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

Station:

 KOAK

Date/Time:

 18 MAR 2010

Temp/Wind data from:

NOAA Digital Forecast

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 50 50 E 5 2966 4000 0 Blue 0
6 AM Thu 50 50 E 5 2966 4000 0 Blue 0
7 AM Thu 48 48 E 5 2966 4000 0 Blue 0
8 AM Thu 49 49 NE 2 2966 4000 0 Blue 0
9 AM Thu 53 54 NE 2 2966 4000 0 Blue 0
10 AM Thu 59 61 NE 2 6940 4000 0 Blue 2
11 AM Thu 61 63 S 7 7217 4696 696 Blue 4
12 Noon Thu 62 65 S 7 7511 7056 3056 Blue 6
1 PM Thu 63 66 S 7 7658 7201 3201 Blue 7
2 PM Thu 63 66 W 4 7658 7201 3201 Blue 7
3 PM Thu 65 67 W 4 7804 7347 3347 Blue 8
4 PM Thu 63 64 W 4 7364 6927 2927 Blue 5
5 PM Thu 63 63 W 1 7217 4696 696 Blue 4
6 PM Thu 59 59 W 1 4518 4000 0 Blue 0
7 PM Thu 56 56 W 1 2966 4000 0 Blue 0
8 PM Thu 54 54 E 7 2966 4000 0 Blue 0
9 PM Thu 53 53 E 7 2966 4000 0 Blue 0
10 PM Thu 52 52 E 7 2966 4000 0 Blue 0
11 PM Thu 52 52 E 13 2966 4000 0 Blue 0
12 Midnight Fri 49 49 E 13 2966 4000 0 Blue 0
1 AM Fri 49 49 E 13 2966 4000 0 Blue 0
2 AM Fri 48 48 E 3 2966 4000 0 Blue 0
3 AM Fri 48 48 E 3 2966 4000 0 Blue 0
4 AM Fri 48 48 E 3 2966 4000 0 Blue 0
5 AM Fri 48 48 E 7 2966 4000 0 Blue 0
6 AM Fri 47 47 E 7 2966 4000 0 Blue 0
7 AM Fri 46 46 E 7 2966 4000 0 Blue 0
8 AM Fri 47 47 E 1 2966 4000 0 Blue 0
9 AM Fri 51 52 E 1 2966 4000 0 Blue 0
10 AM Fri 57 60 E 1 4701 4000 0 Blue 1
11 AM Fri 59 63 SE 3 7217 4696 696 Blue 4
12 Noon Fri 60 65 SE 3 7511 7056 3056 Blue 6
1 PM Fri 61 67 SE 3 7804 7347 3347 Blue 8
2 PM Fri 61 66 SW 5 7658 7201 3201 Blue 7
3 PM Fri 63 67 SW 5 7804 7347 3347 Blue 8
4 PM Fri 62 64 SW 5 7364 6927 2927 Blue 5
5 PM Fri 61 62 W 4 7070 4514 514 Blue 3
6 PM Fri 59 59 W 4 4518 4000 0 Blue 0
7 PM Fri 56 56 W 4 2966 4000 0 Blue 0
8 PM Fri 55 55 W 4 2966 4000 0 Blue 0
9 PM Fri 54 54 W 4 2966 4000 0 Blue 0
10 PM Fri 54 54 W 4 2966 4000 0 Blue 0
11 PM Fri 53 53 E 1 2966 4000 0 Blue 0
12 Midnight Sat 52 52 E 1 2966 4000 0 Blue 0
1 AM Sat 51 51 E 1 2966 4000 0 Blue 0
2 AM Sat 51 51 E 1 2966 4000 0 Blue 0
3 AM Sat 51 51 E 1 2966 4000 0 Blue 0
4 AM Sat 50 50 E 1 2966 4000 0 Blue 0
5 AM Sat 50 50 E 2 2966 4000 0 Blue 0
6 AM Sat 50 50 E 2 2966 4000 0 Blue 0
7 AM Sat 49 49 E 2 2966 4000 0 Blue 0
8 AM Sat 50 50 E 2 2966 4000 0 Blue 0
9 AM Sat 55 56 E 2 2966 4000 0 Blue 0
10 AM Sat 62 64 E 2 7364 6927 2927 Blue 5
11 AM Sat 64 68 S 4 7951 7493 3493 Blue 9
12 Noon Sat 66 71 S 4 10499 7932 3932 Blue 12
1 PM Sat 67 72 S 4 10884 8593 4593 Blue 13
2 PM Sat 67 72 S 4 10884 8593 4593 Blue 13
3 PM Sat 69 73 S 4 11264 9649 5649 Blue 14
4 PM Sat 67 69 S 4 8774 7640 3640 Blue 10
5 PM Sat 67 68 S 2 7951 7493 3493 Blue 9
6 PM Sat 63 63 S 2 7217 4696 696 Blue 4
7 PM Sat 60 60 S 2 4701 4000 0 Blue 1
8 PM Sat 58 58 S 2 3979 4000 0 Blue 0
9 PM Sat 57 57 S 2 3218 4000 0 Blue 0
10 PM Sat 56 56 S 2 2966 4000 0 Blue 0
11 PM Sat 56 56 E 3 2966 4000 0 Blue 0
12 Midnight Sun 53 53 E 3 2966 4000 0 Blue 0
1 AM Sun 53 53 E 3 2966 4000 0 Blue 0
2 AM Sun 52 52 E 3 2966 4000 0 Blue 0
