
9 PM Sat 36 31 N 10 6269 4000 0 Blue 2
10 PM Sat 36 31 NE 10 6269 4000 0 Blue 2
11 PM Sat 35 30 NE 10 4627 4000 0 Blue 1
12 Midnight Sun 34 29 NE 10 3965 4000 0 Blue 0
1 AM Sun 33 28 NE 10 2736 4000 0 Blue 0
2 AM Sun 33 28 NE 10 2736 4000 0 Blue 0
3 AM Sun 33 28 NE 10 2736 4000 0 Blue 0
4 AM Sun 32 27 N 7 2736 4000 0 Blue 0
5 AM Sun 31 26 N 7 2736 4000 0 Blue 0
6 AM Sun 31 26 N 7 2736 4000 0 Blue 0
7 AM Sun 32 27 N 7 2736 4000 0 Blue 0
8 AM Sun 35 30 N 7 4627 4000 0 Blue 1
9 AM Sun 39 35 N 7 8010 7165 3165 White 6
10 AM Sun 43 40 SW 6 9067 8435 4435 White 11
11 AM Sun 46 44 SW 6 9917 9917 5917 White 15
12 Noon Sun 48 46 SW 6 10328 10328 6328 White 17
1 PM Sun 49 47 SW 6 10533 10533 6533 White 18
2 PM Sun 50 47 SW 6 10533 10533 6533 White 18
3 PM Sun 50 46 SW 6 10328 10328 6328 White 17
4 PM Sun 49 44 SW 3 9917 9917 5917 White 15
5 PM Sun 47 42 SW 3 9494 9006 5006 White 13
6 PM Sun 44 39 SW 3 8855 8271 4271 White 10
7 PM Sun 41 36 SW 3 8222 7424 3424 White 7
8 PM Sun 40 35 SW 3 8010 7165 3165 White 6
9 PM Sun 39 34 SW 3 7798 6101 2101 White 5
10 PM Sun 39 34 E 7 7798 6101 2101 White 5
11 PM Sun 38 33 E 7 7456 4611 611 Blue 4
12 Midnight Mon 37 32 E 7 7195 4000 0 Blue 3
1 AM Mon 37 32 E 7 7195 4000 0 Blue 3
2 AM Mon 36 31 E 7 6269 4000 0 Blue 2
3 AM Mon 36 31 E 7 6269 4000 0 Blue 2
4 AM Mon 35 30 E 6 4627 4000 0 Blue 1
5 AM Mon 35 30 E 6 4627 4000 0 Blue 1
6 AM Mon 34 29 E 6 3965 4000 0 Blue 0
7 AM Mon 34 29 E 6 3965 4000 0 Blue 0
8 AM Mon 37 32 E 6 7195 4000 0 Blue 3
9 AM Mon 40 36 E 6 8222 7424 3424 White 7
10 AM Mon 43 38 S 7 8645 8153 4153 White 9
11 AM Mon 45 40 S 7 9067 8435 4435 White 11
12 Noon Mon 45 40 S 7 9067 8435 4435 White 11
1 PM Mon 45 40 S 7 9067 8435 4435 White 11
2 PM Mon 44 39 S 7 8855 8271 4271 White 10
3 PM Mon 44 39 S 7 8855 8271 4271 White 10
4 PM Mon 43 38 NW 6 8645 8153 4153 White 9
5 PM Mon 42 37 NW 6 8435 7877 3877 White 8
6 PM Mon 40 35 NW 6 8010 7165 3165 White 6
7 PM Mon 39 34 NW 6 7798 6101 2101 White 5
8 PM Mon 38 33 NW 6 7456 4611 611 Blue 4
9 PM Mon 38 33 NW 6 7456 4611 611 Blue 4
10 PM Mon 37 32 NE 8 7195 4000 0 Blue 3
11 PM Mon 37 32 NE 8 7195 4000 0 Blue 3
12 Midnight Tue 36 31 NE 8 6269 4000 0 Blue 2