3 AM Sun 52 52 E 3 2966 4000 0 Blue 0
4 AM Sun 52 52 E 3 2966 4000 0 Blue 0
5 AM Sun 52 52 E 4 2966 4000 0 Blue 0
6 AM Sun 51 51 E 4 2966 4000 0 Blue 0
7 AM Sun 50 50 E 4 2966 4000 0 Blue 0
8 AM Sun 51 51 E 4 2966 4000 0 Blue 0
9 AM Sun 57 58 E 4 3979 4000 0 Blue 0
10 AM Sun 64 66 E 4 7658 7201 3201 Blue 7
11 AM Sun 66 69 S 3 8774 7640 3640 Blue 10
12 Noon Sun 68 72 S 3 10884 8593 4593 Blue 13
1 PM Sun 69 73 S 3 11264 9649 5649 Blue 14
2 PM Sun 69 73 S 3 11264 9649 5649 Blue 14
3 PM Sun 71 74 S 3 11637 10415 6415 Blue 15
4 PM Sun 69 71 S 3 10499 7932 3932 Blue 12
5 PM Sun 68 69 SW 4 8774 7640 3640 Blue 10
6 PM Sun 64 64 SW 4 7364 6927 2927 Blue 5
7 PM Sun 60 60 SW 4 4701 4000 0 Blue 1
8 PM Sun 57 57 SW 4 3218 4000 0 Blue 0
9 PM Sun 57 57 SW 4 3218 4000 0 Blue 0
10 PM Sun 56 56 SW 4 2966 4000 0 Blue 0
11 PM Sun 55 55 E 3 2966 4000 0 Blue 0
12 Midnight Mon 52 52 E 3 2966 4000 0 Blue 0
1 AM Mon 52 52 E 3 2966 4000 0 Blue 0
2 AM Mon 51 51 E 3 2966 4000 0 Blue 0
3 AM Mon 51 51 E 3 2966 4000 0 Blue 0
4 AM Mon 50 50 E 3 2966 4000 0 Blue 0
5 AM Mon 50 50 SE 3 2966 4000 0 Blue 0
6 AM Mon 50 50 SE 3 2966 4000 0 Blue 0
7 AM Mon 48 48 SE 3 2966 4000 0 Blue 0
8 AM Mon 49 49 SE 3 2966 4000 0 Blue 0
9 AM Mon 53 54 SE 3 2966 4000 0 Blue 0
10 AM Mon 58 60 SE 3 4701 4000 0 Blue 1
11 AM Mon 59 62 SW 4 7070 4514 514 Blue 3
12 Noon Mon 61 65 SW 4 7511 7056 3056 Blue 6
1 PM Mon 61 65 SW 4 7511 7056 3056 Blue 6
2 PM Mon 62 66 SW 4 7658 7201 3201 Blue 7
3 PM Mon 63 66 SW 4 7658 7201 3201 Blue 7
4 PM Mon 61 63 SW 4 7217 4696 696 Blue 4
5 PM Mon 61 62 W 6 7070 4514 514 Blue 3
6 PM Mon 57 57 W 6 3218 4000 0 Blue 0
7 PM Mon 54 54 W 6 2966 4000 0 Blue 0
8 PM Mon 52 52 W 6 2966 4000 0 Blue 0
9 PM Mon 51 51 W 6 2966 4000 0 Blue 0
10 PM Mon 50 50 W 6 2966 4000 0 Blue 0
11 PM Mon 50 50 NW 3 2966 4000 0 Blue 0
12 Midnight Tue 47 47 NW 3 2966 4000 0 Blue 0
1 AM Tue 47 47 NW 3 2966 4000 0 Blue 0
2 AM Tue 46 46 NW 3 2966 4000 0 Blue 0
3 AM Tue 46 46 NW 3 2966 4000 0 Blue 0
4 AM Tue 46 46 NW 3 2966 4000 0 Blue 0
5 AM Tue 46 46 NW 2 2966 4000 0 Blue 0
6 AM Tue 45 45 NW 2 2966 4000 0 Blue 0
7 AM Tue 44 44 NW 2 2966 4000 0 Blue 0
8 AM Tue 45 45 NW 2 2966 4000 0 Blue 0
9 AM Tue 48 49 NW 2 2966 4000 0 Blue 0
10 AM Tue 53 55 NW 2 2966 4000 0 Blue 0
11 AM Tue 54 57 W 5 3218 4000 0 Blue 0
12 Noon Tue 55 59 W 5 4518 4000 0 Blue 0
1 PM Tue 55 59 W 5 4518 4000 0 Blue 0
2 PM Tue 56 60 W 5 4701 4000 0 Blue 1
3 PM Tue 57 60 W 5 4701 4000 0 Blue 1
4 PM Tue 55 57 W 5 3218 4000 0 Blue 0
5 PM Tue 55 56 W 8 2966 4000 0 Blue 0
6 PM Tue 52 52 W 8 2966 4000 0 Blue 0
7 PM Tue 49 49 W 8 2966 4000 0 Blue 0
8 PM Tue 47 47 W 8 2966 4000 0 Blue 0
9 PM Tue 46 46 W 8 2966 4000 0 Blue 0
10 PM Tue 46 46 W 8 2966 4000 0 Blue 0
11 PM Tue 45 45 E 4 2966 4000 0 Blue 0
12 Midnight Wed 43 43 E 4 2966 4000 0 Blue 0
1 AM Wed 43 43 E 4 2966 4000 0 Blue 0
2 AM Wed 42 42 E 4 2966 4000 0 Blue 0
3 AM Wed 42 42 E 4 2966 4000 0 Blue 0
4 AM Wed 41 41 E 4 2966 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