1 AM Tue 35 30 NE 8 4627 4000 0 Blue 1
2 AM Tue 35 30 NE 8 4627 4000 0 Blue 1
3 AM Tue 35 30 NE 8 4627 4000 0 Blue 1
4 AM Tue 34 29 N 10 3965 4000 0 Blue 0
5 AM Tue 34 29 N 10 3965 4000 0 Blue 0
6 AM Tue 33 28 N 10 2736 4000 0 Blue 0
7 AM Tue 33 28 N 10 2736 4000 0 Blue 0
8 AM Tue 35 30 N 10 4627 4000 0 Blue 1
9 AM Tue 38 33 N 10 7456 4611 611 Blue 4
10 AM Tue 40 35 SW 7 8010 7165 3165 White 6
11 AM Tue 42 38 SW 7 8645 8153 4153 White 9
12 Noon Tue 43 39 SW 7 8855 8271 4271 White 10
1 PM Tue 43 39 SW 7 8855 8271 4271 White 10
2 PM Tue 44 39 SW 7 8855 8271 4271 White 10
3 PM Tue 44 39 SW 7 8855 8271 4271 White 10
4 PM Tue 43 38 NW 9 8645 8153 4153 White 9
5 PM Tue 41 36 NW 9 8222 7424 3424 White 7
6 PM Tue 38 33 NW 9 7456 4611 611 Blue 4
7 PM Tue 35 30 NW 9 4627 4000 0 Blue 1
8 PM Tue 35 30 NW 9 4627 4000 0 Blue 1
9 PM Tue 35 30 NW 9 4627 4000 0 Blue 1
10 PM Tue 35 30 NE 7 4627 4000 0 Blue 1
11 PM Tue 35 30 NE 7 4627 4000 0 Blue 1
12 Midnight Wed 35 30 NE 7 4627 4000 0 Blue 1
1 AM Wed 34 29 NE 7 3965 4000 0 Blue 0
2 AM Wed 33 28 NE 7 2736 4000 0 Blue 0
3 AM Wed 33 28 NE 7 2736 4000 0 Blue 0
4 AM Wed 32 27 N 7 2736 4000 0 Blue 0
5 AM Wed 31 26 N 7 2736 4000 0 Blue 0
6 AM Wed 31 26 N 7 2736 4000 0 Blue 0
7 AM Wed 32 27 N 7 2736 4000 0 Blue 0
8 AM Wed 35 30 N 7 4627 4000 0 Blue 1
9 AM Wed 39 35 N 7 8010 7165 3165 White 6
10 AM Wed 42 39 SW 7 8855 8271 4271 White 10
11 AM Wed 45 43 SW 7 9707 9707 5707 White 14
12 Noon Wed 46 44 SW 7 9917 9917 5917 White 15
1 PM Wed 47 45 SW 7 10123 10123 6123 White 16
2 PM Wed 48 45 SW 7 10123 10123 6123 White 16
3 PM Wed 48 44 SW 7 9917 9917 5917 White 15
4 PM Wed 47 42 W 7 9494 9006 5006 White 13
5 PM Wed 45 40 W 7 9067 8435 4435 White 11
6 PM Wed 43 38 W 7 8645 8153 4153 White 9
7 PM Wed 40 35 W 7 8010 7165 3165 White 6
8 PM Wed 40 35 W 7 8010 7165 3165 White 6
9 PM Wed 39 34 W 7 7798 6101 2101 White 5
10 PM Wed 39 34 E 6 7798 6101 2101 White 5
11 PM Wed 39 34 E 6 7798 6101 2101 White 5
12 Midnight Thu 38 33 E 6 7456 4611 611 Blue 4
1 AM Thu 37 32 E 6 7195 4000 0 Blue 3
2 AM Thu 37 32 E 6 7195 4000 0 Blue 3
3 AM Thu 36 31 E 6 6269 4000 0 Blue 2

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